record_root_in_trans(trans, src, 1);
/*
+ * btrfs_qgroup_inherit relies on a consistent view of the usage for the
+ * src root, so we must run the delayed refs here.
+ *
+ * However this isn't particularly fool proof, because there's no
+ * synchronization keeping us from changing the tree after this point
+ * before we do the qgroup_inherit, or even from making changes while
+ * we're doing the qgroup_inherit. But that's a problem for the future,
+ * for now flush the delayed refs to narrow the race window where the
+ * qgroup counters could end up wrong.
+ */
+ ret = btrfs_run_delayed_refs(trans, (unsigned long)-1);
+ if (ret) {
+ btrfs_abort_transaction(trans, ret);
+ goto out;
+ }
+
+ /*
* We are going to commit transaction, see btrfs_commit_transaction()
* comment for reason locking tree_log_mutex
*/
goto fail;
}
- ret = btrfs_run_delayed_refs(trans, (unsigned long)-1);
- if (ret) {
- btrfs_abort_transaction(trans, ret);
- goto fail;
- }
-
/*
* Do special qgroup accounting for snapshot, as we do some qgroup
* snapshot hack to do fast snapshot.