Fixed flushfs for writback caching.

samples/flushfs/flush_fs.go

@@ -90,6 +90,29 @@ func (fs *flushFS) barAttributes() fuseops.InodeAttributes {
 	}
 }
 
+// LOCKS_REQUIRED(fs.mu)
+func (fs *flushFS) getAttributes(id fuseops.InodeID) (
+	attrs fuseops.InodeAttributes,
+	err error) {
+	switch id {
+	case fuseops.RootInodeID:
+		attrs = fs.rootAttributes()
+		return
+
+	case fooID:
+		attrs = fs.fooAttributes()
+		return
+
+	case barID:
+		attrs = fs.barAttributes()
+		return
+
+	default:
+		err = fuse.ENOENT
+		return
+	}
+}
+
 ////////////////////////////////////////////////////////////////////////
 // FileSystem methods
 ////////////////////////////////////////////////////////////////////////
@@ -134,23 +157,20 @@ func (fs *flushFS) GetInodeAttributes(
 	fs.mu.Lock()
 	defer fs.mu.Unlock()
 
-	switch op.Inode {
-	case fuseops.RootInodeID:
-		op.Attributes = fs.rootAttributes()
+	op.Attributes, err = fs.getAttributes(op.Inode)
 	return
+}
 
-	case fooID:
-		op.Attributes = fs.fooAttributes()
-		return
+func (fs *flushFS) SetInodeAttributes(
+	ctx context.Context,
+	op *fuseops.SetInodeAttributesOp) (err error) {
+	fs.mu.Lock()
+	defer fs.mu.Unlock()
 
-	case barID:
-		op.Attributes = fs.barAttributes()
-		return
+	// Ignore any changes and simply return existing attributes.
+	op.Attributes, err = fs.getAttributes(op.Inode)
 
-	default:
-		err = fuse.ENOENT
 	return
-	}
 }
 
 func (fs *flushFS) OpenFile(

samples/flushfs/flush_fs_test.go

@@ -590,6 +590,8 @@ func (t *NoErrorsTest) Mmap_NoMsync_MunmapBeforeClose() {
 		syscall.MAP_SHARED)
 
 	AssertEq(nil, err)
+	defer syscall.Munmap(data)
+
 	AssertEq("taco", string(data))
 
 	// Modify the contents.
@@ -638,6 +640,8 @@ func (t *NoErrorsTest) Mmap_NoMsync_CloseBeforeMunmap() {
 		syscall.MAP_SHARED)
 
 	AssertEq(nil, err)
+	defer syscall.Munmap(data)
+
 	AssertEq("taco", string(data))
 
 	// Close the file. We should see a flush.
@@ -682,6 +686,8 @@ func (t *NoErrorsTest) Mmap_WithMsync_MunmapBeforeClose() {
 		syscall.MAP_SHARED)
 
 	AssertEq(nil, err)
+	defer syscall.Munmap(data)
+
 	AssertEq("taco", string(data))
 
 	// Modify the contents.
@@ -738,6 +744,8 @@ func (t *NoErrorsTest) Mmap_WithMsync_CloseBeforeMunmap() {
 		syscall.MAP_SHARED)
 
 	AssertEq(nil, err)
+	defer syscall.Munmap(data)
+
 	AssertEq("taco", string(data))
 
 	// Close the file. We should see a flush.
@@ -941,6 +949,7 @@ func (t *FsyncErrorTest) Msync() {
 		syscall.MAP_SHARED)
 
 	AssertEq(nil, err)
+	defer syscall.Munmap(data)
 
 	// msync the mapping.
 	err = msync(data)