btrfs: correctly handle return from ulist_add

ulist_add() can return '1' on sucess, which qgroup_subtree_accounting()
doesn't take into account. As a result, that value can be bubbled up to
callers, causing an error to be printed. Fix this by only returning the
value of ulist_add() when it indicates an error.

Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Chris Mason <clm@fb.com>

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 65b62c467e28e2ce7ae0f599a57b844c8fa30cd8..b497498484bebaf5774aa3c4d016a5e4f0b05ff1 100644 (file)
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1959,6 +1959,7 @@ static int qgroup_subtree_accounting(struct btrfs_trans_handle *trans,
        struct btrfs_qgroup_list *glist;
        struct ulist *parents;
        int ret = 0;
+       int err;
        struct btrfs_qgroup *qg;
        u64 root_obj = 0;
        struct seq_list elem = {};
@@ -2013,10 +2014,12 @@ static int qgroup_subtree_accounting(struct btrfs_trans_handle *trans,
         * while adding parents of the parents to our ulist.
         */
        list_for_each_entry(glist, &qg->groups, next_group) {
-               ret = ulist_add(parents, glist->group->qgroupid,
+               err = ulist_add(parents, glist->group->qgroupid,
                                ptr_to_u64(glist->group), GFP_ATOMIC);
-               if (ret < 0)
+               if (err < 0) {
+                       ret = err;
                        goto out_unlock;
+               }
        }
 
        ULIST_ITER_INIT(&uiter);
@@ -2028,10 +2031,12 @@ static int qgroup_subtree_accounting(struct btrfs_trans_handle *trans,
 
                /* Add any parents of the parents */
                list_for_each_entry(glist, &qg->groups, next_group) {
-                       ret = ulist_add(parents, glist->group->qgroupid,
+                       err = ulist_add(parents, glist->group->qgroupid,
                                        ptr_to_u64(glist->group), GFP_ATOMIC);
-                       if (ret < 0)
+                       if (err < 0) {
+                               ret = err;
                                goto out_unlock;
+                       }
                }
        }