1 files changed, 21 insertions, 0 deletions

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 7f38cce2528d..d059d86c3131 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -2070,6 +2070,8 @@ out:
         } else {
                 pr_err("btrfs: qgroup scan failed with %d\n", err);
         }
+
+        complete_all(&fs_info->qgroup_rescan_completion);
 }
 
 static void
@@ -2110,6 +2112,7 @@ btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
         fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN;
         memset(&fs_info->qgroup_rescan_progress, 0,
                 sizeof(fs_info->qgroup_rescan_progress));
+        init_completion(&fs_info->qgroup_rescan_completion);
 
         /* clear all current qgroup tracking information */
         for (n = rb_first(&fs_info->qgroup_tree); n; n = rb_next(n)) {
@@ -2126,3 +2129,21 @@ btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
 
         return 0;
 }
+
+int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info)
+{
+        int running;
+        int ret = 0;
+
+        mutex_lock(&fs_info->qgroup_rescan_lock);
+        spin_lock(&fs_info->qgroup_lock);
+        running = fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN;
+        spin_unlock(&fs_info->qgroup_lock);
+        mutex_unlock(&fs_info->qgroup_rescan_lock);
+
+        if (running)
+                ret = wait_for_completion_interruptible(
+                                        &fs_info->qgroup_rescan_completion);
+
+        return ret;
+}