Btrfs: don't add a NULL extended attribute

Passing a null extended attribute value means to remove the attribute,
but we don't have to add a new NULL extended attribute.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index e9d384055494..aef6bb3c5f5c 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -122,6 +122,16 @@ static int do_setxattr(struct btrfs_trans_handle *trans,
                  */
                 if (!value)
                         goto out;
+        } else {
+                di = btrfs_lookup_xattr(NULL, root, path, btrfs_ino(inode),
+                                        name, name_len, 0);
+                if (IS_ERR(di)) {
+                        ret = PTR_ERR(di);
+                        goto out;
+                }
+                if (!di && !value)
+                        goto out;
+                btrfs_release_path(path);
         }
 
 again: