1 files changed, 11 insertions, 8 deletions
diff --git a/pkg/sentry/fs/file.go b/pkg/sentry/fs/file.go
index 55ffe6c0c..bb8117f89 100644
--- a/pkg/sentry/fs/file.go
+++ b/pkg/sentry/fs/file.go
@@ -130,14 +130,15 @@ type File struct {
 // to false respectively.
 func NewFile(ctx context.Context, dirent *Dirent, flags FileFlags, fops FileOperations) *File {
 	dirent.IncRef()
-	f := &File{
+	f := File{
 		UniqueID:       uniqueid.GlobalFromContext(ctx),
 		Dirent:         dirent,
 		FileOperations: fops,
 		flags:          flags,
 	}
 	f.mu.Init()
-	return f
+	f.EnableLeakCheck("fs.File")
+	return &f
 }
 
 // DecRef destroys the File when it is no longer referenced.
@@ -310,9 +311,11 @@ func (f *File) Writev(ctx context.Context, src usermem.IOSequence) (int64, error
 		return 0, syserror.ErrInterrupted
 	}
 
+	unlockAppendMu := f.Dirent.Inode.lockAppendMu(f.Flags().Append)
 	// Handle append mode.
 	if f.Flags().Append {
 		if err := f.offsetForAppend(ctx, &f.offset); err != nil {
+			unlockAppendMu()
 			f.mu.Unlock()
 			return 0, err
 		}
@@ -322,6 +325,7 @@ func (f *File) Writev(ctx context.Context, src usermem.IOSequence) (int64, error
 	limit, ok := f.checkLimit(ctx, f.offset)
 	switch {
 	case ok && limit == 0:
+		unlockAppendMu()
 		f.mu.Unlock()
 		return 0, syserror.ErrExceedsFileSizeLimit
 	case ok:
@@ -333,6 +337,7 @@ func (f *File) Writev(ctx context.Context, src usermem.IOSequence) (int64, error
 	if n >= 0 && !f.flags.NonSeekable {
 		atomic.StoreInt64(&f.offset, f.offset+n)
 	}
+	unlockAppendMu()
 	f.mu.Unlock()
 	return n, err
 }
@@ -348,13 +353,11 @@ func (f *File) Pwritev(ctx context.Context, src usermem.IOSequence, offset int64
 	// However, on Linux, if a file is opened with O_APPEND,  pwrite()
 	// appends data to the end of the file, regardless of the value of
 	// offset."
+	unlockAppendMu := f.Dirent.Inode.lockAppendMu(f.Flags().Append)
+	defer unlockAppendMu()
+
 	if f.Flags().Append {
-		if !f.mu.Lock(ctx) {
-			return 0, syserror.ErrInterrupted
-		}
-		defer f.mu.Unlock()
 		if err := f.offsetForAppend(ctx, &offset); err != nil {
-			f.mu.Unlock()
 			return 0, err
 		}
 	}
@@ -373,7 +376,7 @@ func (f *File) Pwritev(ctx context.Context, src usermem.IOSequence, offset int64
 
 // offsetForAppend sets the given offset to the end of the file.
 //
-// Precondition: the underlying file mutex should be held.
+// Precondition: the file.Dirent.Inode.appendMu mutex should be held for writing.
 func (f *File) offsetForAppend(ctx context.Context, offset *int64) error {
 	uattr, err := f.Dirent.Inode.UnstableAttr(ctx)
 	if err != nil {