btrfs: handle btrfs_update_reloc_root failure in prepare_to_merge

btrfs_update_reloc_root will will return errors in the future, so handle
an error properly in prepare_to_merge.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 69f170b47a0e7e25ac6a54a11b5b504f0a13d717..ca97412d72625e784fd8a13ac31e96bffc865517 100644 (file)
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -1870,10 +1870,21 @@ again:
                 */
                if (!err)
                        btrfs_set_root_refs(&reloc_root->root_item, 1);
-               btrfs_update_reloc_root(trans, root);
+               ret = btrfs_update_reloc_root(trans, root);
 
+               /*
+                * Even if we have an error we need this reloc root back on our
+                * list so we can clean up properly.
+                */
                list_add(&reloc_root->root_list, &reloc_roots);
                btrfs_put_root(root);
+
+               if (ret) {
+                       btrfs_abort_transaction(trans, ret);
+                       if (!err)
+                               err = ret;
+                       break;
+               }
        }
 
        list_splice(&reloc_roots, &rc->reloc_roots);