UnionFs: Create should mkdir up to the file in the writable branch.

unionfs/unionfs.go

@@ -262,7 +262,7 @@ func (me *UnionFs) Rmdir(path string) (code fuse.Status) {
 	if r.code != fuse.OK {
 		return r.code
 	}
-	if r.attr.Mode & fuse.S_IFDIR == 0 {
+	if r.attr.Mode&fuse.S_IFDIR == 0 {
 		return syscall.ENOTDIR
 	}
 	if r.branch > 0 {
@@ -321,7 +321,7 @@ func (me *UnionFs) Chmod(name string, mode uint32) (code fuse.Status) {
 		return r.code
 	}
 
-	if r.attr.Mode & fuse.S_IFREG == 0 {
+	if r.attr.Mode&fuse.S_IFREG == 0 {
 		return fuse.EPERM
 	}
 
@@ -375,10 +375,30 @@ func (me *UnionFs) Readlink(name string) (out string, code fuse.Status) {
 	return "", fuse.ENOENT
 }
 
+func IsDir(fs fuse.FileSystem, name string) bool {
+	a, code := fs.GetAttr(name)
+	return code == fuse.OK && a.Mode & fuse.S_IFDIR != 0
+}
+
+func (me *UnionFs) makeDirTo(name string) fuse.Status {
+	dir, base := filepath.Split(name)
+	if base != "" && !IsDir(me.fileSystems[0], dir) {
+		err := os.MkdirAll(me.branches[0].GetPath(dir), 0755)
+		if err != nil {
+			log.Println("Error creating dir leading to path", name, err)
+			return fuse.EPERM
+		}
+	}
+	return fuse.OK
+}
+
 func (me *UnionFs) Create(name string, flags uint32, mode uint32) (fuseFile fuse.File, code fuse.Status) {
-	// TODO(hanwen) - we should check that the name is not a
-	// directory in another branch.
 	writable := me.fileSystems[0]
+
+	code = me.makeDirTo(name)
+	if code != fuse.OK {
+		return nil, code
+	}
 	fuseFile, code = writable.Create(name, flags, mode)
 	if code == fuse.OK {
 		me.removeDeletion(name)

unionfs/unionfs_test.go

@@ -17,7 +17,6 @@ func TestFilePathHash(t *testing.T) {
 	t.Log(filePathHash("xyz/abc"))
 }
 
-
 var testOpts = UnionFsOptions{
 	DeletionCacheTTLSecs: 0.01,
 	DeletionDirName:      "DELETIONS",
@@ -237,6 +236,19 @@ func TestPromote(t *testing.T) {
 	writeToFile(wd + "/mount/subdir/file", "other-content", false)
 }
 
+func TestCreate(t *testing.T) {
+	wd, state := setup(t)
+	defer state.Unmount()
+
+	err := os.MkdirAll(wd + "/ro/subdir/sub2", 0755)
+	CheckSuccess(err)
+	writeToFile(wd + "/mount/subdir/sub2/file", "other-content", true)
+	_, err = os.Lstat(wd + "/mount/subdir/sub2/file")
+	CheckSuccess(err)
+}
+
+
+
 func TestMkdir(t *testing.T) {
 	wd, state := setup(t)
 	defer state.Unmount()