resize support for device-mapper/multipath

Dockerfile

@@ -38,6 +38,9 @@ RUN apt-get update && \
 ADD docker/iscsiadm /usr/local/sbin
 RUN chmod +x /usr/local/sbin/iscsiadm
 
+ADD docker/multipath /usr/local/sbin
+RUN chmod +x /usr/local/sbin/multipath
+
 # Run as a non-root user
 RUN useradd --create-home csi \
         && mkdir /home/csi/app \

docker/multipath

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+chroot /host /usr/bin/env -i PATH="/sbin:/bin:/usr/sbin:/usr/bin" multipath "${@:1}"

src/driver/index.js

@@ -395,6 +395,10 @@ class CsiBaseDriver {
           }
         }
 
+        // let things settle
+        // this will help in dm scenarios
+        await sleep(2000);
+
         // filter duplicates
         iscsiDevices = iscsiDevices.filter((value, index, self) => {
           return self.indexOf(value) === index;
@@ -936,6 +940,7 @@ class CsiBaseDriver {
     let is_block = false;
     let is_formatted;
     let fs_type;
+    let is_device_mapper = false;
 
     const volume_id = call.request.volume_id;
     const volume_path = call.request.volume_path;
@@ -972,7 +977,24 @@ class CsiBaseDriver {
     }
 
     if (is_block) {
-      await filesystem.rescanDevice(device);
+      let rescan_devices = [];
+      // detect if is a multipath device
+      is_device_mapper = await filesystem.isDeviceMapperDevice(device);
+      if (is_device_mapper) {
+        // NOTE: want to make sure we scan the dm device *after* all the underlying slaves
+        rescan_devices = await filesystem.getDeviceMapperDeviceSlaves(device);
+      }
+
+      rescan_devices.push(device);
+
+      for (let sdevice of rescan_devices) {
+        await filesystem.rescanDevice(sdevice);
+      }
+
+      // let things settle
+      // it appears the dm devices can take a second to figure things out
+      await sleep(2000);
+
       if (is_formatted && access_type == "mount") {
         fs_info = await filesystem.getDeviceFilesystemInfo(device);
         fs_type = fs_info.type;

src/utils/filesystem.js

@@ -415,13 +415,20 @@ class Filesystem {
       );
     }
 
+    let is_device_mapper_device = await filesystem.isDeviceMapperDevice(device);
     result = await filesystem.realpath(device);
+
+    if (is_device_mapper_device) {
+      // multipath -r /dev/dm-0
+      result = await filesystem.exec("multipath", ["-r", device]);
+    } else {
       device_name = result.split("/").pop();
 
       // echo 1 > /sys/block/sdb/device/rescan
       const sys_file = `/sys/block/${device_name}/device/rescan`;
       fs.writeFileSync(sys_file, "1");
     }
+  }
 
   /**
    * expand a give filesystem