btrfs: free ulist in qgroup_shared_accounting() error path

If tmp = ulist_alloc(GFP_NOFS) fails, we return without
freeing the previously allocated qgroups = ulist_alloc(GFP_NOFS)
and cause a memory leak.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index cf5aead95a7f..98cb6b2630f9 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1798,8 +1798,10 @@ static int qgroup_shared_accounting(struct btrfs_trans_handle *trans,
                 return -ENOMEM;
 
         tmp = ulist_alloc(GFP_NOFS);
-        if (!tmp)
+        if (!tmp) {
+                ulist_free(qgroups);
                 return -ENOMEM;
+        }
 
         btrfs_get_tree_mod_seq(fs_info, &elem);
         ret = btrfs_find_all_roots(trans, fs_info, oper->bytenr, elem.seq,