Btrfs: make sure we cleanup all reloc roots if error happens

I hit an oops when merging reloc roots fails, the reason is that
new reloc roots may be added and we should make sure we cleanup
all reloc roots.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 0a3f02562053..429c73c374b8 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2409,6 +2409,13 @@ out:
                 btrfs_std_error(root->fs_info, ret);
                 if (!list_empty(&reloc_roots))
                         free_reloc_roots(&reloc_roots);
+
+                /* new reloc root may be added */
+                mutex_lock(&root->fs_info->reloc_mutex);
+                list_splice_init(&rc->reloc_roots, &reloc_roots);
+                mutex_unlock(&root->fs_info->reloc_mutex);
+                if (!list_empty(&reloc_roots))
+                        free_reloc_roots(&reloc_roots);
         }
 
         BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));