Added to vendor

vendor/github.com/containers/storage/LICENSE

@@ -0,0 +1,191 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        https://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
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+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
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+      "Object" form shall mean any form resulting from mechanical
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+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   Copyright 2013-2016 Docker, Inc.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       https://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/containers/storage/NOTICE

@@ -0,0 +1,19 @@
+Docker
+Copyright 2012-2016 Docker, Inc.
+
+This product includes software developed at Docker, Inc. (https://www.docker.com).
+
+This product contains software (https://github.com/kr/pty) developed
+by Keith Rarick, licensed under the MIT License.
+
+The following is courtesy of our legal counsel:
+
+
+Use and transfer of Docker may be subject to certain restrictions by the
+United States and other governments.
+It is your responsibility to ensure that your use and/or transfer does not
+violate applicable laws.
+
+For more information, please see https://www.bis.doc.gov
+
+See also https://www.apache.org/dev/crypto.html and/or seek legal counsel.

vendor/github.com/containers/storage/containers.go

@@ -0,0 +1,531 @@
+package storage
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/containers/storage/pkg/ioutils"
+	"github.com/containers/storage/pkg/stringid"
+	"github.com/containers/storage/pkg/truncindex"
+	digest "github.com/opencontainers/go-digest"
+	"github.com/pkg/errors"
+)
+
+// A Container is a reference to a read-write layer with metadata.
+type Container struct {
+	// ID is either one which was specified at create-time, or a random
+	// value which was generated by the library.
+	ID string `json:"id"`
+
+	// Names is an optional set of user-defined convenience values.  The
+	// container can be referred to by its ID or any of its names.  Names
+	// are unique among containers.
+	Names []string `json:"names,omitempty"`
+
+	// ImageID is the ID of the image which was used to create the container.
+	ImageID string `json:"image"`
+
+	// LayerID is the ID of the read-write layer for the container itself.
+	// It is assumed that the image's top layer is the parent of the container's
+	// read-write layer.
+	LayerID string `json:"layer"`
+
+	// Metadata is data we keep for the convenience of the caller.  It is not
+	// expected to be large, since it is kept in memory.
+	Metadata string `json:"metadata,omitempty"`
+
+	// BigDataNames is a list of names of data items that we keep for the
+	// convenience of the caller.  They can be large, and are only in
+	// memory when being read from or written to disk.
+	BigDataNames []string `json:"big-data-names,omitempty"`
+
+	// BigDataSizes maps the names in BigDataNames to the sizes of the data
+	// that has been stored, if they're known.
+	BigDataSizes map[string]int64 `json:"big-data-sizes,omitempty"`
+
+	// BigDataDigests maps the names in BigDataNames to the digests of the
+	// data that has been stored, if they're known.
+	BigDataDigests map[string]digest.Digest `json:"big-data-digests,omitempty"`
+
+	// Created is the datestamp for when this container was created.  Older
+	// versions of the library did not track this information, so callers
+	// will likely want to use the IsZero() method to verify that a value
+	// is set before using it.
+	Created time.Time `json:"created,omitempty"`
+
+	Flags map[string]interface{} `json:"flags,omitempty"`
+}
+
+// ContainerStore provides bookkeeping for information about Containers.
+type ContainerStore interface {
+	FileBasedStore
+	MetadataStore
+	BigDataStore
+	FlaggableStore
+
+	// Create creates a container that has a specified ID (or generates a
+	// random one if an empty value is supplied) and optional names,
+	// based on the specified image, using the specified layer as its
+	// read-write layer.
+	Create(id string, names []string, image, layer, metadata string) (*Container, error)
+
+	// SetNames updates the list of names associated with the container
+	// with the specified ID.
+	SetNames(id string, names []string) error
+
+	// Get retrieves information about a container given an ID or name.
+	Get(id string) (*Container, error)
+
+	// Exists checks if there is a container with the given ID or name.
+	Exists(id string) bool
+
+	// Delete removes the record of the container.
+	Delete(id string) error
+
+	// Wipe removes records of all containers.
+	Wipe() error
+
+	// Lookup attempts to translate a name to an ID.  Most methods do this
+	// implicitly.
+	Lookup(name string) (string, error)
+
+	// Containers returns a slice enumerating the known containers.
+	Containers() ([]Container, error)
+}
+
+type containerStore struct {
+	lockfile   Locker
+	dir        string
+	containers []*Container
+	idindex    *truncindex.TruncIndex
+	byid       map[string]*Container
+	bylayer    map[string]*Container
+	byname     map[string]*Container
+}
+
+func (r *containerStore) Containers() ([]Container, error) {
+	containers := make([]Container, len(r.containers))
+	for i := range r.containers {
+		containers[i] = *(r.containers[i])
+	}
+	return containers, nil
+}
+
+func (r *containerStore) containerspath() string {
+	return filepath.Join(r.dir, "containers.json")
+}
+
+func (r *containerStore) datadir(id string) string {
+	return filepath.Join(r.dir, id)
+}
+
+func (r *containerStore) datapath(id, key string) string {
+	return filepath.Join(r.datadir(id), makeBigDataBaseName(key))
+}
+
+func (r *containerStore) Load() error {
+	needSave := false
+	rpath := r.containerspath()
+	data, err := ioutil.ReadFile(rpath)
+	if err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	containers := []*Container{}
+	layers := make(map[string]*Container)
+	idlist := []string{}
+	ids := make(map[string]*Container)
+	names := make(map[string]*Container)
+	if err = json.Unmarshal(data, &containers); len(data) == 0 || err == nil {
+		idlist = make([]string, 0, len(containers))
+		for n, container := range containers {
+			idlist = append(idlist, container.ID)
+			ids[container.ID] = containers[n]
+			layers[container.LayerID] = containers[n]
+			for _, name := range container.Names {
+				if conflict, ok := names[name]; ok {
+					r.removeName(conflict, name)
+					needSave = true
+				}
+				names[name] = containers[n]
+			}
+		}
+	}
+	r.containers = containers
+	r.idindex = truncindex.NewTruncIndex(idlist)
+	r.byid = ids
+	r.bylayer = layers
+	r.byname = names
+	if needSave {
+		return r.Save()
+	}
+	return nil
+}
+
+func (r *containerStore) Save() error {
+	rpath := r.containerspath()
+	if err := os.MkdirAll(filepath.Dir(rpath), 0700); err != nil {
+		return err
+	}
+	jdata, err := json.Marshal(&r.containers)
+	if err != nil {
+		return err
+	}
+	defer r.Touch()
+	return ioutils.AtomicWriteFile(rpath, jdata, 0600)
+}
+
+func newContainerStore(dir string) (ContainerStore, error) {
+	if err := os.MkdirAll(dir, 0700); err != nil {
+		return nil, err
+	}
+	lockfile, err := GetLockfile(filepath.Join(dir, "containers.lock"))
+	if err != nil {
+		return nil, err
+	}
+	lockfile.Lock()
+	defer lockfile.Unlock()
+	cstore := containerStore{
+		lockfile:   lockfile,
+		dir:        dir,
+		containers: []*Container{},
+		byid:       make(map[string]*Container),
+		bylayer:    make(map[string]*Container),
+		byname:     make(map[string]*Container),
+	}
+	if err := cstore.Load(); err != nil {
+		return nil, err
+	}
+	return &cstore, nil
+}
+
+func (r *containerStore) lookup(id string) (*Container, bool) {
+	if container, ok := r.byid[id]; ok {
+		return container, ok
+	} else if container, ok := r.byname[id]; ok {
+		return container, ok
+	} else if container, ok := r.bylayer[id]; ok {
+		return container, ok
+	} else if longid, err := r.idindex.Get(id); err == nil {
+		if container, ok := r.byid[longid]; ok {
+			return container, ok
+		}
+	}
+	return nil, false
+}
+
+func (r *containerStore) ClearFlag(id string, flag string) error {
+	container, ok := r.lookup(id)
+	if !ok {
+		return ErrContainerUnknown
+	}
+	delete(container.Flags, flag)
+	return r.Save()
+}
+
+func (r *containerStore) SetFlag(id string, flag string, value interface{}) error {
+	container, ok := r.lookup(id)
+	if !ok {
+		return ErrContainerUnknown
+	}
+	if container.Flags == nil {
+		container.Flags = make(map[string]interface{})
+	}
+	container.Flags[flag] = value
+	return r.Save()
+}
+
+func (r *containerStore) Create(id string, names []string, image, layer, metadata string) (container *Container, err error) {
+	if id == "" {
+		id = stringid.GenerateRandomID()
+		_, idInUse := r.byid[id]
+		for idInUse {
+			id = stringid.GenerateRandomID()
+			_, idInUse = r.byid[id]
+		}
+	}
+	if _, idInUse := r.byid[id]; idInUse {
+		return nil, ErrDuplicateID
+	}
+	names = dedupeNames(names)
+	for _, name := range names {
+		if _, nameInUse := r.byname[name]; nameInUse {
+			return nil, ErrDuplicateName
+		}
+	}
+	if err == nil {
+		container = &Container{
+			ID:             id,
+			Names:          names,
+			ImageID:        image,
+			LayerID:        layer,
+			Metadata:       metadata,
+			BigDataNames:   []string{},
+			BigDataSizes:   make(map[string]int64),
+			BigDataDigests: make(map[string]digest.Digest),
+			Created:        time.Now().UTC(),
+			Flags:          make(map[string]interface{}),
+		}
+		r.containers = append(r.containers, container)
+		r.byid[id] = container
+		r.idindex.Add(id)
+		r.bylayer[layer] = container
+		for _, name := range names {
+			r.byname[name] = container
+		}
+		err = r.Save()
+	}
+	return container, err
+}
+
+func (r *containerStore) Metadata(id string) (string, error) {
+	if container, ok := r.lookup(id); ok {
+		return container.Metadata, nil
+	}
+	return "", ErrContainerUnknown
+}
+
+func (r *containerStore) SetMetadata(id, metadata string) error {
+	if container, ok := r.lookup(id); ok {
+		container.Metadata = metadata
+		return r.Save()
+	}
+	return ErrContainerUnknown
+}
+
+func (r *containerStore) removeName(container *Container, name string) {
+	container.Names = stringSliceWithoutValue(container.Names, name)
+}
+
+func (r *containerStore) SetNames(id string, names []string) error {
+	names = dedupeNames(names)
+	if container, ok := r.lookup(id); ok {
+		for _, name := range container.Names {
+			delete(r.byname, name)
+		}
+		for _, name := range names {
+			if otherContainer, ok := r.byname[name]; ok {
+				r.removeName(otherContainer, name)
+			}
+			r.byname[name] = container
+		}
+		container.Names = names
+		return r.Save()
+	}
+	return ErrContainerUnknown
+}
+
+func (r *containerStore) Delete(id string) error {
+	container, ok := r.lookup(id)
+	if !ok {
+		return ErrContainerUnknown
+	}
+	id = container.ID
+	toDeleteIndex := -1
+	for i, candidate := range r.containers {
+		if candidate.ID == id {
+			toDeleteIndex = i
+			break
+		}
+	}
+	delete(r.byid, id)
+	r.idindex.Delete(id)
+	delete(r.bylayer, container.LayerID)
+	for _, name := range container.Names {
+		delete(r.byname, name)
+	}
+	if toDeleteIndex != -1 {
+		// delete the container at toDeleteIndex
+		if toDeleteIndex == len(r.containers)-1 {
+			r.containers = r.containers[:len(r.containers)-1]
+		} else {
+			r.containers = append(r.containers[:toDeleteIndex], r.containers[toDeleteIndex+1:]...)
+		}
+	}
+	if err := r.Save(); err != nil {
+		return err
+	}
+	if err := os.RemoveAll(r.datadir(id)); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (r *containerStore) Get(id string) (*Container, error) {
+	if container, ok := r.lookup(id); ok {
+		return container, nil
+	}
+	return nil, ErrContainerUnknown
+}
+
+func (r *containerStore) Lookup(name string) (id string, err error) {
+	if container, ok := r.lookup(name); ok {
+		return container.ID, nil
+	}
+	return "", ErrContainerUnknown
+}
+
+func (r *containerStore) Exists(id string) bool {
+	_, ok := r.lookup(id)
+	return ok
+}
+
+func (r *containerStore) BigData(id, key string) ([]byte, error) {
+	if key == "" {
+		return nil, errors.Wrapf(ErrInvalidBigDataName, "can't retrieve container big data value for empty name")
+	}
+	c, ok := r.lookup(id)
+	if !ok {
+		return nil, ErrContainerUnknown
+	}
+	return ioutil.ReadFile(r.datapath(c.ID, key))
+}
+
+func (r *containerStore) BigDataSize(id, key string) (int64, error) {
+	if key == "" {
+		return -1, errors.Wrapf(ErrInvalidBigDataName, "can't retrieve size of container big data with empty name")
+	}
+	c, ok := r.lookup(id)
+	if !ok {
+		return -1, ErrContainerUnknown
+	}
+	if c.BigDataSizes == nil {
+		c.BigDataSizes = make(map[string]int64)
+	}
+	if size, ok := c.BigDataSizes[key]; ok {
+		return size, nil
+	}
+	if data, err := r.BigData(id, key); err == nil && data != nil {
+		if r.SetBigData(id, key, data) == nil {
+			c, ok := r.lookup(id)
+			if !ok {
+				return -1, ErrContainerUnknown
+			}
+			if size, ok := c.BigDataSizes[key]; ok {
+				return size, nil
+			}
+		}
+	}
+	return -1, ErrSizeUnknown
+}
+
+func (r *containerStore) BigDataDigest(id, key string) (digest.Digest, error) {
+	if key == "" {
+		return "", errors.Wrapf(ErrInvalidBigDataName, "can't retrieve digest of container big data value with empty name")
+	}
+	c, ok := r.lookup(id)
+	if !ok {
+		return "", ErrContainerUnknown
+	}
+	if c.BigDataDigests == nil {
+		c.BigDataDigests = make(map[string]digest.Digest)
+	}
+	if d, ok := c.BigDataDigests[key]; ok {
+		return d, nil
+	}
+	if data, err := r.BigData(id, key); err == nil && data != nil {
+		if r.SetBigData(id, key, data) == nil {
+			c, ok := r.lookup(id)
+			if !ok {
+				return "", ErrContainerUnknown
+			}
+			if d, ok := c.BigDataDigests[key]; ok {
+				return d, nil
+			}
+		}
+	}
+	return "", ErrDigestUnknown
+}
+
+func (r *containerStore) BigDataNames(id string) ([]string, error) {
+	c, ok := r.lookup(id)
+	if !ok {
+		return nil, ErrContainerUnknown
+	}
+	return c.BigDataNames, nil
+}
+
+func (r *containerStore) SetBigData(id, key string, data []byte) error {
+	if key == "" {
+		return errors.Wrapf(ErrInvalidBigDataName, "can't set empty name for container big data item")
+	}
+	c, ok := r.lookup(id)
+	if !ok {
+		return ErrContainerUnknown
+	}
+	if err := os.MkdirAll(r.datadir(c.ID), 0700); err != nil {
+		return err
+	}
+	err := ioutils.AtomicWriteFile(r.datapath(c.ID, key), data, 0600)
+	if err == nil {
+		save := false
+		if c.BigDataSizes == nil {
+			c.BigDataSizes = make(map[string]int64)
+		}
+		oldSize, sizeOk := c.BigDataSizes[key]
+		c.BigDataSizes[key] = int64(len(data))
+		if c.BigDataDigests == nil {
+			c.BigDataDigests = make(map[string]digest.Digest)
+		}
+		oldDigest, digestOk := c.BigDataDigests[key]
+		newDigest := digest.Canonical.FromBytes(data)
+		c.BigDataDigests[key] = newDigest
+		if !sizeOk || oldSize != c.BigDataSizes[key] || !digestOk || oldDigest != newDigest {
+			save = true
+		}
+		addName := true
+		for _, name := range c.BigDataNames {
+			if name == key {
+				addName = false
+				break
+			}
+		}
+		if addName {
+			c.BigDataNames = append(c.BigDataNames, key)
+			save = true
+		}
+		if save {
+			err = r.Save()
+		}
+	}
+	return err
+}
+
+func (r *containerStore) Wipe() error {
+	ids := make([]string, 0, len(r.byid))
+	for id := range r.byid {
+		ids = append(ids, id)
+	}
+	for _, id := range ids {
+		if err := r.Delete(id); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (r *containerStore) Lock() {
+	r.lockfile.Lock()
+}
+
+func (r *containerStore) Unlock() {
+	r.lockfile.Unlock()
+}
+
+func (r *containerStore) Touch() error {
+	return r.lockfile.Touch()
+}
+
+func (r *containerStore) Modified() (bool, error) {
+	return r.lockfile.Modified()
+}
+
+func (r *containerStore) IsReadWrite() bool {
+	return r.lockfile.IsReadWrite()
+}
+
+func (r *containerStore) TouchedSince(when time.Time) bool {
+	return r.lockfile.TouchedSince(when)
+}

vendor/github.com/containers/storage/drivers/aufs/aufs.go

@@ -0,0 +1,691 @@
+// +build linux
+
+/*
+
+aufs driver directory structure
+
+  .
+  ├── layers // Metadata of layers
+  │   ├── 1
+  │   ├── 2
+  │   └── 3
+  ├── diff  // Content of the layer
+  │   ├── 1  // Contains layers that need to be mounted for the id
+  │   ├── 2
+  │   └── 3
+  └── mnt    // Mount points for the rw layers to be mounted
+      ├── 1
+      ├── 2
+      └── 3
+
+*/
+
+package aufs
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/containers/storage/drivers"
+	"github.com/containers/storage/pkg/archive"
+	"github.com/containers/storage/pkg/chrootarchive"
+	"github.com/containers/storage/pkg/directory"
+	"github.com/containers/storage/pkg/idtools"
+	"github.com/containers/storage/pkg/locker"
+	mountpk "github.com/containers/storage/pkg/mount"
+	"github.com/containers/storage/pkg/system"
+	rsystem "github.com/opencontainers/runc/libcontainer/system"
+	"github.com/opencontainers/selinux/go-selinux/label"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"github.com/vbatts/tar-split/tar/storage"
+	"golang.org/x/sys/unix"
+)
+
+var (
+	// ErrAufsNotSupported is returned if aufs is not supported by the host.
+	ErrAufsNotSupported = fmt.Errorf("AUFS was not found in /proc/filesystems")
+	// ErrAufsNested means aufs cannot be used bc we are in a user namespace
+	ErrAufsNested = fmt.Errorf("AUFS cannot be used in non-init user namespace")
+	backingFs     = "<unknown>"
+
+	enableDirpermLock sync.Once
+	enableDirperm     bool
+)
+
+func init() {
+	graphdriver.Register("aufs", Init)
+}
+
+// Driver contains information about the filesystem mounted.
+type Driver struct {
+	sync.Mutex
+	root          string
+	uidMaps       []idtools.IDMap
+	gidMaps       []idtools.IDMap
+	ctr           *graphdriver.RefCounter
+	pathCacheLock sync.Mutex
+	pathCache     map[string]string
+	naiveDiff     graphdriver.DiffDriver
+	locker        *locker.Locker
+}
+
+// Init returns a new AUFS driver.
+// An error is returned if AUFS is not supported.
+func Init(root string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
+
+	// Try to load the aufs kernel module
+	if err := supportsAufs(); err != nil {
+		return nil, errors.Wrap(graphdriver.ErrNotSupported, "kernel does not support aufs")
+
+	}
+
+	fsMagic, err := graphdriver.GetFSMagic(root)
+	if err != nil {
+		return nil, err
+	}
+	if fsName, ok := graphdriver.FsNames[fsMagic]; ok {
+		backingFs = fsName
+	}
+
+	switch fsMagic {
+	case graphdriver.FsMagicAufs, graphdriver.FsMagicBtrfs, graphdriver.FsMagicEcryptfs:
+		logrus.Errorf("AUFS is not supported over %s", backingFs)
+		return nil, errors.Wrapf(graphdriver.ErrIncompatibleFS, "AUFS is not supported over %q", backingFs)
+	}
+
+	paths := []string{
+		"mnt",
+		"diff",
+		"layers",
+	}
+
+	a := &Driver{
+		root:      root,
+		uidMaps:   uidMaps,
+		gidMaps:   gidMaps,
+		pathCache: make(map[string]string),
+		ctr:       graphdriver.NewRefCounter(graphdriver.NewFsChecker(graphdriver.FsMagicAufs)),
+		locker:    locker.New(),
+	}
+
+	rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
+	if err != nil {
+		return nil, err
+	}
+	// Create the root aufs driver dir and return
+	// if it already exists
+	// If not populate the dir structure
+	if err := idtools.MkdirAllAs(root, 0700, rootUID, rootGID); err != nil {
+		if os.IsExist(err) {
+			return a, nil
+		}
+		return nil, err
+	}
+
+	if err := mountpk.MakePrivate(root); err != nil {
+		return nil, err
+	}
+
+	// Populate the dir structure
+	for _, p := range paths {
+		if err := idtools.MkdirAllAs(path.Join(root, p), 0700, rootUID, rootGID); err != nil {
+			return nil, err
+		}
+	}
+	logger := logrus.WithFields(logrus.Fields{
+		"module": "graphdriver",
+		"driver": "aufs",
+	})
+
+	for _, path := range []string{"mnt", "diff"} {
+		p := filepath.Join(root, path)
+		entries, err := ioutil.ReadDir(p)
+		if err != nil {
+			logger.WithError(err).WithField("dir", p).Error("error reading dir entries")
+			continue
+		}
+		for _, entry := range entries {
+			if !entry.IsDir() {
+				continue
+			}
+			if strings.HasSuffix(entry.Name(), "-removing") {
+				logger.WithField("dir", entry.Name()).Debug("Cleaning up stale layer dir")
+				if err := system.EnsureRemoveAll(filepath.Join(p, entry.Name())); err != nil {
+					logger.WithField("dir", entry.Name()).WithError(err).Error("Error removing stale layer dir")
+				}
+			}
+		}
+	}
+
+	a.naiveDiff = graphdriver.NewNaiveDiffDriver(a, uidMaps, gidMaps)
+	return a, nil
+}
+
+// Return a nil error if the kernel supports aufs
+// We cannot modprobe because inside dind modprobe fails
+// to run
+func supportsAufs() error {
+	// We can try to modprobe aufs first before looking at
+	// proc/filesystems for when aufs is supported
+	exec.Command("modprobe", "aufs").Run()
+
+	if rsystem.RunningInUserNS() {
+		return ErrAufsNested
+	}
+
+	f, err := os.Open("/proc/filesystems")
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	s := bufio.NewScanner(f)
+	for s.Scan() {
+		if strings.Contains(s.Text(), "aufs") {
+			return nil
+		}
+	}
+	return ErrAufsNotSupported
+}
+
+func (a *Driver) rootPath() string {
+	return a.root
+}
+
+func (*Driver) String() string {
+	return "aufs"
+}
+
+// Status returns current information about the filesystem such as root directory, number of directories mounted, etc.
+func (a *Driver) Status() [][2]string {
+	ids, _ := loadIds(path.Join(a.rootPath(), "layers"))
+	return [][2]string{
+		{"Root Dir", a.rootPath()},
+		{"Backing Filesystem", backingFs},
+		{"Dirs", fmt.Sprintf("%d", len(ids))},
+		{"Dirperm1 Supported", fmt.Sprintf("%v", useDirperm())},
+	}
+}
+
+// Metadata not implemented
+func (a *Driver) Metadata(id string) (map[string]string, error) {
+	return nil, nil
+}
+
+// Exists returns true if the given id is registered with
+// this driver
+func (a *Driver) Exists(id string) bool {
+	if _, err := os.Lstat(path.Join(a.rootPath(), "layers", id)); err != nil {
+		return false
+	}
+	return true
+}
+
+// AdditionalImageStores returns additional image stores supported by the driver
+func (a *Driver) AdditionalImageStores() []string {
+	return nil
+}
+
+// CreateReadWrite creates a layer that is writable for use as a container
+// file system.
+func (a *Driver) CreateReadWrite(id, parent string, opts *graphdriver.CreateOpts) error {
+	return a.Create(id, parent, opts)
+}
+
+// Create three folders for each id
+// mnt, layers, and diff
+func (a *Driver) Create(id, parent string, opts *graphdriver.CreateOpts) error {
+
+	if opts != nil && len(opts.StorageOpt) != 0 {
+		return fmt.Errorf("--storage-opt is not supported for aufs")
+	}
+
+	if err := a.createDirsFor(id); err != nil {
+		return err
+	}
+	// Write the layers metadata
+	f, err := os.Create(path.Join(a.rootPath(), "layers", id))
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	if parent != "" {
+		ids, err := getParentIDs(a.rootPath(), parent)
+		if err != nil {
+			return err
+		}
+
+		if _, err := fmt.Fprintln(f, parent); err != nil {
+			return err
+		}
+		for _, i := range ids {
+			if _, err := fmt.Fprintln(f, i); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+// createDirsFor creates two directories for the given id.
+// mnt and diff
+func (a *Driver) createDirsFor(id string) error {
+	paths := []string{
+		"mnt",
+		"diff",
+	}
+
+	rootUID, rootGID, err := idtools.GetRootUIDGID(a.uidMaps, a.gidMaps)
+	if err != nil {
+		return err
+	}
+	// Directory permission is 0755.
+	// The path of directories are <aufs_root_path>/mnt/<image_id>
+	// and <aufs_root_path>/diff/<image_id>
+	for _, p := range paths {
+		if err := idtools.MkdirAllAs(path.Join(a.rootPath(), p, id), 0755, rootUID, rootGID); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Remove will unmount and remove the given id.
+func (a *Driver) Remove(id string) error {
+	a.locker.Lock(id)
+	defer a.locker.Unlock(id)
+	a.pathCacheLock.Lock()
+	mountpoint, exists := a.pathCache[id]
+	a.pathCacheLock.Unlock()
+	if !exists {
+		mountpoint = a.getMountpoint(id)
+	}
+
+	logger := logrus.WithFields(logrus.Fields{
+		"module": "graphdriver",
+		"driver": "aufs",
+		"layer":  id,
+	})
+
+	var retries int
+	for {
+		mounted, err := a.mounted(mountpoint)
+		if err != nil {
+			if os.IsNotExist(err) {
+				break
+			}
+			return err
+		}
+		if !mounted {
+			break
+		}
+
+		err = a.unmount(mountpoint)
+		if err == nil {
+			break
+		}
+
+		if err != unix.EBUSY {
+			return errors.Wrapf(err, "aufs: unmount error: %s", mountpoint)
+		}
+		if retries >= 5 {
+			return errors.Wrapf(err, "aufs: unmount error after retries: %s", mountpoint)
+		}
+		// If unmount returns EBUSY, it could be a transient error. Sleep and retry.
+		retries++
+		logger.Warnf("unmount failed due to EBUSY: retry count: %d", retries)
+		time.Sleep(100 * time.Millisecond)
+	}
+
+	// Remove the layers file for the id
+	if err := os.Remove(path.Join(a.rootPath(), "layers", id)); err != nil && !os.IsNotExist(err) {
+		return errors.Wrapf(err, "error removing layers dir for %s", id)
+	}
+
+	if err := atomicRemove(a.getDiffPath(id)); err != nil {
+		return errors.Wrapf(err, "could not remove diff path for id %s", id)
+	}
+
+	// Atomically remove each directory in turn by first moving it out of the
+	// way (so that container runtime doesn't find it anymore) before doing removal of
+	// the whole tree.
+	if err := atomicRemove(mountpoint); err != nil {
+		if errors.Cause(err) == unix.EBUSY {
+			logger.WithField("dir", mountpoint).WithError(err).Warn("error performing atomic remove due to EBUSY")
+		}
+		return errors.Wrapf(err, "could not remove mountpoint for id %s", id)
+	}
+
+	a.pathCacheLock.Lock()
+	delete(a.pathCache, id)
+	a.pathCacheLock.Unlock()
+	return nil
+}
+
+func atomicRemove(source string) error {
+	target := source + "-removing"
+
+	err := os.Rename(source, target)
+	switch {
+	case err == nil, os.IsNotExist(err):
+	case os.IsExist(err):
+		// Got error saying the target dir already exists, maybe the source doesn't exist due to a previous (failed) remove
+		if _, e := os.Stat(source); !os.IsNotExist(e) {
+			return errors.Wrapf(err, "target rename dir '%s' exists but should not, this needs to be manually cleaned up")
+		}
+	default:
+		return errors.Wrapf(err, "error preparing atomic delete")
+	}
+
+	return system.EnsureRemoveAll(target)
+}
+
+// Get returns the rootfs path for the id.
+// This will mount the dir at its given path
+func (a *Driver) Get(id, mountLabel string) (string, error) {
+	a.locker.Lock(id)
+	defer a.locker.Unlock(id)
+	parents, err := a.getParentLayerPaths(id)
+	if err != nil && !os.IsNotExist(err) {
+		return "", err
+	}
+
+	a.pathCacheLock.Lock()
+	m, exists := a.pathCache[id]
+	a.pathCacheLock.Unlock()
+
+	if !exists {
+		m = a.getDiffPath(id)
+		if len(parents) > 0 {
+			m = a.getMountpoint(id)
+		}
+	}
+	if count := a.ctr.Increment(m); count > 1 {
+		return m, nil
+	}
+
+	// If a dir does not have a parent ( no layers )do not try to mount
+	// just return the diff path to the data
+	if len(parents) > 0 {
+		if err := a.mount(id, m, mountLabel, parents); err != nil {
+			return "", err
+		}
+	}
+
+	a.pathCacheLock.Lock()
+	a.pathCache[id] = m
+	a.pathCacheLock.Unlock()
+	return m, nil
+}
+
+// Put unmounts and updates list of active mounts.
+func (a *Driver) Put(id string) error {
+	a.locker.Lock(id)
+	defer a.locker.Unlock(id)
+	a.pathCacheLock.Lock()
+	m, exists := a.pathCache[id]
+	if !exists {
+		m = a.getMountpoint(id)
+		a.pathCache[id] = m
+	}
+	a.pathCacheLock.Unlock()
+	if count := a.ctr.Decrement(m); count > 0 {
+		return nil
+	}
+
+	err := a.unmount(m)
+	if err != nil {
+		logrus.Debugf("Failed to unmount %s aufs: %v", id, err)
+	}
+	return err
+}
+
+// isParent returns if the passed in parent is the direct parent of the passed in layer
+func (a *Driver) isParent(id, parent string) bool {
+	parents, _ := getParentIDs(a.rootPath(), id)
+	if parent == "" && len(parents) > 0 {
+		return false
+	}
+	return !(len(parents) > 0 && parent != parents[0])
+}
+
+// Diff produces an archive of the changes between the specified
+// layer and its parent layer which may be "".
+func (a *Driver) Diff(id, parent, mountLabel string) (io.ReadCloser, error) {
+	if !a.isParent(id, parent) {
+		return a.naiveDiff.Diff(id, parent, mountLabel)
+	}
+
+	// AUFS doesn't need the parent layer to produce a diff.
+	return archive.TarWithOptions(path.Join(a.rootPath(), "diff", id), &archive.TarOptions{
+		Compression:     archive.Uncompressed,
+		ExcludePatterns: []string{archive.WhiteoutMetaPrefix + "*", "!" + archive.WhiteoutOpaqueDir},
+		UIDMaps:         a.uidMaps,
+		GIDMaps:         a.gidMaps,
+	})
+}
+
+type fileGetNilCloser struct {
+	storage.FileGetter
+}
+
+func (f fileGetNilCloser) Close() error {
+	return nil
+}
+
+// DiffGetter returns a FileGetCloser that can read files from the directory that
+// contains files for the layer differences. Used for direct access for tar-split.
+func (a *Driver) DiffGetter(id string) (graphdriver.FileGetCloser, error) {
+	p := path.Join(a.rootPath(), "diff", id)
+	return fileGetNilCloser{storage.NewPathFileGetter(p)}, nil
+}
+
+func (a *Driver) applyDiff(id string, diff io.Reader) error {
+	return chrootarchive.UntarUncompressed(diff, path.Join(a.rootPath(), "diff", id), &archive.TarOptions{
+		UIDMaps: a.uidMaps,
+		GIDMaps: a.gidMaps,
+	})
+}
+
+// DiffSize calculates the changes between the specified id
+// and its parent and returns the size in bytes of the changes
+// relative to its base filesystem directory.
+func (a *Driver) DiffSize(id, parent, mountLabel string) (size int64, err error) {
+	if !a.isParent(id, parent) {
+		return a.naiveDiff.DiffSize(id, parent, mountLabel)
+	}
+	// AUFS doesn't need the parent layer to calculate the diff size.
+	return directory.Size(path.Join(a.rootPath(), "diff", id))
+}
+
+// ApplyDiff extracts the changeset from the given diff into the
+// layer with the specified id and parent, returning the size of the
+// new layer in bytes.
+func (a *Driver) ApplyDiff(id, parent, mountLabel string, diff io.Reader) (size int64, err error) {
+	if !a.isParent(id, parent) {
+		return a.naiveDiff.ApplyDiff(id, parent, mountLabel, diff)
+	}
+
+	// AUFS doesn't need the parent id to apply the diff if it is the direct parent.
+	if err = a.applyDiff(id, diff); err != nil {
+		return
+	}
+
+	return a.DiffSize(id, parent, mountLabel)
+}
+
+// Changes produces a list of changes between the specified layer
+// and its parent layer. If parent is "", then all changes will be ADD changes.
+func (a *Driver) Changes(id, parent, mountLabel string) ([]archive.Change, error) {
+	if !a.isParent(id, parent) {
+		return a.naiveDiff.Changes(id, parent, mountLabel)
+	}
+
+	// AUFS doesn't have snapshots, so we need to get changes from all parent
+	// layers.
+	layers, err := a.getParentLayerPaths(id)
+	if err != nil {
+		return nil, err
+	}
+	return archive.Changes(layers, path.Join(a.rootPath(), "diff", id))
+}
+
+func (a *Driver) getParentLayerPaths(id string) ([]string, error) {
+	parentIds, err := getParentIDs(a.rootPath(), id)
+	if err != nil {
+		return nil, err
+	}
+	layers := make([]string, len(parentIds))
+
+	// Get the diff paths for all the parent ids
+	for i, p := range parentIds {
+		layers[i] = path.Join(a.rootPath(), "diff", p)
+	}
+	return layers, nil
+}
+
+func (a *Driver) mount(id string, target string, mountLabel string, layers []string) error {
+	a.Lock()
+	defer a.Unlock()
+
+	// If the id is mounted or we get an error return
+	if mounted, err := a.mounted(target); err != nil || mounted {
+		return err
+	}
+
+	rw := a.getDiffPath(id)
+
+	if err := a.aufsMount(layers, rw, target, mountLabel); err != nil {
+		return fmt.Errorf("error creating aufs mount to %s: %v", target, err)
+	}
+	return nil
+}
+
+func (a *Driver) unmount(mountPath string) error {
+	a.Lock()
+	defer a.Unlock()
+
+	if mounted, err := a.mounted(mountPath); err != nil || !mounted {
+		return err
+	}
+	if err := Unmount(mountPath); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (a *Driver) mounted(mountpoint string) (bool, error) {
+	return graphdriver.Mounted(graphdriver.FsMagicAufs, mountpoint)
+}
+
+// Cleanup aufs and unmount all mountpoints
+func (a *Driver) Cleanup() error {
+	var dirs []string
+	if err := filepath.Walk(a.mntPath(), func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		if !info.IsDir() {
+			return nil
+		}
+		dirs = append(dirs, path)
+		return nil
+	}); err != nil {
+		return err
+	}
+
+	for _, m := range dirs {
+		if err := a.unmount(m); err != nil {
+			logrus.Debugf("aufs error unmounting %s: %s", m, err)
+		}
+	}
+	return mountpk.Unmount(a.root)
+}
+
+func (a *Driver) aufsMount(ro []string, rw, target, mountLabel string) (err error) {
+	defer func() {
+		if err != nil {
+			Unmount(target)
+		}
+	}()
+
+	// Mount options are clipped to page size(4096 bytes). If there are more
+	// layers then these are remounted individually using append.
+
+	offset := 54
+	if useDirperm() {
+		offset += len(",dirperm1")
+	}
+	b := make([]byte, unix.Getpagesize()-len(mountLabel)-offset) // room for xino & mountLabel
+	bp := copy(b, fmt.Sprintf("br:%s=rw", rw))
+
+	index := 0
+	for ; index < len(ro); index++ {
+		layer := fmt.Sprintf(":%s=ro+wh", ro[index])
+		if bp+len(layer) > len(b) {
+			break
+		}
+		bp += copy(b[bp:], layer)
+	}
+
+	opts := "dio,xino=/dev/shm/aufs.xino"
+	if useDirperm() {
+		opts += ",dirperm1"
+	}
+	data := label.FormatMountLabel(fmt.Sprintf("%s,%s", string(b[:bp]), opts), mountLabel)
+	if err = mount("none", target, "aufs", 0, data); err != nil {
+		return
+	}
+
+	for ; index < len(ro); index++ {
+		layer := fmt.Sprintf(":%s=ro+wh", ro[index])
+		data := label.FormatMountLabel(fmt.Sprintf("append%s", layer), mountLabel)
+		if err = mount("none", target, "aufs", unix.MS_REMOUNT, data); err != nil {
+			return
+		}
+	}
+
+	return
+}
+
+// useDirperm checks dirperm1 mount option can be used with the current
+// version of aufs.
+func useDirperm() bool {
+	enableDirpermLock.Do(func() {
+		base, err := ioutil.TempDir("", "storage-aufs-base")
+		if err != nil {
+			logrus.Errorf("error checking dirperm1: %v", err)
+			return
+		}
+		defer os.RemoveAll(base)
+
+		union, err := ioutil.TempDir("", "storage-aufs-union")
+		if err != nil {
+			logrus.Errorf("error checking dirperm1: %v", err)
+			return
+		}
+		defer os.RemoveAll(union)
+
+		opts := fmt.Sprintf("br:%s,dirperm1,xino=/dev/shm/aufs.xino", base)
+		if err := mount("none", union, "aufs", 0, opts); err != nil {
+			return
+		}
+		enableDirperm = true
+		if err := Unmount(union); err != nil {
+			logrus.Errorf("error checking dirperm1: failed to unmount %v", err)
+		}
+	})
+	return enableDirperm
+}

vendor/github.com/containers/storage/drivers/aufs/dirs.go

@@ -0,0 +1,64 @@
+// +build linux
+
+package aufs
+
+import (
+	"bufio"
+	"io/ioutil"
+	"os"
+	"path"
+)
+
+// Return all the directories
+func loadIds(root string) ([]string, error) {
+	dirs, err := ioutil.ReadDir(root)
+	if err != nil {
+		return nil, err
+	}
+	out := []string{}
+	for _, d := range dirs {
+		if !d.IsDir() {
+			out = append(out, d.Name())
+		}
+	}
+	return out, nil
+}
+
+// Read the layers file for the current id and return all the
+// layers represented by new lines in the file
+//
+// If there are no lines in the file then the id has no parent
+// and an empty slice is returned.
+func getParentIDs(root, id string) ([]string, error) {
+	f, err := os.Open(path.Join(root, "layers", id))
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	out := []string{}
+	s := bufio.NewScanner(f)
+
+	for s.Scan() {
+		if t := s.Text(); t != "" {
+			out = append(out, s.Text())
+		}
+	}
+	return out, s.Err()
+}
+
+func (a *Driver) getMountpoint(id string) string {
+	return path.Join(a.mntPath(), id)
+}
+
+func (a *Driver) mntPath() string {
+	return path.Join(a.rootPath(), "mnt")
+}
+
+func (a *Driver) getDiffPath(id string) string {
+	return path.Join(a.diffPath(), id)
+}
+
+func (a *Driver) diffPath() string {
+	return path.Join(a.rootPath(), "diff")
+}

vendor/github.com/containers/storage/drivers/aufs/mount.go

@@ -0,0 +1,21 @@
+// +build linux
+
+package aufs
+
+import (
+	"os/exec"
+
+	"github.com/sirupsen/logrus"
+	"golang.org/x/sys/unix"
+)
+
+// Unmount the target specified.
+func Unmount(target string) error {
+	if err := exec.Command("auplink", target, "flush").Run(); err != nil {
+		logrus.Warnf("Couldn't run auplink before unmount %s: %s", target, err)
+	}
+	if err := unix.Unmount(target, 0); err != nil {
+		return err
+	}
+	return nil
+}

vendor/github.com/containers/storage/drivers/aufs/mount_linux.go

@@ -0,0 +1,7 @@
+package aufs
+
+import "golang.org/x/sys/unix"
+
+func mount(source string, target string, fstype string, flags uintptr, data string) error {
+	return unix.Mount(source, target, fstype, flags, data)
+}

vendor/github.com/containers/storage/drivers/aufs/mount_unsupported.go

@@ -0,0 +1,12 @@
+// +build !linux
+
+package aufs
+
+import "errors"
+
+// MsRemount declared to specify a non-linux system mount.
+const MsRemount = 0
+
+func mount(source string, target string, fstype string, flags uintptr, data string) (err error) {
+	return errors.New("mount is not implemented on this platform")
+}

vendor/github.com/containers/storage/drivers/btrfs/btrfs.go

@@ -0,0 +1,677 @@
+// +build linux
+
+package btrfs
+
+/*
+#include <stdlib.h>
+#include <dirent.h>
+#include <btrfs/ioctl.h>
+#include <btrfs/ctree.h>
+
+static void set_name_btrfs_ioctl_vol_args_v2(struct btrfs_ioctl_vol_args_v2* btrfs_struct, const char* value) {
+    snprintf(btrfs_struct->name, BTRFS_SUBVOL_NAME_MAX, "%s", value);
+}
+*/
+import "C"
+
+import (
+	"fmt"
+	"io/ioutil"
+	"math"
+	"os"
+	"path"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"sync"
+	"unsafe"
+
+	"github.com/containers/storage/drivers"
+	"github.com/containers/storage/pkg/idtools"
+	"github.com/containers/storage/pkg/mount"
+	"github.com/containers/storage/pkg/parsers"
+	"github.com/containers/storage/pkg/system"
+	"github.com/docker/go-units"
+	"github.com/opencontainers/selinux/go-selinux/label"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"golang.org/x/sys/unix"
+)
+
+func init() {
+	graphdriver.Register("btrfs", Init)
+}
+
+type btrfsOptions struct {
+	minSpace uint64
+	size     uint64
+}
+
+// Init returns a new BTRFS driver.
+// An error is returned if BTRFS is not supported.
+func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
+
+	fsMagic, err := graphdriver.GetFSMagic(home)
+	if err != nil {
+		return nil, err
+	}
+
+	if fsMagic != graphdriver.FsMagicBtrfs {
+		return nil, errors.Wrapf(graphdriver.ErrPrerequisites, "%q is not on a btrfs filesystem", home)
+	}
+
+	rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
+	if err != nil {
+		return nil, err
+	}
+	if err := idtools.MkdirAllAs(home, 0700, rootUID, rootGID); err != nil {
+		return nil, err
+	}
+
+	if err := mount.MakePrivate(home); err != nil {
+		return nil, err
+	}
+
+	opt, userDiskQuota, err := parseOptions(options)
+	if err != nil {
+		return nil, err
+	}
+
+	driver := &Driver{
+		home:    home,
+		uidMaps: uidMaps,
+		gidMaps: gidMaps,
+		options: opt,
+	}
+
+	if userDiskQuota {
+		if err := driver.subvolEnableQuota(); err != nil {
+			return nil, err
+		}
+	}
+
+	return graphdriver.NewNaiveDiffDriver(driver, uidMaps, gidMaps), nil
+}
+
+func parseOptions(opt []string) (btrfsOptions, bool, error) {
+	var options btrfsOptions
+	userDiskQuota := false
+	for _, option := range opt {
+		key, val, err := parsers.ParseKeyValueOpt(option)
+		if err != nil {
+			return options, userDiskQuota, err
+		}
+		key = strings.ToLower(key)
+		switch key {
+		case "btrfs.min_space":
+			minSpace, err := units.RAMInBytes(val)
+			if err != nil {
+				return options, userDiskQuota, err
+			}
+			userDiskQuota = true
+			options.minSpace = uint64(minSpace)
+		default:
+			return options, userDiskQuota, fmt.Errorf("Unknown option %s", key)
+		}
+	}
+	return options, userDiskQuota, nil
+}
+
+// Driver contains information about the filesystem mounted.
+type Driver struct {
+	//root of the file system
+	home         string
+	uidMaps      []idtools.IDMap
+	gidMaps      []idtools.IDMap
+	options      btrfsOptions
+	quotaEnabled bool
+	once         sync.Once
+}
+
+// String prints the name of the driver (btrfs).
+func (d *Driver) String() string {
+	return "btrfs"
+}
+
+// Status returns current driver information in a two dimensional string array.
+// Output contains "Build Version" and "Library Version" of the btrfs libraries used.
+// Version information can be used to check compatibility with your kernel.
+func (d *Driver) Status() [][2]string {
+	status := [][2]string{}
+	if bv := btrfsBuildVersion(); bv != "-" {
+		status = append(status, [2]string{"Build Version", bv})
+	}
+	if lv := btrfsLibVersion(); lv != -1 {
+		status = append(status, [2]string{"Library Version", fmt.Sprintf("%d", lv)})
+	}
+	return status
+}
+
+// Metadata returns empty metadata for this driver.
+func (d *Driver) Metadata(id string) (map[string]string, error) {
+	return nil, nil
+}
+
+// Cleanup unmounts the home directory.
+func (d *Driver) Cleanup() error {
+	if err := d.subvolDisableQuota(); err != nil {
+		return err
+	}
+
+	return mount.Unmount(d.home)
+}
+
+func free(p *C.char) {
+	C.free(unsafe.Pointer(p))
+}
+
+func openDir(path string) (*C.DIR, error) {
+	Cpath := C.CString(path)
+	defer free(Cpath)
+
+	dir := C.opendir(Cpath)
+	if dir == nil {
+		return nil, fmt.Errorf("Can't open dir")
+	}
+	return dir, nil
+}
+
+func closeDir(dir *C.DIR) {
+	if dir != nil {
+		C.closedir(dir)
+	}
+}
+
+func getDirFd(dir *C.DIR) uintptr {
+	return uintptr(C.dirfd(dir))
+}
+
+func subvolCreate(path, name string) error {
+	dir, err := openDir(path)
+	if err != nil {
+		return err
+	}
+	defer closeDir(dir)
+
+	var args C.struct_btrfs_ioctl_vol_args
+	for i, c := range []byte(name) {
+		args.name[i] = C.char(c)
+	}
+
+	_, _, errno := unix.Syscall(unix.SYS_IOCTL, getDirFd(dir), C.BTRFS_IOC_SUBVOL_CREATE,
+		uintptr(unsafe.Pointer(&args)))
+	if errno != 0 {
+		return fmt.Errorf("Failed to create btrfs subvolume: %v", errno.Error())
+	}
+	return nil
+}
+
+func subvolSnapshot(src, dest, name string) error {
+	srcDir, err := openDir(src)
+	if err != nil {
+		return err
+	}
+	defer closeDir(srcDir)
+
+	destDir, err := openDir(dest)
+	if err != nil {
+		return err
+	}
+	defer closeDir(destDir)
+
+	var args C.struct_btrfs_ioctl_vol_args_v2
+	args.fd = C.__s64(getDirFd(srcDir))
+
+	var cs = C.CString(name)
+	C.set_name_btrfs_ioctl_vol_args_v2(&args, cs)
+	C.free(unsafe.Pointer(cs))
+
+	_, _, errno := unix.Syscall(unix.SYS_IOCTL, getDirFd(destDir), C.BTRFS_IOC_SNAP_CREATE_V2,
+		uintptr(unsafe.Pointer(&args)))
+	if errno != 0 {
+		return fmt.Errorf("Failed to create btrfs snapshot: %v", errno.Error())
+	}
+	return nil
+}
+
+func isSubvolume(p string) (bool, error) {
+	var bufStat unix.Stat_t
+	if err := unix.Lstat(p, &bufStat); err != nil {
+		return false, err
+	}
+
+	// return true if it is a btrfs subvolume
+	return bufStat.Ino == C.BTRFS_FIRST_FREE_OBJECTID, nil
+}
+
+func subvolDelete(dirpath, name string, quotaEnabled bool) error {
+	dir, err := openDir(dirpath)
+	if err != nil {
+		return err
+	}
+	defer closeDir(dir)
+	fullPath := path.Join(dirpath, name)
+
+	var args C.struct_btrfs_ioctl_vol_args
+
+	// walk the btrfs subvolumes
+	walkSubvolumes := func(p string, f os.FileInfo, err error) error {
+		if err != nil {
+			if os.IsNotExist(err) && p != fullPath {
+				// missing most likely because the path was a subvolume that got removed in the previous iteration
+				// since it's gone anyway, we don't care
+				return nil
+			}
+			return fmt.Errorf("error walking subvolumes: %v", err)
+		}
+		// we want to check children only so skip itself
+		// it will be removed after the filepath walk anyways
+		if f.IsDir() && p != fullPath {
+			sv, err := isSubvolume(p)
+			if err != nil {
+				return fmt.Errorf("Failed to test if %s is a btrfs subvolume: %v", p, err)
+			}
+			if sv {
+				if err := subvolDelete(path.Dir(p), f.Name(), quotaEnabled); err != nil {
+					return fmt.Errorf("Failed to destroy btrfs child subvolume (%s) of parent (%s): %v", p, dirpath, err)
+				}
+			}
+		}
+		return nil
+	}
+	if err := filepath.Walk(path.Join(dirpath, name), walkSubvolumes); err != nil {
+		return fmt.Errorf("Recursively walking subvolumes for %s failed: %v", dirpath, err)
+	}
+
+	if quotaEnabled {
+		if qgroupid, err := subvolLookupQgroup(fullPath); err == nil {
+			var args C.struct_btrfs_ioctl_qgroup_create_args
+			args.qgroupid = C.__u64(qgroupid)
+
+			_, _, errno := unix.Syscall(unix.SYS_IOCTL, getDirFd(dir), C.BTRFS_IOC_QGROUP_CREATE,
+				uintptr(unsafe.Pointer(&args)))
+			if errno != 0 {
+				logrus.Errorf("Failed to delete btrfs qgroup %v for %s: %v", qgroupid, fullPath, errno.Error())
+			}
+		} else {
+			logrus.Errorf("Failed to lookup btrfs qgroup for %s: %v", fullPath, err.Error())
+		}
+	}
+
+	// all subvolumes have been removed
+	// now remove the one originally passed in
+	for i, c := range []byte(name) {
+		args.name[i] = C.char(c)
+	}
+	_, _, errno := unix.Syscall(unix.SYS_IOCTL, getDirFd(dir), C.BTRFS_IOC_SNAP_DESTROY,
+		uintptr(unsafe.Pointer(&args)))
+	if errno != 0 {
+		return fmt.Errorf("Failed to destroy btrfs snapshot %s for %s: %v", dirpath, name, errno.Error())
+	}
+	return nil
+}
+
+func (d *Driver) updateQuotaStatus() {
+	d.once.Do(func() {
+		if !d.quotaEnabled {
+			// In case quotaEnabled is not set, check qgroup and update quotaEnabled as needed
+			if err := subvolQgroupStatus(d.home); err != nil {
+				// quota is still not enabled
+				return
+			}
+			d.quotaEnabled = true
+		}
+	})
+}
+
+func (d *Driver) subvolEnableQuota() error {
+	d.updateQuotaStatus()
+
+	if d.quotaEnabled {
+		return nil
+	}
+
+	dir, err := openDir(d.home)
+	if err != nil {
+		return err
+	}
+	defer closeDir(dir)
+
+	var args C.struct_btrfs_ioctl_quota_ctl_args
+	args.cmd = C.BTRFS_QUOTA_CTL_ENABLE
+	_, _, errno := unix.Syscall(unix.SYS_IOCTL, getDirFd(dir), C.BTRFS_IOC_QUOTA_CTL,
+		uintptr(unsafe.Pointer(&args)))
+	if errno != 0 {
+		return fmt.Errorf("Failed to enable btrfs quota for %s: %v", dir, errno.Error())
+	}
+
+	d.quotaEnabled = true
+
+	return nil
+}
+
+func (d *Driver) subvolDisableQuota() error {
+	d.updateQuotaStatus()
+
+	if !d.quotaEnabled {
+		return nil
+	}
+
+	dir, err := openDir(d.home)
+	if err != nil {
+		return err
+	}
+	defer closeDir(dir)
+
+	var args C.struct_btrfs_ioctl_quota_ctl_args
+	args.cmd = C.BTRFS_QUOTA_CTL_DISABLE
+	_, _, errno := unix.Syscall(unix.SYS_IOCTL, getDirFd(dir), C.BTRFS_IOC_QUOTA_CTL,
+		uintptr(unsafe.Pointer(&args)))
+	if errno != 0 {
+		return fmt.Errorf("Failed to disable btrfs quota for %s: %v", dir, errno.Error())
+	}
+
+	d.quotaEnabled = false
+
+	return nil
+}
+
+func (d *Driver) subvolRescanQuota() error {
+	d.updateQuotaStatus()
+
+	if !d.quotaEnabled {
+		return nil
+	}
+
+	dir, err := openDir(d.home)
+	if err != nil {
+		return err
+	}
+	defer closeDir(dir)
+
+	var args C.struct_btrfs_ioctl_quota_rescan_args
+	_, _, errno := unix.Syscall(unix.SYS_IOCTL, getDirFd(dir), C.BTRFS_IOC_QUOTA_RESCAN_WAIT,
+		uintptr(unsafe.Pointer(&args)))
+	if errno != 0 {
+		return fmt.Errorf("Failed to rescan btrfs quota for %s: %v", dir, errno.Error())
+	}
+
+	return nil
+}
+
+func subvolLimitQgroup(path string, size uint64) error {
+	dir, err := openDir(path)
+	if err != nil {
+		return err
+	}
+	defer closeDir(dir)
+
+	var args C.struct_btrfs_ioctl_qgroup_limit_args
+	args.lim.max_referenced = C.__u64(size)
+	args.lim.flags = C.BTRFS_QGROUP_LIMIT_MAX_RFER
+	_, _, errno := unix.Syscall(unix.SYS_IOCTL, getDirFd(dir), C.BTRFS_IOC_QGROUP_LIMIT,
+		uintptr(unsafe.Pointer(&args)))
+	if errno != 0 {
+		return fmt.Errorf("Failed to limit qgroup for %s: %v", dir, errno.Error())
+	}
+
+	return nil
+}
+
+// subvolQgroupStatus performs a BTRFS_IOC_TREE_SEARCH on the root path
+// with search key of BTRFS_QGROUP_STATUS_KEY.
+// In case qgroup is enabled, the retuned key type will match BTRFS_QGROUP_STATUS_KEY.
+// For more details please see https://github.com/kdave/btrfs-progs/blob/v4.9/qgroup.c#L1035
+func subvolQgroupStatus(path string) error {
+	dir, err := openDir(path)
+	if err != nil {
+		return err
+	}
+	defer closeDir(dir)
+
+	var args C.struct_btrfs_ioctl_search_args
+	args.key.tree_id = C.BTRFS_QUOTA_TREE_OBJECTID
+	args.key.min_type = C.BTRFS_QGROUP_STATUS_KEY
+	args.key.max_type = C.BTRFS_QGROUP_STATUS_KEY
+	args.key.max_objectid = C.__u64(math.MaxUint64)
+	args.key.max_offset = C.__u64(math.MaxUint64)
+	args.key.max_transid = C.__u64(math.MaxUint64)
+	args.key.nr_items = 4096
+
+	_, _, errno := unix.Syscall(unix.SYS_IOCTL, getDirFd(dir), C.BTRFS_IOC_TREE_SEARCH,
+		uintptr(unsafe.Pointer(&args)))
+	if errno != 0 {
+		return fmt.Errorf("Failed to search qgroup for %s: %v", path, errno.Error())
+	}
+	sh := (*C.struct_btrfs_ioctl_search_header)(unsafe.Pointer(&args.buf))
+	if sh._type != C.BTRFS_QGROUP_STATUS_KEY {
+		return fmt.Errorf("Invalid qgroup search header type for %s: %v", path, sh._type)
+	}
+	return nil
+}
+
+func subvolLookupQgroup(path string) (uint64, error) {
+	dir, err := openDir(path)
+	if err != nil {
+		return 0, err
+	}
+	defer closeDir(dir)
+
+	var args C.struct_btrfs_ioctl_ino_lookup_args
+	args.objectid = C.BTRFS_FIRST_FREE_OBJECTID
+
+	_, _, errno := unix.Syscall(unix.SYS_IOCTL, getDirFd(dir), C.BTRFS_IOC_INO_LOOKUP,
+		uintptr(unsafe.Pointer(&args)))
+	if errno != 0 {
+		return 0, fmt.Errorf("Failed to lookup qgroup for %s: %v", dir, errno.Error())
+	}
+	if args.treeid == 0 {
+		return 0, fmt.Errorf("Invalid qgroup id for %s: 0", dir)
+	}
+
+	return uint64(args.treeid), nil
+}
+
+func (d *Driver) subvolumesDir() string {
+	return path.Join(d.home, "subvolumes")
+}
+
+func (d *Driver) subvolumesDirID(id string) string {
+	return path.Join(d.subvolumesDir(), id)
+}
+
+func (d *Driver) quotasDir() string {
+	return path.Join(d.home, "quotas")
+}
+
+func (d *Driver) quotasDirID(id string) string {
+	return path.Join(d.quotasDir(), id)
+}
+
+// CreateReadWrite creates a layer that is writable for use as a container
+// file system.
+func (d *Driver) CreateReadWrite(id, parent string, opts *graphdriver.CreateOpts) error {
+	return d.Create(id, parent, opts)
+}
+
+// Create the filesystem with given id.
+func (d *Driver) Create(id, parent string, opts *graphdriver.CreateOpts) error {
+	quotas := path.Join(d.home, "quotas")
+	subvolumes := path.Join(d.home, "subvolumes")
+	rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
+	if err != nil {
+		return err
+	}
+	if err := idtools.MkdirAllAs(subvolumes, 0700, rootUID, rootGID); err != nil {
+		return err
+	}
+	if parent == "" {
+		if err := subvolCreate(subvolumes, id); err != nil {
+			return err
+		}
+	} else {
+		parentDir := d.subvolumesDirID(parent)
+		st, err := os.Stat(parentDir)
+		if err != nil {
+			return err
+		}
+		if !st.IsDir() {
+			return fmt.Errorf("%s: not a directory", parentDir)
+		}
+		if err := subvolSnapshot(parentDir, subvolumes, id); err != nil {
+			return err
+		}
+	}
+
+	var storageOpt map[string]string
+	if opts != nil {
+		storageOpt = opts.StorageOpt
+	}
+
+	if _, ok := storageOpt["size"]; ok {
+		driver := &Driver{}
+		if err := d.parseStorageOpt(storageOpt, driver); err != nil {
+			return err
+		}
+
+		if err := d.setStorageSize(path.Join(subvolumes, id), driver); err != nil {
+			return err
+		}
+		if err := idtools.MkdirAllAs(quotas, 0700, rootUID, rootGID); err != nil {
+			return err
+		}
+		if err := ioutil.WriteFile(path.Join(quotas, id), []byte(fmt.Sprint(driver.options.size)), 0644); err != nil {
+			return err
+		}
+	}
+
+	// if we have a remapped root (user namespaces enabled), change the created snapshot
+	// dir ownership to match
+	if rootUID != 0 || rootGID != 0 {
+		if err := os.Chown(path.Join(subvolumes, id), rootUID, rootGID); err != nil {
+			return err
+		}
+	}
+
+	mountLabel := ""
+	if opts != nil {
+		mountLabel = opts.MountLabel
+	}
+
+	return label.Relabel(path.Join(subvolumes, id), mountLabel, false)
+}
+
+// Parse btrfs storage options
+func (d *Driver) parseStorageOpt(storageOpt map[string]string, driver *Driver) error {
+	// Read size to change the subvolume disk quota per container
+	for key, val := range storageOpt {
+		key := strings.ToLower(key)
+		switch key {
+		case "size":
+			size, err := units.RAMInBytes(val)
+			if err != nil {
+				return err
+			}
+			driver.options.size = uint64(size)
+		default:
+			return fmt.Errorf("Unknown option %s", key)
+		}
+	}
+
+	return nil
+}
+
+// Set btrfs storage size
+func (d *Driver) setStorageSize(dir string, driver *Driver) error {
+	if driver.options.size <= 0 {
+		return fmt.Errorf("btrfs: invalid storage size: %s", units.HumanSize(float64(driver.options.size)))
+	}
+	if d.options.minSpace > 0 && driver.options.size < d.options.minSpace {
+		return fmt.Errorf("btrfs: storage size cannot be less than %s", units.HumanSize(float64(d.options.minSpace)))
+	}
+
+	if err := d.subvolEnableQuota(); err != nil {
+		return err
+	}
+
+	if err := subvolLimitQgroup(dir, driver.options.size); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Remove the filesystem with given id.
+func (d *Driver) Remove(id string) error {
+	dir := d.subvolumesDirID(id)
+	if _, err := os.Stat(dir); err != nil {
+		return err
+	}
+	quotasDir := d.quotasDirID(id)
+	if _, err := os.Stat(quotasDir); err == nil {
+		if err := os.Remove(quotasDir); err != nil {
+			return err
+		}
+	} else if !os.IsNotExist(err) {
+		return err
+	}
+
+	// Call updateQuotaStatus() to invoke status update
+	d.updateQuotaStatus()
+
+	if err := subvolDelete(d.subvolumesDir(), id, d.quotaEnabled); err != nil {
+		return err
+	}
+	if err := system.EnsureRemoveAll(dir); err != nil {
+		return err
+	}
+	if err := d.subvolRescanQuota(); err != nil {
+		return err
+	}
+	return nil
+}
+
+// Get the requested filesystem id.
+func (d *Driver) Get(id, mountLabel string) (string, error) {
+	dir := d.subvolumesDirID(id)
+	st, err := os.Stat(dir)
+	if err != nil {
+		return "", err
+	}
+
+	if !st.IsDir() {
+		return "", fmt.Errorf("%s: not a directory", dir)
+	}
+
+	if quota, err := ioutil.ReadFile(d.quotasDirID(id)); err == nil {
+		if size, err := strconv.ParseUint(string(quota), 10, 64); err == nil && size >= d.options.minSpace {
+			if err := d.subvolEnableQuota(); err != nil {
+				return "", err
+			}
+			if err := subvolLimitQgroup(dir, size); err != nil {
+				return "", err
+			}
+		}
+	}
+
+	return dir, nil
+}
+
+// Put is not implemented for BTRFS as there is no cleanup required for the id.
+func (d *Driver) Put(id string) error {
+	// Get() creates no runtime resources (like e.g. mounts)
+	// so this doesn't need to do anything.
+	return nil
+}
+
+// Exists checks if the id exists in the filesystem.
+func (d *Driver) Exists(id string) bool {
+	dir := d.subvolumesDirID(id)
+	_, err := os.Stat(dir)
+	return err == nil
+}
+
+// AdditionalImageStores returns additional image stores supported by the driver
+func (d *Driver) AdditionalImageStores() []string {
+	return nil
+}

vendor/github.com/containers/storage/drivers/btrfs/dummy_unsupported.go

@@ -0,0 +1,3 @@
+// +build !linux !cgo
+
+package btrfs

vendor/github.com/containers/storage/drivers/btrfs/version.go

@@ -0,0 +1,26 @@
+// +build linux,!btrfs_noversion
+
+package btrfs
+
+/*
+#include <btrfs/version.h>
+
+// around version 3.16, they did not define lib version yet
+#ifndef BTRFS_LIB_VERSION
+#define BTRFS_LIB_VERSION -1
+#endif
+
+// upstream had removed it, but now it will be coming back
+#ifndef BTRFS_BUILD_VERSION
+#define BTRFS_BUILD_VERSION "-"
+#endif
+*/
+import "C"
+
+func btrfsBuildVersion() string {
+	return string(C.BTRFS_BUILD_VERSION)
+}
+
+func btrfsLibVersion() int {
+	return int(C.BTRFS_LIB_VERSION)
+}

vendor/github.com/containers/storage/drivers/btrfs/version_none.go

@@ -0,0 +1,14 @@
+// +build linux,btrfs_noversion
+
+package btrfs
+
+// TODO(vbatts) remove this work-around once supported linux distros are on
+// btrfs utilities of >= 3.16.1
+
+func btrfsBuildVersion() string {
+	return "-"
+}
+
+func btrfsLibVersion() int {
+	return -1
+}

vendor/github.com/containers/storage/drivers/counter.go

@@ -0,0 +1,59 @@
+package graphdriver
+
+import "sync"
+
+type minfo struct {
+	check bool
+	count int
+}
+
+// RefCounter is a generic counter for use by graphdriver Get/Put calls
+type RefCounter struct {
+	counts  map[string]*minfo
+	mu      sync.Mutex
+	checker Checker
+}
+
+// NewRefCounter returns a new RefCounter
+func NewRefCounter(c Checker) *RefCounter {
+	return &RefCounter{
+		checker: c,
+		counts:  make(map[string]*minfo),
+	}
+}
+
+// Increment increases the ref count for the given id and returns the current count
+func (c *RefCounter) Increment(path string) int {
+	return c.incdec(path, func(minfo *minfo) {
+		minfo.count++
+	})
+}
+
+// Decrement decreases the ref count for the given id and returns the current count
+func (c *RefCounter) Decrement(path string) int {
+	return c.incdec(path, func(minfo *minfo) {
+		minfo.count--
+	})
+}
+
+func (c *RefCounter) incdec(path string, infoOp func(minfo *minfo)) int {
+	c.mu.Lock()
+	m := c.counts[path]
+	if m == nil {
+		m = &minfo{}
+		c.counts[path] = m
+	}
+	// if we are checking this path for the first time check to make sure
+	// if it was already mounted on the system and make sure we have a correct ref
+	// count if it is mounted as it is in use.
+	if !m.check {
+		m.check = true
+		if c.checker.IsMounted(path) {
+			m.count++
+		}
+	}
+	infoOp(m)
+	count := m.count
+	c.mu.Unlock()
+	return count
+}

vendor/github.com/containers/storage/drivers/devmapper/device_setup.go

@@ -0,0 +1,236 @@
+package devmapper
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"reflect"
+	"strings"
+
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+type directLVMConfig struct {
+	Device              string
+	ThinpPercent        uint64
+	ThinpMetaPercent    uint64
+	AutoExtendPercent   uint64
+	AutoExtendThreshold uint64
+}
+
+var (
+	errThinpPercentMissing = errors.New("must set both `dm.thinp_percent` and `dm.thinp_metapercent` if either is specified")
+	errThinpPercentTooBig  = errors.New("combined `dm.thinp_percent` and `dm.thinp_metapercent` must not be greater than 100")
+	errMissingSetupDevice  = errors.New("must provide device path in `dm.setup_device` in order to configure direct-lvm")
+)
+
+func validateLVMConfig(cfg directLVMConfig) error {
+	if reflect.DeepEqual(cfg, directLVMConfig{}) {
+		return nil
+	}
+	if cfg.Device == "" {
+		return errMissingSetupDevice
+	}
+	if (cfg.ThinpPercent > 0 && cfg.ThinpMetaPercent == 0) || cfg.ThinpMetaPercent > 0 && cfg.ThinpPercent == 0 {
+		return errThinpPercentMissing
+	}
+
+	if cfg.ThinpPercent+cfg.ThinpMetaPercent > 100 {
+		return errThinpPercentTooBig
+	}
+	return nil
+}
+
+func checkDevAvailable(dev string) error {
+	lvmScan, err := exec.LookPath("lvmdiskscan")
+	if err != nil {
+		logrus.Debug("could not find lvmdiskscan")
+		return nil
+	}
+
+	out, err := exec.Command(lvmScan).CombinedOutput()
+	if err != nil {
+		logrus.WithError(err).Error(string(out))
+		return nil
+	}
+
+	if !bytes.Contains(out, []byte(dev)) {
+		return errors.Errorf("%s is not available for use with devicemapper", dev)
+	}
+	return nil
+}
+
+func checkDevInVG(dev string) error {
+	pvDisplay, err := exec.LookPath("pvdisplay")
+	if err != nil {
+		logrus.Debug("could not find pvdisplay")
+		return nil
+	}
+
+	out, err := exec.Command(pvDisplay, dev).CombinedOutput()
+	if err != nil {
+		logrus.WithError(err).Error(string(out))
+		return nil
+	}
+
+	scanner := bufio.NewScanner(bytes.NewReader(bytes.TrimSpace(out)))
+	for scanner.Scan() {
+		fields := strings.SplitAfter(strings.TrimSpace(scanner.Text()), "VG Name")
+		if len(fields) > 1 {
+			// got "VG Name" line"
+			vg := strings.TrimSpace(fields[1])
+			if len(vg) > 0 {
+				return errors.Errorf("%s is already part of a volume group %q: must remove this device from any volume group or provide a different device", dev, vg)
+			}
+			logrus.Error(fields)
+			break
+		}
+	}
+	return nil
+}
+
+func checkDevHasFS(dev string) error {
+	blkid, err := exec.LookPath("blkid")
+	if err != nil {
+		logrus.Debug("could not find blkid")
+		return nil
+	}
+
+	out, err := exec.Command(blkid, dev).CombinedOutput()
+	if err != nil {
+		logrus.WithError(err).Error(string(out))
+		return nil
+	}
+
+	fields := bytes.Fields(out)
+	for _, f := range fields {
+		kv := bytes.Split(f, []byte{'='})
+		if bytes.Equal(kv[0], []byte("TYPE")) {
+			v := bytes.Trim(kv[1], "\"")
+			if len(v) > 0 {
+				return errors.Errorf("%s has a filesystem already, use dm.directlvm_device_force=true if you want to wipe the device", dev)
+			}
+			return nil
+		}
+	}
+	return nil
+}
+
+func verifyBlockDevice(dev string, force bool) error {
+	if err := checkDevAvailable(dev); err != nil {
+		return err
+	}
+	if err := checkDevInVG(dev); err != nil {
+		return err
+	}
+
+	if force {
+		return nil
+	}
+
+	if err := checkDevHasFS(dev); err != nil {
+		return err
+	}
+	return nil
+}
+
+func readLVMConfig(root string) (directLVMConfig, error) {
+	var cfg directLVMConfig
+
+	p := filepath.Join(root, "setup-config.json")
+	b, err := ioutil.ReadFile(p)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return cfg, nil
+		}
+		return cfg, errors.Wrap(err, "error reading existing setup config")
+	}
+
+	// check if this is just an empty file, no need to produce a json error later if so
+	if len(b) == 0 {
+		return cfg, nil
+	}
+
+	err = json.Unmarshal(b, &cfg)
+	return cfg, errors.Wrap(err, "error unmarshaling previous device setup config")
+}
+
+func writeLVMConfig(root string, cfg directLVMConfig) error {
+	p := filepath.Join(root, "setup-config.json")
+	b, err := json.Marshal(cfg)
+	if err != nil {
+		return errors.Wrap(err, "error marshalling direct lvm config")
+	}
+	err = ioutil.WriteFile(p, b, 0600)
+	return errors.Wrap(err, "error writing direct lvm config to file")
+}
+
+func setupDirectLVM(cfg directLVMConfig) error {
+	lvmProfileDir := "/etc/lvm/profile"
+	binaries := []string{"pvcreate", "vgcreate", "lvcreate", "lvconvert", "lvchange", "thin_check"}
+
+	for _, bin := range binaries {
+		if _, err := exec.LookPath(bin); err != nil {
+			return errors.Wrap(err, "error looking up command `"+bin+"` while setting up direct lvm")
+		}
+	}
+
+	err := os.MkdirAll(lvmProfileDir, 0755)
+	if err != nil {
+		return errors.Wrap(err, "error creating lvm profile directory")
+	}
+
+	if cfg.AutoExtendPercent == 0 {
+		cfg.AutoExtendPercent = 20
+	}
+
+	if cfg.AutoExtendThreshold == 0 {
+		cfg.AutoExtendThreshold = 80
+	}
+
+	if cfg.ThinpPercent == 0 {
+		cfg.ThinpPercent = 95
+	}
+	if cfg.ThinpMetaPercent == 0 {
+		cfg.ThinpMetaPercent = 1
+	}
+
+	out, err := exec.Command("pvcreate", "-f", cfg.Device).CombinedOutput()
+	if err != nil {
+		return errors.Wrap(err, string(out))
+	}
+
+	out, err = exec.Command("vgcreate", "storage", cfg.Device).CombinedOutput()
+	if err != nil {
+		return errors.Wrap(err, string(out))
+	}
+
+	out, err = exec.Command("lvcreate", "--wipesignatures", "y", "-n", "thinpool", "storage", "--extents", fmt.Sprintf("%d%%VG", cfg.ThinpPercent)).CombinedOutput()
+	if err != nil {
+		return errors.Wrap(err, string(out))
+	}
+	out, err = exec.Command("lvcreate", "--wipesignatures", "y", "-n", "thinpoolmeta", "storage", "--extents", fmt.Sprintf("%d%%VG", cfg.ThinpMetaPercent)).CombinedOutput()
+	if err != nil {
+		return errors.Wrap(err, string(out))
+	}
+
+	out, err = exec.Command("lvconvert", "-y", "--zero", "n", "-c", "512K", "--thinpool", "storage/thinpool", "--poolmetadata", "storage/thinpoolmeta").CombinedOutput()
+	if err != nil {
+		return errors.Wrap(err, string(out))
+	}
+
+	profile := fmt.Sprintf("activation{\nthin_pool_autoextend_threshold=%d\nthin_pool_autoextend_percent=%d\n}", cfg.AutoExtendThreshold, cfg.AutoExtendPercent)
+	err = ioutil.WriteFile(lvmProfileDir+"/storage-thinpool.profile", []byte(profile), 0600)
+	if err != nil {
+		return errors.Wrap(err, "error writing storage thinp autoextend profile")
+	}
+
+	out, err = exec.Command("lvchange", "--metadataprofile", "storage-thinpool", "storage/thinpool").CombinedOutput()
+	return errors.Wrap(err, string(out))
+}

vendor/github.com/containers/storage/drivers/devmapper/devmapper_doc.go

@@ -0,0 +1,106 @@
+package devmapper
+
+// Definition of struct dm_task and sub structures (from lvm2)
+//
+// struct dm_ioctl {
+// 	/*
+// 	 * The version number is made up of three parts:
+// 	 * major - no backward or forward compatibility,
+// 	 * minor - only backwards compatible,
+// 	 * patch - both backwards and forwards compatible.
+// 	 *
+// 	 * All clients of the ioctl interface should fill in the
+// 	 * version number of the interface that they were
+// 	 * compiled with.
+// 	 *
+// 	 * All recognized ioctl commands (ie. those that don't
+// 	 * return -ENOTTY) fill out this field, even if the
+// 	 * command failed.
+// 	 */
+// 	uint32_t version[3];	/* in/out */
+// 	uint32_t data_size;	/* total size of data passed in
+// 				 * including this struct */
+
+// 	uint32_t data_start;	/* offset to start of data
+// 				 * relative to start of this struct */
+
+// 	uint32_t target_count;	/* in/out */
+// 	int32_t open_count;	/* out */
+// 	uint32_t flags;		/* in/out */
+
+// 	/*
+// 	 * event_nr holds either the event number (input and output) or the
+// 	 * udev cookie value (input only).
+// 	 * The DM_DEV_WAIT ioctl takes an event number as input.
+// 	 * The DM_SUSPEND, DM_DEV_REMOVE and DM_DEV_RENAME ioctls
+// 	 * use the field as a cookie to return in the DM_COOKIE
+// 	 * variable with the uevents they issue.
+// 	 * For output, the ioctls return the event number, not the cookie.
+// 	 */
+// 	uint32_t event_nr;      	/* in/out */
+// 	uint32_t padding;
+
+// 	uint64_t dev;		/* in/out */
+
+// 	char name[DM_NAME_LEN];	/* device name */
+// 	char uuid[DM_UUID_LEN];	/* unique identifier for
+// 				 * the block device */
+// 	char data[7];		/* padding or data */
+// };
+
+// struct target {
+// 	uint64_t start;
+// 	uint64_t length;
+// 	char *type;
+// 	char *params;
+
+// 	struct target *next;
+// };
+
+// typedef enum {
+// 	DM_ADD_NODE_ON_RESUME, /* add /dev/mapper node with dmsetup resume */
+// 	DM_ADD_NODE_ON_CREATE  /* add /dev/mapper node with dmsetup create */
+// } dm_add_node_t;
+
+// struct dm_task {
+// 	int type;
+// 	char *dev_name;
+// 	char *mangled_dev_name;
+
+// 	struct target *head, *tail;
+
+// 	int read_only;
+// 	uint32_t event_nr;
+// 	int major;
+// 	int minor;
+// 	int allow_default_major_fallback;
+// 	uid_t uid;
+// 	gid_t gid;
+// 	mode_t mode;
+// 	uint32_t read_ahead;
+// 	uint32_t read_ahead_flags;
+// 	union {
+// 		struct dm_ioctl *v4;
+// 	} dmi;
+// 	char *newname;
+// 	char *message;
+// 	char *geometry;
+// 	uint64_t sector;
+// 	int no_flush;
+// 	int no_open_count;
+// 	int skip_lockfs;
+// 	int query_inactive_table;
+// 	int suppress_identical_reload;
+// 	dm_add_node_t add_node;
+// 	uint64_t existing_table_size;
+// 	int cookie_set;
+// 	int new_uuid;
+// 	int secure_data;
+// 	int retry_remove;
+// 	int enable_checks;
+// 	int expected_errno;
+
+// 	char *uuid;
+// 	char *mangled_uuid;
+// };
+//

vendor/github.com/containers/storage/drivers/devmapper/driver.go

@@ -0,0 +1,240 @@
+// +build linux
+
+package devmapper
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path"
+	"strconv"
+
+	"github.com/sirupsen/logrus"
+
+	"github.com/containers/storage/drivers"
+	"github.com/containers/storage/pkg/devicemapper"
+	"github.com/containers/storage/pkg/idtools"
+	"github.com/containers/storage/pkg/locker"
+	"github.com/containers/storage/pkg/mount"
+	"github.com/containers/storage/pkg/system"
+	units "github.com/docker/go-units"
+)
+
+func init() {
+	graphdriver.Register("devicemapper", Init)
+}
+
+// Driver contains the device set mounted and the home directory
+type Driver struct {
+	*DeviceSet
+	home    string
+	uidMaps []idtools.IDMap
+	gidMaps []idtools.IDMap
+	ctr     *graphdriver.RefCounter
+	locker  *locker.Locker
+}
+
+// Init creates a driver with the given home and the set of options.
+func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
+	deviceSet, err := NewDeviceSet(home, true, options, uidMaps, gidMaps)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := mount.MakePrivate(home); err != nil {
+		return nil, err
+	}
+
+	d := &Driver{
+		DeviceSet: deviceSet,
+		home:      home,
+		uidMaps:   uidMaps,
+		gidMaps:   gidMaps,
+		ctr:       graphdriver.NewRefCounter(graphdriver.NewDefaultChecker()),
+		locker:    locker.New(),
+	}
+
+	return graphdriver.NewNaiveDiffDriver(d, uidMaps, gidMaps), nil
+}
+
+func (d *Driver) String() string {
+	return "devicemapper"
+}
+
+// Status returns the status about the driver in a printable format.
+// Information returned contains Pool Name, Data File, Metadata file, disk usage by
+// the data and metadata, etc.
+func (d *Driver) Status() [][2]string {
+	s := d.DeviceSet.Status()
+
+	status := [][2]string{
+		{"Pool Name", s.PoolName},
+		{"Pool Blocksize", units.HumanSize(float64(s.SectorSize))},
+		{"Base Device Size", units.HumanSize(float64(s.BaseDeviceSize))},
+		{"Backing Filesystem", s.BaseDeviceFS},
+		{"Data file", s.DataFile},
+		{"Metadata file", s.MetadataFile},
+		{"Data Space Used", units.HumanSize(float64(s.Data.Used))},
+		{"Data Space Total", units.HumanSize(float64(s.Data.Total))},
+		{"Data Space Available", units.HumanSize(float64(s.Data.Available))},
+		{"Metadata Space Used", units.HumanSize(float64(s.Metadata.Used))},
+		{"Metadata Space Total", units.HumanSize(float64(s.Metadata.Total))},
+		{"Metadata Space Available", units.HumanSize(float64(s.Metadata.Available))},
+		{"Thin Pool Minimum Free Space", units.HumanSize(float64(s.MinFreeSpace))},
+		{"Udev Sync Supported", fmt.Sprintf("%v", s.UdevSyncSupported)},
+		{"Deferred Removal Enabled", fmt.Sprintf("%v", s.DeferredRemoveEnabled)},
+		{"Deferred Deletion Enabled", fmt.Sprintf("%v", s.DeferredDeleteEnabled)},
+		{"Deferred Deleted Device Count", fmt.Sprintf("%v", s.DeferredDeletedDeviceCount)},
+	}
+	if len(s.DataLoopback) > 0 {
+		status = append(status, [2]string{"Data loop file", s.DataLoopback})
+	}
+	if len(s.MetadataLoopback) > 0 {
+		status = append(status, [2]string{"Metadata loop file", s.MetadataLoopback})
+	}
+	if vStr, err := devicemapper.GetLibraryVersion(); err == nil {
+		status = append(status, [2]string{"Library Version", vStr})
+	}
+	return status
+}
+
+// Metadata returns a map of information about the device.
+func (d *Driver) Metadata(id string) (map[string]string, error) {
+	m, err := d.DeviceSet.exportDeviceMetadata(id)
+
+	if err != nil {
+		return nil, err
+	}
+
+	metadata := make(map[string]string)
+	metadata["DeviceId"] = strconv.Itoa(m.deviceID)
+	metadata["DeviceSize"] = strconv.FormatUint(m.deviceSize, 10)
+	metadata["DeviceName"] = m.deviceName
+	return metadata, nil
+}
+
+// Cleanup unmounts a device.
+func (d *Driver) Cleanup() error {
+	err := d.DeviceSet.Shutdown(d.home)
+
+	if err2 := mount.Unmount(d.home); err == nil {
+		err = err2
+	}
+
+	return err
+}
+
+// CreateReadWrite creates a layer that is writable for use as a container
+// file system.
+func (d *Driver) CreateReadWrite(id, parent string, opts *graphdriver.CreateOpts) error {
+	return d.Create(id, parent, opts)
+}
+
+// Create adds a device with a given id and the parent.
+func (d *Driver) Create(id, parent string, opts *graphdriver.CreateOpts) error {
+	var storageOpt map[string]string
+	if opts != nil {
+		storageOpt = opts.StorageOpt
+	}
+
+	if err := d.DeviceSet.AddDevice(id, parent, storageOpt); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Remove removes a device with a given id, unmounts the filesystem.
+func (d *Driver) Remove(id string) error {
+	d.locker.Lock(id)
+	defer d.locker.Unlock(id)
+	if !d.DeviceSet.HasDevice(id) {
+		// Consider removing a non-existing device a no-op
+		// This is useful to be able to progress on container removal
+		// if the underlying device has gone away due to earlier errors
+		return nil
+	}
+
+	// This assumes the device has been properly Get/Put:ed and thus is unmounted
+	if err := d.DeviceSet.DeleteDevice(id, false); err != nil {
+		return fmt.Errorf("failed to remove device %s: %v", id, err)
+	}
+	return system.EnsureRemoveAll(path.Join(d.home, "mnt", id))
+}
+
+// Get mounts a device with given id into the root filesystem
+func (d *Driver) Get(id, mountLabel string) (string, error) {
+	d.locker.Lock(id)
+	defer d.locker.Unlock(id)
+	mp := path.Join(d.home, "mnt", id)
+	rootFs := path.Join(mp, "rootfs")
+	if count := d.ctr.Increment(mp); count > 1 {
+		return rootFs, nil
+	}
+
+	uid, gid, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
+	if err != nil {
+		d.ctr.Decrement(mp)
+		return "", err
+	}
+
+	// Create the target directories if they don't exist
+	if err := idtools.MkdirAllAs(path.Join(d.home, "mnt"), 0755, uid, gid); err != nil && !os.IsExist(err) {
+		d.ctr.Decrement(mp)
+		return "", err
+	}
+	if err := idtools.MkdirAs(mp, 0755, uid, gid); err != nil && !os.IsExist(err) {
+		d.ctr.Decrement(mp)
+		return "", err
+	}
+
+	// Mount the device
+	if err := d.DeviceSet.MountDevice(id, mp, mountLabel); err != nil {
+		d.ctr.Decrement(mp)
+		return "", err
+	}
+
+	if err := idtools.MkdirAllAs(rootFs, 0755, uid, gid); err != nil && !os.IsExist(err) {
+		d.ctr.Decrement(mp)
+		d.DeviceSet.UnmountDevice(id, mp)
+		return "", err
+	}
+
+	idFile := path.Join(mp, "id")
+	if _, err := os.Stat(idFile); err != nil && os.IsNotExist(err) {
+		// Create an "id" file with the container/image id in it to help reconstruct this in case
+		// of later problems
+		if err := ioutil.WriteFile(idFile, []byte(id), 0600); err != nil {
+			d.ctr.Decrement(mp)
+			d.DeviceSet.UnmountDevice(id, mp)
+			return "", err
+		}
+	}
+
+	return rootFs, nil
+}
+
+// Put unmounts a device and removes it.
+func (d *Driver) Put(id string) error {
+	d.locker.Lock(id)
+	defer d.locker.Unlock(id)
+	mp := path.Join(d.home, "mnt", id)
+	if count := d.ctr.Decrement(mp); count > 0 {
+		return nil
+	}
+	err := d.DeviceSet.UnmountDevice(id, mp)
+	if err != nil {
+		logrus.Errorf("devmapper: Error unmounting device %s: %s", id, err)
+	}
+	return err
+}
+
+// Exists checks to see if the device exists.
+func (d *Driver) Exists(id string) bool {
+	return d.DeviceSet.HasDevice(id)
+}
+
+// AdditionalImageStores returns additional image stores supported by the driver
+func (d *Driver) AdditionalImageStores() []string {
+	return nil
+}

vendor/github.com/containers/storage/drivers/devmapper/mount.go

@@ -0,0 +1,88 @@
+// +build linux
+
+package devmapper
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"golang.org/x/sys/unix"
+)
+
+// FIXME: this is copy-pasted from the aufs driver.
+// It should be moved into the core.
+
+// Mounted returns true if a mount point exists.
+func Mounted(mountpoint string) (bool, error) {
+	var mntpointSt unix.Stat_t
+	if err := unix.Stat(mountpoint, &mntpointSt); err != nil {
+		if os.IsNotExist(err) {
+			return false, nil
+		}
+		return false, err
+	}
+	var parentSt unix.Stat_t
+	if err := unix.Stat(filepath.Join(mountpoint, ".."), &parentSt); err != nil {
+		return false, err
+	}
+	return mntpointSt.Dev != parentSt.Dev, nil
+}
+
+type probeData struct {
+	fsName string
+	magic  string
+	offset uint64
+}
+
+// ProbeFsType returns the filesystem name for the given device id.
+func ProbeFsType(device string) (string, error) {
+	probes := []probeData{
+		{"btrfs", "_BHRfS_M", 0x10040},
+		{"ext4", "\123\357", 0x438},
+		{"xfs", "XFSB", 0},
+	}
+
+	maxLen := uint64(0)
+	for _, p := range probes {
+		l := p.offset + uint64(len(p.magic))
+		if l > maxLen {
+			maxLen = l
+		}
+	}
+
+	file, err := os.Open(device)
+	if err != nil {
+		return "", err
+	}
+	defer file.Close()
+
+	buffer := make([]byte, maxLen)
+	l, err := file.Read(buffer)
+	if err != nil {
+		return "", err
+	}
+
+	if uint64(l) != maxLen {
+		return "", fmt.Errorf("devmapper: unable to detect filesystem type of %s, short read", device)
+	}
+
+	for _, p := range probes {
+		if bytes.Equal([]byte(p.magic), buffer[p.offset:p.offset+uint64(len(p.magic))]) {
+			return p.fsName, nil
+		}
+	}
+
+	return "", fmt.Errorf("devmapper: Unknown filesystem type on %s", device)
+}
+
+func joinMountOptions(a, b string) string {
+	if a == "" {
+		return b
+	}
+	if b == "" {
+		return a
+	}
+	return a + "," + b
+}

vendor/github.com/containers/storage/drivers/driver.go

@@ -0,0 +1,285 @@
+package graphdriver
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"github.com/vbatts/tar-split/tar/storage"
+
+	"github.com/containers/storage/pkg/archive"
+	"github.com/containers/storage/pkg/idtools"
+)
+
+// FsMagic unsigned id of the filesystem in use.
+type FsMagic uint32
+
+const (
+	// FsMagicUnsupported is a predefined constant value other than a valid filesystem id.
+	FsMagicUnsupported = FsMagic(0x00000000)
+)
+
+var (
+	// All registered drivers
+	drivers map[string]InitFunc
+
+	// ErrNotSupported returned when driver is not supported.
+	ErrNotSupported = errors.New("driver not supported")
+	// ErrPrerequisites returned when driver does not meet prerequisites.
+	ErrPrerequisites = errors.New("prerequisites for driver not satisfied (wrong filesystem?)")
+	// ErrIncompatibleFS returned when file system is not supported.
+	ErrIncompatibleFS = fmt.Errorf("backing file system is unsupported for this graph driver")
+)
+
+//CreateOpts contains optional arguments for Create() and CreateReadWrite()
+// methods.
+type CreateOpts struct {
+	MountLabel string
+	StorageOpt map[string]string
+}
+
+// InitFunc initializes the storage driver.
+type InitFunc func(root string, options []string, uidMaps, gidMaps []idtools.IDMap) (Driver, error)
+
+// ProtoDriver defines the basic capabilities of a driver.
+// This interface exists solely to be a minimum set of methods
+// for client code which choose not to implement the entire Driver
+// interface and use the NaiveDiffDriver wrapper constructor.
+//
+// Use of ProtoDriver directly by client code is not recommended.
+type ProtoDriver interface {
+	// String returns a string representation of this driver.
+	String() string
+	// CreateReadWrite creates a new, empty filesystem layer that is ready
+	// to be used as the storage for a container. Additional options can
+	// be passed in opts. parent may be "" and opts may be nil.
+	CreateReadWrite(id, parent string, opts *CreateOpts) error
+	// Create creates a new, empty, filesystem layer with the
+	// specified id and parent and options passed in opts. Parent
+	// may be "" and opts may be nil.
+	Create(id, parent string, opts *CreateOpts) error
+	// Remove attempts to remove the filesystem layer with this id.
+	Remove(id string) error
+	// Get returns the mountpoint for the layered filesystem referred
+	// to by this id. You can optionally specify a mountLabel or "".
+	// Returns the absolute path to the mounted layered filesystem.
+	Get(id, mountLabel string) (dir string, err error)
+	// Put releases the system resources for the specified id,
+	// e.g, unmounting layered filesystem.
+	Put(id string) error
+	// Exists returns whether a filesystem layer with the specified
+	// ID exists on this driver.
+	Exists(id string) bool
+	// Status returns a set of key-value pairs which give low
+	// level diagnostic status about this driver.
+	Status() [][2]string
+	// Returns a set of key-value pairs which give low level information
+	// about the image/container driver is managing.
+	Metadata(id string) (map[string]string, error)
+	// Cleanup performs necessary tasks to release resources
+	// held by the driver, e.g., unmounting all layered filesystems
+	// known to this driver.
+	Cleanup() error
+	// AdditionalImageStores returns additional image stores supported by the driver
+	AdditionalImageStores() []string
+}
+
+// DiffDriver is the interface to use to implement graph diffs
+type DiffDriver interface {
+	// Diff produces an archive of the changes between the specified
+	// layer and its parent layer which may be "".
+	Diff(id, parent, mountLabel string) (io.ReadCloser, error)
+	// Changes produces a list of changes between the specified layer
+	// and its parent layer. If parent is "", then all changes will be ADD changes.
+	Changes(id, parent, mountLabel string) ([]archive.Change, error)
+	// ApplyDiff extracts the changeset from the given diff into the
+	// layer with the specified id and parent, returning the size of the
+	// new layer in bytes.
+	// The io.Reader must be an uncompressed stream.
+	ApplyDiff(id, parent, mountLabel string, diff io.Reader) (size int64, err error)
+	// DiffSize calculates the changes between the specified id
+	// and its parent and returns the size in bytes of the changes
+	// relative to its base filesystem directory.
+	DiffSize(id, parent, mountLabel string) (size int64, err error)
+}
+
+// Driver is the interface for layered/snapshot file system drivers.
+type Driver interface {
+	ProtoDriver
+	DiffDriver
+}
+
+// Capabilities defines a list of capabilities a driver may implement.
+// These capabilities are not required; however, they do determine how a
+// graphdriver can be used.
+type Capabilities struct {
+	// Flags that this driver is capable of reproducing exactly equivalent
+	// diffs for read-only layers. If set, clients can rely on the driver
+	// for consistent tar streams, and avoid extra processing to account
+	// for potential differences (eg: the layer store's use of tar-split).
+	ReproducesExactDiffs bool
+}
+
+// CapabilityDriver is the interface for layered file system drivers that
+// can report on their Capabilities.
+type CapabilityDriver interface {
+	Capabilities() Capabilities
+}
+
+// DiffGetterDriver is the interface for layered file system drivers that
+// provide a specialized function for getting file contents for tar-split.
+type DiffGetterDriver interface {
+	Driver
+	// DiffGetter returns an interface to efficiently retrieve the contents
+	// of files in a layer.
+	DiffGetter(id string) (FileGetCloser, error)
+}
+
+// FileGetCloser extends the storage.FileGetter interface with a Close method
+// for cleaning up.
+type FileGetCloser interface {
+	storage.FileGetter
+	// Close cleans up any resources associated with the FileGetCloser.
+	Close() error
+}
+
+// Checker makes checks on specified filesystems.
+type Checker interface {
+	// IsMounted returns true if the provided path is mounted for the specific checker
+	IsMounted(path string) bool
+}
+
+func init() {
+	drivers = make(map[string]InitFunc)
+}
+
+// Register registers an InitFunc for the driver.
+func Register(name string, initFunc InitFunc) error {
+	if _, exists := drivers[name]; exists {
+		return fmt.Errorf("Name already registered %s", name)
+	}
+	drivers[name] = initFunc
+
+	return nil
+}
+
+// GetDriver initializes and returns the registered driver
+func GetDriver(name string, config Options) (Driver, error) {
+	if initFunc, exists := drivers[name]; exists {
+		return initFunc(filepath.Join(config.Root, name), config.DriverOptions, config.UIDMaps, config.GIDMaps)
+	}
+
+	logrus.Errorf("Failed to GetDriver graph %s %s", name, config.Root)
+	return nil, errors.Wrapf(ErrNotSupported, "failed to GetDriver graph %s %s", name, config.Root)
+}
+
+// getBuiltinDriver initializes and returns the registered driver, but does not try to load from plugins
+func getBuiltinDriver(name, home string, options []string, uidMaps, gidMaps []idtools.IDMap) (Driver, error) {
+	if initFunc, exists := drivers[name]; exists {
+		return initFunc(filepath.Join(home, name), options, uidMaps, gidMaps)
+	}
+	logrus.Errorf("Failed to built-in GetDriver graph %s %s", name, home)
+	return nil, errors.Wrapf(ErrNotSupported, "failed to built-in GetDriver graph %s %s", name, home)
+}
+
+// Options is used to initialize a graphdriver
+type Options struct {
+	Root                string
+	DriverOptions       []string
+	UIDMaps             []idtools.IDMap
+	GIDMaps             []idtools.IDMap
+	ExperimentalEnabled bool
+}
+
+// New creates the driver and initializes it at the specified root.
+func New(name string, config Options) (Driver, error) {
+	if name != "" {
+		logrus.Debugf("[graphdriver] trying provided driver %q", name) // so the logs show specified driver
+		return GetDriver(name, config)
+	}
+
+	// Guess for prior driver
+	driversMap := scanPriorDrivers(config.Root)
+	for _, name := range priority {
+		if name == "vfs" {
+			// don't use vfs even if there is state present.
+			continue
+		}
+		if _, prior := driversMap[name]; prior {
+			// of the state found from prior drivers, check in order of our priority
+			// which we would prefer
+			driver, err := getBuiltinDriver(name, config.Root, config.DriverOptions, config.UIDMaps, config.GIDMaps)
+			if err != nil {
+				// unlike below, we will return error here, because there is prior
+				// state, and now it is no longer supported/prereq/compatible, so
+				// something changed and needs attention. Otherwise the daemon's
+				// images would just "disappear".
+				logrus.Errorf("[graphdriver] prior storage driver %s failed: %s", name, err)
+				return nil, err
+			}
+
+			// abort starting when there are other prior configured drivers
+			// to ensure the user explicitly selects the driver to load
+			if len(driversMap)-1 > 0 {
+				var driversSlice []string
+				for name := range driversMap {
+					driversSlice = append(driversSlice, name)
+				}
+
+				return nil, fmt.Errorf("%s contains several valid graphdrivers: %s; Please cleanup or explicitly choose storage driver (-s <DRIVER>)", config.Root, strings.Join(driversSlice, ", "))
+			}
+
+			logrus.Infof("[graphdriver] using prior storage driver: %s", name)
+			return driver, nil
+		}
+	}
+
+	// Check for priority drivers first
+	for _, name := range priority {
+		driver, err := getBuiltinDriver(name, config.Root, config.DriverOptions, config.UIDMaps, config.GIDMaps)
+		if err != nil {
+			if isDriverNotSupported(err) {
+				continue
+			}
+			return nil, err
+		}
+		return driver, nil
+	}
+
+	// Check all registered drivers if no priority driver is found
+	for name, initFunc := range drivers {
+		driver, err := initFunc(filepath.Join(config.Root, name), config.DriverOptions, config.UIDMaps, config.GIDMaps)
+		if err != nil {
+			if isDriverNotSupported(err) {
+				continue
+			}
+			return nil, err
+		}
+		return driver, nil
+	}
+	return nil, fmt.Errorf("No supported storage backend found")
+}
+
+// isDriverNotSupported returns true if the error initializing
+// the graph driver is a non-supported error.
+func isDriverNotSupported(err error) bool {
+	cause := errors.Cause(err)
+	return cause == ErrNotSupported || cause == ErrPrerequisites || cause == ErrIncompatibleFS
+}
+
+// scanPriorDrivers returns an un-ordered scan of directories of prior storage drivers
+func scanPriorDrivers(root string) map[string]bool {
+	driversMap := make(map[string]bool)
+
+	for driver := range drivers {
+		p := filepath.Join(root, driver)
+		if _, err := os.Stat(p); err == nil && driver != "vfs" {
+			driversMap[driver] = true
+		}
+	}
+	return driversMap
+}

vendor/github.com/containers/storage/drivers/driver_freebsd.go

@@ -0,0 +1,23 @@
+package graphdriver
+
+import (
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+var (
+	// Slice of drivers that should be used in an order
+	priority = []string{
+		"zfs",
+	}
+)
+
+// Mounted checks if the given path is mounted as the fs type
+func Mounted(fsType FsMagic, mountPath string) (bool, error) {
+	var buf unix.Statfs_t
+	if err := syscall.Statfs(mountPath, &buf); err != nil {
+		return false, err
+	}
+	return FsMagic(buf.Type) == fsType, nil
+}

vendor/github.com/containers/storage/drivers/driver_linux.go

@@ -0,0 +1,135 @@
+// +build linux
+
+package graphdriver
+
+import (
+	"path/filepath"
+
+	"github.com/containers/storage/pkg/mount"
+	"golang.org/x/sys/unix"
+)
+
+const (
+	// FsMagicAufs filesystem id for Aufs
+	FsMagicAufs = FsMagic(0x61756673)
+	// FsMagicBtrfs filesystem id for Btrfs
+	FsMagicBtrfs = FsMagic(0x9123683E)
+	// FsMagicCramfs filesystem id for Cramfs
+	FsMagicCramfs = FsMagic(0x28cd3d45)
+	// FsMagicEcryptfs filesystem id for eCryptfs
+	FsMagicEcryptfs = FsMagic(0xf15f)
+	// FsMagicExtfs filesystem id for Extfs
+	FsMagicExtfs = FsMagic(0x0000EF53)
+	// FsMagicF2fs filesystem id for F2fs
+	FsMagicF2fs = FsMagic(0xF2F52010)
+	// FsMagicGPFS filesystem id for GPFS
+	FsMagicGPFS = FsMagic(0x47504653)
+	// FsMagicJffs2Fs filesystem if for Jffs2Fs
+	FsMagicJffs2Fs = FsMagic(0x000072b6)
+	// FsMagicJfs filesystem id for Jfs
+	FsMagicJfs = FsMagic(0x3153464a)
+	// FsMagicNfsFs filesystem id for NfsFs
+	FsMagicNfsFs = FsMagic(0x00006969)
+	// FsMagicRAMFs filesystem id for RamFs
+	FsMagicRAMFs = FsMagic(0x858458f6)
+	// FsMagicReiserFs filesystem id for ReiserFs
+	FsMagicReiserFs = FsMagic(0x52654973)
+	// FsMagicSmbFs filesystem id for SmbFs
+	FsMagicSmbFs = FsMagic(0x0000517B)
+	// FsMagicSquashFs filesystem id for SquashFs
+	FsMagicSquashFs = FsMagic(0x73717368)
+	// FsMagicTmpFs filesystem id for TmpFs
+	FsMagicTmpFs = FsMagic(0x01021994)
+	// FsMagicVxFS filesystem id for VxFs
+	FsMagicVxFS = FsMagic(0xa501fcf5)
+	// FsMagicXfs filesystem id for Xfs
+	FsMagicXfs = FsMagic(0x58465342)
+	// FsMagicZfs filesystem id for Zfs
+	FsMagicZfs = FsMagic(0x2fc12fc1)
+	// FsMagicOverlay filesystem id for overlay
+	FsMagicOverlay = FsMagic(0x794C7630)
+)
+
+var (
+	// Slice of drivers that should be used in an order
+	priority = []string{
+		"overlay",
+		"devicemapper",
+		"aufs",
+		"btrfs",
+		"zfs",
+		"vfs",
+	}
+
+	// FsNames maps filesystem id to name of the filesystem.
+	FsNames = map[FsMagic]string{
+		FsMagicAufs:        "aufs",
+		FsMagicBtrfs:       "btrfs",
+		FsMagicCramfs:      "cramfs",
+		FsMagicEcryptfs:    "ecryptfs",
+		FsMagicExtfs:       "extfs",
+		FsMagicF2fs:        "f2fs",
+		FsMagicGPFS:        "gpfs",
+		FsMagicJffs2Fs:     "jffs2",
+		FsMagicJfs:         "jfs",
+		FsMagicNfsFs:       "nfs",
+		FsMagicOverlay:     "overlayfs",
+		FsMagicRAMFs:       "ramfs",
+		FsMagicReiserFs:    "reiserfs",
+		FsMagicSmbFs:       "smb",
+		FsMagicSquashFs:    "squashfs",
+		FsMagicTmpFs:       "tmpfs",
+		FsMagicUnsupported: "unsupported",
+		FsMagicVxFS:        "vxfs",
+		FsMagicXfs:         "xfs",
+		FsMagicZfs:         "zfs",
+	}
+)
+
+// GetFSMagic returns the filesystem id given the path.
+func GetFSMagic(rootpath string) (FsMagic, error) {
+	var buf unix.Statfs_t
+	if err := unix.Statfs(filepath.Dir(rootpath), &buf); err != nil {
+		return 0, err
+	}
+	return FsMagic(buf.Type), nil
+}
+
+// NewFsChecker returns a checker configured for the provided FsMagic
+func NewFsChecker(t FsMagic) Checker {
+	return &fsChecker{
+		t: t,
+	}
+}
+
+type fsChecker struct {
+	t FsMagic
+}
+
+func (c *fsChecker) IsMounted(path string) bool {
+	m, _ := Mounted(c.t, path)
+	return m
+}
+
+// NewDefaultChecker returns a check that parses /proc/mountinfo to check
+// if the specified path is mounted.
+func NewDefaultChecker() Checker {
+	return &defaultChecker{}
+}
+
+type defaultChecker struct {
+}
+
+func (c *defaultChecker) IsMounted(path string) bool {
+	m, _ := mount.Mounted(path)
+	return m
+}
+
+// Mounted checks if the given path is mounted as the fs type
+func Mounted(fsType FsMagic, mountPath string) (bool, error) {
+	var buf unix.Statfs_t
+	if err := unix.Statfs(mountPath, &buf); err != nil {
+		return false, err
+	}
+	return FsMagic(buf.Type) == fsType, nil
+}

vendor/github.com/containers/storage/drivers/driver_solaris.go

@@ -0,0 +1,96 @@
+// +build solaris,cgo
+
+package graphdriver
+
+/*
+#include <sys/statvfs.h>
+#include <stdlib.h>
+
+static inline struct statvfs *getstatfs(char *s) {
+        struct statvfs *buf;
+        int err;
+        buf = (struct statvfs *)malloc(sizeof(struct statvfs));
+        err = statvfs(s, buf);
+        return buf;
+}
+*/
+import "C"
+import (
+	"path/filepath"
+	"unsafe"
+
+	"github.com/containers/storage/pkg/mount"
+	"github.com/sirupsen/logrus"
+)
+
+const (
+	// FsMagicZfs filesystem id for Zfs
+	FsMagicZfs = FsMagic(0x2fc12fc1)
+)
+
+var (
+	// Slice of drivers that should be used in an order
+	priority = []string{
+		"zfs",
+	}
+
+	// FsNames maps filesystem id to name of the filesystem.
+	FsNames = map[FsMagic]string{
+		FsMagicZfs: "zfs",
+	}
+)
+
+// GetFSMagic returns the filesystem id given the path.
+func GetFSMagic(rootpath string) (FsMagic, error) {
+	return 0, nil
+}
+
+type fsChecker struct {
+	t FsMagic
+}
+
+func (c *fsChecker) IsMounted(path string) bool {
+	m, _ := Mounted(c.t, path)
+	return m
+}
+
+// NewFsChecker returns a checker configured for the provided FsMagic
+func NewFsChecker(t FsMagic) Checker {
+	return &fsChecker{
+		t: t,
+	}
+}
+
+// NewDefaultChecker returns a check that parses /proc/mountinfo to check
+// if the specified path is mounted.
+// No-op on Solaris.
+func NewDefaultChecker() Checker {
+	return &defaultChecker{}
+}
+
+type defaultChecker struct {
+}
+
+func (c *defaultChecker) IsMounted(path string) bool {
+	m, _ := mount.Mounted(path)
+	return m
+}
+
+// Mounted checks if the given path is mounted as the fs type
+//Solaris supports only ZFS for now
+func Mounted(fsType FsMagic, mountPath string) (bool, error) {
+
+	cs := C.CString(filepath.Dir(mountPath))
+	defer C.free(unsafe.Pointer(cs))
+	buf := C.getstatfs(cs)
+	defer C.free(unsafe.Pointer(buf))
+
+	// on Solaris buf.f_basetype contains ['z', 'f', 's', 0 ... ]
+	if (buf.f_basetype[0] != 122) || (buf.f_basetype[1] != 102) || (buf.f_basetype[2] != 115) ||
+		(buf.f_basetype[3] != 0) {
+		logrus.Debugf("[zfs] no zfs dataset found for rootdir '%s'", mountPath)
+		return false, ErrPrerequisites
+	}
+
+	return true, nil
+}

vendor/github.com/containers/storage/drivers/driver_unsupported.go

@@ -0,0 +1,15 @@
+// +build !linux,!windows,!freebsd,!solaris
+
+package graphdriver
+
+var (
+	// Slice of drivers that should be used in an order
+	priority = []string{
+		"unsupported",
+	}
+)
+
+// GetFSMagic returns the filesystem id given the path.
+func GetFSMagic(rootpath string) (FsMagic, error) {
+	return FsMagicUnsupported, nil
+}

vendor/github.com/containers/storage/drivers/driver_windows.go

@@ -0,0 +1,14 @@
+package graphdriver
+
+var (
+	// Slice of drivers that should be used in order
+	priority = []string{
+		"windowsfilter",
+	}
+)
+
+// GetFSMagic returns the filesystem id given the path.
+func GetFSMagic(rootpath string) (FsMagic, error) {
+	// Note it is OK to return FsMagicUnsupported on Windows.
+	return FsMagicUnsupported, nil
+}

vendor/github.com/containers/storage/drivers/fsdiff.go

@@ -0,0 +1,169 @@
+package graphdriver
+
+import (
+	"io"
+	"time"
+
+	"github.com/containers/storage/pkg/archive"
+	"github.com/containers/storage/pkg/chrootarchive"
+	"github.com/containers/storage/pkg/idtools"
+	"github.com/containers/storage/pkg/ioutils"
+	"github.com/sirupsen/logrus"
+)
+
+var (
+	// ApplyUncompressedLayer defines the unpack method used by the graph
+	// driver.
+	ApplyUncompressedLayer = chrootarchive.ApplyUncompressedLayer
+)
+
+// NaiveDiffDriver takes a ProtoDriver and adds the
+// capability of the Diffing methods which it may or may not
+// support on its own. See the comment on the exported
+// NewNaiveDiffDriver function below.
+// Notably, the AUFS driver doesn't need to be wrapped like this.
+type NaiveDiffDriver struct {
+	ProtoDriver
+	uidMaps []idtools.IDMap
+	gidMaps []idtools.IDMap
+}
+
+// NewNaiveDiffDriver returns a fully functional driver that wraps the
+// given ProtoDriver and adds the capability of the following methods which
+// it may or may not support on its own:
+//     Diff(id, parent, mountLabel string) (io.ReadCloser, error)
+//     Changes(id, parent, mountLabel string) ([]archive.Change, error)
+//     ApplyDiff(id, parent, mountLabel string, diff io.Reader) (size int64, err error)
+//     DiffSize(id, parent, mountLabel string) (size int64, err error)
+func NewNaiveDiffDriver(driver ProtoDriver, uidMaps, gidMaps []idtools.IDMap) Driver {
+	return &NaiveDiffDriver{ProtoDriver: driver,
+		uidMaps: uidMaps,
+		gidMaps: gidMaps}
+}
+
+// Diff produces an archive of the changes between the specified
+// layer and its parent layer which may be "".
+func (gdw *NaiveDiffDriver) Diff(id, parent, mountLabel string) (arch io.ReadCloser, err error) {
+	startTime := time.Now()
+	driver := gdw.ProtoDriver
+
+	layerFs, err := driver.Get(id, mountLabel)
+	if err != nil {
+		return nil, err
+	}
+
+	defer func() {
+		if err != nil {
+			driver.Put(id)
+		}
+	}()
+
+	if parent == "" {
+		archive, err := archive.Tar(layerFs, archive.Uncompressed)
+		if err != nil {
+			return nil, err
+		}
+		return ioutils.NewReadCloserWrapper(archive, func() error {
+			err := archive.Close()
+			driver.Put(id)
+			return err
+		}), nil
+	}
+
+	parentFs, err := driver.Get(parent, mountLabel)
+	if err != nil {
+		return nil, err
+	}
+	defer driver.Put(parent)
+
+	changes, err := archive.ChangesDirs(layerFs, parentFs)
+	if err != nil {
+		return nil, err
+	}
+
+	archive, err := archive.ExportChanges(layerFs, changes, gdw.uidMaps, gdw.gidMaps)
+	if err != nil {
+		return nil, err
+	}
+
+	return ioutils.NewReadCloserWrapper(archive, func() error {
+		err := archive.Close()
+		driver.Put(id)
+
+		// NaiveDiffDriver compares file metadata with parent layers. Parent layers
+		// are extracted from tar's with full second precision on modified time.
+		// We need this hack here to make sure calls within same second receive
+		// correct result.
+		time.Sleep(startTime.Truncate(time.Second).Add(time.Second).Sub(time.Now()))
+		return err
+	}), nil
+}
+
+// Changes produces a list of changes between the specified layer
+// and its parent layer. If parent is "", then all changes will be ADD changes.
+func (gdw *NaiveDiffDriver) Changes(id, parent, mountLabel string) ([]archive.Change, error) {
+	driver := gdw.ProtoDriver
+
+	layerFs, err := driver.Get(id, mountLabel)
+	if err != nil {
+		return nil, err
+	}
+	defer driver.Put(id)
+
+	parentFs := ""
+
+	if parent != "" {
+		parentFs, err = driver.Get(parent, mountLabel)
+		if err != nil {
+			return nil, err
+		}
+		defer driver.Put(parent)
+	}
+
+	return archive.ChangesDirs(layerFs, parentFs)
+}
+
+// ApplyDiff extracts the changeset from the given diff into the
+// layer with the specified id and parent, returning the size of the
+// new layer in bytes.
+func (gdw *NaiveDiffDriver) ApplyDiff(id, parent, mountLabel string, diff io.Reader) (size int64, err error) {
+	driver := gdw.ProtoDriver
+
+	// Mount the root filesystem so we can apply the diff/layer.
+	layerFs, err := driver.Get(id, mountLabel)
+	if err != nil {
+		return
+	}
+	defer driver.Put(id)
+
+	options := &archive.TarOptions{UIDMaps: gdw.uidMaps,
+		GIDMaps: gdw.gidMaps}
+	start := time.Now().UTC()
+	logrus.Debug("Start untar layer")
+	if size, err = ApplyUncompressedLayer(layerFs, diff, options); err != nil {
+		return
+	}
+	logrus.Debugf("Untar time: %vs", time.Now().UTC().Sub(start).Seconds())
+
+	return
+}
+
+// DiffSize calculates the changes between the specified layer
+// and its parent and returns the size in bytes of the changes
+// relative to its base filesystem directory.
+func (gdw *NaiveDiffDriver) DiffSize(id, parent, mountLabel string) (size int64, err error) {
+	driver := gdw.ProtoDriver
+
+	changes, err := gdw.Changes(id, parent, mountLabel)
+	if err != nil {
+		return
+	}
+
+	layerFs, err := driver.Get(id, mountLabel)
+	if err != nil {
+		return
+	}
+	defer driver.Put(id)
+
+	return archive.ChangesSize(layerFs, changes), nil
+}

vendor/github.com/containers/storage/drivers/overlay/check.go

@@ -0,0 +1,102 @@
+// +build linux
+
+package overlay
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path"
+	"path/filepath"
+	"syscall"
+
+	"github.com/containers/storage/pkg/system"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"golang.org/x/sys/unix"
+)
+
+// doesSupportNativeDiff checks whether the filesystem has a bug
+// which copies up the opaque flag when copying up an opaque
+// directory or the kernel enable CONFIG_OVERLAY_FS_REDIRECT_DIR.
+// When these exist naive diff should be used.
+func doesSupportNativeDiff(d string) error {
+	td, err := ioutil.TempDir(d, "opaque-bug-check")
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err := os.RemoveAll(td); err != nil {
+			logrus.Warnf("Failed to remove check directory %v: %v", td, err)
+		}
+	}()
+
+	// Make directories l1/d, l1/d1, l2/d, l3, work, merged
+	if err := os.MkdirAll(filepath.Join(td, "l1", "d"), 0755); err != nil {
+		return err
+	}
+	if err := os.MkdirAll(filepath.Join(td, "l1", "d1"), 0755); err != nil {
+		return err
+	}
+	if err := os.MkdirAll(filepath.Join(td, "l2", "d"), 0755); err != nil {
+		return err
+	}
+	if err := os.Mkdir(filepath.Join(td, "l3"), 0755); err != nil {
+		return err
+	}
+	if err := os.Mkdir(filepath.Join(td, "work"), 0755); err != nil {
+		return err
+	}
+	if err := os.Mkdir(filepath.Join(td, "merged"), 0755); err != nil {
+		return err
+	}
+
+	// Mark l2/d as opaque
+	if err := system.Lsetxattr(filepath.Join(td, "l2", "d"), "trusted.overlay.opaque", []byte("y"), 0); err != nil {
+		return errors.Wrap(err, "failed to set opaque flag on middle layer")
+	}
+
+	opts := fmt.Sprintf("lowerdir=%s:%s,upperdir=%s,workdir=%s", path.Join(td, "l2"), path.Join(td, "l1"), path.Join(td, "l3"), path.Join(td, "work"))
+	if err := unix.Mount("overlay", filepath.Join(td, "merged"), "overlay", 0, opts); err != nil {
+		return errors.Wrap(err, "failed to mount overlay")
+	}
+	defer func() {
+		if err := unix.Unmount(filepath.Join(td, "merged"), 0); err != nil {
+			logrus.Warnf("Failed to unmount check directory %v: %v", filepath.Join(td, "merged"), err)
+		}
+	}()
+
+	// Touch file in d to force copy up of opaque directory "d" from "l2" to "l3"
+	if err := ioutil.WriteFile(filepath.Join(td, "merged", "d", "f"), []byte{}, 0644); err != nil {
+		return errors.Wrap(err, "failed to write to merged directory")
+	}
+
+	// Check l3/d does not have opaque flag
+	xattrOpaque, err := system.Lgetxattr(filepath.Join(td, "l3", "d"), "trusted.overlay.opaque")
+	if err != nil {
+		return errors.Wrap(err, "failed to read opaque flag on upper layer")
+	}
+	if string(xattrOpaque) == "y" {
+		return errors.New("opaque flag erroneously copied up, consider update to kernel 4.8 or later to fix")
+	}
+
+	// rename "d1" to "d2"
+	if err := os.Rename(filepath.Join(td, "merged", "d1"), filepath.Join(td, "merged", "d2")); err != nil {
+		// if rename failed with syscall.EXDEV, the kernel doesn't have CONFIG_OVERLAY_FS_REDIRECT_DIR enabled
+		if err.(*os.LinkError).Err == syscall.EXDEV {
+			return nil
+		}
+		return errors.Wrap(err, "failed to rename dir in merged directory")
+	}
+	// get the xattr of "d2"
+	xattrRedirect, err := system.Lgetxattr(filepath.Join(td, "l3", "d2"), "trusted.overlay.redirect")
+	if err != nil {
+		return errors.Wrap(err, "failed to read redirect flag on upper layer")
+	}
+
+	if string(xattrRedirect) == "d1" {
+		return errors.New("kernel has CONFIG_OVERLAY_FS_REDIRECT_DIR enabled")
+	}
+
+	return nil
+}

vendor/github.com/containers/storage/drivers/overlay/mount.go

@@ -0,0 +1,89 @@
+// +build linux
+
+package overlay
+
+import (
+	"bytes"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"os"
+	"runtime"
+
+	"github.com/containers/storage/pkg/reexec"
+	"golang.org/x/sys/unix"
+)
+
+func init() {
+	reexec.Register("storage-mountfrom", mountFromMain)
+}
+
+func fatal(err error) {
+	fmt.Fprint(os.Stderr, err)
+	os.Exit(1)
+}
+
+type mountOptions struct {
+	Device string
+	Target string
+	Type   string
+	Label  string
+	Flag   uint32
+}
+
+func mountFrom(dir, device, target, mType string, flags uintptr, label string) error {
+	options := &mountOptions{
+		Device: device,
+		Target: target,
+		Type:   mType,
+		Flag:   uint32(flags),
+		Label:  label,
+	}
+
+	cmd := reexec.Command("storage-mountfrom", dir)
+	w, err := cmd.StdinPipe()
+	if err != nil {
+		return fmt.Errorf("mountfrom error on pipe creation: %v", err)
+	}
+
+	output := bytes.NewBuffer(nil)
+	cmd.Stdout = output
+	cmd.Stderr = output
+	if err := cmd.Start(); err != nil {
+		w.Close()
+		return fmt.Errorf("mountfrom error on re-exec cmd: %v", err)
+	}
+	//write the options to the pipe for the untar exec to read
+	if err := json.NewEncoder(w).Encode(options); err != nil {
+		w.Close()
+		return fmt.Errorf("mountfrom json encode to pipe failed: %v", err)
+	}
+	w.Close()
+
+	if err := cmd.Wait(); err != nil {
+		return fmt.Errorf("mountfrom re-exec error: %v: output: %v", err, output)
+	}
+	return nil
+}
+
+// mountfromMain is the entry-point for storage-mountfrom on re-exec.
+func mountFromMain() {
+	runtime.LockOSThread()
+	flag.Parse()
+
+	var options *mountOptions
+
+	if err := json.NewDecoder(os.Stdin).Decode(&options); err != nil {
+		fatal(err)
+	}
+
+	if err := os.Chdir(flag.Arg(0)); err != nil {
+		fatal(err)
+	}
+
+	if err := unix.Mount(options.Device, options.Target, options.Type, uintptr(options.Flag), options.Label); err != nil {
+		fatal(err)
+	}
+
+	os.Exit(0)
+}

vendor/github.com/containers/storage/drivers/overlay/overlay.go

@@ -0,0 +1,773 @@
+// +build linux
+
+package overlay
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"sync"
+
+	"github.com/containers/storage/drivers"
+	"github.com/containers/storage/drivers/overlayutils"
+	"github.com/containers/storage/drivers/quota"
+	"github.com/containers/storage/pkg/archive"
+	"github.com/containers/storage/pkg/chrootarchive"
+	"github.com/containers/storage/pkg/directory"
+	"github.com/containers/storage/pkg/fsutils"
+	"github.com/containers/storage/pkg/idtools"
+	"github.com/containers/storage/pkg/locker"
+	"github.com/containers/storage/pkg/mount"
+	"github.com/containers/storage/pkg/parsers"
+	"github.com/containers/storage/pkg/system"
+	units "github.com/docker/go-units"
+	"github.com/opencontainers/selinux/go-selinux/label"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"golang.org/x/sys/unix"
+)
+
+var (
+	// untar defines the untar method
+	untar = chrootarchive.UntarUncompressed
+)
+
+// This backend uses the overlay union filesystem for containers
+// with diff directories for each layer.
+
+// This version of the overlay driver requires at least kernel
+// 4.0.0 in order to support mounting multiple diff directories.
+
+// Each container/image has at least a "diff" directory and "link" file.
+// If there is also a "lower" file when there are diff layers
+// below as well as "merged" and "work" directories. The "diff" directory
+// has the upper layer of the overlay and is used to capture any
+// changes to the layer. The "lower" file contains all the lower layer
+// mounts separated by ":" and ordered from uppermost to lowermost
+// layers. The overlay itself is mounted in the "merged" directory,
+// and the "work" dir is needed for overlay to work.
+
+// The "link" file for each layer contains a unique string for the layer.
+// Under the "l" directory at the root there will be a symbolic link
+// with that unique string pointing the "diff" directory for the layer.
+// The symbolic links are used to reference lower layers in the "lower"
+// file and on mount. The links are used to shorten the total length
+// of a layer reference without requiring changes to the layer identifier
+// or root directory. Mounts are always done relative to root and
+// referencing the symbolic links in order to ensure the number of
+// lower directories can fit in a single page for making the mount
+// syscall. A hard upper limit of 128 lower layers is enforced to ensure
+// that mounts do not fail due to length.
+
+const (
+	linkDir   = "l"
+	lowerFile = "lower"
+	maxDepth  = 128
+
+	// idLength represents the number of random characters
+	// which can be used to create the unique link identifer
+	// for every layer. If this value is too long then the
+	// page size limit for the mount command may be exceeded.
+	// The idLength should be selected such that following equation
+	// is true (512 is a buffer for label metadata).
+	// ((idLength + len(linkDir) + 1) * maxDepth) <= (pageSize - 512)
+	idLength = 26
+)
+
+type overlayOptions struct {
+	overrideKernelCheck bool
+	imageStores         []string
+	quota               quota.Quota
+}
+
+// Driver contains information about the home directory and the list of active mounts that are created using this driver.
+type Driver struct {
+	name          string
+	home          string
+	uidMaps       []idtools.IDMap
+	gidMaps       []idtools.IDMap
+	ctr           *graphdriver.RefCounter
+	quotaCtl      *quota.Control
+	options       overlayOptions
+	naiveDiff     graphdriver.DiffDriver
+	supportsDType bool
+	locker        *locker.Locker
+}
+
+var (
+	backingFs             = "<unknown>"
+	projectQuotaSupported = false
+
+	useNaiveDiffLock sync.Once
+	useNaiveDiffOnly bool
+)
+
+func init() {
+	graphdriver.Register("overlay", Init)
+	graphdriver.Register("overlay2", Init)
+}
+
+// Init returns the a native diff driver for overlay filesystem.
+// If overlay filesystem is not supported on the host, graphdriver.ErrNotSupported is returned as error.
+// If an overlay filesystem is not supported over an existing filesystem then error graphdriver.ErrIncompatibleFS is returned.
+func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
+	opts, err := parseOptions(options)
+	if err != nil {
+		return nil, err
+	}
+
+	fsMagic, err := graphdriver.GetFSMagic(home)
+	if err != nil {
+		return nil, err
+	}
+	if fsName, ok := graphdriver.FsNames[fsMagic]; ok {
+		backingFs = fsName
+	}
+
+	// check if they are running over btrfs, aufs, zfs, overlay, or ecryptfs
+	switch fsMagic {
+	case graphdriver.FsMagicAufs, graphdriver.FsMagicZfs, graphdriver.FsMagicOverlay, graphdriver.FsMagicEcryptfs:
+		logrus.Errorf("'overlay' is not supported over %s", backingFs)
+		return nil, errors.Wrapf(graphdriver.ErrIncompatibleFS, "'overlay' is not supported over %s", backingFs)
+	}
+
+	rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
+	if err != nil {
+		return nil, err
+	}
+
+	// Create the driver home dir
+	if err := idtools.MkdirAllAs(path.Join(home, linkDir), 0700, rootUID, rootGID); err != nil && !os.IsExist(err) {
+		return nil, err
+	}
+
+	supportsDType, err := supportsOverlay(home, fsMagic, rootUID, rootGID)
+	if err != nil {
+		os.Remove(filepath.Join(home, linkDir))
+		os.Remove(home)
+		return nil, errors.Wrap(graphdriver.ErrNotSupported, "kernel does not support overlay fs")
+	}
+
+	if err := mount.MakePrivate(home); err != nil {
+		return nil, err
+	}
+
+	d := &Driver{
+		name:          "overlay",
+		home:          home,
+		uidMaps:       uidMaps,
+		gidMaps:       gidMaps,
+		ctr:           graphdriver.NewRefCounter(graphdriver.NewFsChecker(graphdriver.FsMagicOverlay)),
+		supportsDType: supportsDType,
+		locker:        locker.New(),
+		options:       *opts,
+	}
+
+	d.naiveDiff = graphdriver.NewNaiveDiffDriver(d, uidMaps, gidMaps)
+
+	if backingFs == "xfs" {
+		// Try to enable project quota support over xfs.
+		if d.quotaCtl, err = quota.NewControl(home); err == nil {
+			projectQuotaSupported = true
+		} else if opts.quota.Size > 0 {
+			return nil, fmt.Errorf("Storage option overlay.size not supported. Filesystem does not support Project Quota: %v", err)
+		}
+	} else if opts.quota.Size > 0 {
+		// if xfs is not the backing fs then error out if the storage-opt overlay.size is used.
+		return nil, fmt.Errorf("Storage option overlay.size only supported for backingFS XFS. Found %v", backingFs)
+	}
+
+	logrus.Debugf("backingFs=%s, projectQuotaSupported=%v, useNativeDiff=%v", backingFs, projectQuotaSupported, !useNaiveDiff(home))
+
+	return d, nil
+}
+
+func parseOptions(options []string) (*overlayOptions, error) {
+	o := &overlayOptions{}
+	for _, option := range options {
+		key, val, err := parsers.ParseKeyValueOpt(option)
+		if err != nil {
+			return nil, err
+		}
+		key = strings.ToLower(key)
+		switch key {
+		case ".override_kernel_check", "overlay.override_kernel_check", "overlay2.override_kernel_check":
+			logrus.Debugf("overlay: override_kernelcheck=%s", val)
+			o.overrideKernelCheck, err = strconv.ParseBool(val)
+			if err != nil {
+				return nil, err
+			}
+		case ".size", "overlay.size", "overlay2.size":
+			logrus.Debugf("overlay: size=%s", val)
+			size, err := units.RAMInBytes(val)
+			if err != nil {
+				return nil, err
+			}
+			o.quota.Size = uint64(size)
+		case ".imagestore", "overlay.imagestore", "overlay2.imagestore":
+			logrus.Debugf("overlay: imagestore=%s", val)
+			// Additional read only image stores to use for lower paths
+			for _, store := range strings.Split(val, ",") {
+				store = filepath.Clean(store)
+				if !filepath.IsAbs(store) {
+					return nil, fmt.Errorf("overlay: image path %q is not absolute.  Can not be relative", store)
+				}
+				st, err := os.Stat(store)
+				if err != nil {
+					return nil, fmt.Errorf("overlay: can't stat imageStore dir %s: %v", store, err)
+				}
+				if !st.IsDir() {
+					return nil, fmt.Errorf("overlay: image path %q must be a directory", store)
+				}
+				o.imageStores = append(o.imageStores, store)
+			}
+		default:
+			return nil, fmt.Errorf("overlay: Unknown option %s", key)
+		}
+	}
+	return o, nil
+}
+
+func supportsOverlay(home string, homeMagic graphdriver.FsMagic, rootUID, rootGID int) (supportsDType bool, err error) {
+	// We can try to modprobe overlay first
+	exec.Command("modprobe", "overlay").Run()
+
+	layerDir, err := ioutil.TempDir(home, "compat")
+	if err == nil {
+		// Check if reading the directory's contents populates the d_type field, which is required
+		// for proper operation of the overlay filesystem.
+		supportsDType, err = fsutils.SupportsDType(layerDir)
+		if err != nil {
+			return false, err
+		}
+		if !supportsDType {
+			return false, overlayutils.ErrDTypeNotSupported("overlay", backingFs)
+		}
+
+		// Try a test mount in the specific location we're looking at using.
+		mergedDir := filepath.Join(layerDir, "merged")
+		lower1Dir := filepath.Join(layerDir, "lower1")
+		lower2Dir := filepath.Join(layerDir, "lower2")
+		defer func() {
+			// Permitted to fail, since the various subdirectories
+			// can be empty or not even there, and the home might
+			// legitimately be not empty
+			_ = unix.Unmount(mergedDir, unix.MNT_DETACH)
+			_ = os.RemoveAll(layerDir)
+			_ = os.Remove(home)
+		}()
+		_ = idtools.MkdirAs(mergedDir, 0700, rootUID, rootGID)
+		_ = idtools.MkdirAs(lower1Dir, 0700, rootUID, rootGID)
+		_ = idtools.MkdirAs(lower2Dir, 0700, rootUID, rootGID)
+		flags := fmt.Sprintf("lowerdir=%s:%s", lower1Dir, lower2Dir)
+		if len(flags) < unix.Getpagesize() {
+			if mountFrom(filepath.Dir(home), "overlay", mergedDir, "overlay", 0, flags) == nil {
+				logrus.Debugf("overlay test mount with multiple lowers succeeded")
+				return supportsDType, nil
+			}
+		}
+		flags = fmt.Sprintf("lowerdir=%s", lower1Dir)
+		if len(flags) < unix.Getpagesize() {
+			if mountFrom(filepath.Dir(home), "overlay", mergedDir, "overlay", 0, flags) == nil {
+				logrus.Errorf("overlay test mount with multiple lowers failed, but succeeded with a single lower")
+				return supportsDType, errors.Wrap(graphdriver.ErrNotSupported, "kernel too old to provide multiple lowers feature for overlay")
+			}
+		}
+		logrus.Errorf("'overlay' is not supported over %s at %q", backingFs, home)
+		return supportsDType, errors.Wrapf(graphdriver.ErrIncompatibleFS, "'overlay' is not supported over %s at %q", backingFs, home)
+	}
+
+	logrus.Error("'overlay' not found as a supported filesystem on this host. Please ensure kernel is new enough and has overlay support loaded.")
+	return supportsDType, errors.Wrap(graphdriver.ErrNotSupported, "'overlay' not found as a supported filesystem on this host. Please ensure kernel is new enough and has overlay support loaded.")
+}
+
+func useNaiveDiff(home string) bool {
+	useNaiveDiffLock.Do(func() {
+		if err := doesSupportNativeDiff(home); err != nil {
+			logrus.Warnf("Not using native diff for overlay, this may cause degraded performance for building images: %v", err)
+			useNaiveDiffOnly = true
+		}
+	})
+	return useNaiveDiffOnly
+}
+
+func (d *Driver) String() string {
+	return d.name
+}
+
+// Status returns current driver information in a two dimensional string array.
+// Output contains "Backing Filesystem" used in this implementation.
+func (d *Driver) Status() [][2]string {
+	return [][2]string{
+		{"Backing Filesystem", backingFs},
+		{"Supports d_type", strconv.FormatBool(d.supportsDType)},
+		{"Native Overlay Diff", strconv.FormatBool(!useNaiveDiff(d.home))},
+	}
+}
+
+// Metadata returns meta data about the overlay driver such as
+// LowerDir, UpperDir, WorkDir and MergeDir used to store data.
+func (d *Driver) Metadata(id string) (map[string]string, error) {
+	dir := d.dir(id)
+	if _, err := os.Stat(dir); err != nil {
+		return nil, err
+	}
+
+	metadata := map[string]string{
+		"WorkDir":   path.Join(dir, "work"),
+		"MergedDir": path.Join(dir, "merged"),
+		"UpperDir":  path.Join(dir, "diff"),
+	}
+
+	lowerDirs, err := d.getLowerDirs(id)
+	if err != nil {
+		return nil, err
+	}
+	if len(lowerDirs) > 0 {
+		metadata["LowerDir"] = strings.Join(lowerDirs, ":")
+	}
+
+	return metadata, nil
+}
+
+// Cleanup any state created by overlay which should be cleaned when daemon
+// is being shutdown. For now, we just have to unmount the bind mounted
+// we had created.
+func (d *Driver) Cleanup() error {
+	return mount.Unmount(d.home)
+}
+
+// CreateReadWrite creates a layer that is writable for use as a container
+// file system.
+func (d *Driver) CreateReadWrite(id, parent string, opts *graphdriver.CreateOpts) error {
+	if opts != nil && len(opts.StorageOpt) != 0 && !projectQuotaSupported {
+		return fmt.Errorf("--storage-opt is supported only for overlay over xfs with 'pquota' mount option")
+	}
+
+	if opts == nil {
+		opts = &graphdriver.CreateOpts{
+			StorageOpt: map[string]string{},
+		}
+	}
+
+	if _, ok := opts.StorageOpt["size"]; !ok {
+		if opts.StorageOpt == nil {
+			opts.StorageOpt = map[string]string{}
+		}
+		opts.StorageOpt["size"] = strconv.FormatUint(d.options.quota.Size, 10)
+	}
+
+	return d.create(id, parent, opts)
+}
+
+// Create is used to create the upper, lower, and merge directories required for overlay fs for a given id.
+// The parent filesystem is used to configure these directories for the overlay.
+func (d *Driver) Create(id, parent string, opts *graphdriver.CreateOpts) (retErr error) {
+	if opts != nil && len(opts.StorageOpt) != 0 {
+		if _, ok := opts.StorageOpt["size"]; ok {
+			return fmt.Errorf("--storage-opt size is only supported for ReadWrite Layers")
+		}
+	}
+	return d.create(id, parent, opts)
+}
+
+func (d *Driver) create(id, parent string, opts *graphdriver.CreateOpts) (retErr error) {
+	dir := d.dir(id)
+
+	rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
+	if err != nil {
+		return err
+	}
+	if err := idtools.MkdirAllAs(path.Dir(dir), 0700, rootUID, rootGID); err != nil {
+		return err
+	}
+	if err := idtools.MkdirAs(dir, 0700, rootUID, rootGID); err != nil {
+		return err
+	}
+
+	defer func() {
+		// Clean up on failure
+		if retErr != nil {
+			os.RemoveAll(dir)
+		}
+	}()
+
+	if opts != nil && len(opts.StorageOpt) > 0 {
+		driver := &Driver{}
+		if err := d.parseStorageOpt(opts.StorageOpt, driver); err != nil {
+			return err
+		}
+
+		if driver.options.quota.Size > 0 {
+			// Set container disk quota limit
+			if err := d.quotaCtl.SetQuota(dir, driver.options.quota); err != nil {
+				return err
+			}
+		}
+	}
+
+	if err := idtools.MkdirAs(path.Join(dir, "diff"), 0755, rootUID, rootGID); err != nil {
+		return err
+	}
+
+	lid := generateID(idLength)
+	if err := os.Symlink(path.Join("..", id, "diff"), path.Join(d.home, linkDir, lid)); err != nil {
+		return err
+	}
+
+	// Write link id to link file
+	if err := ioutil.WriteFile(path.Join(dir, "link"), []byte(lid), 0644); err != nil {
+		return err
+	}
+
+	if err := idtools.MkdirAs(path.Join(dir, "work"), 0700, rootUID, rootGID); err != nil {
+		return err
+	}
+	if err := idtools.MkdirAs(path.Join(dir, "merged"), 0700, rootUID, rootGID); err != nil {
+		return err
+	}
+
+	// if no parent directory, create a dummy lower directory and skip writing a "lowers" file
+	if parent == "" {
+		return idtools.MkdirAs(path.Join(dir, "empty"), 0700, rootUID, rootGID)
+	}
+
+	lower, err := d.getLower(parent)
+	if err != nil {
+		return err
+	}
+	if lower != "" {
+		if err := ioutil.WriteFile(path.Join(dir, lowerFile), []byte(lower), 0666); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// Parse overlay storage options
+func (d *Driver) parseStorageOpt(storageOpt map[string]string, driver *Driver) error {
+	// Read size to set the disk project quota per container
+	for key, val := range storageOpt {
+		key := strings.ToLower(key)
+		switch key {
+		case "size":
+			size, err := units.RAMInBytes(val)
+			if err != nil {
+				return err
+			}
+			driver.options.quota.Size = uint64(size)
+		default:
+			return fmt.Errorf("Unknown option %s", key)
+		}
+	}
+
+	return nil
+}
+
+func (d *Driver) getLower(parent string) (string, error) {
+	parentDir := d.dir(parent)
+
+	// Ensure parent exists
+	if _, err := os.Lstat(parentDir); err != nil {
+		return "", err
+	}
+
+	// Read Parent link fileA
+	parentLink, err := ioutil.ReadFile(path.Join(parentDir, "link"))
+	if err != nil {
+		return "", err
+	}
+	lowers := []string{path.Join(linkDir, string(parentLink))}
+
+	parentLower, err := ioutil.ReadFile(path.Join(parentDir, lowerFile))
+	if err == nil {
+		parentLowers := strings.Split(string(parentLower), ":")
+		lowers = append(lowers, parentLowers...)
+	}
+	if len(lowers) > maxDepth {
+		return "", errors.New("max depth exceeded")
+	}
+	return strings.Join(lowers, ":"), nil
+}
+
+func (d *Driver) dir(id string) string {
+	newpath := path.Join(d.home, id)
+	if _, err := os.Stat(newpath); err != nil {
+		for _, p := range d.AdditionalImageStores() {
+			l := path.Join(p, d.name, id)
+			_, err = os.Stat(l)
+			if err == nil {
+				return l
+			}
+		}
+	}
+	return newpath
+}
+
+func (d *Driver) getLowerDirs(id string) ([]string, error) {
+	var lowersArray []string
+	lowers, err := ioutil.ReadFile(path.Join(d.dir(id), lowerFile))
+	if err == nil {
+		for _, s := range strings.Split(string(lowers), ":") {
+			lower := d.dir(s)
+			lp, err := os.Readlink(lower)
+			if err != nil {
+				return nil, err
+			}
+			lowersArray = append(lowersArray, path.Clean(d.dir(path.Join("link", lp))))
+		}
+	} else if !os.IsNotExist(err) {
+		return nil, err
+	}
+	return lowersArray, nil
+}
+
+// Remove cleans the directories that are created for this id.
+func (d *Driver) Remove(id string) error {
+	d.locker.Lock(id)
+	defer d.locker.Unlock(id)
+	dir := d.dir(id)
+	lid, err := ioutil.ReadFile(path.Join(dir, "link"))
+	if err == nil {
+		if err := os.RemoveAll(path.Join(d.home, linkDir, string(lid))); err != nil {
+			logrus.Debugf("Failed to remove link: %v", err)
+		}
+	}
+
+	if err := system.EnsureRemoveAll(dir); err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	return nil
+}
+
+// Get creates and mounts the required file system for the given id and returns the mount path.
+func (d *Driver) Get(id, mountLabel string) (_ string, retErr error) {
+	d.locker.Lock(id)
+	defer d.locker.Unlock(id)
+	dir := d.dir(id)
+	if _, err := os.Stat(dir); err != nil {
+		return "", err
+	}
+
+	diffDir := path.Join(dir, "diff")
+	lowers, err := ioutil.ReadFile(path.Join(dir, lowerFile))
+	if err != nil && !os.IsNotExist(err) {
+		return "", err
+	}
+
+	newlowers := ""
+	for _, l := range strings.Split(string(lowers), ":") {
+		lower := ""
+		newpath := path.Join(d.home, l)
+		if _, err := os.Stat(newpath); err != nil {
+			for _, p := range d.AdditionalImageStores() {
+				lower = path.Join(p, d.name, l)
+				if _, err2 := os.Stat(lower); err2 == nil {
+					break
+				}
+				lower = ""
+			}
+			if lower == "" {
+				return "", fmt.Errorf("Can't stat lower layer %q: %v", newpath, err)
+			}
+		} else {
+			lower = newpath
+		}
+		if newlowers == "" {
+			newlowers = lower
+		} else {
+			newlowers = newlowers + ":" + lower
+		}
+	}
+	if len(lowers) == 0 {
+		newlowers = path.Join(dir, "empty")
+		lowers = []byte(newlowers)
+	}
+
+	mergedDir := path.Join(dir, "merged")
+	if count := d.ctr.Increment(mergedDir); count > 1 {
+		return mergedDir, nil
+	}
+	defer func() {
+		if retErr != nil {
+			if c := d.ctr.Decrement(mergedDir); c <= 0 {
+				if mntErr := unix.Unmount(mergedDir, 0); mntErr != nil {
+					logrus.Errorf("error unmounting %v: %v", mergedDir, mntErr)
+				}
+			}
+		}
+	}()
+
+	workDir := path.Join(dir, "work")
+	opts := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s", newlowers, diffDir, workDir)
+	mountData := label.FormatMountLabel(opts, mountLabel)
+	mount := unix.Mount
+	mountTarget := mergedDir
+
+	pageSize := unix.Getpagesize()
+
+	// Use relative paths and mountFrom when the mount data has exceeded
+	// the page size. The mount syscall fails if the mount data cannot
+	// fit within a page and relative links make the mount data much
+	// smaller at the expense of requiring a fork exec to chroot.
+	if len(mountData) > pageSize {
+		//FIXME: We need to figure out to get this to work with additional stores
+		opts = fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s", string(lowers), path.Join(id, "diff"), path.Join(id, "work"))
+		mountData = label.FormatMountLabel(opts, mountLabel)
+		if len(mountData) > pageSize {
+			return "", fmt.Errorf("cannot mount layer, mount label too large %d", len(mountData))
+		}
+
+		mount = func(source string, target string, mType string, flags uintptr, label string) error {
+			return mountFrom(d.home, source, target, mType, flags, label)
+		}
+		mountTarget = path.Join(id, "merged")
+	}
+	if err := mount("overlay", mountTarget, "overlay", 0, mountData); err != nil {
+		return "", fmt.Errorf("error creating overlay mount to %s: %v", mountTarget, err)
+	}
+
+	// chown "workdir/work" to the remapped root UID/GID. Overlay fs inside a
+	// user namespace requires this to move a directory from lower to upper.
+	rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
+	if err != nil {
+		return "", err
+	}
+
+	if err := os.Chown(path.Join(workDir, "work"), rootUID, rootGID); err != nil {
+		return "", err
+	}
+
+	return mergedDir, nil
+}
+
+// Put unmounts the mount path created for the give id.
+func (d *Driver) Put(id string) error {
+	d.locker.Lock(id)
+	defer d.locker.Unlock(id)
+	dir := d.dir(id)
+	if _, err := os.Stat(dir); err != nil {
+		return err
+	}
+	mountpoint := path.Join(d.dir(id), "merged")
+	if count := d.ctr.Decrement(mountpoint); count > 0 {
+		return nil
+	}
+	if _, err := ioutil.ReadFile(path.Join(dir, lowerFile)); err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	if err := unix.Unmount(mountpoint, unix.MNT_DETACH); err != nil {
+		logrus.Debugf("Failed to unmount %s overlay: %s - %v", id, mountpoint, err)
+	}
+	return nil
+}
+
+// Exists checks to see if the id is already mounted.
+func (d *Driver) Exists(id string) bool {
+	_, err := os.Stat(d.dir(id))
+	return err == nil
+}
+
+// isParent returns if the passed in parent is the direct parent of the passed in layer
+func (d *Driver) isParent(id, parent string) bool {
+	lowers, err := d.getLowerDirs(id)
+	if err != nil {
+		return false
+	}
+	if parent == "" && len(lowers) > 0 {
+		return false
+	}
+
+	parentDir := d.dir(parent)
+	var ld string
+	if len(lowers) > 0 {
+		ld = filepath.Dir(lowers[0])
+	}
+	if ld == "" && parent == "" {
+		return true
+	}
+	return ld == parentDir
+}
+
+// ApplyDiff applies the new layer into a root
+func (d *Driver) ApplyDiff(id, parent, mountLabel string, diff io.Reader) (size int64, err error) {
+	if !d.isParent(id, parent) {
+		return d.naiveDiff.ApplyDiff(id, parent, mountLabel, diff)
+	}
+
+	applyDir := d.getDiffPath(id)
+
+	logrus.Debugf("Applying tar in %s", applyDir)
+	// Overlay doesn't need the parent id to apply the diff
+	if err := untar(diff, applyDir, &archive.TarOptions{
+		UIDMaps:        d.uidMaps,
+		GIDMaps:        d.gidMaps,
+		WhiteoutFormat: archive.OverlayWhiteoutFormat,
+	}); err != nil {
+		return 0, err
+	}
+
+	return directory.Size(applyDir)
+}
+
+func (d *Driver) getDiffPath(id string) string {
+	dir := d.dir(id)
+
+	return path.Join(dir, "diff")
+}
+
+// DiffSize calculates the changes between the specified id
+// and its parent and returns the size in bytes of the changes
+// relative to its base filesystem directory.
+func (d *Driver) DiffSize(id, parent, mountLabel string) (size int64, err error) {
+	if useNaiveDiff(d.home) || !d.isParent(id, parent) {
+		return d.naiveDiff.DiffSize(id, parent, mountLabel)
+	}
+	return directory.Size(d.getDiffPath(id))
+}
+
+// Diff produces an archive of the changes between the specified
+// layer and its parent layer which may be "".
+func (d *Driver) Diff(id, parent, mountLabel string) (io.ReadCloser, error) {
+	if useNaiveDiff(d.home) || !d.isParent(id, parent) {
+		return d.naiveDiff.Diff(id, parent, mountLabel)
+	}
+
+	diffPath := d.getDiffPath(id)
+	logrus.Debugf("Tar with options on %s", diffPath)
+	return archive.TarWithOptions(diffPath, &archive.TarOptions{
+		Compression:    archive.Uncompressed,
+		UIDMaps:        d.uidMaps,
+		GIDMaps:        d.gidMaps,
+		WhiteoutFormat: archive.OverlayWhiteoutFormat,
+	})
+}
+
+// Changes produces a list of changes between the specified layer
+// and its parent layer. If parent is "", then all changes will be ADD changes.
+func (d *Driver) Changes(id, parent, mountLabel string) ([]archive.Change, error) {
+	if useNaiveDiff(d.home) || !d.isParent(id, parent) {
+		return d.naiveDiff.Changes(id, parent, mountLabel)
+	}
+	// Overlay doesn't have snapshots, so we need to get changes from all parent
+	// layers.
+	diffPath := d.getDiffPath(id)
+	layers, err := d.getLowerDirs(id)
+	if err != nil {
+		return nil, err
+	}
+
+	return archive.OverlayChanges(layers, diffPath)
+}
+
+// AdditionalImageStores returns additional image stores supported by the driver
+func (d *Driver) AdditionalImageStores() []string {
+	return d.options.imageStores
+}

vendor/github.com/containers/storage/drivers/overlay/overlay_unsupported.go

@@ -0,0 +1,3 @@
+// +build !linux
+
+package overlay

vendor/github.com/containers/storage/drivers/overlay/randomid.go

@@ -0,0 +1,81 @@
+// +build linux
+
+package overlay
+
+import (
+	"crypto/rand"
+	"encoding/base32"
+	"fmt"
+	"io"
+	"os"
+	"syscall"
+	"time"
+
+	"github.com/sirupsen/logrus"
+	"golang.org/x/sys/unix"
+)
+
+// generateID creates a new random string identifier with the given length
+func generateID(l int) string {
+	const (
+		// ensures we backoff for less than 450ms total. Use the following to
+		// select new value, in units of 10ms:
+		// 	n*(n+1)/2 = d -> n^2 + n - 2d -> n = (sqrt(8d + 1) - 1)/2
+		maxretries = 9
+		backoff    = time.Millisecond * 10
+	)
+
+	var (
+		totalBackoff time.Duration
+		count        int
+		retries      int
+		size         = (l*5 + 7) / 8
+		u            = make([]byte, size)
+	)
+	// TODO: Include time component, counter component, random component
+
+	for {
+		// This should never block but the read may fail. Because of this,
+		// we just try to read the random number generator until we get
+		// something. This is a very rare condition but may happen.
+		b := time.Duration(retries) * backoff
+		time.Sleep(b)
+		totalBackoff += b
+
+		n, err := io.ReadFull(rand.Reader, u[count:])
+		if err != nil {
+			if retryOnError(err) && retries < maxretries {
+				count += n
+				retries++
+				logrus.Errorf("error generating version 4 uuid, retrying: %v", err)
+				continue
+			}
+
+			// Any other errors represent a system problem. What did someone
+			// do to /dev/urandom?
+			panic(fmt.Errorf("error reading random number generator, retried for %v: %v", totalBackoff.String(), err))
+		}
+
+		break
+	}
+
+	s := base32.StdEncoding.EncodeToString(u)
+
+	return s[:l]
+}
+
+// retryOnError tries to detect whether or not retrying would be fruitful.
+func retryOnError(err error) bool {
+	switch err := err.(type) {
+	case *os.PathError:
+		return retryOnError(err.Err) // unpack the target error
+	case syscall.Errno:
+		if err == unix.EPERM {
+			// EPERM represents an entropy pool exhaustion, a condition under
+			// which we backoff and retry.
+			return true
+		}
+	}
+
+	return false
+}

vendor/github.com/containers/storage/drivers/overlayutils/overlayutils.go

@@ -0,0 +1,18 @@
+// +build linux
+
+package overlayutils
+
+import (
+	"errors"
+	"fmt"
+)
+
+// ErrDTypeNotSupported denotes that the backing filesystem doesn't support d_type.
+func ErrDTypeNotSupported(driver, backingFs string) error {
+	msg := fmt.Sprintf("%s: the backing %s filesystem is formatted without d_type support, which leads to incorrect behavior.", driver, backingFs)
+	if backingFs == "xfs" {
+		msg += " Reformat the filesystem with ftype=1 to enable d_type support."
+	}
+	msg += " Running without d_type is not supported."
+	return errors.New(msg)
+}

vendor/github.com/containers/storage/drivers/quota/projectquota.go

@@ -0,0 +1,337 @@
+// +build linux
+
+//
+// projectquota.go - implements XFS project quota controls
+// for setting quota limits on a newly created directory.
+// It currently supports the legacy XFS specific ioctls.
+//
+// TODO: use generic quota control ioctl FS_IOC_FS{GET,SET}XATTR
+//       for both xfs/ext4 for kernel version >= v4.5
+//
+
+package quota
+
+/*
+#include <stdlib.h>
+#include <dirent.h>
+#include <linux/fs.h>
+#include <linux/quota.h>
+#include <linux/dqblk_xfs.h>
+
+#ifndef FS_XFLAG_PROJINHERIT
+struct fsxattr {
+	__u32		fsx_xflags;
+	__u32		fsx_extsize;
+	__u32		fsx_nextents;
+	__u32		fsx_projid;
+	unsigned char	fsx_pad[12];
+};
+#define FS_XFLAG_PROJINHERIT	0x00000200
+#endif
+#ifndef FS_IOC_FSGETXATTR
+#define FS_IOC_FSGETXATTR		_IOR ('X', 31, struct fsxattr)
+#endif
+#ifndef FS_IOC_FSSETXATTR
+#define FS_IOC_FSSETXATTR		_IOW ('X', 32, struct fsxattr)
+#endif
+
+#ifndef PRJQUOTA
+#define PRJQUOTA	2
+#endif
+#ifndef XFS_PROJ_QUOTA
+#define XFS_PROJ_QUOTA	2
+#endif
+#ifndef Q_XSETPQLIM
+#define Q_XSETPQLIM QCMD(Q_XSETQLIM, PRJQUOTA)
+#endif
+#ifndef Q_XGETPQUOTA
+#define Q_XGETPQUOTA QCMD(Q_XGETQUOTA, PRJQUOTA)
+#endif
+*/
+import "C"
+import (
+	"fmt"
+	"io/ioutil"
+	"path"
+	"path/filepath"
+	"unsafe"
+
+	"github.com/sirupsen/logrus"
+	"golang.org/x/sys/unix"
+)
+
+// Quota limit params - currently we only control blocks hard limit
+type Quota struct {
+	Size uint64
+}
+
+// Control - Context to be used by storage driver (e.g. overlay)
+// who wants to apply project quotas to container dirs
+type Control struct {
+	backingFsBlockDev string
+	nextProjectID     uint32
+	quotas            map[string]uint32
+}
+
+// NewControl - initialize project quota support.
+// Test to make sure that quota can be set on a test dir and find
+// the first project id to be used for the next container create.
+//
+// Returns nil (and error) if project quota is not supported.
+//
+// First get the project id of the home directory.
+// This test will fail if the backing fs is not xfs.
+//
+// xfs_quota tool can be used to assign a project id to the driver home directory, e.g.:
+//    echo 999:/var/lib/containers/storage/overlay >> /etc/projects
+//    echo storage:999 >> /etc/projid
+//    xfs_quota -x -c 'project -s storage' /<xfs mount point>
+//
+// In that case, the home directory project id will be used as a "start offset"
+// and all containers will be assigned larger project ids (e.g. >= 1000).
+// This is a way to prevent xfs_quota management from conflicting with containers/storage.
+//
+// Then try to create a test directory with the next project id and set a quota
+// on it. If that works, continue to scan existing containers to map allocated
+// project ids.
+//
+func NewControl(basePath string) (*Control, error) {
+	//
+	// Get project id of parent dir as minimal id to be used by driver
+	//
+	minProjectID, err := getProjectID(basePath)
+	if err != nil {
+		return nil, err
+	}
+	minProjectID++
+
+	//
+	// create backing filesystem device node
+	//
+	backingFsBlockDev, err := makeBackingFsDev(basePath)
+	if err != nil {
+		return nil, err
+	}
+
+	//
+	// Test if filesystem supports project quotas by trying to set
+	// a quota on the first available project id
+	//
+	quota := Quota{
+		Size: 0,
+	}
+	if err := setProjectQuota(backingFsBlockDev, minProjectID, quota); err != nil {
+		return nil, err
+	}
+
+	q := Control{
+		backingFsBlockDev: backingFsBlockDev,
+		nextProjectID:     minProjectID + 1,
+		quotas:            make(map[string]uint32),
+	}
+
+	//
+	// get first project id to be used for next container
+	//
+	err = q.findNextProjectID(basePath)
+	if err != nil {
+		return nil, err
+	}
+
+	logrus.Debugf("NewControl(%s): nextProjectID = %d", basePath, q.nextProjectID)
+	return &q, nil
+}
+
+// SetQuota - assign a unique project id to directory and set the quota limits
+// for that project id
+func (q *Control) SetQuota(targetPath string, quota Quota) error {
+
+	projectID, ok := q.quotas[targetPath]
+	if !ok {
+		projectID = q.nextProjectID
+
+		//
+		// assign project id to new container directory
+		//
+		err := setProjectID(targetPath, projectID)
+		if err != nil {
+			return err
+		}
+
+		q.quotas[targetPath] = projectID
+		q.nextProjectID++
+	}
+
+	//
+	// set the quota limit for the container's project id
+	//
+	logrus.Debugf("SetQuota(%s, %d): projectID=%d", targetPath, quota.Size, projectID)
+	return setProjectQuota(q.backingFsBlockDev, projectID, quota)
+}
+
+// setProjectQuota - set the quota for project id on xfs block device
+func setProjectQuota(backingFsBlockDev string, projectID uint32, quota Quota) error {
+	var d C.fs_disk_quota_t
+	d.d_version = C.FS_DQUOT_VERSION
+	d.d_id = C.__u32(projectID)
+	d.d_flags = C.XFS_PROJ_QUOTA
+
+	d.d_fieldmask = C.FS_DQ_BHARD | C.FS_DQ_BSOFT
+	d.d_blk_hardlimit = C.__u64(quota.Size / 512)
+	d.d_blk_softlimit = d.d_blk_hardlimit
+
+	var cs = C.CString(backingFsBlockDev)
+	defer C.free(unsafe.Pointer(cs))
+
+	_, _, errno := unix.Syscall6(unix.SYS_QUOTACTL, C.Q_XSETPQLIM,
+		uintptr(unsafe.Pointer(cs)), uintptr(d.d_id),
+		uintptr(unsafe.Pointer(&d)), 0, 0)
+	if errno != 0 {
+		return fmt.Errorf("Failed to set quota limit for projid %d on %s: %v",
+			projectID, backingFsBlockDev, errno.Error())
+	}
+
+	return nil
+}
+
+// GetQuota - get the quota limits of a directory that was configured with SetQuota
+func (q *Control) GetQuota(targetPath string, quota *Quota) error {
+
+	projectID, ok := q.quotas[targetPath]
+	if !ok {
+		return fmt.Errorf("quota not found for path : %s", targetPath)
+	}
+
+	//
+	// get the quota limit for the container's project id
+	//
+	var d C.fs_disk_quota_t
+
+	var cs = C.CString(q.backingFsBlockDev)
+	defer C.free(unsafe.Pointer(cs))
+
+	_, _, errno := unix.Syscall6(unix.SYS_QUOTACTL, C.Q_XGETPQUOTA,
+		uintptr(unsafe.Pointer(cs)), uintptr(C.__u32(projectID)),
+		uintptr(unsafe.Pointer(&d)), 0, 0)
+	if errno != 0 {
+		return fmt.Errorf("Failed to get quota limit for projid %d on %s: %v",
+			projectID, q.backingFsBlockDev, errno.Error())
+	}
+	quota.Size = uint64(d.d_blk_hardlimit) * 512
+
+	return nil
+}
+
+// getProjectID - get the project id of path on xfs
+func getProjectID(targetPath string) (uint32, error) {
+	dir, err := openDir(targetPath)
+	if err != nil {
+		return 0, err
+	}
+	defer closeDir(dir)
+
+	var fsx C.struct_fsxattr
+	_, _, errno := unix.Syscall(unix.SYS_IOCTL, getDirFd(dir), C.FS_IOC_FSGETXATTR,
+		uintptr(unsafe.Pointer(&fsx)))
+	if errno != 0 {
+		return 0, fmt.Errorf("Failed to get projid for %s: %v", targetPath, errno.Error())
+	}
+
+	return uint32(fsx.fsx_projid), nil
+}
+
+// setProjectID - set the project id of path on xfs
+func setProjectID(targetPath string, projectID uint32) error {
+	dir, err := openDir(targetPath)
+	if err != nil {
+		return err
+	}
+	defer closeDir(dir)
+
+	var fsx C.struct_fsxattr
+	_, _, errno := unix.Syscall(unix.SYS_IOCTL, getDirFd(dir), C.FS_IOC_FSGETXATTR,
+		uintptr(unsafe.Pointer(&fsx)))
+	if errno != 0 {
+		return fmt.Errorf("Failed to get projid for %s: %v", targetPath, errno.Error())
+	}
+	fsx.fsx_projid = C.__u32(projectID)
+	fsx.fsx_xflags |= C.FS_XFLAG_PROJINHERIT
+	_, _, errno = unix.Syscall(unix.SYS_IOCTL, getDirFd(dir), C.FS_IOC_FSSETXATTR,
+		uintptr(unsafe.Pointer(&fsx)))
+	if errno != 0 {
+		return fmt.Errorf("Failed to set projid for %s: %v", targetPath, errno.Error())
+	}
+
+	return nil
+}
+
+// findNextProjectID - find the next project id to be used for containers
+// by scanning driver home directory to find used project ids
+func (q *Control) findNextProjectID(home string) error {
+	files, err := ioutil.ReadDir(home)
+	if err != nil {
+		return fmt.Errorf("read directory failed : %s", home)
+	}
+	for _, file := range files {
+		if !file.IsDir() {
+			continue
+		}
+		path := filepath.Join(home, file.Name())
+		projid, err := getProjectID(path)
+		if err != nil {
+			return err
+		}
+		if projid > 0 {
+			q.quotas[path] = projid
+		}
+		if q.nextProjectID <= projid {
+			q.nextProjectID = projid + 1
+		}
+	}
+
+	return nil
+}
+
+func free(p *C.char) {
+	C.free(unsafe.Pointer(p))
+}
+
+func openDir(path string) (*C.DIR, error) {
+	Cpath := C.CString(path)
+	defer free(Cpath)
+
+	dir := C.opendir(Cpath)
+	if dir == nil {
+		return nil, fmt.Errorf("Can't open dir")
+	}
+	return dir, nil
+}
+
+func closeDir(dir *C.DIR) {
+	if dir != nil {
+		C.closedir(dir)
+	}
+}
+
+func getDirFd(dir *C.DIR) uintptr {
+	return uintptr(C.dirfd(dir))
+}
+
+// Get the backing block device of the driver home directory
+// and create a block device node under the home directory
+// to be used by quotactl commands
+func makeBackingFsDev(home string) (string, error) {
+	var stat unix.Stat_t
+	if err := unix.Stat(home, &stat); err != nil {
+		return "", err
+	}
+
+	backingFsBlockDev := path.Join(home, "backingFsBlockDev")
+	// Re-create just in case someone copied the home directory over to a new device
+	unix.Unlink(backingFsBlockDev)
+	if err := unix.Mknod(backingFsBlockDev, unix.S_IFBLK|0600, int(stat.Dev)); err != nil {
+		return "", fmt.Errorf("Failed to mknod %s: %v", backingFsBlockDev, err)
+	}
+
+	return backingFsBlockDev, nil
+}

vendor/github.com/containers/storage/drivers/register/register_aufs.go

@@ -0,0 +1,8 @@
+// +build !exclude_graphdriver_aufs,linux
+
+package register
+
+import (
+	// register the aufs graphdriver
+	_ "github.com/containers/storage/drivers/aufs"
+)

vendor/github.com/containers/storage/drivers/register/register_btrfs.go

@@ -0,0 +1,8 @@
+// +build !exclude_graphdriver_btrfs,linux
+
+package register
+
+import (
+	// register the btrfs graphdriver
+	_ "github.com/containers/storage/drivers/btrfs"
+)

vendor/github.com/containers/storage/drivers/register/register_devicemapper.go

@@ -0,0 +1,8 @@
+// +build !exclude_graphdriver_devicemapper,linux
+
+package register
+
+import (
+	// register the devmapper graphdriver
+	_ "github.com/containers/storage/drivers/devmapper"
+)

vendor/github.com/containers/storage/drivers/register/register_overlay.go

@@ -0,0 +1,8 @@
+// +build !exclude_graphdriver_overlay,linux
+
+package register
+
+import (
+	// register the overlay graphdriver
+	_ "github.com/containers/storage/drivers/overlay"
+)

vendor/github.com/containers/storage/drivers/register/register_vfs.go

@@ -0,0 +1,6 @@
+package register
+
+import (
+	// register vfs
+	_ "github.com/containers/storage/drivers/vfs"
+)

vendor/github.com/containers/storage/drivers/register/register_windows.go

@@ -0,0 +1,6 @@
+package register
+
+import (
+	// register the windows graph driver
+	_ "github.com/containers/storage/drivers/windows"
+)

vendor/github.com/containers/storage/drivers/register/register_zfs.go

@@ -0,0 +1,8 @@
+// +build !exclude_graphdriver_zfs,linux !exclude_graphdriver_zfs,freebsd, solaris
+
+package register
+
+import (
+	// register the zfs driver
+	_ "github.com/containers/storage/drivers/zfs"
+)

vendor/github.com/containers/storage/drivers/vfs/driver.go

@@ -0,0 +1,160 @@
+package vfs
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/containers/storage/drivers"
+	"github.com/containers/storage/pkg/chrootarchive"
+	"github.com/containers/storage/pkg/idtools"
+	"github.com/containers/storage/pkg/system"
+	"github.com/opencontainers/selinux/go-selinux/label"
+)
+
+var (
+	// CopyWithTar defines the copy method to use.
+	CopyWithTar = chrootarchive.NewArchiver(nil).CopyWithTar
+)
+
+func init() {
+	graphdriver.Register("vfs", Init)
+}
+
+// Init returns a new VFS driver.
+// This sets the home directory for the driver and returns NaiveDiffDriver.
+func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
+	d := &Driver{
+		homes:      []string{home},
+		idMappings: idtools.NewIDMappingsFromMaps(uidMaps, gidMaps),
+	}
+	rootIDs := d.idMappings.RootPair()
+	if err := idtools.MkdirAllAndChown(home, 0700, rootIDs); err != nil {
+		return nil, err
+	}
+	for _, option := range options {
+		if strings.HasPrefix(option, "vfs.imagestore=") {
+			d.homes = append(d.homes, strings.Split(option[15:], ",")...)
+			continue
+		}
+		if strings.HasPrefix(option, ".imagestore=") {
+			d.homes = append(d.homes, strings.Split(option[12:], ",")...)
+			continue
+		}
+	}
+	return graphdriver.NewNaiveDiffDriver(d, uidMaps, gidMaps), nil
+}
+
+// Driver holds information about the driver, home directory of the driver.
+// Driver implements graphdriver.ProtoDriver. It uses only basic vfs operations.
+// In order to support layering, files are copied from the parent layer into the new layer. There is no copy-on-write support.
+// Driver must be wrapped in NaiveDiffDriver to be used as a graphdriver.Driver
+type Driver struct {
+	homes      []string
+	idMappings *idtools.IDMappings
+}
+
+func (d *Driver) String() string {
+	return "vfs"
+}
+
+// Status is used for implementing the graphdriver.ProtoDriver interface. VFS does not currently have any status information.
+func (d *Driver) Status() [][2]string {
+	return nil
+}
+
+// Metadata is used for implementing the graphdriver.ProtoDriver interface. VFS does not currently have any meta data.
+func (d *Driver) Metadata(id string) (map[string]string, error) {
+	return nil, nil
+}
+
+// Cleanup is used to implement graphdriver.ProtoDriver. There is no cleanup required for this driver.
+func (d *Driver) Cleanup() error {
+	return nil
+}
+
+// CreateReadWrite creates a layer that is writable for use as a container
+// file system.
+func (d *Driver) CreateReadWrite(id, parent string, opts *graphdriver.CreateOpts) error {
+	return d.Create(id, parent, opts)
+}
+
+// Create prepares the filesystem for the VFS driver and copies the directory for the given id under the parent.
+func (d *Driver) Create(id, parent string, opts *graphdriver.CreateOpts) error {
+	if opts != nil && len(opts.StorageOpt) != 0 {
+		return fmt.Errorf("--storage-opt is not supported for vfs")
+	}
+
+	dir := d.dir(id)
+	rootIDs := d.idMappings.RootPair()
+	if err := idtools.MkdirAllAndChown(filepath.Dir(dir), 0700, rootIDs); err != nil {
+		return err
+	}
+	if err := idtools.MkdirAndChown(dir, 0755, rootIDs); err != nil {
+		return err
+	}
+	labelOpts := []string{"level:s0"}
+	if _, mountLabel, err := label.InitLabels(labelOpts); err == nil {
+		label.SetFileLabel(dir, mountLabel)
+	}
+	if parent == "" {
+		return nil
+	}
+	parentDir, err := d.Get(parent, "")
+	if err != nil {
+		return fmt.Errorf("%s: %s", parent, err)
+	}
+	return CopyWithTar(parentDir, dir)
+}
+
+func (d *Driver) dir(id string) string {
+	for i, home := range d.homes {
+		if i > 0 {
+			home = filepath.Join(home, d.String())
+		}
+		candidate := filepath.Join(home, "dir", filepath.Base(id))
+		fi, err := os.Stat(candidate)
+		if err == nil && fi.IsDir() {
+			return candidate
+		}
+	}
+	return filepath.Join(d.homes[0], "dir", filepath.Base(id))
+}
+
+// Remove deletes the content from the directory for a given id.
+func (d *Driver) Remove(id string) error {
+	return system.EnsureRemoveAll(d.dir(id))
+}
+
+// Get returns the directory for the given id.
+func (d *Driver) Get(id, mountLabel string) (string, error) {
+	dir := d.dir(id)
+	if st, err := os.Stat(dir); err != nil {
+		return "", err
+	} else if !st.IsDir() {
+		return "", fmt.Errorf("%s: not a directory", dir)
+	}
+	return dir, nil
+}
+
+// Put is a noop for vfs that return nil for the error, since this driver has no runtime resources to clean up.
+func (d *Driver) Put(id string) error {
+	// The vfs driver has no runtime resources (e.g. mounts)
+	// to clean up, so we don't need anything here
+	return nil
+}
+
+// Exists checks to see if the directory exists for the given id.
+func (d *Driver) Exists(id string) bool {
+	_, err := os.Stat(d.dir(id))
+	return err == nil
+}
+
+// AdditionalImageStores returns additional image stores supported by the driver
+func (d *Driver) AdditionalImageStores() []string {
+	if len(d.homes) > 1 {
+		return d.homes[1:]
+	}
+	return nil
+}

vendor/github.com/containers/storage/drivers/windows/windows.go

@@ -0,0 +1,965 @@
+//+build windows
+
+package windows
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"sync"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"github.com/Microsoft/go-winio"
+	"github.com/Microsoft/go-winio/archive/tar"
+	"github.com/Microsoft/go-winio/backuptar"
+	"github.com/Microsoft/hcsshim"
+	"github.com/containers/storage/drivers"
+	"github.com/containers/storage/pkg/archive"
+	"github.com/containers/storage/pkg/idtools"
+	"github.com/containers/storage/pkg/ioutils"
+	"github.com/containers/storage/pkg/longpath"
+	"github.com/containers/storage/pkg/reexec"
+	"github.com/containers/storage/pkg/system"
+	units "github.com/docker/go-units"
+	"github.com/sirupsen/logrus"
+	"golang.org/x/sys/windows"
+)
+
+// filterDriver is an HCSShim driver type for the Windows Filter driver.
+const filterDriver = 1
+
+var (
+	// mutatedFiles is a list of files that are mutated by the import process
+	// and must be backed up and restored.
+	mutatedFiles = map[string]string{
+		"UtilityVM/Files/EFI/Microsoft/Boot/BCD":      "bcd.bak",
+		"UtilityVM/Files/EFI/Microsoft/Boot/BCD.LOG":  "bcd.log.bak",
+		"UtilityVM/Files/EFI/Microsoft/Boot/BCD.LOG1": "bcd.log1.bak",
+		"UtilityVM/Files/EFI/Microsoft/Boot/BCD.LOG2": "bcd.log2.bak",
+	}
+	noreexec = false
+)
+
+// init registers the windows graph drivers to the register.
+func init() {
+	graphdriver.Register("windowsfilter", InitFilter)
+	// DOCKER_WINDOWSFILTER_NOREEXEC allows for inline processing which makes
+	// debugging issues in the re-exec codepath significantly easier.
+	if os.Getenv("DOCKER_WINDOWSFILTER_NOREEXEC") != "" {
+		logrus.Warnf("WindowsGraphDriver is set to not re-exec. This is intended for debugging purposes only.")
+		noreexec = true
+	} else {
+		reexec.Register("docker-windows-write-layer", writeLayerReexec)
+	}
+}
+
+type checker struct {
+}
+
+func (c *checker) IsMounted(path string) bool {
+	return false
+}
+
+// Driver represents a windows graph driver.
+type Driver struct {
+	// info stores the shim driver information
+	info hcsshim.DriverInfo
+	ctr  *graphdriver.RefCounter
+	// it is safe for windows to use a cache here because it does not support
+	// restoring containers when the daemon dies.
+	cacheMu sync.Mutex
+	cache   map[string]string
+}
+
+// InitFilter returns a new Windows storage filter driver.
+func InitFilter(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
+	logrus.Debugf("WindowsGraphDriver InitFilter at %s", home)
+
+	fsType, err := getFileSystemType(string(home[0]))
+	if err != nil {
+		return nil, err
+	}
+	if strings.ToLower(fsType) == "refs" {
+		return nil, fmt.Errorf("%s is on an ReFS volume - ReFS volumes are not supported", home)
+	}
+
+	if err := idtools.MkdirAllAs(home, 0700, 0, 0); err != nil {
+		return nil, fmt.Errorf("windowsfilter failed to create '%s': %v", home, err)
+	}
+
+	d := &Driver{
+		info: hcsshim.DriverInfo{
+			HomeDir: home,
+			Flavour: filterDriver,
+		},
+		cache: make(map[string]string),
+		ctr:   graphdriver.NewRefCounter(&checker{}),
+	}
+	return d, nil
+}
+
+// win32FromHresult is a helper function to get the win32 error code from an HRESULT
+func win32FromHresult(hr uintptr) uintptr {
+	if hr&0x1fff0000 == 0x00070000 {
+		return hr & 0xffff
+	}
+	return hr
+}
+
+// getFileSystemType obtains the type of a file system through GetVolumeInformation
+// https://msdn.microsoft.com/en-us/library/windows/desktop/aa364993(v=vs.85).aspx
+func getFileSystemType(drive string) (fsType string, hr error) {
+	var (
+		modkernel32              = windows.NewLazySystemDLL("kernel32.dll")
+		procGetVolumeInformation = modkernel32.NewProc("GetVolumeInformationW")
+		buf                      = make([]uint16, 255)
+		size                     = windows.MAX_PATH + 1
+	)
+	if len(drive) != 1 {
+		hr = errors.New("getFileSystemType must be called with a drive letter")
+		return
+	}
+	drive += `:\`
+	n := uintptr(unsafe.Pointer(nil))
+	r0, _, _ := syscall.Syscall9(procGetVolumeInformation.Addr(), 8, uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(drive))), n, n, n, n, n, uintptr(unsafe.Pointer(&buf[0])), uintptr(size), 0)
+	if int32(r0) < 0 {
+		hr = syscall.Errno(win32FromHresult(r0))
+	}
+	fsType = windows.UTF16ToString(buf)
+	return
+}
+
+// String returns the string representation of a driver. This should match
+// the name the graph driver has been registered with.
+func (d *Driver) String() string {
+	return "windowsfilter"
+}
+
+// Status returns the status of the driver.
+func (d *Driver) Status() [][2]string {
+	return [][2]string{
+		{"Windows", ""},
+	}
+}
+
+// panicIfUsedByLcow does exactly what it says.
+// TODO @jhowardmsft - this is a temporary measure for the bring-up of
+// Linux containers on Windows. It is a failsafe to ensure that the right
+// graphdriver is used.
+func panicIfUsedByLcow() {
+	if system.LCOWSupported() {
+		panic("inconsistency - windowsfilter graphdriver should not be used when in LCOW mode")
+	}
+}
+
+// Exists returns true if the given id is registered with this driver.
+func (d *Driver) Exists(id string) bool {
+	panicIfUsedByLcow()
+	rID, err := d.resolveID(id)
+	if err != nil {
+		return false
+	}
+	result, err := hcsshim.LayerExists(d.info, rID)
+	if err != nil {
+		return false
+	}
+	return result
+}
+
+// CreateReadWrite creates a layer that is writable for use as a container
+// file system.
+func (d *Driver) CreateReadWrite(id, parent string, opts *graphdriver.CreateOpts) error {
+	panicIfUsedByLcow()
+	if opts != nil {
+		return d.create(id, parent, opts.MountLabel, false, opts.StorageOpt)
+	}
+	return d.create(id, parent, "", false, nil)
+}
+
+// Create creates a new read-only layer with the given id.
+func (d *Driver) Create(id, parent string, opts *graphdriver.CreateOpts) error {
+	panicIfUsedByLcow()
+	if opts != nil {
+		return d.create(id, parent, opts.MountLabel, true, opts.StorageOpt)
+	}
+	return d.create(id, parent, "", true, nil)
+}
+
+func (d *Driver) create(id, parent, mountLabel string, readOnly bool, storageOpt map[string]string) error {
+	rPId, err := d.resolveID(parent)
+	if err != nil {
+		return err
+	}
+
+	parentChain, err := d.getLayerChain(rPId)
+	if err != nil {
+		return err
+	}
+
+	var layerChain []string
+
+	if rPId != "" {
+		parentPath, err := hcsshim.GetLayerMountPath(d.info, rPId)
+		if err != nil {
+			return err
+		}
+		if _, err := os.Stat(filepath.Join(parentPath, "Files")); err == nil {
+			// This is a legitimate parent layer (not the empty "-init" layer),
+			// so include it in the layer chain.
+			layerChain = []string{parentPath}
+		}
+	}
+
+	layerChain = append(layerChain, parentChain...)
+
+	if readOnly {
+		if err := hcsshim.CreateLayer(d.info, id, rPId); err != nil {
+			return err
+		}
+	} else {
+		var parentPath string
+		if len(layerChain) != 0 {
+			parentPath = layerChain[0]
+		}
+
+		if err := hcsshim.CreateSandboxLayer(d.info, id, parentPath, layerChain); err != nil {
+			return err
+		}
+
+		storageOptions, err := parseStorageOpt(storageOpt)
+		if err != nil {
+			return fmt.Errorf("Failed to parse storage options - %s", err)
+		}
+
+		if storageOptions.size != 0 {
+			if err := hcsshim.ExpandSandboxSize(d.info, id, storageOptions.size); err != nil {
+				return err
+			}
+		}
+	}
+
+	if _, err := os.Lstat(d.dir(parent)); err != nil {
+		if err2 := hcsshim.DestroyLayer(d.info, id); err2 != nil {
+			logrus.Warnf("Failed to DestroyLayer %s: %s", id, err2)
+		}
+		return fmt.Errorf("Cannot create layer with missing parent %s: %s", parent, err)
+	}
+
+	if err := d.setLayerChain(id, layerChain); err != nil {
+		if err2 := hcsshim.DestroyLayer(d.info, id); err2 != nil {
+			logrus.Warnf("Failed to DestroyLayer %s: %s", id, err2)
+		}
+		return err
+	}
+
+	return nil
+}
+
+// dir returns the absolute path to the layer.
+func (d *Driver) dir(id string) string {
+	return filepath.Join(d.info.HomeDir, filepath.Base(id))
+}
+
+// Remove unmounts and removes the dir information.
+func (d *Driver) Remove(id string) error {
+	panicIfUsedByLcow()
+	rID, err := d.resolveID(id)
+	if err != nil {
+		return err
+	}
+
+	// This retry loop is due to a bug in Windows (Internal bug #9432268)
+	// if GetContainers fails with ErrVmcomputeOperationInvalidState
+	// it is a transient error. Retry until it succeeds.
+	var computeSystems []hcsshim.ContainerProperties
+	retryCount := 0
+	osv := system.GetOSVersion()
+	for {
+		// Get and terminate any template VMs that are currently using the layer.
+		// Note: It is unfortunate that we end up in the graphdrivers Remove() call
+		// for both containers and images, but the logic for template VMs is only
+		// needed for images - specifically we are looking to see if a base layer
+		// is in use by a template VM as a result of having started a Hyper-V
+		// container at some point.
+		//
+		// We have a retry loop for ErrVmcomputeOperationInvalidState and
+		// ErrVmcomputeOperationAccessIsDenied as there is a race condition
+		// in RS1 and RS2 building during enumeration when a silo is going away
+		// for example under it, in HCS. AccessIsDenied added to fix 30278.
+		//
+		// TODO @jhowardmsft - For RS3, we can remove the retries. Also consider
+		// using platform APIs (if available) to get this more succinctly. Also
+		// consider enhancing the Remove() interface to have context of why
+		// the remove is being called - that could improve efficiency by not
+		// enumerating compute systems during a remove of a container as it's
+		// not required.
+		computeSystems, err = hcsshim.GetContainers(hcsshim.ComputeSystemQuery{})
+		if err != nil {
+			if (osv.Build < 15139) &&
+				((err == hcsshim.ErrVmcomputeOperationInvalidState) || (err == hcsshim.ErrVmcomputeOperationAccessIsDenied)) {
+				if retryCount >= 500 {
+					break
+				}
+				retryCount++
+				time.Sleep(10 * time.Millisecond)
+				continue
+			}
+			return err
+		}
+		break
+	}
+
+	for _, computeSystem := range computeSystems {
+		if strings.Contains(computeSystem.RuntimeImagePath, id) && computeSystem.IsRuntimeTemplate {
+			container, err := hcsshim.OpenContainer(computeSystem.ID)
+			if err != nil {
+				return err
+			}
+			defer container.Close()
+			err = container.Terminate()
+			if hcsshim.IsPending(err) {
+				err = container.Wait()
+			} else if hcsshim.IsAlreadyStopped(err) {
+				err = nil
+			}
+
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	layerPath := filepath.Join(d.info.HomeDir, rID)
+	tmpID := fmt.Sprintf("%s-removing", rID)
+	tmpLayerPath := filepath.Join(d.info.HomeDir, tmpID)
+	if err := os.Rename(layerPath, tmpLayerPath); err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	if err := hcsshim.DestroyLayer(d.info, tmpID); err != nil {
+		logrus.Errorf("Failed to DestroyLayer %s: %s", id, err)
+	}
+
+	return nil
+}
+
+// Get returns the rootfs path for the id. This will mount the dir at its given path.
+func (d *Driver) Get(id, mountLabel string) (string, error) {
+	panicIfUsedByLcow()
+	logrus.Debugf("WindowsGraphDriver Get() id %s mountLabel %s", id, mountLabel)
+	var dir string
+
+	rID, err := d.resolveID(id)
+	if err != nil {
+		return "", err
+	}
+	if count := d.ctr.Increment(rID); count > 1 {
+		return d.cache[rID], nil
+	}
+
+	// Getting the layer paths must be done outside of the lock.
+	layerChain, err := d.getLayerChain(rID)
+	if err != nil {
+		d.ctr.Decrement(rID)
+		return "", err
+	}
+
+	if err := hcsshim.ActivateLayer(d.info, rID); err != nil {
+		d.ctr.Decrement(rID)
+		return "", err
+	}
+	if err := hcsshim.PrepareLayer(d.info, rID, layerChain); err != nil {
+		d.ctr.Decrement(rID)
+		if err2 := hcsshim.DeactivateLayer(d.info, rID); err2 != nil {
+			logrus.Warnf("Failed to Deactivate %s: %s", id, err)
+		}
+		return "", err
+	}
+
+	mountPath, err := hcsshim.GetLayerMountPath(d.info, rID)
+	if err != nil {
+		d.ctr.Decrement(rID)
+		if err := hcsshim.UnprepareLayer(d.info, rID); err != nil {
+			logrus.Warnf("Failed to Unprepare %s: %s", id, err)
+		}
+		if err2 := hcsshim.DeactivateLayer(d.info, rID); err2 != nil {
+			logrus.Warnf("Failed to Deactivate %s: %s", id, err)
+		}
+		return "", err
+	}
+	d.cacheMu.Lock()
+	d.cache[rID] = mountPath
+	d.cacheMu.Unlock()
+
+	// If the layer has a mount path, use that. Otherwise, use the
+	// folder path.
+	if mountPath != "" {
+		dir = mountPath
+	} else {
+		dir = d.dir(id)
+	}
+
+	return dir, nil
+}
+
+// Put adds a new layer to the driver.
+func (d *Driver) Put(id string) error {
+	panicIfUsedByLcow()
+	logrus.Debugf("WindowsGraphDriver Put() id %s", id)
+
+	rID, err := d.resolveID(id)
+	if err != nil {
+		return err
+	}
+	if count := d.ctr.Decrement(rID); count > 0 {
+		return nil
+	}
+	d.cacheMu.Lock()
+	_, exists := d.cache[rID]
+	delete(d.cache, rID)
+	d.cacheMu.Unlock()
+
+	// If the cache was not populated, then the layer was left unprepared and deactivated
+	if !exists {
+		return nil
+	}
+
+	if err := hcsshim.UnprepareLayer(d.info, rID); err != nil {
+		return err
+	}
+	return hcsshim.DeactivateLayer(d.info, rID)
+}
+
+// Cleanup ensures the information the driver stores is properly removed.
+// We use this opportunity to cleanup any -removing folders which may be
+// still left if the daemon was killed while it was removing a layer.
+func (d *Driver) Cleanup() error {
+	items, err := ioutil.ReadDir(d.info.HomeDir)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil
+		}
+		return err
+	}
+
+	// Note we don't return an error below - it's possible the files
+	// are locked. However, next time around after the daemon exits,
+	// we likely will be able to to cleanup successfully. Instead we log
+	// warnings if there are errors.
+	for _, item := range items {
+		if item.IsDir() && strings.HasSuffix(item.Name(), "-removing") {
+			if err := hcsshim.DestroyLayer(d.info, item.Name()); err != nil {
+				logrus.Warnf("Failed to cleanup %s: %s", item.Name(), err)
+			} else {
+				logrus.Infof("Cleaned up %s", item.Name())
+			}
+		}
+	}
+
+	return nil
+}
+
+// Diff produces an archive of the changes between the specified
+// layer and its parent layer which may be "".
+// The layer should be mounted when calling this function
+func (d *Driver) Diff(id, parent, mountLabel string) (_ io.ReadCloser, err error) {
+	panicIfUsedByLcow()
+	rID, err := d.resolveID(id)
+	if err != nil {
+		return
+	}
+
+	layerChain, err := d.getLayerChain(rID)
+	if err != nil {
+		return
+	}
+
+	// this is assuming that the layer is unmounted
+	if err := hcsshim.UnprepareLayer(d.info, rID); err != nil {
+		return nil, err
+	}
+	prepare := func() {
+		if err := hcsshim.PrepareLayer(d.info, rID, layerChain); err != nil {
+			logrus.Warnf("Failed to Deactivate %s: %s", rID, err)
+		}
+	}
+
+	arch, err := d.exportLayer(rID, layerChain)
+	if err != nil {
+		prepare()
+		return
+	}
+	return ioutils.NewReadCloserWrapper(arch, func() error {
+		err := arch.Close()
+		prepare()
+		return err
+	}), nil
+}
+
+// Changes produces a list of changes between the specified layer
+// and its parent layer. If parent is "", then all changes will be ADD changes.
+// The layer should not be mounted when calling this function.
+func (d *Driver) Changes(id, parent, mountLabel string) ([]archive.Change, error) {
+	panicIfUsedByLcow()
+	rID, err := d.resolveID(id)
+	if err != nil {
+		return nil, err
+	}
+	parentChain, err := d.getLayerChain(rID)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := hcsshim.ActivateLayer(d.info, rID); err != nil {
+		return nil, err
+	}
+	defer func() {
+		if err2 := hcsshim.DeactivateLayer(d.info, rID); err2 != nil {
+			logrus.Errorf("changes() failed to DeactivateLayer %s %s: %s", id, rID, err2)
+		}
+	}()
+
+	var changes []archive.Change
+	err = winio.RunWithPrivilege(winio.SeBackupPrivilege, func() error {
+		r, err := hcsshim.NewLayerReader(d.info, id, parentChain)
+		if err != nil {
+			return err
+		}
+		defer r.Close()
+
+		for {
+			name, _, fileInfo, err := r.Next()
+			if err == io.EOF {
+				return nil
+			}
+			if err != nil {
+				return err
+			}
+			name = filepath.ToSlash(name)
+			if fileInfo == nil {
+				changes = append(changes, archive.Change{Path: name, Kind: archive.ChangeDelete})
+			} else {
+				// Currently there is no way to tell between an add and a modify.
+				changes = append(changes, archive.Change{Path: name, Kind: archive.ChangeModify})
+			}
+		}
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return changes, nil
+}
+
+// ApplyDiff extracts the changeset from the given diff into the
+// layer with the specified id and parent, returning the size of the
+// new layer in bytes.
+// The layer should not be mounted when calling this function
+func (d *Driver) ApplyDiff(id, parent, mountLabel string, diff io.Reader) (int64, error) {
+	panicIfUsedByLcow()
+	var layerChain []string
+	if parent != "" {
+		rPId, err := d.resolveID(parent)
+		if err != nil {
+			return 0, err
+		}
+		parentChain, err := d.getLayerChain(rPId)
+		if err != nil {
+			return 0, err
+		}
+		parentPath, err := hcsshim.GetLayerMountPath(d.info, rPId)
+		if err != nil {
+			return 0, err
+		}
+		layerChain = append(layerChain, parentPath)
+		layerChain = append(layerChain, parentChain...)
+	}
+
+	size, err := d.importLayer(id, diff, layerChain)
+	if err != nil {
+		return 0, err
+	}
+
+	if err = d.setLayerChain(id, layerChain); err != nil {
+		return 0, err
+	}
+
+	return size, nil
+}
+
+// DiffSize calculates the changes between the specified layer
+// and its parent and returns the size in bytes of the changes
+// relative to its base filesystem directory.
+func (d *Driver) DiffSize(id, parent, mountLabel string) (size int64, err error) {
+	panicIfUsedByLcow()
+	rPId, err := d.resolveID(parent)
+	if err != nil {
+		return
+	}
+
+	changes, err := d.Changes(id, rPId, mountLabel)
+	if err != nil {
+		return
+	}
+
+	layerFs, err := d.Get(id, "")
+	if err != nil {
+		return
+	}
+	defer d.Put(id)
+
+	return archive.ChangesSize(layerFs, changes), nil
+}
+
+// Metadata returns custom driver information.
+func (d *Driver) Metadata(id string) (map[string]string, error) {
+	panicIfUsedByLcow()
+	m := make(map[string]string)
+	m["dir"] = d.dir(id)
+	return m, nil
+}
+
+func writeTarFromLayer(r hcsshim.LayerReader, w io.Writer) error {
+	t := tar.NewWriter(w)
+	for {
+		name, size, fileInfo, err := r.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+		if fileInfo == nil {
+			// Write a whiteout file.
+			hdr := &tar.Header{
+				Name: filepath.ToSlash(filepath.Join(filepath.Dir(name), archive.WhiteoutPrefix+filepath.Base(name))),
+			}
+			err := t.WriteHeader(hdr)
+			if err != nil {
+				return err
+			}
+		} else {
+			err = backuptar.WriteTarFileFromBackupStream(t, r, name, size, fileInfo)
+			if err != nil {
+				return err
+			}
+		}
+	}
+	return t.Close()
+}
+
+// exportLayer generates an archive from a layer based on the given ID.
+func (d *Driver) exportLayer(id string, parentLayerPaths []string) (io.ReadCloser, error) {
+	archive, w := io.Pipe()
+	go func() {
+		err := winio.RunWithPrivilege(winio.SeBackupPrivilege, func() error {
+			r, err := hcsshim.NewLayerReader(d.info, id, parentLayerPaths)
+			if err != nil {
+				return err
+			}
+
+			err = writeTarFromLayer(r, w)
+			cerr := r.Close()
+			if err == nil {
+				err = cerr
+			}
+			return err
+		})
+		w.CloseWithError(err)
+	}()
+
+	return archive, nil
+}
+
+// writeBackupStreamFromTarAndSaveMutatedFiles reads data from a tar stream and
+// writes it to a backup stream, and also saves any files that will be mutated
+// by the import layer process to a backup location.
+func writeBackupStreamFromTarAndSaveMutatedFiles(buf *bufio.Writer, w io.Writer, t *tar.Reader, hdr *tar.Header, root string) (nextHdr *tar.Header, err error) {
+	var bcdBackup *os.File
+	var bcdBackupWriter *winio.BackupFileWriter
+	if backupPath, ok := mutatedFiles[hdr.Name]; ok {
+		bcdBackup, err = os.Create(filepath.Join(root, backupPath))
+		if err != nil {
+			return nil, err
+		}
+		defer func() {
+			cerr := bcdBackup.Close()
+			if err == nil {
+				err = cerr
+			}
+		}()
+
+		bcdBackupWriter = winio.NewBackupFileWriter(bcdBackup, false)
+		defer func() {
+			cerr := bcdBackupWriter.Close()
+			if err == nil {
+				err = cerr
+			}
+		}()
+
+		buf.Reset(io.MultiWriter(w, bcdBackupWriter))
+	} else {
+		buf.Reset(w)
+	}
+
+	defer func() {
+		ferr := buf.Flush()
+		if err == nil {
+			err = ferr
+		}
+	}()
+
+	return backuptar.WriteBackupStreamFromTarFile(buf, t, hdr)
+}
+
+func writeLayerFromTar(r io.Reader, w hcsshim.LayerWriter, root string) (int64, error) {
+	t := tar.NewReader(r)
+	hdr, err := t.Next()
+	totalSize := int64(0)
+	buf := bufio.NewWriter(nil)
+	for err == nil {
+		base := path.Base(hdr.Name)
+		if strings.HasPrefix(base, archive.WhiteoutPrefix) {
+			name := path.Join(path.Dir(hdr.Name), base[len(archive.WhiteoutPrefix):])
+			err = w.Remove(filepath.FromSlash(name))
+			if err != nil {
+				return 0, err
+			}
+			hdr, err = t.Next()
+		} else if hdr.Typeflag == tar.TypeLink {
+			err = w.AddLink(filepath.FromSlash(hdr.Name), filepath.FromSlash(hdr.Linkname))
+			if err != nil {
+				return 0, err
+			}
+			hdr, err = t.Next()
+		} else {
+			var (
+				name     string
+				size     int64
+				fileInfo *winio.FileBasicInfo
+			)
+			name, size, fileInfo, err = backuptar.FileInfoFromHeader(hdr)
+			if err != nil {
+				return 0, err
+			}
+			err = w.Add(filepath.FromSlash(name), fileInfo)
+			if err != nil {
+				return 0, err
+			}
+			hdr, err = writeBackupStreamFromTarAndSaveMutatedFiles(buf, w, t, hdr, root)
+			totalSize += size
+		}
+	}
+	if err != io.EOF {
+		return 0, err
+	}
+	return totalSize, nil
+}
+
+// importLayer adds a new layer to the tag and graph store based on the given data.
+func (d *Driver) importLayer(id string, layerData io.Reader, parentLayerPaths []string) (size int64, err error) {
+	if !noreexec {
+		cmd := reexec.Command(append([]string{"docker-windows-write-layer", d.info.HomeDir, id}, parentLayerPaths...)...)
+		output := bytes.NewBuffer(nil)
+		cmd.Stdin = layerData
+		cmd.Stdout = output
+		cmd.Stderr = output
+
+		if err = cmd.Start(); err != nil {
+			return
+		}
+
+		if err = cmd.Wait(); err != nil {
+			return 0, fmt.Errorf("re-exec error: %v: output: %s", err, output)
+		}
+
+		return strconv.ParseInt(output.String(), 10, 64)
+	}
+	return writeLayer(layerData, d.info.HomeDir, id, parentLayerPaths...)
+}
+
+// writeLayerReexec is the re-exec entry point for writing a layer from a tar file
+func writeLayerReexec() {
+	size, err := writeLayer(os.Stdin, os.Args[1], os.Args[2], os.Args[3:]...)
+	if err != nil {
+		fmt.Fprint(os.Stderr, err)
+		os.Exit(1)
+	}
+	fmt.Fprint(os.Stdout, size)
+}
+
+// writeLayer writes a layer from a tar file.
+func writeLayer(layerData io.Reader, home string, id string, parentLayerPaths ...string) (int64, error) {
+	err := winio.EnableProcessPrivileges([]string{winio.SeBackupPrivilege, winio.SeRestorePrivilege})
+	if err != nil {
+		return 0, err
+	}
+	if noreexec {
+		defer func() {
+			if err := winio.DisableProcessPrivileges([]string{winio.SeBackupPrivilege, winio.SeRestorePrivilege}); err != nil {
+				// This should never happen, but just in case when in debugging mode.
+				// See https://github.com/docker/docker/pull/28002#discussion_r86259241 for rationale.
+				panic("Failed to disabled process privileges while in non re-exec mode")
+			}
+		}()
+	}
+
+	info := hcsshim.DriverInfo{
+		Flavour: filterDriver,
+		HomeDir: home,
+	}
+
+	w, err := hcsshim.NewLayerWriter(info, id, parentLayerPaths)
+	if err != nil {
+		return 0, err
+	}
+
+	size, err := writeLayerFromTar(layerData, w, filepath.Join(home, id))
+	if err != nil {
+		return 0, err
+	}
+
+	err = w.Close()
+	if err != nil {
+		return 0, err
+	}
+
+	return size, nil
+}
+
+// resolveID computes the layerID information based on the given id.
+func (d *Driver) resolveID(id string) (string, error) {
+	content, err := ioutil.ReadFile(filepath.Join(d.dir(id), "layerID"))
+	if os.IsNotExist(err) {
+		return id, nil
+	} else if err != nil {
+		return "", err
+	}
+	return string(content), nil
+}
+
+// setID stores the layerId in disk.
+func (d *Driver) setID(id, altID string) error {
+	return ioutil.WriteFile(filepath.Join(d.dir(id), "layerId"), []byte(altID), 0600)
+}
+
+// getLayerChain returns the layer chain information.
+func (d *Driver) getLayerChain(id string) ([]string, error) {
+	jPath := filepath.Join(d.dir(id), "layerchain.json")
+	content, err := ioutil.ReadFile(jPath)
+	if os.IsNotExist(err) {
+		return nil, nil
+	} else if err != nil {
+		return nil, fmt.Errorf("Unable to read layerchain file - %s", err)
+	}
+
+	var layerChain []string
+	err = json.Unmarshal(content, &layerChain)
+	if err != nil {
+		return nil, fmt.Errorf("Failed to unmarshall layerchain json - %s", err)
+	}
+
+	return layerChain, nil
+}
+
+// setLayerChain stores the layer chain information in disk.
+func (d *Driver) setLayerChain(id string, chain []string) error {
+	content, err := json.Marshal(&chain)
+	if err != nil {
+		return fmt.Errorf("Failed to marshall layerchain json - %s", err)
+	}
+
+	jPath := filepath.Join(d.dir(id), "layerchain.json")
+	err = ioutil.WriteFile(jPath, content, 0600)
+	if err != nil {
+		return fmt.Errorf("Unable to write layerchain file - %s", err)
+	}
+
+	return nil
+}
+
+type fileGetCloserWithBackupPrivileges struct {
+	path string
+}
+
+func (fg *fileGetCloserWithBackupPrivileges) Get(filename string) (io.ReadCloser, error) {
+	if backupPath, ok := mutatedFiles[filename]; ok {
+		return os.Open(filepath.Join(fg.path, backupPath))
+	}
+
+	var f *os.File
+	// Open the file while holding the Windows backup privilege. This ensures that the
+	// file can be opened even if the caller does not actually have access to it according
+	// to the security descriptor. Also use sequential file access to avoid depleting the
+	// standby list - Microsoft VSO Bug Tracker #9900466
+	err := winio.RunWithPrivilege(winio.SeBackupPrivilege, func() error {
+		path := longpath.AddPrefix(filepath.Join(fg.path, filename))
+		p, err := windows.UTF16FromString(path)
+		if err != nil {
+			return err
+		}
+		const fileFlagSequentialScan = 0x08000000 // FILE_FLAG_SEQUENTIAL_SCAN
+		h, err := windows.CreateFile(&p[0], windows.GENERIC_READ, windows.FILE_SHARE_READ, nil, windows.OPEN_EXISTING, windows.FILE_FLAG_BACKUP_SEMANTICS|fileFlagSequentialScan, 0)
+		if err != nil {
+			return &os.PathError{Op: "open", Path: path, Err: err}
+		}
+		f = os.NewFile(uintptr(h), path)
+		return nil
+	})
+	return f, err
+}
+
+func (fg *fileGetCloserWithBackupPrivileges) Close() error {
+	return nil
+}
+
+// DiffGetter returns a FileGetCloser that can read files from the directory that
+// contains files for the layer differences. Used for direct access for tar-split.
+func (d *Driver) DiffGetter(id string) (graphdriver.FileGetCloser, error) {
+	panicIfUsedByLcow()
+	id, err := d.resolveID(id)
+	if err != nil {
+		return nil, err
+	}
+
+	return &fileGetCloserWithBackupPrivileges{d.dir(id)}, nil
+}
+
+// AdditionalImageStores returns additional image stores supported by the driver
+func (d *Driver) AdditionalImageStores() []string {
+	return nil
+}
+
+type storageOptions struct {
+	size uint64
+}
+
+func parseStorageOpt(storageOpt map[string]string) (*storageOptions, error) {
+	options := storageOptions{}
+
+	// Read size to change the block device size per container.
+	for key, val := range storageOpt {
+		key := strings.ToLower(key)
+		switch key {
+		case "size":
+			size, err := units.RAMInBytes(val)
+			if err != nil {
+				return nil, err
+			}
+			options.size = uint64(size)
+		default:
+			return nil, fmt.Errorf("Unknown storage option: %s", key)
+		}
+	}
+	return &options, nil
+}

vendor/github.com/containers/storage/drivers/zfs/zfs.go

@@ -0,0 +1,426 @@
+// +build linux freebsd solaris
+
+package zfs
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/containers/storage/drivers"
+	"github.com/containers/storage/pkg/idtools"
+	"github.com/containers/storage/pkg/mount"
+	"github.com/containers/storage/pkg/parsers"
+	zfs "github.com/mistifyio/go-zfs"
+	"github.com/opencontainers/selinux/go-selinux/label"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"golang.org/x/sys/unix"
+)
+
+type zfsOptions struct {
+	fsName    string
+	mountPath string
+}
+
+func init() {
+	graphdriver.Register("zfs", Init)
+}
+
+// Logger returns a zfs logger implementation.
+type Logger struct{}
+
+// Log wraps log message from ZFS driver with a prefix '[zfs]'.
+func (*Logger) Log(cmd []string) {
+	logrus.Debugf("[zfs] %s", strings.Join(cmd, " "))
+}
+
+// Init returns a new ZFS driver.
+// It takes base mount path and an array of options which are represented as key value pairs.
+// Each option is in the for key=value. 'zfs.fsname' is expected to be a valid key in the options.
+func Init(base string, opt []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
+	var err error
+
+	if _, err := exec.LookPath("zfs"); err != nil {
+		logrus.Debugf("[zfs] zfs command is not available: %v", err)
+		return nil, errors.Wrap(graphdriver.ErrPrerequisites, "the 'zfs' command is not available")
+	}
+
+	file, err := os.OpenFile("/dev/zfs", os.O_RDWR, 600)
+	if err != nil {
+		logrus.Debugf("[zfs] cannot open /dev/zfs: %v", err)
+		return nil, errors.Wrapf(graphdriver.ErrPrerequisites, "could not open /dev/zfs: %v", err)
+	}
+	defer file.Close()
+
+	options, err := parseOptions(opt)
+	if err != nil {
+		return nil, err
+	}
+	options.mountPath = base
+
+	rootdir := path.Dir(base)
+
+	if options.fsName == "" {
+		err = checkRootdirFs(rootdir)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if options.fsName == "" {
+		options.fsName, err = lookupZfsDataset(rootdir)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	zfs.SetLogger(new(Logger))
+
+	filesystems, err := zfs.Filesystems(options.fsName)
+	if err != nil {
+		return nil, fmt.Errorf("Cannot find root filesystem %s: %v", options.fsName, err)
+	}
+
+	filesystemsCache := make(map[string]bool, len(filesystems))
+	var rootDataset *zfs.Dataset
+	for _, fs := range filesystems {
+		if fs.Name == options.fsName {
+			rootDataset = fs
+		}
+		filesystemsCache[fs.Name] = true
+	}
+
+	if rootDataset == nil {
+		return nil, fmt.Errorf("BUG: zfs get all -t filesystem -rHp '%s' should contain '%s'", options.fsName, options.fsName)
+	}
+
+	rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
+	if err != nil {
+		return nil, fmt.Errorf("Failed to get root uid/guid: %v", err)
+	}
+	if err := idtools.MkdirAllAs(base, 0700, rootUID, rootGID); err != nil {
+		return nil, fmt.Errorf("Failed to create '%s': %v", base, err)
+	}
+
+	if err := mount.MakePrivate(base); err != nil {
+		return nil, err
+	}
+	d := &Driver{
+		dataset:          rootDataset,
+		options:          options,
+		filesystemsCache: filesystemsCache,
+		uidMaps:          uidMaps,
+		gidMaps:          gidMaps,
+		ctr:              graphdriver.NewRefCounter(graphdriver.NewDefaultChecker()),
+	}
+	return graphdriver.NewNaiveDiffDriver(d, uidMaps, gidMaps), nil
+}
+
+func parseOptions(opt []string) (zfsOptions, error) {
+	var options zfsOptions
+	options.fsName = ""
+	for _, option := range opt {
+		key, val, err := parsers.ParseKeyValueOpt(option)
+		if err != nil {
+			return options, err
+		}
+		key = strings.ToLower(key)
+		switch key {
+		case "zfs.fsname":
+			options.fsName = val
+		default:
+			return options, fmt.Errorf("Unknown option %s", key)
+		}
+	}
+	return options, nil
+}
+
+func lookupZfsDataset(rootdir string) (string, error) {
+	var stat unix.Stat_t
+	if err := unix.Stat(rootdir, &stat); err != nil {
+		return "", fmt.Errorf("Failed to access '%s': %s", rootdir, err)
+	}
+	wantedDev := stat.Dev
+
+	mounts, err := mount.GetMounts()
+	if err != nil {
+		return "", err
+	}
+	for _, m := range mounts {
+		if err := unix.Stat(m.Mountpoint, &stat); err != nil {
+			logrus.Debugf("[zfs] failed to stat '%s' while scanning for zfs mount: %v", m.Mountpoint, err)
+			continue // may fail on fuse file systems
+		}
+
+		if stat.Dev == wantedDev && m.Fstype == "zfs" {
+			return m.Source, nil
+		}
+	}
+
+	return "", fmt.Errorf("Failed to find zfs dataset mounted on '%s' in /proc/mounts", rootdir)
+}
+
+// Driver holds information about the driver, such as zfs dataset, options and cache.
+type Driver struct {
+	dataset          *zfs.Dataset
+	options          zfsOptions
+	sync.Mutex       // protects filesystem cache against concurrent access
+	filesystemsCache map[string]bool
+	uidMaps          []idtools.IDMap
+	gidMaps          []idtools.IDMap
+	ctr              *graphdriver.RefCounter
+}
+
+func (d *Driver) String() string {
+	return "zfs"
+}
+
+// Cleanup is used to implement graphdriver.ProtoDriver. There is no cleanup required for this driver.
+func (d *Driver) Cleanup() error {
+	return nil
+}
+
+// Status returns information about the ZFS filesystem. It returns a two dimensional array of information
+// such as pool name, dataset name, disk usage, parent quota and compression used.
+// Currently it return 'Zpool', 'Zpool Health', 'Parent Dataset', 'Space Used By Parent',
+// 'Space Available', 'Parent Quota' and 'Compression'.
+func (d *Driver) Status() [][2]string {
+	parts := strings.Split(d.dataset.Name, "/")
+	pool, err := zfs.GetZpool(parts[0])
+
+	var poolName, poolHealth string
+	if err == nil {
+		poolName = pool.Name
+		poolHealth = pool.Health
+	} else {
+		poolName = fmt.Sprintf("error while getting pool information %v", err)
+		poolHealth = "not available"
+	}
+
+	quota := "no"
+	if d.dataset.Quota != 0 {
+		quota = strconv.FormatUint(d.dataset.Quota, 10)
+	}
+
+	return [][2]string{
+		{"Zpool", poolName},
+		{"Zpool Health", poolHealth},
+		{"Parent Dataset", d.dataset.Name},
+		{"Space Used By Parent", strconv.FormatUint(d.dataset.Used, 10)},
+		{"Space Available", strconv.FormatUint(d.dataset.Avail, 10)},
+		{"Parent Quota", quota},
+		{"Compression", d.dataset.Compression},
+	}
+}
+
+// Metadata returns image/container metadata related to graph driver
+func (d *Driver) Metadata(id string) (map[string]string, error) {
+	return map[string]string{
+		"Mountpoint": d.mountPath(id),
+		"Dataset":    d.zfsPath(id),
+	}, nil
+}
+
+func (d *Driver) cloneFilesystem(name, parentName string) error {
+	snapshotName := fmt.Sprintf("%d", time.Now().Nanosecond())
+	parentDataset := zfs.Dataset{Name: parentName}
+	snapshot, err := parentDataset.Snapshot(snapshotName /*recursive */, false)
+	if err != nil {
+		return err
+	}
+
+	_, err = snapshot.Clone(name, map[string]string{"mountpoint": "legacy"})
+	if err == nil {
+		d.Lock()
+		d.filesystemsCache[name] = true
+		d.Unlock()
+	}
+
+	if err != nil {
+		snapshot.Destroy(zfs.DestroyDeferDeletion)
+		return err
+	}
+	return snapshot.Destroy(zfs.DestroyDeferDeletion)
+}
+
+func (d *Driver) zfsPath(id string) string {
+	return d.options.fsName + "/" + id
+}
+
+func (d *Driver) mountPath(id string) string {
+	return path.Join(d.options.mountPath, "graph", getMountpoint(id))
+}
+
+// CreateReadWrite creates a layer that is writable for use as a container
+// file system.
+func (d *Driver) CreateReadWrite(id, parent string, opts *graphdriver.CreateOpts) error {
+	return d.Create(id, parent, opts)
+}
+
+// Create prepares the dataset and filesystem for the ZFS driver for the given id under the parent.
+func (d *Driver) Create(id, parent string, opts *graphdriver.CreateOpts) error {
+	var storageOpt map[string]string
+	if opts != nil {
+		storageOpt = opts.StorageOpt
+	}
+
+	err := d.create(id, parent, storageOpt)
+	if err == nil {
+		return nil
+	}
+	if zfsError, ok := err.(*zfs.Error); ok {
+		if !strings.HasSuffix(zfsError.Stderr, "dataset already exists\n") {
+			return err
+		}
+		// aborted build -> cleanup
+	} else {
+		return err
+	}
+
+	dataset := zfs.Dataset{Name: d.zfsPath(id)}
+	if err := dataset.Destroy(zfs.DestroyRecursiveClones); err != nil {
+		return err
+	}
+
+	// retry
+	return d.create(id, parent, storageOpt)
+}
+
+func (d *Driver) create(id, parent string, storageOpt map[string]string) error {
+	name := d.zfsPath(id)
+	quota, err := parseStorageOpt(storageOpt)
+	if err != nil {
+		return err
+	}
+	if parent == "" {
+		mountoptions := map[string]string{"mountpoint": "legacy"}
+		fs, err := zfs.CreateFilesystem(name, mountoptions)
+		if err == nil {
+			err = setQuota(name, quota)
+			if err == nil {
+				d.Lock()
+				d.filesystemsCache[fs.Name] = true
+				d.Unlock()
+			}
+		}
+		return err
+	}
+	err = d.cloneFilesystem(name, d.zfsPath(parent))
+	if err == nil {
+		err = setQuota(name, quota)
+	}
+	return err
+}
+
+func parseStorageOpt(storageOpt map[string]string) (string, error) {
+	// Read size to change the disk quota per container
+	for k, v := range storageOpt {
+		key := strings.ToLower(k)
+		switch key {
+		case "size":
+			return v, nil
+		default:
+			return "0", fmt.Errorf("Unknown option %s", key)
+		}
+	}
+	return "0", nil
+}
+
+func setQuota(name string, quota string) error {
+	if quota == "0" {
+		return nil
+	}
+	fs, err := zfs.GetDataset(name)
+	if err != nil {
+		return err
+	}
+	return fs.SetProperty("quota", quota)
+}
+
+// Remove deletes the dataset, filesystem and the cache for the given id.
+func (d *Driver) Remove(id string) error {
+	name := d.zfsPath(id)
+	dataset := zfs.Dataset{Name: name}
+	err := dataset.Destroy(zfs.DestroyRecursive)
+	if err == nil {
+		d.Lock()
+		delete(d.filesystemsCache, name)
+		d.Unlock()
+	}
+	return err
+}
+
+// Get returns the mountpoint for the given id after creating the target directories if necessary.
+func (d *Driver) Get(id, mountLabel string) (string, error) {
+	mountpoint := d.mountPath(id)
+	if count := d.ctr.Increment(mountpoint); count > 1 {
+		return mountpoint, nil
+	}
+
+	filesystem := d.zfsPath(id)
+	options := label.FormatMountLabel("", mountLabel)
+	logrus.Debugf(`[zfs] mount("%s", "%s", "%s")`, filesystem, mountpoint, options)
+
+	rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
+	if err != nil {
+		d.ctr.Decrement(mountpoint)
+		return "", err
+	}
+	// Create the target directories if they don't exist
+	if err := idtools.MkdirAllAs(mountpoint, 0755, rootUID, rootGID); err != nil {
+		d.ctr.Decrement(mountpoint)
+		return "", err
+	}
+
+	if err := mount.Mount(filesystem, mountpoint, "zfs", options); err != nil {
+		d.ctr.Decrement(mountpoint)
+		return "", fmt.Errorf("error creating zfs mount of %s to %s: %v", filesystem, mountpoint, err)
+	}
+
+	// this could be our first mount after creation of the filesystem, and the root dir may still have root
+	// permissions instead of the remapped root uid:gid (if user namespaces are enabled):
+	if err := os.Chown(mountpoint, rootUID, rootGID); err != nil {
+		mount.Unmount(mountpoint)
+		d.ctr.Decrement(mountpoint)
+		return "", fmt.Errorf("error modifying zfs mountpoint (%s) directory ownership: %v", mountpoint, err)
+	}
+
+	return mountpoint, nil
+}
+
+// Put removes the existing mountpoint for the given id if it exists.
+func (d *Driver) Put(id string) error {
+	mountpoint := d.mountPath(id)
+	if count := d.ctr.Decrement(mountpoint); count > 0 {
+		return nil
+	}
+	mounted, err := graphdriver.Mounted(graphdriver.FsMagicZfs, mountpoint)
+	if err != nil || !mounted {
+		return err
+	}
+
+	logrus.Debugf(`[zfs] unmount("%s")`, mountpoint)
+
+	if err := mount.Unmount(mountpoint); err != nil {
+		return fmt.Errorf("error unmounting to %s: %v", mountpoint, err)
+	}
+	return nil
+}
+
+// Exists checks to see if the cache entry exists for the given id.
+func (d *Driver) Exists(id string) bool {
+	d.Lock()
+	defer d.Unlock()
+	return d.filesystemsCache[d.zfsPath(id)]
+}
+
+// AdditionalImageStores returns additional image stores supported by the driver
+func (d *Driver) AdditionalImageStores() []string {
+	return nil
+}

vendor/github.com/containers/storage/drivers/zfs/zfs_freebsd.go

@@ -0,0 +1,39 @@
+package zfs
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/containers/storage/drivers"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"golang.org/x/sys/unix"
+)
+
+func checkRootdirFs(rootdir string) error {
+	var buf unix.Statfs_t
+	if err := unix.Statfs(rootdir, &buf); err != nil {
+		return fmt.Errorf("Failed to access '%s': %s", rootdir, err)
+	}
+
+	// on FreeBSD buf.Fstypename contains ['z', 'f', 's', 0 ... ]
+	if (buf.Fstypename[0] != 122) || (buf.Fstypename[1] != 102) || (buf.Fstypename[2] != 115) || (buf.Fstypename[3] != 0) {
+		logrus.Debugf("[zfs] no zfs dataset found for rootdir '%s'", rootdir)
+		return errors.Wrapf(graphdriver.ErrPrerequisites, "no zfs dataset found for rootdir '%s'", rootdir)
+	}
+
+	return nil
+}
+
+func getMountpoint(id string) string {
+	maxlen := 12
+
+	// we need to preserve filesystem suffix
+	suffix := strings.SplitN(id, "-", 2)
+
+	if len(suffix) > 1 {
+		return id[:maxlen] + "-" + suffix[1]
+	}
+
+	return id[:maxlen]
+}

vendor/github.com/containers/storage/drivers/zfs/zfs_linux.go

@@ -0,0 +1,28 @@
+package zfs
+
+import (
+	"fmt"
+
+	"github.com/containers/storage/drivers"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"golang.org/x/sys/unix"
+)
+
+func checkRootdirFs(rootdir string) error {
+	var buf unix.Statfs_t
+	if err := unix.Statfs(rootdir, &buf); err != nil {
+		return fmt.Errorf("Failed to access '%s': %s", rootdir, err)
+	}
+
+	if graphdriver.FsMagic(buf.Type) != graphdriver.FsMagicZfs {
+		logrus.Debugf("[zfs] no zfs dataset found for rootdir '%s'", rootdir)
+		return errors.Wrapf(graphdriver.ErrPrerequisites, "no zfs dataset found for rootdir '%s'", rootdir)
+	}
+
+	return nil
+}
+
+func getMountpoint(id string) string {
+	return id
+}

vendor/github.com/containers/storage/drivers/zfs/zfs_solaris.go

@@ -0,0 +1,59 @@
+// +build solaris,cgo
+
+package zfs
+
+/*
+#include <sys/statvfs.h>
+#include <stdlib.h>
+
+static inline struct statvfs *getstatfs(char *s) {
+        struct statvfs *buf;
+        int err;
+        buf = (struct statvfs *)malloc(sizeof(struct statvfs));
+        err = statvfs(s, buf);
+        return buf;
+}
+*/
+import "C"
+import (
+	"path/filepath"
+	"strings"
+	"unsafe"
+
+	"github.com/containers/storage/drivers"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+func checkRootdirFs(rootdir string) error {
+
+	cs := C.CString(filepath.Dir(rootdir))
+	defer C.free(unsafe.Pointer(cs))
+	buf := C.getstatfs(cs)
+	defer C.free(unsafe.Pointer(buf))
+
+	// on Solaris buf.f_basetype contains ['z', 'f', 's', 0 ... ]
+	if (buf.f_basetype[0] != 122) || (buf.f_basetype[1] != 102) || (buf.f_basetype[2] != 115) ||
+		(buf.f_basetype[3] != 0) {
+		logrus.Debugf("[zfs] no zfs dataset found for rootdir '%s'", rootdir)
+		return errors.Wrapf(graphdriver.ErrPrerequisites, "no zfs dataset found for rootdir '%s'", rootdir)
+	}
+
+	return nil
+}
+
+/* rootfs is introduced to comply with the OCI spec
+which states that root filesystem must be mounted at <CID>/rootfs/ instead of <CID>/
+*/
+func getMountpoint(id string) string {
+	maxlen := 12
+
+	// we need to preserve filesystem suffix
+	suffix := strings.SplitN(id, "-", 2)
+
+	if len(suffix) > 1 {
+		return filepath.Join(id[:maxlen]+"-"+suffix[1], "rootfs", "root")
+	}
+
+	return filepath.Join(id[:maxlen], "rootfs", "root")
+}

vendor/github.com/containers/storage/drivers/zfs/zfs_unsupported.go

@@ -0,0 +1,11 @@
+// +build !linux,!freebsd,!solaris
+
+package zfs
+
+func checkRootdirFs(rootdir string) error {
+	return nil
+}
+
+func getMountpoint(id string) string {
+	return id
+}

vendor/github.com/containers/storage/errors.go

@@ -0,0 +1,56 @@
+package storage
+
+import (
+	"errors"
+)
+
+var (
+	// ErrContainerUnknown indicates that there was no container with the specified name or ID.
+	ErrContainerUnknown = errors.New("container not known")
+	// ErrImageUnknown indicates that there was no image with the specified name or ID.
+	ErrImageUnknown = errors.New("image not known")
+	// ErrParentUnknown indicates that we didn't record the ID of the parent of the specified layer.
+	ErrParentUnknown = errors.New("parent of layer not known")
+	// ErrLayerUnknown indicates that there was no layer with the specified name or ID.
+	ErrLayerUnknown = errors.New("layer not known")
+	// ErrLoadError indicates that there was an initialization error.
+	ErrLoadError = errors.New("error loading storage metadata")
+	// ErrDuplicateID indicates that an ID which is to be assigned to a new item is already being used.
+	ErrDuplicateID = errors.New("that ID is already in use")
+	// ErrDuplicateName indicates that a name which is to be assigned to a new item is already being used.
+	ErrDuplicateName = errors.New("that name is already in use")
+	// ErrParentIsContainer is returned when a caller attempts to create a layer as a child of a container's layer.
+	ErrParentIsContainer = errors.New("would-be parent layer is a container")
+	// ErrNotAContainer is returned when the caller attempts to delete a container that isn't a container.
+	ErrNotAContainer = errors.New("identifier is not a container")
+	// ErrNotAnImage is returned when the caller attempts to delete an image that isn't an image.
+	ErrNotAnImage = errors.New("identifier is not an image")
+	// ErrNotALayer is returned when the caller attempts to delete a layer that isn't a layer.
+	ErrNotALayer = errors.New("identifier is not a layer")
+	// ErrNotAnID is returned when the caller attempts to read or write metadata from an item that doesn't exist.
+	ErrNotAnID = errors.New("identifier is not a layer, image, or container")
+	// ErrLayerHasChildren is returned when the caller attempts to delete a layer that has children.
+	ErrLayerHasChildren = errors.New("layer has children")
+	// ErrLayerUsedByImage is returned when the caller attempts to delete a layer that is an image's top layer.
+	ErrLayerUsedByImage = errors.New("layer is in use by an image")
+	// ErrLayerUsedByContainer is returned when the caller attempts to delete a layer that is a container's layer.
+	ErrLayerUsedByContainer = errors.New("layer is in use by a container")
+	// ErrImageUsedByContainer is returned when the caller attempts to delete an image that is a container's image.
+	ErrImageUsedByContainer = errors.New("image is in use by a container")
+	// ErrIncompleteOptions is returned when the caller attempts to initialize a Store without providing required information.
+	ErrIncompleteOptions = errors.New("missing necessary StoreOptions")
+	// ErrSizeUnknown is returned when the caller asks for the size of a big data item, but the Store couldn't determine the answer.
+	ErrSizeUnknown = errors.New("size is not known")
+	// ErrStoreIsReadOnly is returned when the caller makes a call to a read-only store that would require modifying its contents.
+	ErrStoreIsReadOnly = errors.New("called a write method on a read-only store")
+	// ErrLockReadOnly indicates that the caller only took a read-only lock, and is not allowed to write.
+	ErrLockReadOnly = errors.New("lock is not a read-write lock")
+	// ErrDuplicateImageNames indicates that the read-only store uses the same name for multiple images.
+	ErrDuplicateImageNames = errors.New("read-only image store assigns the same name to multiple images")
+	// ErrDuplicateLayerNames indicates that the read-only store uses the same name for multiple layers.
+	ErrDuplicateLayerNames = errors.New("read-only layer store assigns the same name to multiple layers")
+	// ErrInvalidBigDataName indicates that the name for a big data item is not acceptable; it may be empty.
+	ErrInvalidBigDataName = errors.New("not a valid name for a big data item")
+	// ErrDigestUnknown indicates that we were unable to compute the digest of a specified item.
+	ErrDigestUnknown = errors.New("could not compute digest of item")
+)

vendor/github.com/containers/storage/hack/generate-authors.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+set -e
+
+cd "$(dirname "$(readlink -f "$BASH_SOURCE")")/.."
+
+# see also ".mailmap" for how email addresses and names are deduplicated
+
+{
+	cat <<-'EOH'
+	# This file lists all individuals having contributed content to the repository.
+	# For how it is generated, see `hack/generate-authors.sh`.
+	EOH
+	echo
+	git log --format='%aN <%aE>' | LC_ALL=C.UTF-8 sort -uf
+} > AUTHORS

vendor/github.com/containers/storage/images.go

@@ -0,0 +1,673 @@
+package storage
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/containers/storage/pkg/ioutils"
+	"github.com/containers/storage/pkg/stringid"
+	"github.com/containers/storage/pkg/truncindex"
+	digest "github.com/opencontainers/go-digest"
+	"github.com/pkg/errors"
+)
+
+const (
+	// ImageDigestBigDataKey is the name of the big data item whose
+	// contents we consider useful for computing a "digest" of the
+	// image, by which we can locate the image later.
+	ImageDigestBigDataKey = "manifest"
+)
+
+// An Image is a reference to a layer and an associated metadata string.
+type Image struct {
+	// ID is either one which was specified at create-time, or a random
+	// value which was generated by the library.
+	ID string `json:"id"`
+
+	// Digest is a digest value that we can use to locate the image.
+	Digest digest.Digest `json:"digest,omitempty"`
+
+	// Names is an optional set of user-defined convenience values.  The
+	// image can be referred to by its ID or any of its names.  Names are
+	// unique among images.
+	Names []string `json:"names,omitempty"`
+
+	// TopLayer is the ID of the topmost layer of the image itself, if the
+	// image contains one or more layers.  Multiple images can refer to the
+	// same top layer.
+	TopLayer string `json:"layer,omitempty"`
+
+	// Metadata is data we keep for the convenience of the caller.  It is not
+	// expected to be large, since it is kept in memory.
+	Metadata string `json:"metadata,omitempty"`
+
+	// BigDataNames is a list of names of data items that we keep for the
+	// convenience of the caller.  They can be large, and are only in
+	// memory when being read from or written to disk.
+	BigDataNames []string `json:"big-data-names,omitempty"`
+
+	// BigDataSizes maps the names in BigDataNames to the sizes of the data
+	// that has been stored, if they're known.
+	BigDataSizes map[string]int64 `json:"big-data-sizes,omitempty"`
+
+	// BigDataDigests maps the names in BigDataNames to the digests of the
+	// data that has been stored, if they're known.
+	BigDataDigests map[string]digest.Digest `json:"big-data-digests,omitempty"`
+
+	// Created is the datestamp for when this image was created.  Older
+	// versions of the library did not track this information, so callers
+	// will likely want to use the IsZero() method to verify that a value
+	// is set before using it.
+	Created time.Time `json:"created,omitempty"`
+
+	Flags map[string]interface{} `json:"flags,omitempty"`
+}
+
+// ROImageStore provides bookkeeping for information about Images.
+type ROImageStore interface {
+	ROFileBasedStore
+	ROMetadataStore
+	ROBigDataStore
+
+	// Exists checks if there is an image with the given ID or name.
+	Exists(id string) bool
+
+	// Get retrieves information about an image given an ID or name.
+	Get(id string) (*Image, error)
+
+	// Lookup attempts to translate a name to an ID.  Most methods do this
+	// implicitly.
+	Lookup(name string) (string, error)
+
+	// Images returns a slice enumerating the known images.
+	Images() ([]Image, error)
+
+	// Images returns a slice enumerating the images which have a big data
+	// item with the name ImageDigestBigDataKey and the specified digest.
+	ByDigest(d digest.Digest) ([]*Image, error)
+}
+
+// ImageStore provides bookkeeping for information about Images.
+type ImageStore interface {
+	ROImageStore
+	RWFileBasedStore
+	RWMetadataStore
+	RWBigDataStore
+	FlaggableStore
+
+	// Create creates an image that has a specified ID (or a random one) and
+	// optional names, using the specified layer as its topmost (hopefully
+	// read-only) layer.  That layer can be referenced by multiple images.
+	Create(id string, names []string, layer, metadata string, created time.Time, searchableDigest digest.Digest) (*Image, error)
+
+	// SetNames replaces the list of names associated with an image with the
+	// supplied values.
+	SetNames(id string, names []string) error
+
+	// Delete removes the record of the image.
+	Delete(id string) error
+
+	// Wipe removes records of all images.
+	Wipe() error
+}
+
+type imageStore struct {
+	lockfile Locker
+	dir      string
+	images   []*Image
+	idindex  *truncindex.TruncIndex
+	byid     map[string]*Image
+	byname   map[string]*Image
+	bydigest map[digest.Digest][]*Image
+}
+
+func (r *imageStore) Images() ([]Image, error) {
+	images := make([]Image, len(r.images))
+	for i := range r.images {
+		images[i] = *(r.images[i])
+	}
+	return images, nil
+}
+
+func (r *imageStore) imagespath() string {
+	return filepath.Join(r.dir, "images.json")
+}
+
+func (r *imageStore) datadir(id string) string {
+	return filepath.Join(r.dir, id)
+}
+
+func (r *imageStore) datapath(id, key string) string {
+	return filepath.Join(r.datadir(id), makeBigDataBaseName(key))
+}
+
+func (r *imageStore) Load() error {
+	shouldSave := false
+	rpath := r.imagespath()
+	data, err := ioutil.ReadFile(rpath)
+	if err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	images := []*Image{}
+	idlist := []string{}
+	ids := make(map[string]*Image)
+	names := make(map[string]*Image)
+	digests := make(map[digest.Digest][]*Image)
+	if err = json.Unmarshal(data, &images); len(data) == 0 || err == nil {
+		idlist = make([]string, 0, len(images))
+		for n, image := range images {
+			ids[image.ID] = images[n]
+			idlist = append(idlist, image.ID)
+			for _, name := range image.Names {
+				if conflict, ok := names[name]; ok {
+					r.removeName(conflict, name)
+					shouldSave = true
+				}
+				names[name] = images[n]
+			}
+			// Implicit digest
+			if digest, ok := image.BigDataDigests[ImageDigestBigDataKey]; ok {
+				digests[digest] = append(digests[digest], images[n])
+			}
+			// Explicit digest
+			if image.Digest == "" {
+				image.Digest = image.BigDataDigests[ImageDigestBigDataKey]
+			} else if image.Digest != image.BigDataDigests[ImageDigestBigDataKey] {
+				digests[image.Digest] = append(digests[image.Digest], images[n])
+			}
+		}
+	}
+	if shouldSave && !r.IsReadWrite() {
+		return ErrDuplicateImageNames
+	}
+	r.images = images
+	r.idindex = truncindex.NewTruncIndex(idlist)
+	r.byid = ids
+	r.byname = names
+	r.bydigest = digests
+	if shouldSave {
+		return r.Save()
+	}
+	return nil
+}
+
+func (r *imageStore) Save() error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to modify the image store at %q", r.imagespath())
+	}
+	rpath := r.imagespath()
+	if err := os.MkdirAll(filepath.Dir(rpath), 0700); err != nil {
+		return err
+	}
+	jdata, err := json.Marshal(&r.images)
+	if err != nil {
+		return err
+	}
+	defer r.Touch()
+	return ioutils.AtomicWriteFile(rpath, jdata, 0600)
+}
+
+func newImageStore(dir string) (ImageStore, error) {
+	if err := os.MkdirAll(dir, 0700); err != nil {
+		return nil, err
+	}
+	lockfile, err := GetLockfile(filepath.Join(dir, "images.lock"))
+	if err != nil {
+		return nil, err
+	}
+	lockfile.Lock()
+	defer lockfile.Unlock()
+	istore := imageStore{
+		lockfile: lockfile,
+		dir:      dir,
+		images:   []*Image{},
+		byid:     make(map[string]*Image),
+		byname:   make(map[string]*Image),
+		bydigest: make(map[digest.Digest][]*Image),
+	}
+	if err := istore.Load(); err != nil {
+		return nil, err
+	}
+	return &istore, nil
+}
+
+func newROImageStore(dir string) (ROImageStore, error) {
+	lockfile, err := GetROLockfile(filepath.Join(dir, "images.lock"))
+	if err != nil {
+		return nil, err
+	}
+	lockfile.Lock()
+	defer lockfile.Unlock()
+	istore := imageStore{
+		lockfile: lockfile,
+		dir:      dir,
+		images:   []*Image{},
+		byid:     make(map[string]*Image),
+		byname:   make(map[string]*Image),
+		bydigest: make(map[digest.Digest][]*Image),
+	}
+	if err := istore.Load(); err != nil {
+		return nil, err
+	}
+	return &istore, nil
+}
+
+func (r *imageStore) lookup(id string) (*Image, bool) {
+	if image, ok := r.byid[id]; ok {
+		return image, ok
+	} else if image, ok := r.byname[id]; ok {
+		return image, ok
+	} else if longid, err := r.idindex.Get(id); err == nil {
+		image, ok := r.byid[longid]
+		return image, ok
+	}
+	return nil, false
+}
+
+func (r *imageStore) ClearFlag(id string, flag string) error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to clear flags on images at %q", r.imagespath())
+	}
+	image, ok := r.lookup(id)
+	if !ok {
+		return ErrImageUnknown
+	}
+	delete(image.Flags, flag)
+	return r.Save()
+}
+
+func (r *imageStore) SetFlag(id string, flag string, value interface{}) error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to set flags on images at %q", r.imagespath())
+	}
+	image, ok := r.lookup(id)
+	if !ok {
+		return ErrImageUnknown
+	}
+	if image.Flags == nil {
+		image.Flags = make(map[string]interface{})
+	}
+	image.Flags[flag] = value
+	return r.Save()
+}
+
+func (r *imageStore) Create(id string, names []string, layer, metadata string, created time.Time, searchableDigest digest.Digest) (image *Image, err error) {
+	if !r.IsReadWrite() {
+		return nil, errors.Wrapf(ErrStoreIsReadOnly, "not allowed to create new images at %q", r.imagespath())
+	}
+	if id == "" {
+		id = stringid.GenerateRandomID()
+		_, idInUse := r.byid[id]
+		for idInUse {
+			id = stringid.GenerateRandomID()
+			_, idInUse = r.byid[id]
+		}
+	}
+	if _, idInUse := r.byid[id]; idInUse {
+		return nil, ErrDuplicateID
+	}
+	names = dedupeNames(names)
+	for _, name := range names {
+		if _, nameInUse := r.byname[name]; nameInUse {
+			return nil, ErrDuplicateName
+		}
+	}
+	if created.IsZero() {
+		created = time.Now().UTC()
+	}
+	if err == nil {
+		image = &Image{
+			ID:             id,
+			Digest:         searchableDigest,
+			Names:          names,
+			TopLayer:       layer,
+			Metadata:       metadata,
+			BigDataNames:   []string{},
+			BigDataSizes:   make(map[string]int64),
+			BigDataDigests: make(map[string]digest.Digest),
+			Created:        created,
+			Flags:          make(map[string]interface{}),
+		}
+		r.images = append(r.images, image)
+		r.idindex.Add(id)
+		r.byid[id] = image
+		if searchableDigest != "" {
+			list := r.bydigest[searchableDigest]
+			r.bydigest[searchableDigest] = append(list, image)
+		}
+		for _, name := range names {
+			r.byname[name] = image
+		}
+		err = r.Save()
+	}
+	return image, err
+}
+
+func (r *imageStore) Metadata(id string) (string, error) {
+	if image, ok := r.lookup(id); ok {
+		return image.Metadata, nil
+	}
+	return "", ErrImageUnknown
+}
+
+func (r *imageStore) SetMetadata(id, metadata string) error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to modify image metadata at %q", r.imagespath())
+	}
+	if image, ok := r.lookup(id); ok {
+		image.Metadata = metadata
+		return r.Save()
+	}
+	return ErrImageUnknown
+}
+
+func (r *imageStore) removeName(image *Image, name string) {
+	image.Names = stringSliceWithoutValue(image.Names, name)
+}
+
+func (r *imageStore) SetNames(id string, names []string) error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to change image name assignments at %q", r.imagespath())
+	}
+	names = dedupeNames(names)
+	if image, ok := r.lookup(id); ok {
+		for _, name := range image.Names {
+			delete(r.byname, name)
+		}
+		for _, name := range names {
+			if otherImage, ok := r.byname[name]; ok {
+				r.removeName(otherImage, name)
+			}
+			r.byname[name] = image
+		}
+		image.Names = names
+		return r.Save()
+	}
+	return ErrImageUnknown
+}
+
+func (r *imageStore) Delete(id string) error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to delete images at %q", r.imagespath())
+	}
+	image, ok := r.lookup(id)
+	if !ok {
+		return ErrImageUnknown
+	}
+	id = image.ID
+	toDeleteIndex := -1
+	for i, candidate := range r.images {
+		if candidate.ID == id {
+			toDeleteIndex = i
+		}
+	}
+	delete(r.byid, id)
+	r.idindex.Delete(id)
+	for _, name := range image.Names {
+		delete(r.byname, name)
+	}
+	if toDeleteIndex != -1 {
+		// delete the image at toDeleteIndex
+		if toDeleteIndex == len(r.images)-1 {
+			r.images = r.images[:len(r.images)-1]
+		} else {
+			r.images = append(r.images[:toDeleteIndex], r.images[toDeleteIndex+1:]...)
+		}
+	}
+	if digest, ok := image.BigDataDigests[ImageDigestBigDataKey]; ok {
+		// remove the image from the digest-based index
+		if list, ok := r.bydigest[digest]; ok {
+			prunedList := imageSliceWithoutValue(list, image)
+			if len(prunedList) == 0 {
+				delete(r.bydigest, digest)
+			} else {
+				r.bydigest[digest] = prunedList
+			}
+		}
+	}
+	if image.Digest != "" {
+		// remove the image's hard-coded digest from the digest-based index
+		if list, ok := r.bydigest[image.Digest]; ok {
+			prunedList := imageSliceWithoutValue(list, image)
+			if len(prunedList) == 0 {
+				delete(r.bydigest, image.Digest)
+			} else {
+				r.bydigest[image.Digest] = prunedList
+			}
+		}
+	}
+	if err := r.Save(); err != nil {
+		return err
+	}
+	if err := os.RemoveAll(r.datadir(id)); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (r *imageStore) Get(id string) (*Image, error) {
+	if image, ok := r.lookup(id); ok {
+		return image, nil
+	}
+	return nil, ErrImageUnknown
+}
+
+func (r *imageStore) Lookup(name string) (id string, err error) {
+	if image, ok := r.lookup(name); ok {
+		return image.ID, nil
+	}
+	return "", ErrImageUnknown
+}
+
+func (r *imageStore) Exists(id string) bool {
+	_, ok := r.lookup(id)
+	return ok
+}
+
+func (r *imageStore) ByDigest(d digest.Digest) ([]*Image, error) {
+	if images, ok := r.bydigest[d]; ok {
+		return images, nil
+	}
+	return nil, ErrImageUnknown
+}
+
+func (r *imageStore) BigData(id, key string) ([]byte, error) {
+	if key == "" {
+		return nil, errors.Wrapf(ErrInvalidBigDataName, "can't retrieve image big data value for empty name")
+	}
+	image, ok := r.lookup(id)
+	if !ok {
+		return nil, ErrImageUnknown
+	}
+	return ioutil.ReadFile(r.datapath(image.ID, key))
+}
+
+func (r *imageStore) BigDataSize(id, key string) (int64, error) {
+	if key == "" {
+		return -1, errors.Wrapf(ErrInvalidBigDataName, "can't retrieve size of image big data with empty name")
+	}
+	image, ok := r.lookup(id)
+	if !ok {
+		return -1, ErrImageUnknown
+	}
+	if image.BigDataSizes == nil {
+		image.BigDataSizes = make(map[string]int64)
+	}
+	if size, ok := image.BigDataSizes[key]; ok {
+		return size, nil
+	}
+	if data, err := r.BigData(id, key); err == nil && data != nil {
+		if r.SetBigData(id, key, data) == nil {
+			image, ok := r.lookup(id)
+			if !ok {
+				return -1, ErrImageUnknown
+			}
+			if size, ok := image.BigDataSizes[key]; ok {
+				return size, nil
+			}
+		}
+	}
+	return -1, ErrSizeUnknown
+}
+
+func (r *imageStore) BigDataDigest(id, key string) (digest.Digest, error) {
+	if key == "" {
+		return "", errors.Wrapf(ErrInvalidBigDataName, "can't retrieve digest of image big data value with empty name")
+	}
+	image, ok := r.lookup(id)
+	if !ok {
+		return "", ErrImageUnknown
+	}
+	if image.BigDataDigests == nil {
+		image.BigDataDigests = make(map[string]digest.Digest)
+	}
+	if d, ok := image.BigDataDigests[key]; ok {
+		return d, nil
+	}
+	if data, err := r.BigData(id, key); err == nil && data != nil {
+		if r.SetBigData(id, key, data) == nil {
+			image, ok := r.lookup(id)
+			if !ok {
+				return "", ErrImageUnknown
+			}
+			if d, ok := image.BigDataDigests[key]; ok {
+				return d, nil
+			}
+		}
+	}
+	return "", ErrDigestUnknown
+}
+
+func (r *imageStore) BigDataNames(id string) ([]string, error) {
+	image, ok := r.lookup(id)
+	if !ok {
+		return nil, ErrImageUnknown
+	}
+	return image.BigDataNames, nil
+}
+
+func imageSliceWithoutValue(slice []*Image, value *Image) []*Image {
+	modified := make([]*Image, 0, len(slice))
+	for _, v := range slice {
+		if v == value {
+			continue
+		}
+		modified = append(modified, v)
+	}
+	return modified
+}
+
+func (r *imageStore) SetBigData(id, key string, data []byte) error {
+	if key == "" {
+		return errors.Wrapf(ErrInvalidBigDataName, "can't set empty name for image big data item")
+	}
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to save data items associated with images at %q", r.imagespath())
+	}
+	image, ok := r.lookup(id)
+	if !ok {
+		return ErrImageUnknown
+	}
+	if err := os.MkdirAll(r.datadir(image.ID), 0700); err != nil {
+		return err
+	}
+	err := ioutils.AtomicWriteFile(r.datapath(image.ID, key), data, 0600)
+	if err == nil {
+		save := false
+		if image.BigDataSizes == nil {
+			image.BigDataSizes = make(map[string]int64)
+		}
+		oldSize, sizeOk := image.BigDataSizes[key]
+		image.BigDataSizes[key] = int64(len(data))
+		if image.BigDataDigests == nil {
+			image.BigDataDigests = make(map[string]digest.Digest)
+		}
+		oldDigest, digestOk := image.BigDataDigests[key]
+		newDigest := digest.Canonical.FromBytes(data)
+		image.BigDataDigests[key] = newDigest
+		if !sizeOk || oldSize != image.BigDataSizes[key] || !digestOk || oldDigest != newDigest {
+			save = true
+		}
+		addName := true
+		for _, name := range image.BigDataNames {
+			if name == key {
+				addName = false
+				break
+			}
+		}
+		if addName {
+			image.BigDataNames = append(image.BigDataNames, key)
+			save = true
+		}
+		if key == ImageDigestBigDataKey {
+			if oldDigest != "" && oldDigest != newDigest && oldDigest != image.Digest {
+				// remove the image from the list of images in the digest-based
+				// index which corresponds to the old digest for this item, unless
+				// it's also the hard-coded digest
+				if list, ok := r.bydigest[oldDigest]; ok {
+					prunedList := imageSliceWithoutValue(list, image)
+					if len(prunedList) == 0 {
+						delete(r.bydigest, oldDigest)
+					} else {
+						r.bydigest[oldDigest] = prunedList
+					}
+				}
+			}
+			// add the image to the list of images in the digest-based index which
+			// corresponds to the new digest for this item, unless it's already there
+			list := r.bydigest[newDigest]
+			if len(list) == len(imageSliceWithoutValue(list, image)) {
+				// the list isn't shortened by trying to prune this image from it,
+				// so it's not in there yet
+				r.bydigest[newDigest] = append(list, image)
+			}
+		}
+		if save {
+			err = r.Save()
+		}
+	}
+	return err
+}
+
+func (r *imageStore) Wipe() error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to delete images at %q", r.imagespath())
+	}
+	ids := make([]string, 0, len(r.byid))
+	for id := range r.byid {
+		ids = append(ids, id)
+	}
+	for _, id := range ids {
+		if err := r.Delete(id); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (r *imageStore) Lock() {
+	r.lockfile.Lock()
+}
+
+func (r *imageStore) Unlock() {
+	r.lockfile.Unlock()
+}
+
+func (r *imageStore) Touch() error {
+	return r.lockfile.Touch()
+}
+
+func (r *imageStore) Modified() (bool, error) {
+	return r.lockfile.Modified()
+}
+
+func (r *imageStore) IsReadWrite() bool {
+	return r.lockfile.IsReadWrite()
+}
+
+func (r *imageStore) TouchedSince(when time.Time) bool {
+	return r.lockfile.TouchedSince(when)
+}

vendor/github.com/containers/storage/lockfile.go

@@ -0,0 +1,82 @@
+package storage
+
+import (
+	"fmt"
+	"path/filepath"
+	"sync"
+	"time"
+
+	"github.com/pkg/errors"
+)
+
+// A Locker represents a file lock where the file is used to cache an
+// identifier of the last party that made changes to whatever's being protected
+// by the lock.
+type Locker interface {
+	sync.Locker
+
+	// Touch records, for others sharing the lock, that the caller was the
+	// last writer.  It should only be called with the lock held.
+	Touch() error
+
+	// Modified() checks if the most recent writer was a party other than the
+	// last recorded writer.  It should only be called with the lock held.
+	Modified() (bool, error)
+
+	// TouchedSince() checks if the most recent writer modified the file (likely using Touch()) after the specified time.
+	TouchedSince(when time.Time) bool
+
+	// IsReadWrite() checks if the lock file is read-write
+	IsReadWrite() bool
+}
+
+var (
+	lockfiles     map[string]Locker
+	lockfilesLock sync.Mutex
+)
+
+// GetLockfile opens a read-write lock file, creating it if necessary.  The
+// Locker object it returns will be returned unlocked.
+func GetLockfile(path string) (Locker, error) {
+	lockfilesLock.Lock()
+	defer lockfilesLock.Unlock()
+	if lockfiles == nil {
+		lockfiles = make(map[string]Locker)
+	}
+	cleanPath := filepath.Clean(path)
+	if locker, ok := lockfiles[cleanPath]; ok {
+		if !locker.IsReadWrite() {
+			return nil, errors.Wrapf(ErrLockReadOnly, "lock %q is a read-only lock", cleanPath)
+		}
+		return locker, nil
+	}
+	locker, err := getLockFile(path, false) // platform dependent locker
+	if err != nil {
+		return nil, err
+	}
+	lockfiles[filepath.Clean(path)] = locker
+	return locker, nil
+}
+
+// GetROLockfile opens a read-only lock file.  The Locker object it returns
+// will be returned unlocked.
+func GetROLockfile(path string) (Locker, error) {
+	lockfilesLock.Lock()
+	defer lockfilesLock.Unlock()
+	if lockfiles == nil {
+		lockfiles = make(map[string]Locker)
+	}
+	cleanPath := filepath.Clean(path)
+	if locker, ok := lockfiles[cleanPath]; ok {
+		if locker.IsReadWrite() {
+			return nil, fmt.Errorf("lock %q is a read-write lock", cleanPath)
+		}
+		return locker, nil
+	}
+	locker, err := getLockFile(path, true) // platform dependent locker
+	if err != nil {
+		return nil, err
+	}
+	lockfiles[filepath.Clean(path)] = locker
+	return locker, nil
+}

vendor/github.com/containers/storage/lockfile_darwin.go

@@ -0,0 +1,19 @@
+// +build darwin freebsd
+
+package storage
+
+import (
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+func (l *lockfile) TouchedSince(when time.Time) bool {
+	st := unix.Stat_t{}
+	err := unix.Fstat(int(l.fd), &st)
+	if err != nil {
+		return true
+	}
+	touched := time.Unix(st.Mtimespec.Unix())
+	return when.Before(touched)
+}

vendor/github.com/containers/storage/lockfile_linux.go

@@ -0,0 +1,20 @@
+// +build linux solaris
+
+package storage
+
+import (
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+// TouchedSince indicates if the lock file has been touched since the specified time
+func (l *lockfile) TouchedSince(when time.Time) bool {
+	st := unix.Stat_t{}
+	err := unix.Fstat(int(l.fd), &st)
+	if err != nil {
+		return true
+	}
+	touched := time.Unix(st.Mtim.Unix())
+	return when.Before(touched)
+}

vendor/github.com/containers/storage/lockfile_unix.go

@@ -0,0 +1,115 @@
+// +build linux solaris darwin freebsd
+
+package storage
+
+import (
+	"os"
+	"sync"
+	"time"
+
+	"github.com/containers/storage/pkg/stringid"
+	"github.com/pkg/errors"
+	"golang.org/x/sys/unix"
+)
+
+func getLockFile(path string, ro bool) (Locker, error) {
+	var fd int
+	var err error
+	if ro {
+		fd, err = unix.Open(path, os.O_RDONLY, 0)
+	} else {
+		fd, err = unix.Open(path, os.O_RDWR|os.O_CREATE, unix.S_IRUSR|unix.S_IWUSR)
+	}
+	if err != nil {
+		return nil, errors.Wrapf(err, "error opening %q", path)
+	}
+	unix.CloseOnExec(fd)
+	if ro {
+		return &lockfile{file: path, fd: uintptr(fd), lw: stringid.GenerateRandomID(), locktype: unix.F_RDLCK}, nil
+	}
+	return &lockfile{file: path, fd: uintptr(fd), lw: stringid.GenerateRandomID(), locktype: unix.F_WRLCK}, nil
+}
+
+type lockfile struct {
+	mu       sync.Mutex
+	file     string
+	fd       uintptr
+	lw       string
+	locktype int16
+}
+
+// Lock locks the lock file
+func (l *lockfile) Lock() {
+	lk := unix.Flock_t{
+		Type:   l.locktype,
+		Whence: int16(os.SEEK_SET),
+		Start:  0,
+		Len:    0,
+		Pid:    int32(os.Getpid()),
+	}
+	l.mu.Lock()
+	for unix.FcntlFlock(l.fd, unix.F_SETLKW, &lk) != nil {
+		time.Sleep(10 * time.Millisecond)
+	}
+}
+
+// Unlock unlocks the lock file
+func (l *lockfile) Unlock() {
+	lk := unix.Flock_t{
+		Type:   unix.F_UNLCK,
+		Whence: int16(os.SEEK_SET),
+		Start:  0,
+		Len:    0,
+		Pid:    int32(os.Getpid()),
+	}
+	for unix.FcntlFlock(l.fd, unix.F_SETLKW, &lk) != nil {
+		time.Sleep(10 * time.Millisecond)
+	}
+	l.mu.Unlock()
+}
+
+// Touch updates the lock file with the UID of the user
+func (l *lockfile) Touch() error {
+	l.lw = stringid.GenerateRandomID()
+	id := []byte(l.lw)
+	_, err := unix.Seek(int(l.fd), 0, os.SEEK_SET)
+	if err != nil {
+		return err
+	}
+	n, err := unix.Write(int(l.fd), id)
+	if err != nil {
+		return err
+	}
+	if n != len(id) {
+		return unix.ENOSPC
+	}
+	err = unix.Fsync(int(l.fd))
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// Modified indicates if the lock file has been updated since the last time it was loaded
+func (l *lockfile) Modified() (bool, error) {
+	id := []byte(l.lw)
+	_, err := unix.Seek(int(l.fd), 0, os.SEEK_SET)
+	if err != nil {
+		return true, err
+	}
+	n, err := unix.Read(int(l.fd), id)
+	if err != nil {
+		return true, err
+	}
+	if n != len(id) {
+		return true, unix.ENOSPC
+	}
+	lw := l.lw
+	l.lw = string(id)
+	return l.lw != lw, nil
+}
+
+// IsRWLock indicates if the lock file is a read-write lock
+func (l *lockfile) IsReadWrite() bool {
+	return (l.locktype == unix.F_WRLCK)
+}

vendor/github.com/containers/storage/lockfile_windows.go

@@ -0,0 +1,40 @@
+// +build windows
+
+package storage
+
+import (
+	"os"
+	"sync"
+	"time"
+)
+
+func getLockFile(path string, ro bool) (Locker, error) {
+	return &lockfile{}, nil
+}
+
+type lockfile struct {
+	mu   sync.Mutex
+	file string
+}
+
+func (l *lockfile) Lock() {
+}
+func (l *lockfile) Unlock() {
+}
+func (l *lockfile) Modified() (bool, error) {
+	return false, nil
+}
+func (l *lockfile) Touch() error {
+	return nil
+}
+func (l *lockfile) IsReadWrite() bool {
+	return false
+}
+
+func (l *lockfile) TouchedSince(when time.Time) bool {
+	stat, err := os.Stat(l.file)
+	if err != nil {
+		return true
+	}
+	return when.Before(stat.ModTime())
+}

vendor/github.com/containers/storage/pkg/archive/archive_linux.go

@@ -0,0 +1,92 @@
+package archive
+
+import (
+	"archive/tar"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/containers/storage/pkg/system"
+	"golang.org/x/sys/unix"
+)
+
+func getWhiteoutConverter(format WhiteoutFormat) tarWhiteoutConverter {
+	if format == OverlayWhiteoutFormat {
+		return overlayWhiteoutConverter{}
+	}
+	return nil
+}
+
+type overlayWhiteoutConverter struct{}
+
+func (overlayWhiteoutConverter) ConvertWrite(hdr *tar.Header, path string, fi os.FileInfo) (wo *tar.Header, err error) {
+	// convert whiteouts to AUFS format
+	if fi.Mode()&os.ModeCharDevice != 0 && hdr.Devmajor == 0 && hdr.Devminor == 0 {
+		// we just rename the file and make it normal
+		dir, filename := filepath.Split(hdr.Name)
+		hdr.Name = filepath.Join(dir, WhiteoutPrefix+filename)
+		hdr.Mode = 0600
+		hdr.Typeflag = tar.TypeReg
+		hdr.Size = 0
+	}
+
+	if fi.Mode()&os.ModeDir != 0 {
+		// convert opaque dirs to AUFS format by writing an empty file with the prefix
+		opaque, err := system.Lgetxattr(path, "trusted.overlay.opaque")
+		if err != nil {
+			return nil, err
+		}
+		if len(opaque) == 1 && opaque[0] == 'y' {
+			if hdr.Xattrs != nil {
+				delete(hdr.Xattrs, "trusted.overlay.opaque")
+			}
+
+			// create a header for the whiteout file
+			// it should inherit some properties from the parent, but be a regular file
+			wo = &tar.Header{
+				Typeflag:   tar.TypeReg,
+				Mode:       hdr.Mode & int64(os.ModePerm),
+				Name:       filepath.Join(hdr.Name, WhiteoutOpaqueDir),
+				Size:       0,
+				Uid:        hdr.Uid,
+				Uname:      hdr.Uname,
+				Gid:        hdr.Gid,
+				Gname:      hdr.Gname,
+				AccessTime: hdr.AccessTime,
+				ChangeTime: hdr.ChangeTime,
+			}
+		}
+	}
+
+	return
+}
+
+func (overlayWhiteoutConverter) ConvertRead(hdr *tar.Header, path string) (bool, error) {
+	base := filepath.Base(path)
+	dir := filepath.Dir(path)
+
+	// if a directory is marked as opaque by the AUFS special file, we need to translate that to overlay
+	if base == WhiteoutOpaqueDir {
+		err := unix.Setxattr(dir, "trusted.overlay.opaque", []byte{'y'}, 0)
+		// don't write the file itself
+		return false, err
+	}
+
+	// if a file was deleted and we are using overlay, we need to create a character device
+	if strings.HasPrefix(base, WhiteoutPrefix) {
+		originalBase := base[len(WhiteoutPrefix):]
+		originalPath := filepath.Join(dir, originalBase)
+
+		if err := unix.Mknod(originalPath, unix.S_IFCHR, 0); err != nil {
+			return false, err
+		}
+		if err := os.Chown(originalPath, hdr.Uid, hdr.Gid); err != nil {
+			return false, err
+		}
+
+		// don't write the file itself
+		return false, nil
+	}
+
+	return true, nil
+}

vendor/github.com/containers/storage/pkg/archive/archive_other.go

@@ -0,0 +1,7 @@
+// +build !linux
+
+package archive
+
+func getWhiteoutConverter(format WhiteoutFormat) tarWhiteoutConverter {
+	return nil
+}

vendor/github.com/containers/storage/pkg/archive/archive_unix.go

@@ -0,0 +1,122 @@
+// +build !windows
+
+package archive
+
+import (
+	"archive/tar"
+	"errors"
+	"os"
+	"path/filepath"
+	"syscall"
+
+	"github.com/containers/storage/pkg/idtools"
+	"github.com/containers/storage/pkg/system"
+	rsystem "github.com/opencontainers/runc/libcontainer/system"
+	"golang.org/x/sys/unix"
+)
+
+// fixVolumePathPrefix does platform specific processing to ensure that if
+// the path being passed in is not in a volume path format, convert it to one.
+func fixVolumePathPrefix(srcPath string) string {
+	return srcPath
+}
+
+// getWalkRoot calculates the root path when performing a TarWithOptions.
+// We use a separate function as this is platform specific. On Linux, we
+// can't use filepath.Join(srcPath,include) because this will clean away
+// a trailing "." or "/" which may be important.
+func getWalkRoot(srcPath string, include string) string {
+	return srcPath + string(filepath.Separator) + include
+}
+
+// CanonicalTarNameForPath returns platform-specific filepath
+// to canonical posix-style path for tar archival. p is relative
+// path.
+func CanonicalTarNameForPath(p string) (string, error) {
+	return p, nil // already unix-style
+}
+
+// chmodTarEntry is used to adjust the file permissions used in tar header based
+// on the platform the archival is done.
+
+func chmodTarEntry(perm os.FileMode) os.FileMode {
+	return perm // noop for unix as golang APIs provide perm bits correctly
+}
+
+func setHeaderForSpecialDevice(hdr *tar.Header, name string, stat interface{}) (err error) {
+	s, ok := stat.(*syscall.Stat_t)
+
+	if ok {
+		// Currently go does not fill in the major/minors
+		if s.Mode&unix.S_IFBLK != 0 ||
+			s.Mode&unix.S_IFCHR != 0 {
+			hdr.Devmajor = int64(major(uint64(s.Rdev))) // nolint: unconvert
+			hdr.Devminor = int64(minor(uint64(s.Rdev))) // nolint: unconvert
+		}
+	}
+
+	return
+}
+
+func getInodeFromStat(stat interface{}) (inode uint64, err error) {
+	s, ok := stat.(*syscall.Stat_t)
+
+	if ok {
+		inode = s.Ino
+	}
+
+	return
+}
+
+func getFileUIDGID(stat interface{}) (idtools.IDPair, error) {
+	s, ok := stat.(*syscall.Stat_t)
+
+	if !ok {
+		return idtools.IDPair{}, errors.New("cannot convert stat value to syscall.Stat_t")
+	}
+	return idtools.IDPair{UID: int(s.Uid), GID: int(s.Gid)}, nil
+}
+
+func major(device uint64) uint64 {
+	return (device >> 8) & 0xfff
+}
+
+func minor(device uint64) uint64 {
+	return (device & 0xff) | ((device >> 12) & 0xfff00)
+}
+
+// handleTarTypeBlockCharFifo is an OS-specific helper function used by
+// createTarFile to handle the following types of header: Block; Char; Fifo
+func handleTarTypeBlockCharFifo(hdr *tar.Header, path string) error {
+	if rsystem.RunningInUserNS() {
+		// cannot create a device if running in user namespace
+		return nil
+	}
+
+	mode := uint32(hdr.Mode & 07777)
+	switch hdr.Typeflag {
+	case tar.TypeBlock:
+		mode |= unix.S_IFBLK
+	case tar.TypeChar:
+		mode |= unix.S_IFCHR
+	case tar.TypeFifo:
+		mode |= unix.S_IFIFO
+	}
+
+	return system.Mknod(path, mode, int(system.Mkdev(hdr.Devmajor, hdr.Devminor)))
+}
+
+func handleLChmod(hdr *tar.Header, path string, hdrInfo os.FileInfo) error {
+	if hdr.Typeflag == tar.TypeLink {
+		if fi, err := os.Lstat(hdr.Linkname); err == nil && (fi.Mode()&os.ModeSymlink == 0) {
+			if err := os.Chmod(path, hdrInfo.Mode()); err != nil {
+				return err
+			}
+		}
+	} else if hdr.Typeflag != tar.TypeSymlink {
+		if err := os.Chmod(path, hdrInfo.Mode()); err != nil {
+			return err
+		}
+	}
+	return nil
+}

vendor/github.com/containers/storage/pkg/archive/archive_windows.go

@@ -0,0 +1,79 @@
+// +build windows
+
+package archive
+
+import (
+	"archive/tar"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/containers/storage/pkg/idtools"
+	"github.com/containers/storage/pkg/longpath"
+)
+
+// fixVolumePathPrefix does platform specific processing to ensure that if
+// the path being passed in is not in a volume path format, convert it to one.
+func fixVolumePathPrefix(srcPath string) string {
+	return longpath.AddPrefix(srcPath)
+}
+
+// getWalkRoot calculates the root path when performing a TarWithOptions.
+// We use a separate function as this is platform specific.
+func getWalkRoot(srcPath string, include string) string {
+	return filepath.Join(srcPath, include)
+}
+
+// CanonicalTarNameForPath returns platform-specific filepath
+// to canonical posix-style path for tar archival. p is relative
+// path.
+func CanonicalTarNameForPath(p string) (string, error) {
+	// windows: convert windows style relative path with backslashes
+	// into forward slashes. Since windows does not allow '/' or '\'
+	// in file names, it is mostly safe to replace however we must
+	// check just in case
+	if strings.Contains(p, "/") {
+		return "", fmt.Errorf("Windows path contains forward slash: %s", p)
+	}
+	return strings.Replace(p, string(os.PathSeparator), "/", -1), nil
+
+}
+
+// chmodTarEntry is used to adjust the file permissions used in tar header based
+// on the platform the archival is done.
+func chmodTarEntry(perm os.FileMode) os.FileMode {
+	//perm &= 0755 // this 0-ed out tar flags (like link, regular file, directory marker etc.)
+	permPart := perm & os.ModePerm
+	noPermPart := perm &^ os.ModePerm
+	// Add the x bit: make everything +x from windows
+	permPart |= 0111
+	permPart &= 0755
+
+	return noPermPart | permPart
+}
+
+func setHeaderForSpecialDevice(hdr *tar.Header, name string, stat interface{}) (err error) {
+	// do nothing. no notion of Rdev, Nlink in stat on Windows
+	return
+}
+
+func getInodeFromStat(stat interface{}) (inode uint64, err error) {
+	// do nothing. no notion of Inode in stat on Windows
+	return
+}
+
+// handleTarTypeBlockCharFifo is an OS-specific helper function used by
+// createTarFile to handle the following types of header: Block; Char; Fifo
+func handleTarTypeBlockCharFifo(hdr *tar.Header, path string) error {
+	return nil
+}
+
+func handleLChmod(hdr *tar.Header, path string, hdrInfo os.FileInfo) error {
+	return nil
+}
+
+func getFileUIDGID(stat interface{}) (idtools.IDPair, error) {
+	// no notion of file ownership mapping yet on Windows
+	return idtools.IDPair{0, 0}, nil
+}

vendor/github.com/containers/storage/pkg/archive/changes.go

@@ -0,0 +1,441 @@
+package archive
+
+import (
+	"archive/tar"
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/containers/storage/pkg/idtools"
+	"github.com/containers/storage/pkg/pools"
+	"github.com/containers/storage/pkg/system"
+	"github.com/sirupsen/logrus"
+)
+
+// ChangeType represents the change type.
+type ChangeType int
+
+const (
+	// ChangeModify represents the modify operation.
+	ChangeModify = iota
+	// ChangeAdd represents the add operation.
+	ChangeAdd
+	// ChangeDelete represents the delete operation.
+	ChangeDelete
+)
+
+func (c ChangeType) String() string {
+	switch c {
+	case ChangeModify:
+		return "C"
+	case ChangeAdd:
+		return "A"
+	case ChangeDelete:
+		return "D"
+	}
+	return ""
+}
+
+// Change represents a change, it wraps the change type and path.
+// It describes changes of the files in the path respect to the
+// parent layers. The change could be modify, add, delete.
+// This is used for layer diff.
+type Change struct {
+	Path string
+	Kind ChangeType
+}
+
+func (change *Change) String() string {
+	return fmt.Sprintf("%s %s", change.Kind, change.Path)
+}
+
+// for sort.Sort
+type changesByPath []Change
+
+func (c changesByPath) Less(i, j int) bool { return c[i].Path < c[j].Path }
+func (c changesByPath) Len() int           { return len(c) }
+func (c changesByPath) Swap(i, j int)      { c[j], c[i] = c[i], c[j] }
+
+// Gnu tar and the go tar writer don't have sub-second mtime
+// precision, which is problematic when we apply changes via tar
+// files, we handle this by comparing for exact times, *or* same
+// second count and either a or b having exactly 0 nanoseconds
+func sameFsTime(a, b time.Time) bool {
+	return a == b ||
+		(a.Unix() == b.Unix() &&
+			(a.Nanosecond() == 0 || b.Nanosecond() == 0))
+}
+
+func sameFsTimeSpec(a, b syscall.Timespec) bool {
+	return a.Sec == b.Sec &&
+		(a.Nsec == b.Nsec || a.Nsec == 0 || b.Nsec == 0)
+}
+
+// Changes walks the path rw and determines changes for the files in the path,
+// with respect to the parent layers
+func Changes(layers []string, rw string) ([]Change, error) {
+	return changes(layers, rw, aufsDeletedFile, aufsMetadataSkip)
+}
+
+func aufsMetadataSkip(path string) (skip bool, err error) {
+	skip, err = filepath.Match(string(os.PathSeparator)+WhiteoutMetaPrefix+"*", path)
+	if err != nil {
+		skip = true
+	}
+	return
+}
+
+func aufsDeletedFile(root, path string, fi os.FileInfo) (string, error) {
+	f := filepath.Base(path)
+
+	// If there is a whiteout, then the file was removed
+	if strings.HasPrefix(f, WhiteoutPrefix) {
+		originalFile := f[len(WhiteoutPrefix):]
+		return filepath.Join(filepath.Dir(path), originalFile), nil
+	}
+
+	return "", nil
+}
+
+type skipChange func(string) (bool, error)
+type deleteChange func(string, string, os.FileInfo) (string, error)
+
+func changes(layers []string, rw string, dc deleteChange, sc skipChange) ([]Change, error) {
+	var (
+		changes     []Change
+		changedDirs = make(map[string]struct{})
+	)
+
+	err := filepath.Walk(rw, func(path string, f os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		// Rebase path
+		path, err = filepath.Rel(rw, path)
+		if err != nil {
+			return err
+		}
+
+		// As this runs on the daemon side, file paths are OS specific.
+		path = filepath.Join(string(os.PathSeparator), path)
+
+		// Skip root
+		if path == string(os.PathSeparator) {
+			return nil
+		}
+
+		if sc != nil {
+			if skip, err := sc(path); skip {
+				return err
+			}
+		}
+
+		change := Change{
+			Path: path,
+		}
+
+		deletedFile, err := dc(rw, path, f)
+		if err != nil {
+			return err
+		}
+
+		// Find out what kind of modification happened
+		if deletedFile != "" {
+			change.Path = deletedFile
+			change.Kind = ChangeDelete
+		} else {
+			// Otherwise, the file was added
+			change.Kind = ChangeAdd
+
+			// ...Unless it already existed in a top layer, in which case, it's a modification
+			for _, layer := range layers {
+				stat, err := os.Stat(filepath.Join(layer, path))
+				if err != nil && !os.IsNotExist(err) {
+					return err
+				}
+				if err == nil {
+					// The file existed in the top layer, so that's a modification
+
+					// However, if it's a directory, maybe it wasn't actually modified.
+					// If you modify /foo/bar/baz, then /foo will be part of the changed files only because it's the parent of bar
+					if stat.IsDir() && f.IsDir() {
+						if f.Size() == stat.Size() && f.Mode() == stat.Mode() && sameFsTime(f.ModTime(), stat.ModTime()) {
+							// Both directories are the same, don't record the change
+							return nil
+						}
+					}
+					change.Kind = ChangeModify
+					break
+				}
+			}
+		}
+
+		// If /foo/bar/file.txt is modified, then /foo/bar must be part of the changed files.
+		// This block is here to ensure the change is recorded even if the
+		// modify time, mode and size of the parent directory in the rw and ro layers are all equal.
+		// Check https://github.com/docker/docker/pull/13590 for details.
+		if f.IsDir() {
+			changedDirs[path] = struct{}{}
+		}
+		if change.Kind == ChangeAdd || change.Kind == ChangeDelete {
+			parent := filepath.Dir(path)
+			if _, ok := changedDirs[parent]; !ok && parent != "/" {
+				changes = append(changes, Change{Path: parent, Kind: ChangeModify})
+				changedDirs[parent] = struct{}{}
+			}
+		}
+
+		// Record change
+		changes = append(changes, change)
+		return nil
+	})
+	if err != nil && !os.IsNotExist(err) {
+		return nil, err
+	}
+	return changes, nil
+}
+
+// FileInfo describes the information of a file.
+type FileInfo struct {
+	parent     *FileInfo
+	name       string
+	stat       *system.StatT
+	children   map[string]*FileInfo
+	capability []byte
+	added      bool
+}
+
+// LookUp looks up the file information of a file.
+func (info *FileInfo) LookUp(path string) *FileInfo {
+	// As this runs on the daemon side, file paths are OS specific.
+	parent := info
+	if path == string(os.PathSeparator) {
+		return info
+	}
+
+	pathElements := strings.Split(path, string(os.PathSeparator))
+	for _, elem := range pathElements {
+		if elem != "" {
+			child := parent.children[elem]
+			if child == nil {
+				return nil
+			}
+			parent = child
+		}
+	}
+	return parent
+}
+
+func (info *FileInfo) path() string {
+	if info.parent == nil {
+		// As this runs on the daemon side, file paths are OS specific.
+		return string(os.PathSeparator)
+	}
+	return filepath.Join(info.parent.path(), info.name)
+}
+
+func (info *FileInfo) addChanges(oldInfo *FileInfo, changes *[]Change) {
+
+	sizeAtEntry := len(*changes)
+
+	if oldInfo == nil {
+		// add
+		change := Change{
+			Path: info.path(),
+			Kind: ChangeAdd,
+		}
+		*changes = append(*changes, change)
+		info.added = true
+	}
+
+	// We make a copy so we can modify it to detect additions
+	// also, we only recurse on the old dir if the new info is a directory
+	// otherwise any previous delete/change is considered recursive
+	oldChildren := make(map[string]*FileInfo)
+	if oldInfo != nil && info.isDir() {
+		for k, v := range oldInfo.children {
+			oldChildren[k] = v
+		}
+	}
+
+	for name, newChild := range info.children {
+		oldChild := oldChildren[name]
+		if oldChild != nil {
+			// change?
+			oldStat := oldChild.stat
+			newStat := newChild.stat
+			// Note: We can't compare inode or ctime or blocksize here, because these change
+			// when copying a file into a container. However, that is not generally a problem
+			// because any content change will change mtime, and any status change should
+			// be visible when actually comparing the stat fields. The only time this
+			// breaks down is if some code intentionally hides a change by setting
+			// back mtime
+			if statDifferent(oldStat, newStat) ||
+				!bytes.Equal(oldChild.capability, newChild.capability) {
+				change := Change{
+					Path: newChild.path(),
+					Kind: ChangeModify,
+				}
+				*changes = append(*changes, change)
+				newChild.added = true
+			}
+
+			// Remove from copy so we can detect deletions
+			delete(oldChildren, name)
+		}
+
+		newChild.addChanges(oldChild, changes)
+	}
+	for _, oldChild := range oldChildren {
+		// delete
+		change := Change{
+			Path: oldChild.path(),
+			Kind: ChangeDelete,
+		}
+		*changes = append(*changes, change)
+	}
+
+	// If there were changes inside this directory, we need to add it, even if the directory
+	// itself wasn't changed. This is needed to properly save and restore filesystem permissions.
+	// As this runs on the daemon side, file paths are OS specific.
+	if len(*changes) > sizeAtEntry && info.isDir() && !info.added && info.path() != string(os.PathSeparator) {
+		change := Change{
+			Path: info.path(),
+			Kind: ChangeModify,
+		}
+		// Let's insert the directory entry before the recently added entries located inside this dir
+		*changes = append(*changes, change) // just to resize the slice, will be overwritten
+		copy((*changes)[sizeAtEntry+1:], (*changes)[sizeAtEntry:])
+		(*changes)[sizeAtEntry] = change
+	}
+
+}
+
+// Changes add changes to file information.
+func (info *FileInfo) Changes(oldInfo *FileInfo) []Change {
+	var changes []Change
+
+	info.addChanges(oldInfo, &changes)
+
+	return changes
+}
+
+func newRootFileInfo() *FileInfo {
+	// As this runs on the daemon side, file paths are OS specific.
+	root := &FileInfo{
+		name:     string(os.PathSeparator),
+		children: make(map[string]*FileInfo),
+	}
+	return root
+}
+
+// ChangesDirs compares two directories and generates an array of Change objects describing the changes.
+// If oldDir is "", then all files in newDir will be Add-Changes.
+func ChangesDirs(newDir, oldDir string) ([]Change, error) {
+	var (
+		oldRoot, newRoot *FileInfo
+	)
+	if oldDir == "" {
+		emptyDir, err := ioutil.TempDir("", "empty")
+		if err != nil {
+			return nil, err
+		}
+		defer os.Remove(emptyDir)
+		oldDir = emptyDir
+	}
+	oldRoot, newRoot, err := collectFileInfoForChanges(oldDir, newDir)
+	if err != nil {
+		return nil, err
+	}
+
+	return newRoot.Changes(oldRoot), nil
+}
+
+// ChangesSize calculates the size in bytes of the provided changes, based on newDir.
+func ChangesSize(newDir string, changes []Change) int64 {
+	var (
+		size int64
+		sf   = make(map[uint64]struct{})
+	)
+	for _, change := range changes {
+		if change.Kind == ChangeModify || change.Kind == ChangeAdd {
+			file := filepath.Join(newDir, change.Path)
+			fileInfo, err := os.Lstat(file)
+			if err != nil {
+				logrus.Errorf("Can not stat %q: %s", file, err)
+				continue
+			}
+
+			if fileInfo != nil && !fileInfo.IsDir() {
+				if hasHardlinks(fileInfo) {
+					inode := getIno(fileInfo)
+					if _, ok := sf[inode]; !ok {
+						size += fileInfo.Size()
+						sf[inode] = struct{}{}
+					}
+				} else {
+					size += fileInfo.Size()
+				}
+			}
+		}
+	}
+	return size
+}
+
+// ExportChanges produces an Archive from the provided changes, relative to dir.
+func ExportChanges(dir string, changes []Change, uidMaps, gidMaps []idtools.IDMap) (io.ReadCloser, error) {
+	reader, writer := io.Pipe()
+	go func() {
+		ta := newTarAppender(idtools.NewIDMappingsFromMaps(uidMaps, gidMaps), writer, nil)
+
+		// this buffer is needed for the duration of this piped stream
+		defer pools.BufioWriter32KPool.Put(ta.Buffer)
+
+		sort.Sort(changesByPath(changes))
+
+		// In general we log errors here but ignore them because
+		// during e.g. a diff operation the container can continue
+		// mutating the filesystem and we can see transient errors
+		// from this
+		for _, change := range changes {
+			if change.Kind == ChangeDelete {
+				whiteOutDir := filepath.Dir(change.Path)
+				whiteOutBase := filepath.Base(change.Path)
+				whiteOut := filepath.Join(whiteOutDir, WhiteoutPrefix+whiteOutBase)
+				timestamp := time.Now()
+				hdr := &tar.Header{
+					Name:       whiteOut[1:],
+					Size:       0,
+					ModTime:    timestamp,
+					AccessTime: timestamp,
+					ChangeTime: timestamp,
+				}
+				if err := ta.TarWriter.WriteHeader(hdr); err != nil {
+					logrus.Debugf("Can't write whiteout header: %s", err)
+				}
+			} else {
+				path := filepath.Join(dir, change.Path)
+				if err := ta.addTarFile(path, change.Path[1:]); err != nil {
+					logrus.Debugf("Can't add file %s to tar: %s", path, err)
+				}
+			}
+		}
+
+		// Make sure to check the error on Close.
+		if err := ta.TarWriter.Close(); err != nil {
+			logrus.Debugf("Can't close layer: %s", err)
+		}
+		if err := writer.Close(); err != nil {
+			logrus.Debugf("failed close Changes writer: %s", err)
+		}
+	}()
+	return reader, nil
+}

vendor/github.com/containers/storage/pkg/archive/changes_linux.go

@@ -0,0 +1,313 @@
+package archive
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"syscall"
+	"unsafe"
+
+	"github.com/containers/storage/pkg/system"
+	"golang.org/x/sys/unix"
+)
+
+// walker is used to implement collectFileInfoForChanges on linux. Where this
+// method in general returns the entire contents of two directory trees, we
+// optimize some FS calls out on linux. In particular, we take advantage of the
+// fact that getdents(2) returns the inode of each file in the directory being
+// walked, which, when walking two trees in parallel to generate a list of
+// changes, can be used to prune subtrees without ever having to lstat(2) them
+// directly. Eliminating stat calls in this way can save up to seconds on large
+// images.
+type walker struct {
+	dir1  string
+	dir2  string
+	root1 *FileInfo
+	root2 *FileInfo
+}
+
+// collectFileInfoForChanges returns a complete representation of the trees
+// rooted at dir1 and dir2, with one important exception: any subtree or
+// leaf where the inode and device numbers are an exact match between dir1
+// and dir2 will be pruned from the results. This method is *only* to be used
+// to generating a list of changes between the two directories, as it does not
+// reflect the full contents.
+func collectFileInfoForChanges(dir1, dir2 string) (*FileInfo, *FileInfo, error) {
+	w := &walker{
+		dir1:  dir1,
+		dir2:  dir2,
+		root1: newRootFileInfo(),
+		root2: newRootFileInfo(),
+	}
+
+	i1, err := os.Lstat(w.dir1)
+	if err != nil {
+		return nil, nil, err
+	}
+	i2, err := os.Lstat(w.dir2)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	if err := w.walk("/", i1, i2); err != nil {
+		return nil, nil, err
+	}
+
+	return w.root1, w.root2, nil
+}
+
+// Given a FileInfo, its path info, and a reference to the root of the tree
+// being constructed, register this file with the tree.
+func walkchunk(path string, fi os.FileInfo, dir string, root *FileInfo) error {
+	if fi == nil {
+		return nil
+	}
+	parent := root.LookUp(filepath.Dir(path))
+	if parent == nil {
+		return fmt.Errorf("walkchunk: Unexpectedly no parent for %s", path)
+	}
+	info := &FileInfo{
+		name:     filepath.Base(path),
+		children: make(map[string]*FileInfo),
+		parent:   parent,
+	}
+	cpath := filepath.Join(dir, path)
+	stat, err := system.FromStatT(fi.Sys().(*syscall.Stat_t))
+	if err != nil {
+		return err
+	}
+	info.stat = stat
+	info.capability, _ = system.Lgetxattr(cpath, "security.capability") // lgetxattr(2): fs access
+	parent.children[info.name] = info
+	return nil
+}
+
+// Walk a subtree rooted at the same path in both trees being iterated. For
+// example, /docker/overlay/1234/a/b/c/d and /docker/overlay/8888/a/b/c/d
+func (w *walker) walk(path string, i1, i2 os.FileInfo) (err error) {
+	// Register these nodes with the return trees, unless we're still at the
+	// (already-created) roots:
+	if path != "/" {
+		if err := walkchunk(path, i1, w.dir1, w.root1); err != nil {
+			return err
+		}
+		if err := walkchunk(path, i2, w.dir2, w.root2); err != nil {
+			return err
+		}
+	}
+
+	is1Dir := i1 != nil && i1.IsDir()
+	is2Dir := i2 != nil && i2.IsDir()
+
+	sameDevice := false
+	if i1 != nil && i2 != nil {
+		si1 := i1.Sys().(*syscall.Stat_t)
+		si2 := i2.Sys().(*syscall.Stat_t)
+		if si1.Dev == si2.Dev {
+			sameDevice = true
+		}
+	}
+
+	// If these files are both non-existent, or leaves (non-dirs), we are done.
+	if !is1Dir && !is2Dir {
+		return nil
+	}
+
+	// Fetch the names of all the files contained in both directories being walked:
+	var names1, names2 []nameIno
+	if is1Dir {
+		names1, err = readdirnames(filepath.Join(w.dir1, path)) // getdents(2): fs access
+		if err != nil {
+			return err
+		}
+	}
+	if is2Dir {
+		names2, err = readdirnames(filepath.Join(w.dir2, path)) // getdents(2): fs access
+		if err != nil {
+			return err
+		}
+	}
+
+	// We have lists of the files contained in both parallel directories, sorted
+	// in the same order. Walk them in parallel, generating a unique merged list
+	// of all items present in either or both directories.
+	var names []string
+	ix1 := 0
+	ix2 := 0
+
+	for {
+		if ix1 >= len(names1) {
+			break
+		}
+		if ix2 >= len(names2) {
+			break
+		}
+
+		ni1 := names1[ix1]
+		ni2 := names2[ix2]
+
+		switch bytes.Compare([]byte(ni1.name), []byte(ni2.name)) {
+		case -1: // ni1 < ni2 -- advance ni1
+			// we will not encounter ni1 in names2
+			names = append(names, ni1.name)
+			ix1++
+		case 0: // ni1 == ni2
+			if ni1.ino != ni2.ino || !sameDevice {
+				names = append(names, ni1.name)
+			}
+			ix1++
+			ix2++
+		case 1: // ni1 > ni2 -- advance ni2
+			// we will not encounter ni2 in names1
+			names = append(names, ni2.name)
+			ix2++
+		}
+	}
+	for ix1 < len(names1) {
+		names = append(names, names1[ix1].name)
+		ix1++
+	}
+	for ix2 < len(names2) {
+		names = append(names, names2[ix2].name)
+		ix2++
+	}
+
+	// For each of the names present in either or both of the directories being
+	// iterated, stat the name under each root, and recurse the pair of them:
+	for _, name := range names {
+		fname := filepath.Join(path, name)
+		var cInfo1, cInfo2 os.FileInfo
+		if is1Dir {
+			cInfo1, err = os.Lstat(filepath.Join(w.dir1, fname)) // lstat(2): fs access
+			if err != nil && !os.IsNotExist(err) {
+				return err
+			}
+		}
+		if is2Dir {
+			cInfo2, err = os.Lstat(filepath.Join(w.dir2, fname)) // lstat(2): fs access
+			if err != nil && !os.IsNotExist(err) {
+				return err
+			}
+		}
+		if err = w.walk(fname, cInfo1, cInfo2); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// {name,inode} pairs used to support the early-pruning logic of the walker type
+type nameIno struct {
+	name string
+	ino  uint64
+}
+
+type nameInoSlice []nameIno
+
+func (s nameInoSlice) Len() int           { return len(s) }
+func (s nameInoSlice) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s nameInoSlice) Less(i, j int) bool { return s[i].name < s[j].name }
+
+// readdirnames is a hacked-apart version of the Go stdlib code, exposing inode
+// numbers further up the stack when reading directory contents. Unlike
+// os.Readdirnames, which returns a list of filenames, this function returns a
+// list of {filename,inode} pairs.
+func readdirnames(dirname string) (names []nameIno, err error) {
+	var (
+		size = 100
+		buf  = make([]byte, 4096)
+		nbuf int
+		bufp int
+		nb   int
+	)
+
+	f, err := os.Open(dirname)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	names = make([]nameIno, 0, size) // Empty with room to grow.
+	for {
+		// Refill the buffer if necessary
+		if bufp >= nbuf {
+			bufp = 0
+			nbuf, err = unix.ReadDirent(int(f.Fd()), buf) // getdents on linux
+			if nbuf < 0 {
+				nbuf = 0
+			}
+			if err != nil {
+				return nil, os.NewSyscallError("readdirent", err)
+			}
+			if nbuf <= 0 {
+				break // EOF
+			}
+		}
+
+		// Drain the buffer
+		nb, names = parseDirent(buf[bufp:nbuf], names)
+		bufp += nb
+	}
+
+	sl := nameInoSlice(names)
+	sort.Sort(sl)
+	return sl, nil
+}
+
+// parseDirent is a minor modification of unix.ParseDirent (linux version)
+// which returns {name,inode} pairs instead of just names.
+func parseDirent(buf []byte, names []nameIno) (consumed int, newnames []nameIno) {
+	origlen := len(buf)
+	for len(buf) > 0 {
+		dirent := (*unix.Dirent)(unsafe.Pointer(&buf[0]))
+		buf = buf[dirent.Reclen:]
+		if dirent.Ino == 0 { // File absent in directory.
+			continue
+		}
+		bytes := (*[10000]byte)(unsafe.Pointer(&dirent.Name[0]))
+		var name = string(bytes[0:clen(bytes[:])])
+		if name == "." || name == ".." { // Useless names
+			continue
+		}
+		names = append(names, nameIno{name, dirent.Ino})
+	}
+	return origlen - len(buf), names
+}
+
+func clen(n []byte) int {
+	for i := 0; i < len(n); i++ {
+		if n[i] == 0 {
+			return i
+		}
+	}
+	return len(n)
+}
+
+// OverlayChanges walks the path rw and determines changes for the files in the path,
+// with respect to the parent layers
+func OverlayChanges(layers []string, rw string) ([]Change, error) {
+	return changes(layers, rw, overlayDeletedFile, nil)
+}
+
+func overlayDeletedFile(root, path string, fi os.FileInfo) (string, error) {
+	if fi.Mode()&os.ModeCharDevice != 0 {
+		s := fi.Sys().(*syscall.Stat_t)
+		if major(s.Rdev) == 0 && minor(s.Rdev) == 0 {
+			return path, nil
+		}
+	}
+	if fi.Mode()&os.ModeDir != 0 {
+		opaque, err := system.Lgetxattr(filepath.Join(root, path), "trusted.overlay.opaque")
+		if err != nil {
+			return "", err
+		}
+		if len(opaque) == 1 && opaque[0] == 'y' {
+			return path, nil
+		}
+	}
+
+	return "", nil
+
+}

vendor/github.com/containers/storage/pkg/archive/changes_other.go

@@ -0,0 +1,97 @@
+// +build !linux
+
+package archive
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+
+	"github.com/containers/storage/pkg/system"
+)
+
+func collectFileInfoForChanges(oldDir, newDir string) (*FileInfo, *FileInfo, error) {
+	var (
+		oldRoot, newRoot *FileInfo
+		err1, err2       error
+		errs             = make(chan error, 2)
+	)
+	go func() {
+		oldRoot, err1 = collectFileInfo(oldDir)
+		errs <- err1
+	}()
+	go func() {
+		newRoot, err2 = collectFileInfo(newDir)
+		errs <- err2
+	}()
+
+	// block until both routines have returned
+	for i := 0; i < 2; i++ {
+		if err := <-errs; err != nil {
+			return nil, nil, err
+		}
+	}
+
+	return oldRoot, newRoot, nil
+}
+
+func collectFileInfo(sourceDir string) (*FileInfo, error) {
+	root := newRootFileInfo()
+
+	err := filepath.Walk(sourceDir, func(path string, f os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		// Rebase path
+		relPath, err := filepath.Rel(sourceDir, path)
+		if err != nil {
+			return err
+		}
+
+		// As this runs on the daemon side, file paths are OS specific.
+		relPath = filepath.Join(string(os.PathSeparator), relPath)
+
+		// See https://github.com/golang/go/issues/9168 - bug in filepath.Join.
+		// Temporary workaround. If the returned path starts with two backslashes,
+		// trim it down to a single backslash. Only relevant on Windows.
+		if runtime.GOOS == "windows" {
+			if strings.HasPrefix(relPath, `\\`) {
+				relPath = relPath[1:]
+			}
+		}
+
+		if relPath == string(os.PathSeparator) {
+			return nil
+		}
+
+		parent := root.LookUp(filepath.Dir(relPath))
+		if parent == nil {
+			return fmt.Errorf("collectFileInfo: Unexpectedly no parent for %s", relPath)
+		}
+
+		info := &FileInfo{
+			name:     filepath.Base(relPath),
+			children: make(map[string]*FileInfo),
+			parent:   parent,
+		}
+
+		s, err := system.Lstat(path)
+		if err != nil {
+			return err
+		}
+		info.stat = s
+
+		info.capability, _ = system.Lgetxattr(path, "security.capability")
+
+		parent.children[info.name] = info
+
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	return root, nil
+}

vendor/github.com/containers/storage/pkg/archive/changes_unix.go

@@ -0,0 +1,37 @@
+// +build !windows
+
+package archive
+
+import (
+	"os"
+	"syscall"
+
+	"github.com/containers/storage/pkg/system"
+	"golang.org/x/sys/unix"
+)
+
+func statDifferent(oldStat *system.StatT, newStat *system.StatT) bool {
+	// Don't look at size for dirs, its not a good measure of change
+	if oldStat.Mode() != newStat.Mode() ||
+		oldStat.UID() != newStat.UID() ||
+		oldStat.GID() != newStat.GID() ||
+		oldStat.Rdev() != newStat.Rdev() ||
+		// Don't look at size for dirs, its not a good measure of change
+		(oldStat.Mode()&unix.S_IFDIR != unix.S_IFDIR &&
+			(!sameFsTimeSpec(oldStat.Mtim(), newStat.Mtim()) || (oldStat.Size() != newStat.Size()))) {
+		return true
+	}
+	return false
+}
+
+func (info *FileInfo) isDir() bool {
+	return info.parent == nil || info.stat.Mode()&unix.S_IFDIR != 0
+}
+
+func getIno(fi os.FileInfo) uint64 {
+	return fi.Sys().(*syscall.Stat_t).Ino
+}
+
+func hasHardlinks(fi os.FileInfo) bool {
+	return fi.Sys().(*syscall.Stat_t).Nlink > 1
+}

vendor/github.com/containers/storage/pkg/archive/changes_windows.go

@@ -0,0 +1,30 @@
+package archive
+
+import (
+	"os"
+
+	"github.com/containers/storage/pkg/system"
+)
+
+func statDifferent(oldStat *system.StatT, newStat *system.StatT) bool {
+
+	// Don't look at size for dirs, its not a good measure of change
+	if oldStat.Mtim() != newStat.Mtim() ||
+		oldStat.Mode() != newStat.Mode() ||
+		oldStat.Size() != newStat.Size() && !oldStat.Mode().IsDir() {
+		return true
+	}
+	return false
+}
+
+func (info *FileInfo) isDir() bool {
+	return info.parent == nil || info.stat.Mode().IsDir()
+}
+
+func getIno(fi os.FileInfo) (inode uint64) {
+	return
+}
+
+func hasHardlinks(fi os.FileInfo) bool {
+	return false
+}

vendor/github.com/containers/storage/pkg/archive/copy.go

@@ -0,0 +1,461 @@
+package archive
+
+import (
+	"archive/tar"
+	"errors"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/containers/storage/pkg/system"
+	"github.com/sirupsen/logrus"
+)
+
+// Errors used or returned by this file.
+var (
+	ErrNotDirectory      = errors.New("not a directory")
+	ErrDirNotExists      = errors.New("no such directory")
+	ErrCannotCopyDir     = errors.New("cannot copy directory")
+	ErrInvalidCopySource = errors.New("invalid copy source content")
+)
+
+// PreserveTrailingDotOrSeparator returns the given cleaned path (after
+// processing using any utility functions from the path or filepath stdlib
+// packages) and appends a trailing `/.` or `/` if its corresponding  original
+// path (from before being processed by utility functions from the path or
+// filepath stdlib packages) ends with a trailing `/.` or `/`. If the cleaned
+// path already ends in a `.` path segment, then another is not added. If the
+// clean path already ends in a path separator, then another is not added.
+func PreserveTrailingDotOrSeparator(cleanedPath, originalPath string) string {
+	// Ensure paths are in platform semantics
+	cleanedPath = normalizePath(cleanedPath)
+	originalPath = normalizePath(originalPath)
+
+	if !specifiesCurrentDir(cleanedPath) && specifiesCurrentDir(originalPath) {
+		if !hasTrailingPathSeparator(cleanedPath) {
+			// Add a separator if it doesn't already end with one (a cleaned
+			// path would only end in a separator if it is the root).
+			cleanedPath += string(filepath.Separator)
+		}
+		cleanedPath += "."
+	}
+
+	if !hasTrailingPathSeparator(cleanedPath) && hasTrailingPathSeparator(originalPath) {
+		cleanedPath += string(filepath.Separator)
+	}
+
+	return cleanedPath
+}
+
+// assertsDirectory returns whether the given path is
+// asserted to be a directory, i.e., the path ends with
+// a trailing '/' or `/.`, assuming a path separator of `/`.
+func assertsDirectory(path string) bool {
+	return hasTrailingPathSeparator(path) || specifiesCurrentDir(path)
+}
+
+// hasTrailingPathSeparator returns whether the given
+// path ends with the system's path separator character.
+func hasTrailingPathSeparator(path string) bool {
+	return len(path) > 0 && os.IsPathSeparator(path[len(path)-1])
+}
+
+// specifiesCurrentDir returns whether the given path specifies
+// a "current directory", i.e., the last path segment is `.`.
+func specifiesCurrentDir(path string) bool {
+	return filepath.Base(path) == "."
+}
+
+// SplitPathDirEntry splits the given path between its directory name and its
+// basename by first cleaning the path but preserves a trailing "." if the
+// original path specified the current directory.
+func SplitPathDirEntry(path string) (dir, base string) {
+	cleanedPath := filepath.Clean(normalizePath(path))
+
+	if specifiesCurrentDir(path) {
+		cleanedPath += string(filepath.Separator) + "."
+	}
+
+	return filepath.Dir(cleanedPath), filepath.Base(cleanedPath)
+}
+
+// TarResource archives the resource described by the given CopyInfo to a Tar
+// archive. A non-nil error is returned if sourcePath does not exist or is
+// asserted to be a directory but exists as another type of file.
+//
+// This function acts as a convenient wrapper around TarWithOptions, which
+// requires a directory as the source path. TarResource accepts either a
+// directory or a file path and correctly sets the Tar options.
+func TarResource(sourceInfo CopyInfo) (content io.ReadCloser, err error) {
+	return TarResourceRebase(sourceInfo.Path, sourceInfo.RebaseName)
+}
+
+// TarResourceRebase is like TarResource but renames the first path element of
+// items in the resulting tar archive to match the given rebaseName if not "".
+func TarResourceRebase(sourcePath, rebaseName string) (content io.ReadCloser, err error) {
+	sourcePath = normalizePath(sourcePath)
+	if _, err = os.Lstat(sourcePath); err != nil {
+		// Catches the case where the source does not exist or is not a
+		// directory if asserted to be a directory, as this also causes an
+		// error.
+		return
+	}
+
+	// Separate the source path between its directory and
+	// the entry in that directory which we are archiving.
+	sourceDir, sourceBase := SplitPathDirEntry(sourcePath)
+
+	filter := []string{sourceBase}
+
+	logrus.Debugf("copying %q from %q", sourceBase, sourceDir)
+
+	return TarWithOptions(sourceDir, &TarOptions{
+		Compression:      Uncompressed,
+		IncludeFiles:     filter,
+		IncludeSourceDir: true,
+		RebaseNames: map[string]string{
+			sourceBase: rebaseName,
+		},
+	})
+}
+
+// CopyInfo holds basic info about the source
+// or destination path of a copy operation.
+type CopyInfo struct {
+	Path       string
+	Exists     bool
+	IsDir      bool
+	RebaseName string
+}
+
+// CopyInfoSourcePath stats the given path to create a CopyInfo
+// struct representing that resource for the source of an archive copy
+// operation. The given path should be an absolute local path. A source path
+// has all symlinks evaluated that appear before the last path separator ("/"
+// on Unix). As it is to be a copy source, the path must exist.
+func CopyInfoSourcePath(path string, followLink bool) (CopyInfo, error) {
+	// normalize the file path and then evaluate the symbol link
+	// we will use the target file instead of the symbol link if
+	// followLink is set
+	path = normalizePath(path)
+
+	resolvedPath, rebaseName, err := ResolveHostSourcePath(path, followLink)
+	if err != nil {
+		return CopyInfo{}, err
+	}
+
+	stat, err := os.Lstat(resolvedPath)
+	if err != nil {
+		return CopyInfo{}, err
+	}
+
+	return CopyInfo{
+		Path:       resolvedPath,
+		Exists:     true,
+		IsDir:      stat.IsDir(),
+		RebaseName: rebaseName,
+	}, nil
+}
+
+// CopyInfoDestinationPath stats the given path to create a CopyInfo
+// struct representing that resource for the destination of an archive copy
+// operation. The given path should be an absolute local path.
+func CopyInfoDestinationPath(path string) (info CopyInfo, err error) {
+	maxSymlinkIter := 10 // filepath.EvalSymlinks uses 255, but 10 already seems like a lot.
+	path = normalizePath(path)
+	originalPath := path
+
+	stat, err := os.Lstat(path)
+
+	if err == nil && stat.Mode()&os.ModeSymlink == 0 {
+		// The path exists and is not a symlink.
+		return CopyInfo{
+			Path:   path,
+			Exists: true,
+			IsDir:  stat.IsDir(),
+		}, nil
+	}
+
+	// While the path is a symlink.
+	for n := 0; err == nil && stat.Mode()&os.ModeSymlink != 0; n++ {
+		if n > maxSymlinkIter {
+			// Don't follow symlinks more than this arbitrary number of times.
+			return CopyInfo{}, errors.New("too many symlinks in " + originalPath)
+		}
+
+		// The path is a symbolic link. We need to evaluate it so that the
+		// destination of the copy operation is the link target and not the
+		// link itself. This is notably different than CopyInfoSourcePath which
+		// only evaluates symlinks before the last appearing path separator.
+		// Also note that it is okay if the last path element is a broken
+		// symlink as the copy operation should create the target.
+		var linkTarget string
+
+		linkTarget, err = os.Readlink(path)
+		if err != nil {
+			return CopyInfo{}, err
+		}
+
+		if !system.IsAbs(linkTarget) {
+			// Join with the parent directory.
+			dstParent, _ := SplitPathDirEntry(path)
+			linkTarget = filepath.Join(dstParent, linkTarget)
+		}
+
+		path = linkTarget
+		stat, err = os.Lstat(path)
+	}
+
+	if err != nil {
+		// It's okay if the destination path doesn't exist. We can still
+		// continue the copy operation if the parent directory exists.
+		if !os.IsNotExist(err) {
+			return CopyInfo{}, err
+		}
+
+		// Ensure destination parent dir exists.
+		dstParent, _ := SplitPathDirEntry(path)
+
+		parentDirStat, err := os.Lstat(dstParent)
+		if err != nil {
+			return CopyInfo{}, err
+		}
+		if !parentDirStat.IsDir() {
+			return CopyInfo{}, ErrNotDirectory
+		}
+
+		return CopyInfo{Path: path}, nil
+	}
+
+	// The path exists after resolving symlinks.
+	return CopyInfo{
+		Path:   path,
+		Exists: true,
+		IsDir:  stat.IsDir(),
+	}, nil
+}
+
+// PrepareArchiveCopy prepares the given srcContent archive, which should
+// contain the archived resource described by srcInfo, to the destination
+// described by dstInfo. Returns the possibly modified content archive along
+// with the path to the destination directory which it should be extracted to.
+func PrepareArchiveCopy(srcContent io.Reader, srcInfo, dstInfo CopyInfo) (dstDir string, content io.ReadCloser, err error) {
+	// Ensure in platform semantics
+	srcInfo.Path = normalizePath(srcInfo.Path)
+	dstInfo.Path = normalizePath(dstInfo.Path)
+
+	// Separate the destination path between its directory and base
+	// components in case the source archive contents need to be rebased.
+	dstDir, dstBase := SplitPathDirEntry(dstInfo.Path)
+	_, srcBase := SplitPathDirEntry(srcInfo.Path)
+
+	switch {
+	case dstInfo.Exists && dstInfo.IsDir:
+		// The destination exists as a directory. No alteration
+		// to srcContent is needed as its contents can be
+		// simply extracted to the destination directory.
+		return dstInfo.Path, ioutil.NopCloser(srcContent), nil
+	case dstInfo.Exists && srcInfo.IsDir:
+		// The destination exists as some type of file and the source
+		// content is a directory. This is an error condition since
+		// you cannot copy a directory to an existing file location.
+		return "", nil, ErrCannotCopyDir
+	case dstInfo.Exists:
+		// The destination exists as some type of file and the source content
+		// is also a file. The source content entry will have to be renamed to
+		// have a basename which matches the destination path's basename.
+		if len(srcInfo.RebaseName) != 0 {
+			srcBase = srcInfo.RebaseName
+		}
+		return dstDir, RebaseArchiveEntries(srcContent, srcBase, dstBase), nil
+	case srcInfo.IsDir:
+		// The destination does not exist and the source content is an archive
+		// of a directory. The archive should be extracted to the parent of
+		// the destination path instead, and when it is, the directory that is
+		// created as a result should take the name of the destination path.
+		// The source content entries will have to be renamed to have a
+		// basename which matches the destination path's basename.
+		if len(srcInfo.RebaseName) != 0 {
+			srcBase = srcInfo.RebaseName
+		}
+		return dstDir, RebaseArchiveEntries(srcContent, srcBase, dstBase), nil
+	case assertsDirectory(dstInfo.Path):
+		// The destination does not exist and is asserted to be created as a
+		// directory, but the source content is not a directory. This is an
+		// error condition since you cannot create a directory from a file
+		// source.
+		return "", nil, ErrDirNotExists
+	default:
+		// The last remaining case is when the destination does not exist, is
+		// not asserted to be a directory, and the source content is not an
+		// archive of a directory. It this case, the destination file will need
+		// to be created when the archive is extracted and the source content
+		// entry will have to be renamed to have a basename which matches the
+		// destination path's basename.
+		if len(srcInfo.RebaseName) != 0 {
+			srcBase = srcInfo.RebaseName
+		}
+		return dstDir, RebaseArchiveEntries(srcContent, srcBase, dstBase), nil
+	}
+
+}
+
+// RebaseArchiveEntries rewrites the given srcContent archive replacing
+// an occurrence of oldBase with newBase at the beginning of entry names.
+func RebaseArchiveEntries(srcContent io.Reader, oldBase, newBase string) io.ReadCloser {
+	if oldBase == string(os.PathSeparator) {
+		// If oldBase specifies the root directory, use an empty string as
+		// oldBase instead so that newBase doesn't replace the path separator
+		// that all paths will start with.
+		oldBase = ""
+	}
+
+	rebased, w := io.Pipe()
+
+	go func() {
+		srcTar := tar.NewReader(srcContent)
+		rebasedTar := tar.NewWriter(w)
+
+		for {
+			hdr, err := srcTar.Next()
+			if err == io.EOF {
+				// Signals end of archive.
+				rebasedTar.Close()
+				w.Close()
+				return
+			}
+			if err != nil {
+				w.CloseWithError(err)
+				return
+			}
+
+			hdr.Name = strings.Replace(hdr.Name, oldBase, newBase, 1)
+			if hdr.Typeflag == tar.TypeLink {
+				hdr.Linkname = strings.Replace(hdr.Linkname, oldBase, newBase, 1)
+			}
+
+			if err = rebasedTar.WriteHeader(hdr); err != nil {
+				w.CloseWithError(err)
+				return
+			}
+
+			if _, err = io.Copy(rebasedTar, srcTar); err != nil {
+				w.CloseWithError(err)
+				return
+			}
+		}
+	}()
+
+	return rebased
+}
+
+// CopyResource performs an archive copy from the given source path to the
+// given destination path. The source path MUST exist and the destination
+// path's parent directory must exist.
+func CopyResource(srcPath, dstPath string, followLink bool) error {
+	var (
+		srcInfo CopyInfo
+		err     error
+	)
+
+	// Ensure in platform semantics
+	srcPath = normalizePath(srcPath)
+	dstPath = normalizePath(dstPath)
+
+	// Clean the source and destination paths.
+	srcPath = PreserveTrailingDotOrSeparator(filepath.Clean(srcPath), srcPath)
+	dstPath = PreserveTrailingDotOrSeparator(filepath.Clean(dstPath), dstPath)
+
+	if srcInfo, err = CopyInfoSourcePath(srcPath, followLink); err != nil {
+		return err
+	}
+
+	content, err := TarResource(srcInfo)
+	if err != nil {
+		return err
+	}
+	defer content.Close()
+
+	return CopyTo(content, srcInfo, dstPath)
+}
+
+// CopyTo handles extracting the given content whose
+// entries should be sourced from srcInfo to dstPath.
+func CopyTo(content io.Reader, srcInfo CopyInfo, dstPath string) error {
+	// The destination path need not exist, but CopyInfoDestinationPath will
+	// ensure that at least the parent directory exists.
+	dstInfo, err := CopyInfoDestinationPath(normalizePath(dstPath))
+	if err != nil {
+		return err
+	}
+
+	dstDir, copyArchive, err := PrepareArchiveCopy(content, srcInfo, dstInfo)
+	if err != nil {
+		return err
+	}
+	defer copyArchive.Close()
+
+	options := &TarOptions{
+		NoLchown:             true,
+		NoOverwriteDirNonDir: true,
+	}
+
+	return Untar(copyArchive, dstDir, options)
+}
+
+// ResolveHostSourcePath decides real path need to be copied with parameters such as
+// whether to follow symbol link or not, if followLink is true, resolvedPath will return
+// link target of any symbol link file, else it will only resolve symlink of directory
+// but return symbol link file itself without resolving.
+func ResolveHostSourcePath(path string, followLink bool) (resolvedPath, rebaseName string, err error) {
+	if followLink {
+		resolvedPath, err = filepath.EvalSymlinks(path)
+		if err != nil {
+			return
+		}
+
+		resolvedPath, rebaseName = GetRebaseName(path, resolvedPath)
+	} else {
+		dirPath, basePath := filepath.Split(path)
+
+		// if not follow symbol link, then resolve symbol link of parent dir
+		var resolvedDirPath string
+		resolvedDirPath, err = filepath.EvalSymlinks(dirPath)
+		if err != nil {
+			return
+		}
+		// resolvedDirPath will have been cleaned (no trailing path separators) so
+		// we can manually join it with the base path element.
+		resolvedPath = resolvedDirPath + string(filepath.Separator) + basePath
+		if hasTrailingPathSeparator(path) && filepath.Base(path) != filepath.Base(resolvedPath) {
+			rebaseName = filepath.Base(path)
+		}
+	}
+	return resolvedPath, rebaseName, nil
+}
+
+// GetRebaseName normalizes and compares path and resolvedPath,
+// return completed resolved path and rebased file name
+func GetRebaseName(path, resolvedPath string) (string, string) {
+	// linkTarget will have been cleaned (no trailing path separators and dot) so
+	// we can manually join it with them
+	var rebaseName string
+	if specifiesCurrentDir(path) && !specifiesCurrentDir(resolvedPath) {
+		resolvedPath += string(filepath.Separator) + "."
+	}
+
+	if hasTrailingPathSeparator(path) && !hasTrailingPathSeparator(resolvedPath) {
+		resolvedPath += string(filepath.Separator)
+	}
+
+	if filepath.Base(path) != filepath.Base(resolvedPath) {
+		// In the case where the path had a trailing separator and a symlink
+		// evaluation has changed the last path component, we will need to
+		// rebase the name in the archive that is being copied to match the
+		// originally requested name.
+		rebaseName = filepath.Base(path)
+	}
+	return resolvedPath, rebaseName
+}

vendor/github.com/containers/storage/pkg/archive/copy_unix.go

@@ -0,0 +1,11 @@
+// +build !windows
+
+package archive
+
+import (
+	"path/filepath"
+)
+
+func normalizePath(path string) string {
+	return filepath.ToSlash(path)
+}

vendor/github.com/containers/storage/pkg/archive/copy_windows.go

@@ -0,0 +1,9 @@
+package archive
+
+import (
+	"path/filepath"
+)
+
+func normalizePath(path string) string {
+	return filepath.FromSlash(path)
+}

vendor/github.com/containers/storage/pkg/archive/diff.go

@@ -0,0 +1,256 @@
+package archive
+
+import (
+	"archive/tar"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+
+	"github.com/containers/storage/pkg/idtools"
+	"github.com/containers/storage/pkg/pools"
+	"github.com/containers/storage/pkg/system"
+	"github.com/sirupsen/logrus"
+)
+
+// UnpackLayer unpack `layer` to a `dest`. The stream `layer` can be
+// compressed or uncompressed.
+// Returns the size in bytes of the contents of the layer.
+func UnpackLayer(dest string, layer io.Reader, options *TarOptions) (size int64, err error) {
+	tr := tar.NewReader(layer)
+	trBuf := pools.BufioReader32KPool.Get(tr)
+	defer pools.BufioReader32KPool.Put(trBuf)
+
+	var dirs []*tar.Header
+	unpackedPaths := make(map[string]struct{})
+
+	if options == nil {
+		options = &TarOptions{}
+	}
+	if options.ExcludePatterns == nil {
+		options.ExcludePatterns = []string{}
+	}
+	idMappings := idtools.NewIDMappingsFromMaps(options.UIDMaps, options.GIDMaps)
+
+	aufsTempdir := ""
+	aufsHardlinks := make(map[string]*tar.Header)
+
+	// Iterate through the files in the archive.
+	for {
+		hdr, err := tr.Next()
+		if err == io.EOF {
+			// end of tar archive
+			break
+		}
+		if err != nil {
+			return 0, err
+		}
+
+		size += hdr.Size
+
+		// Normalize name, for safety and for a simple is-root check
+		hdr.Name = filepath.Clean(hdr.Name)
+
+		// Windows does not support filenames with colons in them. Ignore
+		// these files. This is not a problem though (although it might
+		// appear that it is). Let's suppose a client is running docker pull.
+		// The daemon it points to is Windows. Would it make sense for the
+		// client to be doing a docker pull Ubuntu for example (which has files
+		// with colons in the name under /usr/share/man/man3)? No, absolutely
+		// not as it would really only make sense that they were pulling a
+		// Windows image. However, for development, it is necessary to be able
+		// to pull Linux images which are in the repository.
+		//
+		// TODO Windows. Once the registry is aware of what images are Windows-
+		// specific or Linux-specific, this warning should be changed to an error
+		// to cater for the situation where someone does manage to upload a Linux
+		// image but have it tagged as Windows inadvertently.
+		if runtime.GOOS == "windows" {
+			if strings.Contains(hdr.Name, ":") {
+				logrus.Warnf("Windows: Ignoring %s (is this a Linux image?)", hdr.Name)
+				continue
+			}
+		}
+
+		// Note as these operations are platform specific, so must the slash be.
+		if !strings.HasSuffix(hdr.Name, string(os.PathSeparator)) {
+			// Not the root directory, ensure that the parent directory exists.
+			// This happened in some tests where an image had a tarfile without any
+			// parent directories.
+			parent := filepath.Dir(hdr.Name)
+			parentPath := filepath.Join(dest, parent)
+
+			if _, err := os.Lstat(parentPath); err != nil && os.IsNotExist(err) {
+				err = system.MkdirAll(parentPath, 0600, "")
+				if err != nil {
+					return 0, err
+				}
+			}
+		}
+
+		// Skip AUFS metadata dirs
+		if strings.HasPrefix(hdr.Name, WhiteoutMetaPrefix) {
+			// Regular files inside /.wh..wh.plnk can be used as hardlink targets
+			// We don't want this directory, but we need the files in them so that
+			// such hardlinks can be resolved.
+			if strings.HasPrefix(hdr.Name, WhiteoutLinkDir) && hdr.Typeflag == tar.TypeReg {
+				basename := filepath.Base(hdr.Name)
+				aufsHardlinks[basename] = hdr
+				if aufsTempdir == "" {
+					if aufsTempdir, err = ioutil.TempDir("", "storageplnk"); err != nil {
+						return 0, err
+					}
+					defer os.RemoveAll(aufsTempdir)
+				}
+				if err := createTarFile(filepath.Join(aufsTempdir, basename), dest, hdr, tr, true, nil, options.InUserNS); err != nil {
+					return 0, err
+				}
+			}
+
+			if hdr.Name != WhiteoutOpaqueDir {
+				continue
+			}
+		}
+		path := filepath.Join(dest, hdr.Name)
+		rel, err := filepath.Rel(dest, path)
+		if err != nil {
+			return 0, err
+		}
+
+		// Note as these operations are platform specific, so must the slash be.
+		if strings.HasPrefix(rel, ".."+string(os.PathSeparator)) {
+			return 0, breakoutError(fmt.Errorf("%q is outside of %q", hdr.Name, dest))
+		}
+		base := filepath.Base(path)
+
+		if strings.HasPrefix(base, WhiteoutPrefix) {
+			dir := filepath.Dir(path)
+			if base == WhiteoutOpaqueDir {
+				_, err := os.Lstat(dir)
+				if err != nil {
+					return 0, err
+				}
+				err = filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
+					if err != nil {
+						if os.IsNotExist(err) {
+							err = nil // parent was deleted
+						}
+						return err
+					}
+					if path == dir {
+						return nil
+					}
+					if _, exists := unpackedPaths[path]; !exists {
+						err := os.RemoveAll(path)
+						return err
+					}
+					return nil
+				})
+				if err != nil {
+					return 0, err
+				}
+			} else {
+				originalBase := base[len(WhiteoutPrefix):]
+				originalPath := filepath.Join(dir, originalBase)
+				if err := os.RemoveAll(originalPath); err != nil {
+					return 0, err
+				}
+			}
+		} else {
+			// If path exits we almost always just want to remove and replace it.
+			// The only exception is when it is a directory *and* the file from
+			// the layer is also a directory. Then we want to merge them (i.e.
+			// just apply the metadata from the layer).
+			if fi, err := os.Lstat(path); err == nil {
+				if !(fi.IsDir() && hdr.Typeflag == tar.TypeDir) {
+					if err := os.RemoveAll(path); err != nil {
+						return 0, err
+					}
+				}
+			}
+
+			trBuf.Reset(tr)
+			srcData := io.Reader(trBuf)
+			srcHdr := hdr
+
+			// Hard links into /.wh..wh.plnk don't work, as we don't extract that directory, so
+			// we manually retarget these into the temporary files we extracted them into
+			if hdr.Typeflag == tar.TypeLink && strings.HasPrefix(filepath.Clean(hdr.Linkname), WhiteoutLinkDir) {
+				linkBasename := filepath.Base(hdr.Linkname)
+				srcHdr = aufsHardlinks[linkBasename]
+				if srcHdr == nil {
+					return 0, fmt.Errorf("Invalid aufs hardlink")
+				}
+				tmpFile, err := os.Open(filepath.Join(aufsTempdir, linkBasename))
+				if err != nil {
+					return 0, err
+				}
+				defer tmpFile.Close()
+				srcData = tmpFile
+			}
+
+			if err := remapIDs(idMappings, srcHdr); err != nil {
+				return 0, err
+			}
+
+			if err := createTarFile(path, dest, srcHdr, srcData, true, nil, options.InUserNS); err != nil {
+				return 0, err
+			}
+
+			// Directory mtimes must be handled at the end to avoid further
+			// file creation in them to modify the directory mtime
+			if hdr.Typeflag == tar.TypeDir {
+				dirs = append(dirs, hdr)
+			}
+			unpackedPaths[path] = struct{}{}
+		}
+	}
+
+	for _, hdr := range dirs {
+		path := filepath.Join(dest, hdr.Name)
+		if err := system.Chtimes(path, hdr.AccessTime, hdr.ModTime); err != nil {
+			return 0, err
+		}
+	}
+
+	return size, nil
+}
+
+// ApplyLayer parses a diff in the standard layer format from `layer`,
+// and applies it to the directory `dest`. The stream `layer` can be
+// compressed or uncompressed.
+// Returns the size in bytes of the contents of the layer.
+func ApplyLayer(dest string, layer io.Reader) (int64, error) {
+	return applyLayerHandler(dest, layer, &TarOptions{}, true)
+}
+
+// ApplyUncompressedLayer parses a diff in the standard layer format from
+// `layer`, and applies it to the directory `dest`. The stream `layer`
+// can only be uncompressed.
+// Returns the size in bytes of the contents of the layer.
+func ApplyUncompressedLayer(dest string, layer io.Reader, options *TarOptions) (int64, error) {
+	return applyLayerHandler(dest, layer, options, false)
+}
+
+// do the bulk load of ApplyLayer, but allow for not calling DecompressStream
+func applyLayerHandler(dest string, layer io.Reader, options *TarOptions, decompress bool) (int64, error) {
+	dest = filepath.Clean(dest)
+
+	// We need to be able to set any perms
+	oldmask, err := system.Umask(0)
+	if err != nil {
+		return 0, err
+	}
+	defer system.Umask(oldmask) // ignore err, ErrNotSupportedPlatform
+
+	if decompress {
+		layer, err = DecompressStream(layer)
+		if err != nil {
+			return 0, err
+		}
+	}
+	return UnpackLayer(dest, layer, options)
+}

vendor/github.com/containers/storage/pkg/archive/example_changes.go

@@ -0,0 +1,97 @@
+// +build ignore
+
+// Simple tool to create an archive stream from an old and new directory
+//
+// By default it will stream the comparison of two temporary directories with junk files
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path"
+
+	"github.com/containers/storage/pkg/archive"
+	"github.com/sirupsen/logrus"
+)
+
+var (
+	flDebug  = flag.Bool("D", false, "debugging output")
+	flNewDir = flag.String("newdir", "", "")
+	flOldDir = flag.String("olddir", "", "")
+	log      = logrus.New()
+)
+
+func main() {
+	flag.Usage = func() {
+		fmt.Println("Produce a tar from comparing two directory paths. By default a demo tar is created of around 200 files (including hardlinks)")
+		fmt.Printf("%s [OPTIONS]\n", os.Args[0])
+		flag.PrintDefaults()
+	}
+	flag.Parse()
+	log.Out = os.Stderr
+	if (len(os.Getenv("DEBUG")) > 0) || *flDebug {
+		logrus.SetLevel(logrus.DebugLevel)
+	}
+	var newDir, oldDir string
+
+	if len(*flNewDir) == 0 {
+		var err error
+		newDir, err = ioutil.TempDir("", "storage-test-newDir")
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer os.RemoveAll(newDir)
+		if _, err := prepareUntarSourceDirectory(100, newDir, true); err != nil {
+			log.Fatal(err)
+		}
+	} else {
+		newDir = *flNewDir
+	}
+
+	if len(*flOldDir) == 0 {
+		oldDir, err := ioutil.TempDir("", "storage-test-oldDir")
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer os.RemoveAll(oldDir)
+	} else {
+		oldDir = *flOldDir
+	}
+
+	changes, err := archive.ChangesDirs(newDir, oldDir)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	a, err := archive.ExportChanges(newDir, changes)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer a.Close()
+
+	i, err := io.Copy(os.Stdout, a)
+	if err != nil && err != io.EOF {
+		log.Fatal(err)
+	}
+	fmt.Fprintf(os.Stderr, "wrote archive of %d bytes", i)
+}
+
+func prepareUntarSourceDirectory(numberOfFiles int, targetPath string, makeLinks bool) (int, error) {
+	fileData := []byte("fooo")
+	for n := 0; n < numberOfFiles; n++ {
+		fileName := fmt.Sprintf("file-%d", n)
+		if err := ioutil.WriteFile(path.Join(targetPath, fileName), fileData, 0700); err != nil {
+			return 0, err
+		}
+		if makeLinks {
+			if err := os.Link(path.Join(targetPath, fileName), path.Join(targetPath, fileName+"-link")); err != nil {
+				return 0, err
+			}
+		}
+	}
+	totalSize := numberOfFiles * len(fileData)
+	return totalSize, nil
+}

vendor/github.com/containers/storage/pkg/archive/time_linux.go

@@ -0,0 +1,16 @@
+package archive
+
+import (
+	"syscall"
+	"time"
+)
+
+func timeToTimespec(time time.Time) (ts syscall.Timespec) {
+	if time.IsZero() {
+		// Return UTIME_OMIT special value
+		ts.Sec = 0
+		ts.Nsec = ((1 << 30) - 2)
+		return
+	}
+	return syscall.NsecToTimespec(time.UnixNano())
+}

vendor/github.com/containers/storage/pkg/archive/time_unsupported.go

@@ -0,0 +1,16 @@
+// +build !linux
+
+package archive
+
+import (
+	"syscall"
+	"time"
+)
+
+func timeToTimespec(time time.Time) (ts syscall.Timespec) {
+	nsec := int64(0)
+	if !time.IsZero() {
+		nsec = time.UnixNano()
+	}
+	return syscall.NsecToTimespec(nsec)
+}

vendor/github.com/containers/storage/pkg/archive/whiteouts.go

@@ -0,0 +1,23 @@
+package archive
+
+// Whiteouts are files with a special meaning for the layered filesystem.
+// Docker uses AUFS whiteout files inside exported archives. In other
+// filesystems these files are generated/handled on tar creation/extraction.
+
+// WhiteoutPrefix prefix means file is a whiteout. If this is followed by a
+// filename this means that file has been removed from the base layer.
+const WhiteoutPrefix = ".wh."
+
+// WhiteoutMetaPrefix prefix means whiteout has a special meaning and is not
+// for removing an actual file. Normally these files are excluded from exported
+// archives.
+const WhiteoutMetaPrefix = WhiteoutPrefix + WhiteoutPrefix
+
+// WhiteoutLinkDir is a directory AUFS uses for storing hardlink links to other
+// layers. Normally these should not go into exported archives and all changed
+// hardlinks should be copied to the top layer.
+const WhiteoutLinkDir = WhiteoutMetaPrefix + "plnk"
+
+// WhiteoutOpaqueDir file means directory has been made opaque - meaning
+// readdir calls to this directory do not follow to lower layers.
+const WhiteoutOpaqueDir = WhiteoutMetaPrefix + ".opq"

vendor/github.com/containers/storage/pkg/archive/wrap.go

@@ -0,0 +1,59 @@
+package archive
+
+import (
+	"archive/tar"
+	"bytes"
+	"io"
+)
+
+// Generate generates a new archive from the content provided
+// as input.
+//
+// `files` is a sequence of path/content pairs. A new file is
+// added to the archive for each pair.
+// If the last pair is incomplete, the file is created with an
+// empty content. For example:
+//
+// Generate("foo.txt", "hello world", "emptyfile")
+//
+// The above call will return an archive with 2 files:
+//  * ./foo.txt with content "hello world"
+//  * ./empty with empty content
+//
+// FIXME: stream content instead of buffering
+// FIXME: specify permissions and other archive metadata
+func Generate(input ...string) (io.Reader, error) {
+	files := parseStringPairs(input...)
+	buf := new(bytes.Buffer)
+	tw := tar.NewWriter(buf)
+	for _, file := range files {
+		name, content := file[0], file[1]
+		hdr := &tar.Header{
+			Name: name,
+			Size: int64(len(content)),
+		}
+		if err := tw.WriteHeader(hdr); err != nil {
+			return nil, err
+		}
+		if _, err := tw.Write([]byte(content)); err != nil {
+			return nil, err
+		}
+	}
+	if err := tw.Close(); err != nil {
+		return nil, err
+	}
+	return buf, nil
+}
+
+func parseStringPairs(input ...string) (output [][2]string) {
+	output = make([][2]string, 0, len(input)/2+1)
+	for i := 0; i < len(input); i += 2 {
+		var pair [2]string
+		pair[0] = input[i]
+		if i+1 < len(input) {
+			pair[1] = input[i+1]
+		}
+		output = append(output, pair)
+	}
+	return
+}

vendor/github.com/containers/storage/pkg/chrootarchive/archive.go

@@ -0,0 +1,70 @@
+package chrootarchive
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/containers/storage/pkg/archive"
+	"github.com/containers/storage/pkg/idtools"
+)
+
+// NewArchiver returns a new Archiver which uses chrootarchive.Untar
+func NewArchiver(idMappings *idtools.IDMappings) *archive.Archiver {
+	if idMappings == nil {
+		idMappings = &idtools.IDMappings{}
+	}
+	return &archive.Archiver{Untar: Untar, IDMappings: idMappings}
+}
+
+// Untar reads a stream of bytes from `archive`, parses it as a tar archive,
+// and unpacks it into the directory at `dest`.
+// The archive may be compressed with one of the following algorithms:
+//  identity (uncompressed), gzip, bzip2, xz.
+func Untar(tarArchive io.Reader, dest string, options *archive.TarOptions) error {
+	return untarHandler(tarArchive, dest, options, true)
+}
+
+// UntarUncompressed reads a stream of bytes from `archive`, parses it as a tar archive,
+// and unpacks it into the directory at `dest`.
+// The archive must be an uncompressed stream.
+func UntarUncompressed(tarArchive io.Reader, dest string, options *archive.TarOptions) error {
+	return untarHandler(tarArchive, dest, options, false)
+}
+
+// Handler for teasing out the automatic decompression
+func untarHandler(tarArchive io.Reader, dest string, options *archive.TarOptions, decompress bool) error {
+	if tarArchive == nil {
+		return fmt.Errorf("Empty archive")
+	}
+	if options == nil {
+		options = &archive.TarOptions{}
+	}
+	if options.ExcludePatterns == nil {
+		options.ExcludePatterns = []string{}
+	}
+
+	idMappings := idtools.NewIDMappingsFromMaps(options.UIDMaps, options.GIDMaps)
+	rootIDs := idMappings.RootPair()
+
+	dest = filepath.Clean(dest)
+	if _, err := os.Stat(dest); os.IsNotExist(err) {
+		if err := idtools.MkdirAllAndChownNew(dest, 0755, rootIDs); err != nil {
+			return err
+		}
+	}
+
+	r := ioutil.NopCloser(tarArchive)
+	if decompress {
+		decompressedArchive, err := archive.DecompressStream(tarArchive)
+		if err != nil {
+			return err
+		}
+		defer decompressedArchive.Close()
+		r = decompressedArchive
+	}
+
+	return invokeUnpack(r, dest, options)
+}

vendor/github.com/containers/storage/pkg/chrootarchive/archive_unix.go

@@ -0,0 +1,86 @@
+// +build !windows
+
+package chrootarchive
+
+import (
+	"bytes"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"runtime"
+
+	"github.com/containers/storage/pkg/archive"
+	"github.com/containers/storage/pkg/reexec"
+)
+
+// untar is the entry-point for storage-untar on re-exec. This is not used on
+// Windows as it does not support chroot, hence no point sandboxing through
+// chroot and rexec.
+func untar() {
+	runtime.LockOSThread()
+	flag.Parse()
+
+	var options *archive.TarOptions
+
+	//read the options from the pipe "ExtraFiles"
+	if err := json.NewDecoder(os.NewFile(3, "options")).Decode(&options); err != nil {
+		fatal(err)
+	}
+
+	if err := chroot(flag.Arg(0)); err != nil {
+		fatal(err)
+	}
+
+	if err := archive.Unpack(os.Stdin, "/", options); err != nil {
+		fatal(err)
+	}
+	// fully consume stdin in case it is zero padded
+	if _, err := flush(os.Stdin); err != nil {
+		fatal(err)
+	}
+
+	os.Exit(0)
+}
+
+func invokeUnpack(decompressedArchive io.Reader, dest string, options *archive.TarOptions) error {
+
+	// We can't pass a potentially large exclude list directly via cmd line
+	// because we easily overrun the kernel's max argument/environment size
+	// when the full image list is passed (e.g. when this is used by
+	// `docker load`). We will marshall the options via a pipe to the
+	// child
+	r, w, err := os.Pipe()
+	if err != nil {
+		return fmt.Errorf("Untar pipe failure: %v", err)
+	}
+
+	cmd := reexec.Command("storage-untar", dest)
+	cmd.Stdin = decompressedArchive
+
+	cmd.ExtraFiles = append(cmd.ExtraFiles, r)
+	output := bytes.NewBuffer(nil)
+	cmd.Stdout = output
+	cmd.Stderr = output
+
+	if err := cmd.Start(); err != nil {
+		return fmt.Errorf("Untar error on re-exec cmd: %v", err)
+	}
+	//write the options to the pipe for the untar exec to read
+	if err := json.NewEncoder(w).Encode(options); err != nil {
+		return fmt.Errorf("Untar json encode to pipe failed: %v", err)
+	}
+	w.Close()
+
+	if err := cmd.Wait(); err != nil {
+		// when `xz -d -c -q | storage-untar ...` failed on storage-untar side,
+		// we need to exhaust `xz`'s output, otherwise the `xz` side will be
+		// pending on write pipe forever
+		io.Copy(ioutil.Discard, decompressedArchive)
+
+		return fmt.Errorf("Error processing tar file(%v): %s", err, output)
+	}
+	return nil
+}

vendor/github.com/containers/storage/pkg/chrootarchive/archive_windows.go

@@ -0,0 +1,22 @@
+package chrootarchive
+
+import (
+	"io"
+
+	"github.com/containers/storage/pkg/archive"
+	"github.com/containers/storage/pkg/longpath"
+)
+
+// chroot is not supported by Windows
+func chroot(path string) error {
+	return nil
+}
+
+func invokeUnpack(decompressedArchive io.ReadCloser,
+	dest string,
+	options *archive.TarOptions) error {
+	// Windows is different to Linux here because Windows does not support
+	// chroot. Hence there is no point sandboxing a chrooted process to
+	// do the unpack. We call inline instead within the daemon process.
+	return archive.Unpack(decompressedArchive, longpath.AddPrefix(dest), options)
+}

vendor/github.com/containers/storage/pkg/chrootarchive/chroot_linux.go

@@ -0,0 +1,108 @@
+package chrootarchive
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/containers/storage/pkg/mount"
+	rsystem "github.com/opencontainers/runc/libcontainer/system"
+	"golang.org/x/sys/unix"
+)
+
+// chroot on linux uses pivot_root instead of chroot
+// pivot_root takes a new root and an old root.
+// Old root must be a sub-dir of new root, it is where the current rootfs will reside after the call to pivot_root.
+// New root is where the new rootfs is set to.
+// Old root is removed after the call to pivot_root so it is no longer available under the new root.
+// This is similar to how libcontainer sets up a container's rootfs
+func chroot(path string) (err error) {
+	// if the engine is running in a user namespace we need to use actual chroot
+	if rsystem.RunningInUserNS() {
+		return realChroot(path)
+	}
+	if err := unix.Unshare(unix.CLONE_NEWNS); err != nil {
+		return fmt.Errorf("Error creating mount namespace before pivot: %v", err)
+	}
+
+	// make everything in new ns private
+	if err := mount.MakeRPrivate("/"); err != nil {
+		return err
+	}
+
+	if mounted, _ := mount.Mounted(path); !mounted {
+		if err := mount.Mount(path, path, "bind", "rbind,rw"); err != nil {
+			return realChroot(path)
+		}
+	}
+
+	// setup oldRoot for pivot_root
+	pivotDir, err := ioutil.TempDir(path, ".pivot_root")
+	if err != nil {
+		return fmt.Errorf("Error setting up pivot dir: %v", err)
+	}
+
+	var mounted bool
+	defer func() {
+		if mounted {
+			// make sure pivotDir is not mounted before we try to remove it
+			if errCleanup := unix.Unmount(pivotDir, unix.MNT_DETACH); errCleanup != nil {
+				if err == nil {
+					err = errCleanup
+				}
+				return
+			}
+		}
+
+		errCleanup := os.Remove(pivotDir)
+		// pivotDir doesn't exist if pivot_root failed and chroot+chdir was successful
+		// because we already cleaned it up on failed pivot_root
+		if errCleanup != nil && !os.IsNotExist(errCleanup) {
+			errCleanup = fmt.Errorf("Error cleaning up after pivot: %v", errCleanup)
+			if err == nil {
+				err = errCleanup
+			}
+		}
+	}()
+
+	if err := unix.PivotRoot(path, pivotDir); err != nil {
+		// If pivot fails, fall back to the normal chroot after cleaning up temp dir
+		if err := os.Remove(pivotDir); err != nil {
+			return fmt.Errorf("Error cleaning up after failed pivot: %v", err)
+		}
+		return realChroot(path)
+	}
+	mounted = true
+
+	// This is the new path for where the old root (prior to the pivot) has been moved to
+	// This dir contains the rootfs of the caller, which we need to remove so it is not visible during extraction
+	pivotDir = filepath.Join("/", filepath.Base(pivotDir))
+
+	if err := unix.Chdir("/"); err != nil {
+		return fmt.Errorf("Error changing to new root: %v", err)
+	}
+
+	// Make the pivotDir (where the old root lives) private so it can be unmounted without propagating to the host
+	if err := unix.Mount("", pivotDir, "", unix.MS_PRIVATE|unix.MS_REC, ""); err != nil {
+		return fmt.Errorf("Error making old root private after pivot: %v", err)
+	}
+
+	// Now unmount the old root so it's no longer visible from the new root
+	if err := unix.Unmount(pivotDir, unix.MNT_DETACH); err != nil {
+		return fmt.Errorf("Error while unmounting old root after pivot: %v", err)
+	}
+	mounted = false
+
+	return nil
+}
+
+func realChroot(path string) error {
+	if err := unix.Chroot(path); err != nil {
+		return fmt.Errorf("Error after fallback to chroot: %v", err)
+	}
+	if err := unix.Chdir("/"); err != nil {
+		return fmt.Errorf("Error changing to new root after chroot: %v", err)
+	}
+	return nil
+}

vendor/github.com/containers/storage/pkg/chrootarchive/chroot_unix.go

@@ -0,0 +1,12 @@
+// +build !windows,!linux
+
+package chrootarchive
+
+import "golang.org/x/sys/unix"
+
+func chroot(path string) error {
+	if err := unix.Chroot(path); err != nil {
+		return err
+	}
+	return unix.Chdir("/")
+}

vendor/github.com/containers/storage/pkg/chrootarchive/diff.go

@@ -0,0 +1,23 @@
+package chrootarchive
+
+import (
+	"io"
+
+	"github.com/containers/storage/pkg/archive"
+)
+
+// ApplyLayer parses a diff in the standard layer format from `layer`,
+// and applies it to the directory `dest`. The stream `layer` can only be
+// uncompressed.
+// Returns the size in bytes of the contents of the layer.
+func ApplyLayer(dest string, layer io.Reader) (size int64, err error) {
+	return applyLayerHandler(dest, layer, &archive.TarOptions{}, true)
+}
+
+// ApplyUncompressedLayer parses a diff in the standard layer format from
+// `layer`, and applies it to the directory `dest`. The stream `layer`
+// can only be uncompressed.
+// Returns the size in bytes of the contents of the layer.
+func ApplyUncompressedLayer(dest string, layer io.Reader, options *archive.TarOptions) (int64, error) {
+	return applyLayerHandler(dest, layer, options, false)
+}

vendor/github.com/containers/storage/pkg/chrootarchive/diff_unix.go

@@ -0,0 +1,130 @@
+//+build !windows
+
+package chrootarchive
+
+import (
+	"bytes"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"runtime"
+
+	"github.com/containers/storage/pkg/archive"
+	"github.com/containers/storage/pkg/reexec"
+	"github.com/containers/storage/pkg/system"
+	rsystem "github.com/opencontainers/runc/libcontainer/system"
+)
+
+type applyLayerResponse struct {
+	LayerSize int64 `json:"layerSize"`
+}
+
+// applyLayer is the entry-point for storage-applylayer on re-exec. This is not
+// used on Windows as it does not support chroot, hence no point sandboxing
+// through chroot and rexec.
+func applyLayer() {
+
+	var (
+		tmpDir  string
+		err     error
+		options *archive.TarOptions
+	)
+	runtime.LockOSThread()
+	flag.Parse()
+
+	inUserns := rsystem.RunningInUserNS()
+	if err := chroot(flag.Arg(0)); err != nil {
+		fatal(err)
+	}
+
+	// We need to be able to set any perms
+	oldmask, err := system.Umask(0)
+	defer system.Umask(oldmask)
+	if err != nil {
+		fatal(err)
+	}
+
+	if err := json.Unmarshal([]byte(os.Getenv("OPT")), &options); err != nil {
+		fatal(err)
+	}
+
+	if inUserns {
+		options.InUserNS = true
+	}
+
+	if tmpDir, err = ioutil.TempDir("/", "temp-storage-extract"); err != nil {
+		fatal(err)
+	}
+
+	os.Setenv("TMPDIR", tmpDir)
+	size, err := archive.UnpackLayer("/", os.Stdin, options)
+	os.RemoveAll(tmpDir)
+	if err != nil {
+		fatal(err)
+	}
+
+	encoder := json.NewEncoder(os.Stdout)
+	if err := encoder.Encode(applyLayerResponse{size}); err != nil {
+		fatal(fmt.Errorf("unable to encode layerSize JSON: %s", err))
+	}
+
+	if _, err := flush(os.Stdin); err != nil {
+		fatal(err)
+	}
+
+	os.Exit(0)
+}
+
+// applyLayerHandler parses a diff in the standard layer format from `layer`, and
+// applies it to the directory `dest`. Returns the size in bytes of the
+// contents of the layer.
+func applyLayerHandler(dest string, layer io.Reader, options *archive.TarOptions, decompress bool) (size int64, err error) {
+	dest = filepath.Clean(dest)
+	if decompress {
+		decompressed, err := archive.DecompressStream(layer)
+		if err != nil {
+			return 0, err
+		}
+		defer decompressed.Close()
+
+		layer = decompressed
+	}
+	if options == nil {
+		options = &archive.TarOptions{}
+		if rsystem.RunningInUserNS() {
+			options.InUserNS = true
+		}
+	}
+	if options.ExcludePatterns == nil {
+		options.ExcludePatterns = []string{}
+	}
+
+	data, err := json.Marshal(options)
+	if err != nil {
+		return 0, fmt.Errorf("ApplyLayer json encode: %v", err)
+	}
+
+	cmd := reexec.Command("storage-applyLayer", dest)
+	cmd.Stdin = layer
+	cmd.Env = append(cmd.Env, fmt.Sprintf("OPT=%s", data))
+
+	outBuf, errBuf := new(bytes.Buffer), new(bytes.Buffer)
+	cmd.Stdout, cmd.Stderr = outBuf, errBuf
+
+	if err = cmd.Run(); err != nil {
+		return 0, fmt.Errorf("ApplyLayer %s stdout: %s stderr: %s", err, outBuf, errBuf)
+	}
+
+	// Stdout should be a valid JSON struct representing an applyLayerResponse.
+	response := applyLayerResponse{}
+	decoder := json.NewDecoder(outBuf)
+	if err = decoder.Decode(&response); err != nil {
+		return 0, fmt.Errorf("unable to decode ApplyLayer JSON response: %s", err)
+	}
+
+	return response.LayerSize, nil
+}

vendor/github.com/containers/storage/pkg/chrootarchive/diff_windows.go

@@ -0,0 +1,45 @@
+package chrootarchive
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/containers/storage/pkg/archive"
+	"github.com/containers/storage/pkg/longpath"
+)
+
+// applyLayerHandler parses a diff in the standard layer format from `layer`, and
+// applies it to the directory `dest`. Returns the size in bytes of the
+// contents of the layer.
+func applyLayerHandler(dest string, layer io.Reader, options *archive.TarOptions, decompress bool) (size int64, err error) {
+	dest = filepath.Clean(dest)
+
+	// Ensure it is a Windows-style volume path
+	dest = longpath.AddPrefix(dest)
+
+	if decompress {
+		decompressed, err := archive.DecompressStream(layer)
+		if err != nil {
+			return 0, err
+		}
+		defer decompressed.Close()
+
+		layer = decompressed
+	}
+
+	tmpDir, err := ioutil.TempDir(os.Getenv("temp"), "temp-storage-extract")
+	if err != nil {
+		return 0, fmt.Errorf("ApplyLayer failed to create temp-storage-extract under %s. %s", dest, err)
+	}
+
+	s, err := archive.UnpackLayer(dest, layer, nil)
+	os.RemoveAll(tmpDir)
+	if err != nil {
+		return 0, fmt.Errorf("ApplyLayer %s failed UnpackLayer to %s: %s", layer, dest, err)
+	}
+
+	return s, nil
+}

vendor/github.com/containers/storage/pkg/chrootarchive/init_unix.go

@@ -0,0 +1,28 @@
+// +build !windows
+
+package chrootarchive
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+
+	"github.com/containers/storage/pkg/reexec"
+)
+
+func init() {
+	reexec.Register("storage-applyLayer", applyLayer)
+	reexec.Register("storage-untar", untar)
+}
+
+func fatal(err error) {
+	fmt.Fprint(os.Stderr, err)
+	os.Exit(1)
+}
+
+// flush consumes all the bytes from the reader discarding
+// any errors
+func flush(r io.Reader) (bytes int64, err error) {
+	return io.Copy(ioutil.Discard, r)
+}

vendor/github.com/containers/storage/pkg/chrootarchive/init_windows.go

@@ -0,0 +1,4 @@
+package chrootarchive
+
+func init() {
+}

vendor/github.com/containers/storage/pkg/devicemapper/devmapper.go

@@ -0,0 +1,821 @@
+// +build linux,cgo
+
+package devicemapper
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"runtime"
+	"unsafe"
+
+	"github.com/sirupsen/logrus"
+	"golang.org/x/sys/unix"
+)
+
+// Same as DM_DEVICE_* enum values from libdevmapper.h
+// nolint: deadcode
+const (
+	deviceCreate TaskType = iota
+	deviceReload
+	deviceRemove
+	deviceRemoveAll
+	deviceSuspend
+	deviceResume
+	deviceInfo
+	deviceDeps
+	deviceRename
+	deviceVersion
+	deviceStatus
+	deviceTable
+	deviceWaitevent
+	deviceList
+	deviceClear
+	deviceMknodes
+	deviceListVersions
+	deviceTargetMsg
+	deviceSetGeometry
+)
+
+const (
+	addNodeOnResume AddNodeType = iota
+	addNodeOnCreate
+)
+
+// List of errors returned when using devicemapper.
+var (
+	ErrTaskRun              = errors.New("dm_task_run failed")
+	ErrTaskSetName          = errors.New("dm_task_set_name failed")
+	ErrTaskSetMessage       = errors.New("dm_task_set_message failed")
+	ErrTaskSetAddNode       = errors.New("dm_task_set_add_node failed")
+	ErrTaskSetRo            = errors.New("dm_task_set_ro failed")
+	ErrTaskAddTarget        = errors.New("dm_task_add_target failed")
+	ErrTaskSetSector        = errors.New("dm_task_set_sector failed")
+	ErrTaskGetDeps          = errors.New("dm_task_get_deps failed")
+	ErrTaskGetInfo          = errors.New("dm_task_get_info failed")
+	ErrTaskGetDriverVersion = errors.New("dm_task_get_driver_version failed")
+	ErrTaskDeferredRemove   = errors.New("dm_task_deferred_remove failed")
+	ErrTaskSetCookie        = errors.New("dm_task_set_cookie failed")
+	ErrNilCookie            = errors.New("cookie ptr can't be nil")
+	ErrGetBlockSize         = errors.New("Can't get block size")
+	ErrUdevWait             = errors.New("wait on udev cookie failed")
+	ErrSetDevDir            = errors.New("dm_set_dev_dir failed")
+	ErrGetLibraryVersion    = errors.New("dm_get_library_version failed")
+	ErrCreateRemoveTask     = errors.New("Can't create task of type deviceRemove")
+	ErrRunRemoveDevice      = errors.New("running RemoveDevice failed")
+	ErrInvalidAddNode       = errors.New("Invalid AddNode type")
+	ErrBusy                 = errors.New("Device is Busy")
+	ErrDeviceIDExists       = errors.New("Device Id Exists")
+	ErrEnxio                = errors.New("No such device or address")
+)
+
+var (
+	dmSawBusy  bool
+	dmSawExist bool
+	dmSawEnxio bool // No Such Device or Address
+)
+
+type (
+	// Task represents a devicemapper task (like lvcreate, etc.) ; a task is needed for each ioctl
+	// command to execute.
+	Task struct {
+		unmanaged *cdmTask
+	}
+	// Deps represents dependents (layer) of a device.
+	Deps struct {
+		Count  uint32
+		Filler uint32
+		Device []uint64
+	}
+	// Info represents information about a device.
+	Info struct {
+		Exists         int
+		Suspended      int
+		LiveTable      int
+		InactiveTable  int
+		OpenCount      int32
+		EventNr        uint32
+		Major          uint32
+		Minor          uint32
+		ReadOnly       int
+		TargetCount    int32
+		DeferredRemove int
+	}
+	// TaskType represents a type of task
+	TaskType int
+	// AddNodeType represents a type of node to be added
+	AddNodeType int
+)
+
+// DeviceIDExists returns whether error conveys the information about device Id already
+// exist or not. This will be true if device creation or snap creation
+// operation fails if device or snap device already exists in pool.
+// Current implementation is little crude as it scans the error string
+// for exact pattern match. Replacing it with more robust implementation
+// is desirable.
+func DeviceIDExists(err error) bool {
+	return fmt.Sprint(err) == fmt.Sprint(ErrDeviceIDExists)
+}
+
+func (t *Task) destroy() {
+	if t != nil {
+		DmTaskDestroy(t.unmanaged)
+		runtime.SetFinalizer(t, nil)
+	}
+}
+
+// TaskCreateNamed is a convenience function for TaskCreate when a name
+// will be set on the task as well
+func TaskCreateNamed(t TaskType, name string) (*Task, error) {
+	task := TaskCreate(t)
+	if task == nil {
+		return nil, fmt.Errorf("devicemapper: Can't create task of type %d", int(t))
+	}
+	if err := task.setName(name); err != nil {
+		return nil, fmt.Errorf("devicemapper: Can't set task name %s", name)
+	}
+	return task, nil
+}
+
+// TaskCreate initializes a devicemapper task of tasktype
+func TaskCreate(tasktype TaskType) *Task {
+	Ctask := DmTaskCreate(int(tasktype))
+	if Ctask == nil {
+		return nil
+	}
+	task := &Task{unmanaged: Ctask}
+	runtime.SetFinalizer(task, (*Task).destroy)
+	return task
+}
+
+func (t *Task) run() error {
+	if res := DmTaskRun(t.unmanaged); res != 1 {
+		return ErrTaskRun
+	}
+	runtime.KeepAlive(t)
+	return nil
+}
+
+func (t *Task) setName(name string) error {
+	if res := DmTaskSetName(t.unmanaged, name); res != 1 {
+		return ErrTaskSetName
+	}
+	return nil
+}
+
+func (t *Task) setMessage(message string) error {
+	if res := DmTaskSetMessage(t.unmanaged, message); res != 1 {
+		return ErrTaskSetMessage
+	}
+	return nil
+}
+
+func (t *Task) setSector(sector uint64) error {
+	if res := DmTaskSetSector(t.unmanaged, sector); res != 1 {
+		return ErrTaskSetSector
+	}
+	return nil
+}
+
+func (t *Task) setCookie(cookie *uint, flags uint16) error {
+	if cookie == nil {
+		return ErrNilCookie
+	}
+	if res := DmTaskSetCookie(t.unmanaged, cookie, flags); res != 1 {
+		return ErrTaskSetCookie
+	}
+	return nil
+}
+
+func (t *Task) setAddNode(addNode AddNodeType) error {
+	if addNode != addNodeOnResume && addNode != addNodeOnCreate {
+		return ErrInvalidAddNode
+	}
+	if res := DmTaskSetAddNode(t.unmanaged, addNode); res != 1 {
+		return ErrTaskSetAddNode
+	}
+	return nil
+}
+
+func (t *Task) setRo() error {
+	if res := DmTaskSetRo(t.unmanaged); res != 1 {
+		return ErrTaskSetRo
+	}
+	return nil
+}
+
+func (t *Task) addTarget(start, size uint64, ttype, params string) error {
+	if res := DmTaskAddTarget(t.unmanaged, start, size,
+		ttype, params); res != 1 {
+		return ErrTaskAddTarget
+	}
+	return nil
+}
+
+func (t *Task) getDeps() (*Deps, error) {
+	var deps *Deps
+	if deps = DmTaskGetDeps(t.unmanaged); deps == nil {
+		return nil, ErrTaskGetDeps
+	}
+	return deps, nil
+}
+
+func (t *Task) getInfo() (*Info, error) {
+	info := &Info{}
+	if res := DmTaskGetInfo(t.unmanaged, info); res != 1 {
+		return nil, ErrTaskGetInfo
+	}
+	return info, nil
+}
+
+func (t *Task) getInfoWithDeferred() (*Info, error) {
+	info := &Info{}
+	if res := DmTaskGetInfoWithDeferred(t.unmanaged, info); res != 1 {
+		return nil, ErrTaskGetInfo
+	}
+	return info, nil
+}
+
+func (t *Task) getDriverVersion() (string, error) {
+	res := DmTaskGetDriverVersion(t.unmanaged)
+	if res == "" {
+		return "", ErrTaskGetDriverVersion
+	}
+	return res, nil
+}
+
+func (t *Task) getNextTarget(next unsafe.Pointer) (nextPtr unsafe.Pointer, start uint64,
+	length uint64, targetType string, params string) {
+
+	return DmGetNextTarget(t.unmanaged, next, &start, &length,
+			&targetType, &params),
+		start, length, targetType, params
+}
+
+// UdevWait waits for any processes that are waiting for udev to complete the specified cookie.
+func UdevWait(cookie *uint) error {
+	if res := DmUdevWait(*cookie); res != 1 {
+		logrus.Debugf("devicemapper: Failed to wait on udev cookie %d, %d", *cookie, res)
+		return ErrUdevWait
+	}
+	return nil
+}
+
+// SetDevDir sets the dev folder for the device mapper library (usually /dev).
+func SetDevDir(dir string) error {
+	if res := DmSetDevDir(dir); res != 1 {
+		logrus.Debug("devicemapper: Error dm_set_dev_dir")
+		return ErrSetDevDir
+	}
+	return nil
+}
+
+// GetLibraryVersion returns the device mapper library version.
+func GetLibraryVersion() (string, error) {
+	var version string
+	if res := DmGetLibraryVersion(&version); res != 1 {
+		return "", ErrGetLibraryVersion
+	}
+	return version, nil
+}
+
+// UdevSyncSupported returns whether device-mapper is able to sync with udev
+//
+// This is essential otherwise race conditions can arise where both udev and
+// device-mapper attempt to create and destroy devices.
+func UdevSyncSupported() bool {
+	return DmUdevGetSyncSupport() != 0
+}
+
+// UdevSetSyncSupport allows setting whether the udev sync should be enabled.
+// The return bool indicates the state of whether the sync is enabled.
+func UdevSetSyncSupport(enable bool) bool {
+	if enable {
+		DmUdevSetSyncSupport(1)
+	} else {
+		DmUdevSetSyncSupport(0)
+	}
+
+	return UdevSyncSupported()
+}
+
+// CookieSupported returns whether the version of device-mapper supports the
+// use of cookie's in the tasks.
+// This is largely a lower level call that other functions use.
+func CookieSupported() bool {
+	return DmCookieSupported() != 0
+}
+
+// RemoveDevice is a useful helper for cleaning up a device.
+func RemoveDevice(name string) error {
+	task, err := TaskCreateNamed(deviceRemove, name)
+	if task == nil {
+		return err
+	}
+
+	cookie := new(uint)
+	if err := task.setCookie(cookie, 0); err != nil {
+		return fmt.Errorf("devicemapper: Can not set cookie: %s", err)
+	}
+	defer UdevWait(cookie)
+
+	dmSawBusy = false // reset before the task is run
+	dmSawEnxio = false
+	if err = task.run(); err != nil {
+		if dmSawBusy {
+			return ErrBusy
+		}
+		if dmSawEnxio {
+			return ErrEnxio
+		}
+		return fmt.Errorf("devicemapper: Error running RemoveDevice %s", err)
+	}
+
+	return nil
+}
+
+// RemoveDeviceDeferred is a useful helper for cleaning up a device, but deferred.
+func RemoveDeviceDeferred(name string) error {
+	logrus.Debugf("devicemapper: RemoveDeviceDeferred START(%s)", name)
+	defer logrus.Debugf("devicemapper: RemoveDeviceDeferred END(%s)", name)
+	task, err := TaskCreateNamed(deviceRemove, name)
+	if task == nil {
+		return err
+	}
+
+	if err := DmTaskDeferredRemove(task.unmanaged); err != 1 {
+		return ErrTaskDeferredRemove
+	}
+
+	// set a task cookie and disable library fallback, or else libdevmapper will
+	// disable udev dm rules and delete the symlink under /dev/mapper by itself,
+	// even if the removal is deferred by the kernel.
+	cookie := new(uint)
+	var flags uint16
+	flags = DmUdevDisableLibraryFallback
+	if err := task.setCookie(cookie, flags); err != nil {
+		return fmt.Errorf("devicemapper: Can not set cookie: %s", err)
+	}
+
+	// libdevmapper and udev relies on System V semaphore for synchronization,
+	// semaphores created in `task.setCookie` will be cleaned up in `UdevWait`.
+	// So these two function call must come in pairs, otherwise semaphores will
+	// be leaked, and the  limit of number of semaphores defined in `/proc/sys/kernel/sem`
+	// will be reached, which will eventually make all following calls to 'task.SetCookie'
+	// fail.
+	// this call will not wait for the deferred removal's final executing, since no
+	// udev event will be generated, and the semaphore's value will not be incremented
+	// by udev, what UdevWait is just cleaning up the semaphore.
+	defer UdevWait(cookie)
+
+	dmSawEnxio = false
+	if err = task.run(); err != nil {
+		if dmSawEnxio {
+			return ErrEnxio
+		}
+		return fmt.Errorf("devicemapper: Error running RemoveDeviceDeferred %s", err)
+	}
+
+	return nil
+}
+
+// CancelDeferredRemove cancels a deferred remove for a device.
+func CancelDeferredRemove(deviceName string) error {
+	task, err := TaskCreateNamed(deviceTargetMsg, deviceName)
+	if task == nil {
+		return err
+	}
+
+	if err := task.setSector(0); err != nil {
+		return fmt.Errorf("devicemapper: Can't set sector %s", err)
+	}
+
+	if err := task.setMessage(fmt.Sprintf("@cancel_deferred_remove")); err != nil {
+		return fmt.Errorf("devicemapper: Can't set message %s", err)
+	}
+
+	dmSawBusy = false
+	dmSawEnxio = false
+	if err := task.run(); err != nil {
+		// A device might be being deleted already
+		if dmSawBusy {
+			return ErrBusy
+		} else if dmSawEnxio {
+			return ErrEnxio
+		}
+		return fmt.Errorf("devicemapper: Error running CancelDeferredRemove %s", err)
+
+	}
+	return nil
+}
+
+// GetBlockDeviceSize returns the size of a block device identified by the specified file.
+func GetBlockDeviceSize(file *os.File) (uint64, error) {
+	size, err := ioctlBlkGetSize64(file.Fd())
+	if err != nil {
+		logrus.Errorf("devicemapper: Error getblockdevicesize: %s", err)
+		return 0, ErrGetBlockSize
+	}
+	return uint64(size), nil
+}
+
+// BlockDeviceDiscard runs discard for the given path.
+// This is used as a workaround for the kernel not discarding block so
+// on the thin pool when we remove a thinp device, so we do it
+// manually
+func BlockDeviceDiscard(path string) error {
+	file, err := os.OpenFile(path, os.O_RDWR, 0)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	size, err := GetBlockDeviceSize(file)
+	if err != nil {
+		return err
+	}
+
+	if err := ioctlBlkDiscard(file.Fd(), 0, size); err != nil {
+		return err
+	}
+
+	// Without this sometimes the remove of the device that happens after
+	// discard fails with EBUSY.
+	unix.Sync()
+
+	return nil
+}
+
+// CreatePool is the programmatic example of "dmsetup create".
+// It creates a device with the specified poolName, data and metadata file and block size.
+func CreatePool(poolName string, dataFile, metadataFile *os.File, poolBlockSize uint32) error {
+	task, err := TaskCreateNamed(deviceCreate, poolName)
+	if task == nil {
+		return err
+	}
+
+	size, err := GetBlockDeviceSize(dataFile)
+	if err != nil {
+		return fmt.Errorf("devicemapper: Can't get data size %s", err)
+	}
+
+	params := fmt.Sprintf("%s %s %d 32768 1 skip_block_zeroing", metadataFile.Name(), dataFile.Name(), poolBlockSize)
+	if err := task.addTarget(0, size/512, "thin-pool", params); err != nil {
+		return fmt.Errorf("devicemapper: Can't add target %s", err)
+	}
+
+	cookie := new(uint)
+	var flags uint16
+	flags = DmUdevDisableSubsystemRulesFlag | DmUdevDisableDiskRulesFlag | DmUdevDisableOtherRulesFlag
+	if err := task.setCookie(cookie, flags); err != nil {
+		return fmt.Errorf("devicemapper: Can't set cookie %s", err)
+	}
+	defer UdevWait(cookie)
+
+	if err := task.run(); err != nil {
+		return fmt.Errorf("devicemapper: Error running deviceCreate (CreatePool) %s", err)
+	}
+
+	return nil
+}
+
+// ReloadPool is the programmatic example of "dmsetup reload".
+// It reloads the table with the specified poolName, data and metadata file and block size.
+func ReloadPool(poolName string, dataFile, metadataFile *os.File, poolBlockSize uint32) error {
+	task, err := TaskCreateNamed(deviceReload, poolName)
+	if task == nil {
+		return err
+	}
+
+	size, err := GetBlockDeviceSize(dataFile)
+	if err != nil {
+		return fmt.Errorf("devicemapper: Can't get data size %s", err)
+	}
+
+	params := fmt.Sprintf("%s %s %d 32768 1 skip_block_zeroing", metadataFile.Name(), dataFile.Name(), poolBlockSize)
+	if err := task.addTarget(0, size/512, "thin-pool", params); err != nil {
+		return fmt.Errorf("devicemapper: Can't add target %s", err)
+	}
+
+	if err := task.run(); err != nil {
+		return fmt.Errorf("devicemapper: Error running ReloadPool %s", err)
+	}
+
+	return nil
+}
+
+// GetDeps is the programmatic example of "dmsetup deps".
+// It outputs a list of devices referenced by the live table for the specified device.
+func GetDeps(name string) (*Deps, error) {
+	task, err := TaskCreateNamed(deviceDeps, name)
+	if task == nil {
+		return nil, err
+	}
+	if err := task.run(); err != nil {
+		return nil, err
+	}
+	return task.getDeps()
+}
+
+// GetInfo is the programmatic example of "dmsetup info".
+// It outputs some brief information about the device.
+func GetInfo(name string) (*Info, error) {
+	task, err := TaskCreateNamed(deviceInfo, name)
+	if task == nil {
+		return nil, err
+	}
+	if err := task.run(); err != nil {
+		return nil, err
+	}
+	return task.getInfo()
+}
+
+// GetInfoWithDeferred is the programmatic example of "dmsetup info", but deferred.
+// It outputs some brief information about the device.
+func GetInfoWithDeferred(name string) (*Info, error) {
+	task, err := TaskCreateNamed(deviceInfo, name)
+	if task == nil {
+		return nil, err
+	}
+	if err := task.run(); err != nil {
+		return nil, err
+	}
+	return task.getInfoWithDeferred()
+}
+
+// GetDriverVersion is the programmatic example of "dmsetup version".
+// It outputs version information of the driver.
+func GetDriverVersion() (string, error) {
+	task := TaskCreate(deviceVersion)
+	if task == nil {
+		return "", fmt.Errorf("devicemapper: Can't create deviceVersion task")
+	}
+	if err := task.run(); err != nil {
+		return "", err
+	}
+	return task.getDriverVersion()
+}
+
+// GetStatus is the programmatic example of "dmsetup status".
+// It outputs status information for the specified device name.
+func GetStatus(name string) (uint64, uint64, string, string, error) {
+	task, err := TaskCreateNamed(deviceStatus, name)
+	if task == nil {
+		logrus.Debugf("devicemapper: GetStatus() Error TaskCreateNamed: %s", err)
+		return 0, 0, "", "", err
+	}
+	if err := task.run(); err != nil {
+		logrus.Debugf("devicemapper: GetStatus() Error Run: %s", err)
+		return 0, 0, "", "", err
+	}
+
+	devinfo, err := task.getInfo()
+	if err != nil {
+		logrus.Debugf("devicemapper: GetStatus() Error GetInfo: %s", err)
+		return 0, 0, "", "", err
+	}
+	if devinfo.Exists == 0 {
+		logrus.Debugf("devicemapper: GetStatus() Non existing device %s", name)
+		return 0, 0, "", "", fmt.Errorf("devicemapper: Non existing device %s", name)
+	}
+
+	_, start, length, targetType, params := task.getNextTarget(unsafe.Pointer(nil))
+	return start, length, targetType, params, nil
+}
+
+// GetTable is the programmatic example for "dmsetup table".
+// It outputs the current table for the specified device name.
+func GetTable(name string) (uint64, uint64, string, string, error) {
+	task, err := TaskCreateNamed(deviceTable, name)
+	if task == nil {
+		logrus.Debugf("devicemapper: GetTable() Error TaskCreateNamed: %s", err)
+		return 0, 0, "", "", err
+	}
+	if err := task.run(); err != nil {
+		logrus.Debugf("devicemapper: GetTable() Error Run: %s", err)
+		return 0, 0, "", "", err
+	}
+
+	devinfo, err := task.getInfo()
+	if err != nil {
+		logrus.Debugf("devicemapper: GetTable() Error GetInfo: %s", err)
+		return 0, 0, "", "", err
+	}
+	if devinfo.Exists == 0 {
+		logrus.Debugf("devicemapper: GetTable() Non existing device %s", name)
+		return 0, 0, "", "", fmt.Errorf("devicemapper: Non existing device %s", name)
+	}
+
+	_, start, length, targetType, params := task.getNextTarget(unsafe.Pointer(nil))
+	return start, length, targetType, params, nil
+}
+
+// SetTransactionID sets a transaction id for the specified device name.
+func SetTransactionID(poolName string, oldID uint64, newID uint64) error {
+	task, err := TaskCreateNamed(deviceTargetMsg, poolName)
+	if task == nil {
+		return err
+	}
+
+	if err := task.setSector(0); err != nil {
+		return fmt.Errorf("devicemapper: Can't set sector %s", err)
+	}
+
+	if err := task.setMessage(fmt.Sprintf("set_transaction_id %d %d", oldID, newID)); err != nil {
+		return fmt.Errorf("devicemapper: Can't set message %s", err)
+	}
+
+	if err := task.run(); err != nil {
+		return fmt.Errorf("devicemapper: Error running SetTransactionID %s", err)
+	}
+	return nil
+}
+
+// SuspendDevice is the programmatic example of "dmsetup suspend".
+// It suspends the specified device.
+func SuspendDevice(name string) error {
+	task, err := TaskCreateNamed(deviceSuspend, name)
+	if task == nil {
+		return err
+	}
+	if err := task.run(); err != nil {
+		return fmt.Errorf("devicemapper: Error running deviceSuspend %s", err)
+	}
+	return nil
+}
+
+// ResumeDevice is the programmatic example of "dmsetup resume".
+// It un-suspends the specified device.
+func ResumeDevice(name string) error {
+	task, err := TaskCreateNamed(deviceResume, name)
+	if task == nil {
+		return err
+	}
+
+	cookie := new(uint)
+	if err := task.setCookie(cookie, 0); err != nil {
+		return fmt.Errorf("devicemapper: Can't set cookie %s", err)
+	}
+	defer UdevWait(cookie)
+
+	if err := task.run(); err != nil {
+		return fmt.Errorf("devicemapper: Error running deviceResume %s", err)
+	}
+
+	return nil
+}
+
+// CreateDevice creates a device with the specified poolName with the specified device id.
+func CreateDevice(poolName string, deviceID int) error {
+	logrus.Debugf("devicemapper: CreateDevice(poolName=%v, deviceID=%v)", poolName, deviceID)
+	task, err := TaskCreateNamed(deviceTargetMsg, poolName)
+	if task == nil {
+		return err
+	}
+
+	if err := task.setSector(0); err != nil {
+		return fmt.Errorf("devicemapper: Can't set sector %s", err)
+	}
+
+	if err := task.setMessage(fmt.Sprintf("create_thin %d", deviceID)); err != nil {
+		return fmt.Errorf("devicemapper: Can't set message %s", err)
+	}
+
+	dmSawExist = false // reset before the task is run
+	if err := task.run(); err != nil {
+		// Caller wants to know about ErrDeviceIDExists so that it can try with a different device id.
+		if dmSawExist {
+			return ErrDeviceIDExists
+		}
+
+		return fmt.Errorf("devicemapper: Error running CreateDevice %s", err)
+
+	}
+	return nil
+}
+
+// DeleteDevice deletes a device with the specified poolName with the specified device id.
+func DeleteDevice(poolName string, deviceID int) error {
+	task, err := TaskCreateNamed(deviceTargetMsg, poolName)
+	if task == nil {
+		return err
+	}
+
+	if err := task.setSector(0); err != nil {
+		return fmt.Errorf("devicemapper: Can't set sector %s", err)
+	}
+
+	if err := task.setMessage(fmt.Sprintf("delete %d", deviceID)); err != nil {
+		return fmt.Errorf("devicemapper: Can't set message %s", err)
+	}
+
+	dmSawBusy = false
+	if err := task.run(); err != nil {
+		if dmSawBusy {
+			return ErrBusy
+		}
+		return fmt.Errorf("devicemapper: Error running DeleteDevice %s", err)
+	}
+	return nil
+}
+
+// ActivateDevice activates the device identified by the specified
+// poolName, name and deviceID with the specified size.
+func ActivateDevice(poolName string, name string, deviceID int, size uint64) error {
+	return activateDevice(poolName, name, deviceID, size, "")
+}
+
+// ActivateDeviceWithExternal activates the device identified by the specified
+// poolName, name and deviceID with the specified size.
+func ActivateDeviceWithExternal(poolName string, name string, deviceID int, size uint64, external string) error {
+	return activateDevice(poolName, name, deviceID, size, external)
+}
+
+func activateDevice(poolName string, name string, deviceID int, size uint64, external string) error {
+	task, err := TaskCreateNamed(deviceCreate, name)
+	if task == nil {
+		return err
+	}
+
+	var params string
+	if len(external) > 0 {
+		params = fmt.Sprintf("%s %d %s", poolName, deviceID, external)
+	} else {
+		params = fmt.Sprintf("%s %d", poolName, deviceID)
+	}
+	if err := task.addTarget(0, size/512, "thin", params); err != nil {
+		return fmt.Errorf("devicemapper: Can't add target %s", err)
+	}
+	if err := task.setAddNode(addNodeOnCreate); err != nil {
+		return fmt.Errorf("devicemapper: Can't add node %s", err)
+	}
+
+	cookie := new(uint)
+	if err := task.setCookie(cookie, 0); err != nil {
+		return fmt.Errorf("devicemapper: Can't set cookie %s", err)
+	}
+
+	defer UdevWait(cookie)
+
+	if err := task.run(); err != nil {
+		return fmt.Errorf("devicemapper: Error running deviceCreate (ActivateDevice) %s", err)
+	}
+
+	return nil
+}
+
+// CreateSnapDeviceRaw creates a snapshot device. Caller needs to suspend and resume the origin device if it is active.
+func CreateSnapDeviceRaw(poolName string, deviceID int, baseDeviceID int) error {
+	task, err := TaskCreateNamed(deviceTargetMsg, poolName)
+	if task == nil {
+		return err
+	}
+
+	if err := task.setSector(0); err != nil {
+		return fmt.Errorf("devicemapper: Can't set sector %s", err)
+	}
+
+	if err := task.setMessage(fmt.Sprintf("create_snap %d %d", deviceID, baseDeviceID)); err != nil {
+		return fmt.Errorf("devicemapper: Can't set message %s", err)
+	}
+
+	dmSawExist = false // reset before the task is run
+	if err := task.run(); err != nil {
+		// Caller wants to know about ErrDeviceIDExists so that it can try with a different device id.
+		if dmSawExist {
+			return ErrDeviceIDExists
+		}
+		return fmt.Errorf("devicemapper: Error running deviceCreate (CreateSnapDeviceRaw) %s", err)
+	}
+
+	return nil
+}
+
+// CreateSnapDevice creates a snapshot based on the device identified by the baseName and baseDeviceId,
+func CreateSnapDevice(poolName string, deviceID int, baseName string, baseDeviceID int) error {
+	devinfo, _ := GetInfo(baseName)
+	doSuspend := devinfo != nil && devinfo.Exists != 0
+
+	if doSuspend {
+		if err := SuspendDevice(baseName); err != nil {
+			return err
+		}
+	}
+
+	if err := CreateSnapDeviceRaw(poolName, deviceID, baseDeviceID); err != nil {
+		if doSuspend {
+			if err2 := ResumeDevice(baseName); err2 != nil {
+				return fmt.Errorf("CreateSnapDeviceRaw Error: (%v): ResumeDevice Error: (%v)", err, err2)
+			}
+		}
+		return err
+	}
+
+	if doSuspend {
+		if err := ResumeDevice(baseName); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

vendor/github.com/containers/storage/pkg/devicemapper/devmapper_log.go

@@ -0,0 +1,121 @@
+// +build linux,cgo
+
+package devicemapper
+
+import "C"
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/sirupsen/logrus"
+)
+
+// DevmapperLogger defines methods required to register as a callback for
+// logging events recieved from devicemapper. Note that devicemapper will send
+// *all* logs regardless to callbacks (including debug logs) so it's
+// recommended to not spam the console with the outputs.
+type DevmapperLogger interface {
+	// DMLog is the logging callback containing all of the information from
+	// devicemapper. The interface is identical to the C libdm counterpart.
+	DMLog(level int, file string, line int, dmError int, message string)
+}
+
+// dmLogger is the current logger in use that is being forwarded our messages.
+var dmLogger DevmapperLogger
+
+// LogInit changes the logging callback called after processing libdm logs for
+// error message information. The default logger simply forwards all logs to
+// logrus. Calling LogInit(nil) disables the calling of callbacks.
+func LogInit(logger DevmapperLogger) {
+	dmLogger = logger
+}
+
+// Due to the way cgo works this has to be in a separate file, as devmapper.go has
+// definitions in the cgo block, which is incompatible with using "//export"
+
+// StorageDevmapperLogCallback exports the devmapper log callback for cgo. Note that
+// because we are using callbacks, this function will be called for *every* log
+// in libdm (even debug ones because there's no way of setting the verbosity
+// level for an external logging callback).
+//export StorageDevmapperLogCallback
+func StorageDevmapperLogCallback(level C.int, file *C.char, line, dmErrnoOrClass C.int, message *C.char) {
+	msg := C.GoString(message)
+
+	// Track what errno libdm saw, because the library only gives us 0 or 1.
+	if level < LogLevelDebug {
+		if strings.Contains(msg, "busy") {
+			dmSawBusy = true
+		}
+
+		if strings.Contains(msg, "File exists") {
+			dmSawExist = true
+		}
+
+		if strings.Contains(msg, "No such device or address") {
+			dmSawEnxio = true
+		}
+	}
+
+	if dmLogger != nil {
+		dmLogger.DMLog(int(level), C.GoString(file), int(line), int(dmErrnoOrClass), msg)
+	}
+}
+
+// DefaultLogger is the default logger used by pkg/devicemapper. It forwards
+// all logs that are of higher or equal priority to the given level to the
+// corresponding logrus level.
+type DefaultLogger struct {
+	// Level corresponds to the highest libdm level that will be forwarded to
+	// logrus. In order to change this, register a new DefaultLogger.
+	Level int
+}
+
+// DMLog is the logging callback containing all of the information from
+// devicemapper. The interface is identical to the C libdm counterpart.
+func (l DefaultLogger) DMLog(level int, file string, line, dmError int, message string) {
+	if level <= l.Level {
+		// Forward the log to the correct logrus level, if allowed by dmLogLevel.
+		logMsg := fmt.Sprintf("libdevmapper(%d): %s:%d (%d) %s", level, file, line, dmError, message)
+		switch level {
+		case LogLevelFatal, LogLevelErr:
+			logrus.Error(logMsg)
+		case LogLevelWarn:
+			logrus.Warn(logMsg)
+		case LogLevelNotice, LogLevelInfo:
+			logrus.Info(logMsg)
+		case LogLevelDebug:
+			logrus.Debug(logMsg)
+		default:
+			// Don't drop any "unknown" levels.
+			logrus.Info(logMsg)
+		}
+	}
+}
+
+// registerLogCallback registers our own logging callback function for libdm
+// (which is StorageDevmapperLogCallback).
+//
+// Because libdm only gives us {0,1} error codes we need to parse the logs
+// produced by libdm (to set dmSawBusy and so on). Note that by registering a
+// callback using StorageDevmapperLogCallback, libdm will no longer output logs to
+// stderr so we have to log everything ourselves. None of this handling is
+// optional because we depend on log callbacks to parse the logs, and if we
+// don't forward the log information we'll be in a lot of trouble when
+// debugging things.
+func registerLogCallback() {
+	LogWithErrnoInit()
+}
+
+func init() {
+	// Use the default logger by default. We only allow LogLevelFatal by
+	// default, because internally we mask a lot of libdm errors by retrying
+	// and similar tricks. Also, libdm is very chatty and we don't want to
+	// worry users for no reason.
+	dmLogger = DefaultLogger{
+		Level: LogLevelFatal,
+	}
+
+	// Register as early as possible so we don't miss anything.
+	registerLogCallback()
+}

vendor/github.com/containers/storage/pkg/devicemapper/devmapper_wrapper.go

@@ -0,0 +1,252 @@
+// +build linux,cgo
+
+package devicemapper
+
+/*
+#define _GNU_SOURCE
+#include <libdevmapper.h>
+#include <linux/fs.h>   // FIXME: present only for BLKGETSIZE64, maybe we can remove it?
+
+// FIXME: Can't we find a way to do the logging in pure Go?
+extern void StorageDevmapperLogCallback(int level, char *file, int line, int dm_errno_or_class, char *str);
+
+static void	log_cb(int level, const char *file, int line, int dm_errno_or_class, const char *f, ...)
+{
+	char *buffer = NULL;
+	va_list ap;
+	int ret;
+
+	va_start(ap, f);
+	ret = vasprintf(&buffer, f, ap);
+	va_end(ap);
+	if (ret < 0) {
+		// memory allocation failed -- should never happen?
+		return;
+	}
+
+	StorageDevmapperLogCallback(level, (char *)file, line, dm_errno_or_class, buffer);
+	free(buffer);
+}
+
+static void	log_with_errno_init()
+{
+	dm_log_with_errno_init(log_cb);
+}
+*/
+import "C"
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+type (
+	cdmTask C.struct_dm_task
+)
+
+// IOCTL consts
+const (
+	BlkGetSize64 = C.BLKGETSIZE64
+	BlkDiscard   = C.BLKDISCARD
+)
+
+// Devicemapper cookie flags.
+const (
+	DmUdevDisableSubsystemRulesFlag = C.DM_UDEV_DISABLE_SUBSYSTEM_RULES_FLAG
+	DmUdevDisableDiskRulesFlag      = C.DM_UDEV_DISABLE_DISK_RULES_FLAG
+	DmUdevDisableOtherRulesFlag     = C.DM_UDEV_DISABLE_OTHER_RULES_FLAG
+	DmUdevDisableLibraryFallback    = C.DM_UDEV_DISABLE_LIBRARY_FALLBACK
+)
+
+// DeviceMapper mapped functions.
+var (
+	DmGetLibraryVersion       = dmGetLibraryVersionFct
+	DmGetNextTarget           = dmGetNextTargetFct
+	DmSetDevDir               = dmSetDevDirFct
+	DmTaskAddTarget           = dmTaskAddTargetFct
+	DmTaskCreate              = dmTaskCreateFct
+	DmTaskDestroy             = dmTaskDestroyFct
+	DmTaskGetDeps             = dmTaskGetDepsFct
+	DmTaskGetInfo             = dmTaskGetInfoFct
+	DmTaskGetDriverVersion    = dmTaskGetDriverVersionFct
+	DmTaskRun                 = dmTaskRunFct
+	DmTaskSetAddNode          = dmTaskSetAddNodeFct
+	DmTaskSetCookie           = dmTaskSetCookieFct
+	DmTaskSetMessage          = dmTaskSetMessageFct
+	DmTaskSetName             = dmTaskSetNameFct
+	DmTaskSetRo               = dmTaskSetRoFct
+	DmTaskSetSector           = dmTaskSetSectorFct
+	DmUdevWait                = dmUdevWaitFct
+	DmUdevSetSyncSupport      = dmUdevSetSyncSupportFct
+	DmUdevGetSyncSupport      = dmUdevGetSyncSupportFct
+	DmCookieSupported         = dmCookieSupportedFct
+	LogWithErrnoInit          = logWithErrnoInitFct
+	DmTaskDeferredRemove      = dmTaskDeferredRemoveFct
+	DmTaskGetInfoWithDeferred = dmTaskGetInfoWithDeferredFct
+)
+
+func free(p *C.char) {
+	C.free(unsafe.Pointer(p))
+}
+
+func dmTaskDestroyFct(task *cdmTask) {
+	C.dm_task_destroy((*C.struct_dm_task)(task))
+}
+
+func dmTaskCreateFct(taskType int) *cdmTask {
+	return (*cdmTask)(C.dm_task_create(C.int(taskType)))
+}
+
+func dmTaskRunFct(task *cdmTask) int {
+	ret, _ := C.dm_task_run((*C.struct_dm_task)(task))
+	return int(ret)
+}
+
+func dmTaskSetNameFct(task *cdmTask, name string) int {
+	Cname := C.CString(name)
+	defer free(Cname)
+
+	return int(C.dm_task_set_name((*C.struct_dm_task)(task), Cname))
+}
+
+func dmTaskSetMessageFct(task *cdmTask, message string) int {
+	Cmessage := C.CString(message)
+	defer free(Cmessage)
+
+	return int(C.dm_task_set_message((*C.struct_dm_task)(task), Cmessage))
+}
+
+func dmTaskSetSectorFct(task *cdmTask, sector uint64) int {
+	return int(C.dm_task_set_sector((*C.struct_dm_task)(task), C.uint64_t(sector)))
+}
+
+func dmTaskSetCookieFct(task *cdmTask, cookie *uint, flags uint16) int {
+	cCookie := C.uint32_t(*cookie)
+	defer func() {
+		*cookie = uint(cCookie)
+	}()
+	return int(C.dm_task_set_cookie((*C.struct_dm_task)(task), &cCookie, C.uint16_t(flags)))
+}
+
+func dmTaskSetAddNodeFct(task *cdmTask, addNode AddNodeType) int {
+	return int(C.dm_task_set_add_node((*C.struct_dm_task)(task), C.dm_add_node_t(addNode)))
+}
+
+func dmTaskSetRoFct(task *cdmTask) int {
+	return int(C.dm_task_set_ro((*C.struct_dm_task)(task)))
+}
+
+func dmTaskAddTargetFct(task *cdmTask,
+	start, size uint64, ttype, params string) int {
+
+	Cttype := C.CString(ttype)
+	defer free(Cttype)
+
+	Cparams := C.CString(params)
+	defer free(Cparams)
+
+	return int(C.dm_task_add_target((*C.struct_dm_task)(task), C.uint64_t(start), C.uint64_t(size), Cttype, Cparams))
+}
+
+func dmTaskGetDepsFct(task *cdmTask) *Deps {
+	Cdeps := C.dm_task_get_deps((*C.struct_dm_task)(task))
+	if Cdeps == nil {
+		return nil
+	}
+
+	// golang issue: https://github.com/golang/go/issues/11925
+	hdr := reflect.SliceHeader{
+		Data: uintptr(unsafe.Pointer(uintptr(unsafe.Pointer(Cdeps)) + unsafe.Sizeof(*Cdeps))),
+		Len:  int(Cdeps.count),
+		Cap:  int(Cdeps.count),
+	}
+	devices := *(*[]C.uint64_t)(unsafe.Pointer(&hdr))
+
+	deps := &Deps{
+		Count:  uint32(Cdeps.count),
+		Filler: uint32(Cdeps.filler),
+	}
+	for _, device := range devices {
+		deps.Device = append(deps.Device, uint64(device))
+	}
+	return deps
+}
+
+func dmTaskGetInfoFct(task *cdmTask, info *Info) int {
+	Cinfo := C.struct_dm_info{}
+	defer func() {
+		info.Exists = int(Cinfo.exists)
+		info.Suspended = int(Cinfo.suspended)
+		info.LiveTable = int(Cinfo.live_table)
+		info.InactiveTable = int(Cinfo.inactive_table)
+		info.OpenCount = int32(Cinfo.open_count)
+		info.EventNr = uint32(Cinfo.event_nr)
+		info.Major = uint32(Cinfo.major)
+		info.Minor = uint32(Cinfo.minor)
+		info.ReadOnly = int(Cinfo.read_only)
+		info.TargetCount = int32(Cinfo.target_count)
+	}()
+	return int(C.dm_task_get_info((*C.struct_dm_task)(task), &Cinfo))
+}
+
+func dmTaskGetDriverVersionFct(task *cdmTask) string {
+	buffer := C.malloc(128)
+	defer C.free(buffer)
+	res := C.dm_task_get_driver_version((*C.struct_dm_task)(task), (*C.char)(buffer), 128)
+	if res == 0 {
+		return ""
+	}
+	return C.GoString((*C.char)(buffer))
+}
+
+func dmGetNextTargetFct(task *cdmTask, next unsafe.Pointer, start, length *uint64, target, params *string) unsafe.Pointer {
+	var (
+		Cstart, Clength      C.uint64_t
+		CtargetType, Cparams *C.char
+	)
+	defer func() {
+		*start = uint64(Cstart)
+		*length = uint64(Clength)
+		*target = C.GoString(CtargetType)
+		*params = C.GoString(Cparams)
+	}()
+
+	nextp := C.dm_get_next_target((*C.struct_dm_task)(task), next, &Cstart, &Clength, &CtargetType, &Cparams)
+	return nextp
+}
+
+func dmUdevSetSyncSupportFct(syncWithUdev int) {
+	(C.dm_udev_set_sync_support(C.int(syncWithUdev)))
+}
+
+func dmUdevGetSyncSupportFct() int {
+	return int(C.dm_udev_get_sync_support())
+}
+
+func dmUdevWaitFct(cookie uint) int {
+	return int(C.dm_udev_wait(C.uint32_t(cookie)))
+}
+
+func dmCookieSupportedFct() int {
+	return int(C.dm_cookie_supported())
+}
+
+func logWithErrnoInitFct() {
+	C.log_with_errno_init()
+}
+
+func dmSetDevDirFct(dir string) int {
+	Cdir := C.CString(dir)
+	defer free(Cdir)
+
+	return int(C.dm_set_dev_dir(Cdir))
+}
+
+func dmGetLibraryVersionFct(version *string) int {
+	buffer := C.CString(string(make([]byte, 128)))
+	defer free(buffer)
+	defer func() {
+		*version = C.GoString(buffer)
+	}()
+	return int(C.dm_get_library_version(buffer, 128))
+}

vendor/github.com/containers/storage/pkg/devicemapper/devmapper_wrapper_deferred_remove.go

@@ -0,0 +1,31 @@
+// +build linux,cgo,!libdm_no_deferred_remove
+
+package devicemapper
+
+// #include <libdevmapper.h>
+import "C"
+
+// LibraryDeferredRemovalSupport tells if the feature is enabled in the build
+const LibraryDeferredRemovalSupport = true
+
+func dmTaskDeferredRemoveFct(task *cdmTask) int {
+	return int(C.dm_task_deferred_remove((*C.struct_dm_task)(task)))
+}
+
+func dmTaskGetInfoWithDeferredFct(task *cdmTask, info *Info) int {
+	Cinfo := C.struct_dm_info{}
+	defer func() {
+		info.Exists = int(Cinfo.exists)
+		info.Suspended = int(Cinfo.suspended)
+		info.LiveTable = int(Cinfo.live_table)
+		info.InactiveTable = int(Cinfo.inactive_table)
+		info.OpenCount = int32(Cinfo.open_count)
+		info.EventNr = uint32(Cinfo.event_nr)
+		info.Major = uint32(Cinfo.major)
+		info.Minor = uint32(Cinfo.minor)
+		info.ReadOnly = int(Cinfo.read_only)
+		info.TargetCount = int32(Cinfo.target_count)
+		info.DeferredRemove = int(Cinfo.deferred_remove)
+	}()
+	return int(C.dm_task_get_info((*C.struct_dm_task)(task), &Cinfo))
+}

vendor/github.com/containers/storage/pkg/devicemapper/devmapper_wrapper_dynamic.go

@@ -0,0 +1,6 @@
+// +build linux,cgo,!static_build
+
+package devicemapper
+
+// #cgo pkg-config: devmapper
+import "C"

vendor/github.com/containers/storage/pkg/devicemapper/devmapper_wrapper_no_deferred_remove.go

@@ -0,0 +1,15 @@
+// +build linux,cgo,libdm_no_deferred_remove
+
+package devicemapper
+
+// LibraryDeferredRemovalSupport tells if the feature is enabled in the build
+const LibraryDeferredRemovalSupport = false
+
+func dmTaskDeferredRemoveFct(task *cdmTask) int {
+	// Error. Nobody should be calling it.
+	return -1
+}
+
+func dmTaskGetInfoWithDeferredFct(task *cdmTask, info *Info) int {
+	return -1
+}

vendor/github.com/containers/storage/pkg/devicemapper/devmapper_wrapper_static.go

@@ -0,0 +1,6 @@
+// +build linux,cgo,static_build
+
+package devicemapper
+
+// #cgo pkg-config: --static devmapper
+import "C"

vendor/github.com/containers/storage/pkg/devicemapper/ioctl.go

@@ -0,0 +1,28 @@
+// +build linux,cgo
+
+package devicemapper
+
+import (
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+func ioctlBlkGetSize64(fd uintptr) (int64, error) {
+	var size int64
+	if _, _, err := unix.Syscall(unix.SYS_IOCTL, fd, BlkGetSize64, uintptr(unsafe.Pointer(&size))); err != 0 {
+		return 0, err
+	}
+	return size, nil
+}
+
+func ioctlBlkDiscard(fd uintptr, offset, length uint64) error {
+	var r [2]uint64
+	r[0] = offset
+	r[1] = length
+
+	if _, _, err := unix.Syscall(unix.SYS_IOCTL, fd, BlkDiscard, uintptr(unsafe.Pointer(&r[0]))); err != 0 {
+		return err
+	}
+	return nil
+}

vendor/github.com/containers/storage/pkg/devicemapper/log.go

@@ -0,0 +1,11 @@
+package devicemapper
+
+// definitions from lvm2 lib/log/log.h
+const (
+	LogLevelFatal  = 2 + iota // _LOG_FATAL
+	LogLevelErr               // _LOG_ERR
+	LogLevelWarn              // _LOG_WARN
+	LogLevelNotice            // _LOG_NOTICE
+	LogLevelInfo              // _LOG_INFO
+	LogLevelDebug             // _LOG_DEBUG
+)

vendor/github.com/containers/storage/pkg/directory/directory.go

@@ -0,0 +1,26 @@
+package directory
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+)
+
+// MoveToSubdir moves all contents of a directory to a subdirectory underneath the original path
+func MoveToSubdir(oldpath, subdir string) error {
+
+	infos, err := ioutil.ReadDir(oldpath)
+	if err != nil {
+		return err
+	}
+	for _, info := range infos {
+		if info.Name() != subdir {
+			oldName := filepath.Join(oldpath, info.Name())
+			newName := filepath.Join(oldpath, subdir, info.Name())
+			if err := os.Rename(oldName, newName); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}

vendor/github.com/containers/storage/pkg/directory/directory_unix.go

@@ -0,0 +1,48 @@
+// +build linux freebsd solaris
+
+package directory
+
+import (
+	"os"
+	"path/filepath"
+	"syscall"
+)
+
+// Size walks a directory tree and returns its total size in bytes.
+func Size(dir string) (size int64, err error) {
+	data := make(map[uint64]struct{})
+	err = filepath.Walk(dir, func(d string, fileInfo os.FileInfo, err error) error {
+		if err != nil {
+			// if dir does not exist, Size() returns the error.
+			// if dir/x disappeared while walking, Size() ignores dir/x.
+			if os.IsNotExist(err) && d != dir {
+				return nil
+			}
+			return err
+		}
+
+		// Ignore directory sizes
+		if fileInfo == nil {
+			return nil
+		}
+
+		s := fileInfo.Size()
+		if fileInfo.IsDir() || s == 0 {
+			return nil
+		}
+
+		// Check inode to handle hard links correctly
+		inode := fileInfo.Sys().(*syscall.Stat_t).Ino
+		// inode is not a uint64 on all platforms. Cast it to avoid issues.
+		if _, exists := data[uint64(inode)]; exists {
+			return nil
+		}
+		// inode is not a uint64 on all platforms. Cast it to avoid issues.
+		data[uint64(inode)] = struct{}{}
+
+		size += s
+
+		return nil
+	})
+	return
+}

vendor/github.com/containers/storage/pkg/directory/directory_windows.go

@@ -0,0 +1,37 @@
+// +build windows
+
+package directory
+
+import (
+	"os"
+	"path/filepath"
+)
+
+// Size walks a directory tree and returns its total size in bytes.
+func Size(dir string) (size int64, err error) {
+	err = filepath.Walk(dir, func(d string, fileInfo os.FileInfo, err error) error {
+		if err != nil {
+			// if dir does not exist, Size() returns the error.
+			// if dir/x disappeared while walking, Size() ignores dir/x.
+			if os.IsNotExist(err) && d != dir {
+				return nil
+			}
+			return err
+		}
+
+		// Ignore directory sizes
+		if fileInfo == nil {
+			return nil
+		}
+
+		s := fileInfo.Size()
+		if fileInfo.IsDir() || s == 0 {
+			return nil
+		}
+
+		size += s
+
+		return nil
+	})
+	return
+}