From 0ef9ab34f442f7236b5a84a6691959c67639f8b9 Mon Sep 17 00:00:00 2001 From: Alan Huang Date: Thu, 10 Oct 2024 21:21:50 +0800 Subject: [PATCH] bcachefs: Do not allow no fail lock request to fail If the transaction chose itself as a victim before and restarted, it might request a no fail lock request this time. But it might be added to others' lock graph and be chose as the victim again, it's no longer safe without additional check. We can also convert the cycle detector to be fully RCU-based to solve that unsoundness, but the latency added to trans_put and additional memory required may not worth it. Signed-off-by: Alan Huang Signed-off-by: Kent Overstreet --- fs/bcachefs/btree_locking.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/bcachefs/btree_locking.c b/fs/bcachefs/btree_locking.c index c1a0f8f78eb4..771d531d6533 100644 --- a/fs/bcachefs/btree_locking.c +++ b/fs/bcachefs/btree_locking.c @@ -281,7 +281,7 @@ int bch2_check_for_deadlock(struct btree_trans *trans, struct printbuf *cycle) g.nr = 0; - if (trans->lock_must_abort) { + if (trans->lock_must_abort && !trans->lock_may_not_fail) { if (cycle) return -1; -- 2.50.1