[PATCH 36/39] union-mount: Implement union-aware lchown()

[Valerie Aurora <vaurora@redhat.com>]

Signed-off-by: Valerie Aurora <vaurora@redhat.com>
---
 fs/open.c |   23 ++++++++++++++++++++---
 1 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/fs/open.c b/fs/open.c
index 5c9933f..693258f 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -646,18 +646,35 @@ out:
 SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group)
 {
 	struct path path;
+	struct nameidata nd;
+	struct vfsmount *mnt;
+	char *tmp;
 	int error;
 
-	error = user_lpath(filename, &path);
+	error = user_path_nd(AT_FDCWD, filename, 0, &nd, &path, &tmp);
 	if (error)
 		goto out;
-	error = mnt_want_write(path.mnt);
+
+	if (IS_DIR_UNIONED(nd.path.dentry))
+		mnt = nd.path.mnt;
+	else
+		mnt = path.mnt;
+
+	error = mnt_want_write(mnt);
 	if (error)
 		goto out_release;
+
+	error = union_copyup(&nd, &path);
+	if (error)
+		goto out_drop_write;
+
 	error = chown_common(&path, user, group);
-	mnt_drop_write(path.mnt);
+out_drop_write:
+	mnt_drop_write(mnt);
 out_release:
 	path_put(&path);
+	path_put(&nd.path);
+	putname(tmp);
 out:
 	return error;
 }
-- 
1.6.3.3