1 files changed, 3 insertions, 0 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 38b76cc02f48..1c2bd1723e40 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -9889,6 +9889,8 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
                 }
                 spin_unlock(&fs_info->unused_bgs_lock);
 
+                mutex_lock(&root->fs_info->delete_unused_bgs_mutex);
+
                 /* Don't want to race with allocators so take the groups_sem */
                 down_write(&space_info->groups_sem);
                 spin_lock(&block_group->lock);
@@ -9983,6 +9985,7 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
 end_trans:
                 btrfs_end_transaction(trans, root);
 next:
+                mutex_unlock(&root->fs_info->delete_unused_bgs_mutex);
                 btrfs_put_block_group(block_group);
                 spin_lock(&fs_info->unused_bgs_lock);
         }