diff options
| -rw-r--r-- | fs/btrfs/transaction.c | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 7bb58c3ddcd1..dbbd46417534 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -1433,6 +1433,23 @@ static int qgroup_account_snapshot(struct btrfs_trans_handle *trans, 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 */ @@ -1685,12 +1702,6 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, 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. |