From 3f6c982ae1258c882c470650cc3d5a41cedbf098 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 1 Apr 2026 00:50:15 +0000
Subject: [PATCH] fix: remove duplicate mutex, reuse getNamedRWMutex, restore
 on write failure, add test barrier

Agent-Logs-Url: https://github.com/helmfile/helmfile/sessions/f93746bf-82fa-46b1-b8f0-b34bc9aa749c

Co-authored-by: yxxhero <11087727+yxxhero@users.noreply.github.com>
---
 pkg/state/chart_dependencies_rewrite_test.go | 10 ++++++-
 pkg/state/state.go                           | 29 ++++----------------
 2 files changed, 15 insertions(+), 24 deletions(-)

diff --git a/pkg/state/chart_dependencies_rewrite_test.go b/pkg/state/chart_dependencies_rewrite_test.go
index e917c76f..1792ff81 100644
--- a/pkg/state/chart_dependencies_rewrite_test.go
+++ b/pkg/state/chart_dependencies_rewrite_test.go
@@ -527,16 +527,21 @@ dependencies:
 		t.Fatalf("failed to write Chart.yaml: %v", err)
 	}
 
-	// Run multiple goroutines concurrently on the same chart path
+	// Run multiple goroutines concurrently on the same chart path.
+	// A start barrier ensures all goroutines attempt rewriteChartDependencies simultaneously.
 	numGoroutines := 10
 	var wg sync.WaitGroup
 	errCh := make(chan error, numGoroutines)
+	ready := make(chan struct{})
 
 	for i := 0; i < numGoroutines; i++ {
 		wg.Add(1)
 		go func() {
 			defer wg.Done()
 
+			// Wait until all goroutines are ready so they start simultaneously.
+			<-ready
+
 			logger := zap.NewNop().Sugar()
 			st := &HelmState{
 				logger: logger,
@@ -552,6 +557,9 @@ dependencies:
 		}()
 	}
 
+	// Release all goroutines at once to maximize contention.
+	close(ready)
+
 	wg.Wait()
 	close(errCh)
 
diff --git a/pkg/state/state.go b/pkg/state/state.go
index 19155b65..d48b664b 100644
--- a/pkg/state/state.go
+++ b/pkg/state/state.go
@@ -1407,28 +1407,6 @@ type PrepareChartKey struct {
 	Namespace, Name, KubeContext string
 }
 
-// PrepareCharts creates temporary directories of charts.
-//
-// Each resulting "chart" can be one of the followings:
-//
-// (1) local chart
-// (2) temporary local chart generated from kustomization or manifests
-// (3) remote chart
-//
-// When running `helmfile template` on helm v2, or `helmfile lint` on both helm v2 and v3,
-// PrepareCharts will download and untar charts for linting and templating.
-var chartDepsMutexMap sync.Map
-
-func (st *HelmState) getChartDepsMutex(chartPath string) *sync.Mutex {
-	mu, ok := chartDepsMutexMap.Load(chartPath)
-	if ok {
-		return mu.(*sync.Mutex)
-	}
-	newMu := &sync.Mutex{}
-	actualMu, _ := chartDepsMutexMap.LoadOrStore(chartPath, newMu)
-	return actualMu.(*sync.Mutex)
-}
-
 // rewriteChartDependencies rewrites relative file:// dependencies in Chart.yaml to absolute paths
 // to ensure they can be resolved from chartify's temporary directory
 func (st *HelmState) rewriteChartDependencies(chartPath string) (func(), error) {
@@ -1439,7 +1417,8 @@ func (st *HelmState) rewriteChartDependencies(chartPath string) (func(), error)
 		return func() {}, nil
 	}
 
-	mu := st.getChartDepsMutex(chartPath)
+	// Reuse the existing per-path RWMutex for exclusive access to the chart directory.
+	mu := st.getNamedRWMutex(chartPath)
 	mu.Lock()
 
 	// Read Chart.yaml
@@ -1508,6 +1487,10 @@ func (st *HelmState) rewriteChartDependencies(chartPath string) (func(), error)
 		}
 
 		if err := os.WriteFile(chartYamlPath, updatedData, 0644); err != nil {
+			// File may be truncated/partially written; restore original content before releasing the lock.
+			if restoreErr := os.WriteFile(chartYamlPath, originalContent, 0644); restoreErr != nil {
+				st.logger.Warnf("Failed to restore Chart.yaml at %s after write error (%v): %v", chartYamlPath, err, restoreErr)
+			}
 			mu.Unlock()
 			return func() {}, fmt.Errorf("failed to write Chart.yaml: %w", err)
 		}