Btrfs: Metadata reservation for orphan inodes

reserve metadata space for handling orphan inodes

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index a0686658a3f6..4cdb98cf26de 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1297,10 +1297,12 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
         dest->root_item.drop_level = 0;
         btrfs_set_root_refs(&dest->root_item, 0);
 
-        ret = btrfs_insert_orphan_item(trans,
-                                root->fs_info->tree_root,
-                                dest->root_key.objectid);
-        BUG_ON(ret);
+        if (!xchg(&dest->orphan_item_inserted, 1)) {
+                ret = btrfs_insert_orphan_item(trans,
+                                        root->fs_info->tree_root,
+                                        dest->root_key.objectid);
+                BUG_ON(ret);
+        }
 
         ret = btrfs_commit_transaction(trans, root);
         BUG_ON(ret);