+ if (fs_info->balance_ctl) {
+ /* this is either (2) or (3) */
+ if (!atomic_read(&fs_info->balance_running)) {
+ mutex_unlock(&fs_info->balance_mutex);
+ if (!mutex_trylock(&fs_info->volume_mutex))
+ goto again;
+ mutex_lock(&fs_info->balance_mutex);
+
+ if (fs_info->balance_ctl &&
+ !atomic_read(&fs_info->balance_running)) {
+ /* this is (3) */
+ need_unlock = false;
+ goto locked;
+ }
+
+ mutex_unlock(&fs_info->balance_mutex);
+ mutex_unlock(&fs_info->volume_mutex);
+ goto again;
+ } else {
+ /* this is (2) */
+ mutex_unlock(&fs_info->balance_mutex);
+ ret = -EINPROGRESS;
+ goto out;
+ }
+ } else {
+ /* this is (1) */
+ mutex_unlock(&fs_info->balance_mutex);
+ pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+locked:
+ BUG_ON(!atomic_read(&fs_info->mutually_exclusive_operation_running));