[PATCH 5.13 251/800] block, bfq: fix delayed stable merge check
From: Greg Kroah-Hartman
Date: Mon Jul 12 2021 - 04:29:21 EST
From: Luca Mariotti <mariottiluca1@xxxxxxxxxx>
[ Upstream commit e03f2ab78a4a673e4af23c3b855591c48b9de4d7 ]
When attempting to schedule a merge of a given bfq_queue with the currently
in-service bfq_queue or with a cooperating bfq_queue among the scheduled
bfq_queues, delayed stable merge is checked for rotational or non-queueing
devs. For this stable merge to be performed, some conditions must be met.
If the current bfq_queue underwent some split from some merged bfq_queue,
one of these conditions is that two hundred milliseconds must elapse from
split, otherwise this condition is always met.
Unfortunately, by mistake, time_is_after_jiffies() was written instead of
time_is_before_jiffies() for this check, verifying that less than two
hundred milliseconds have elapsed instead of verifying that at least two
hundred milliseconds have elapsed.
Fix this issue by replacing time_is_after_jiffies() with
time_is_before_jiffies().
Signed-off-by: Luca Mariotti <mariottiluca1@xxxxxxxxxx>
Signed-off-by: Paolo Valente <paolo.valente@xxxxxxxxxx>
Signed-off-by: Pietro Pedroni <pedroni.pietro.96@xxxxxxxxx>
Link: https://lore.kernel.org/r/20210619140948.98712-3-paolo.valente@xxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
block/bfq-iosched.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index acd1f881273e..2adb1e69c9d2 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -2697,7 +2697,7 @@ bfq_setup_cooperator(struct bfq_data *bfqd, struct bfq_queue *bfqq,
if (unlikely(!bfqd->nonrot_with_queueing)) {
if (bic->stable_merge_bfqq &&
!bfq_bfqq_just_created(bfqq) &&
- time_is_after_jiffies(bfqq->split_time +
+ time_is_before_jiffies(bfqq->split_time +
msecs_to_jiffies(200))) {
struct bfq_queue *stable_merge_bfqq =
bic->stable_merge_bfqq;
--
2.30.2