From ada02c207c0168e0e9173983d00f82c9b5de90c8 Mon Sep 17 00:00:00 2001 From: Brian Foster Date: Fri, 1 Mar 2024 12:49:24 -0500 Subject: [PATCH] bcachefs: fix lost journal buf wakeup due to improved pipelining The journal_write_done() handler was reworked into a loop in commit 746a33c96b7a ("bcachefs: better journal pipelining"). As part of this, the journal buffer wake was factored into a post-loop branch that executes if at least one journal buffer has completed. The journal buffer processing loop iterates on the journal buffer pointer, however. This means that w refers to the last buffer processed by the loop, which may or may not be done. This also means that if multiple buffers are processed by the loop, only the last is awoken. This lost wakeup behavior has lead to stalling problems in various CI and fstests, such as generic/703. Lift the wake into the loop so each done buffer sees a wake call as it is processed. Signed-off-by: Brian Foster Signed-off-by: Kent Overstreet --- fs/bcachefs/journal_io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/bcachefs/journal_io.c b/fs/bcachefs/journal_io.c index 0b49b2383d82..8ded059591c7 100644 --- a/fs/bcachefs/journal_io.c +++ b/fs/bcachefs/journal_io.c @@ -1672,6 +1672,7 @@ static CLOSURE_CALLBACK(journal_write_done) new.unwritten_idx++; } while ((v = atomic64_cmpxchg(&j->reservations.counter, old.v, new.v)) != old.v); + closure_wake_up(&w->wait); completed = true; } @@ -1682,7 +1683,6 @@ static CLOSURE_CALLBACK(journal_write_done) track_event_change(&c->times[BCH_TIME_blocked_journal_max_in_flight], &j->max_in_flight_start, false); - closure_wake_up(&w->wait); journal_wake(j); }