[PATCH 5.3 114/166] block, bfq: push up injection only after setting service time

Greg Kroah-Hartman
2019-10-06T17:44:07Z

From: Paolo Valente <paolo.valente@linaro.org>

[ Upstream commit 58494c980f40274c465ebfdece02d401def088bf ]

If equal to 0, the injection limit for a bfq_queue is pushed to 1
after a first sample of the total service time of the I/O requests of
the queue is computed (to allow injection to start). Yet, because of a
mistake in the branch that performs this action, the push may happen
also in some other case. This commit fixes this issue.

Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
block/bfq-iosched.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index b33be928d164f..70bcbd02edcb1 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5809,12 +5809,14 @@ static void bfq_update_inject_limit(struct bfq_data *bfqd,
*/
if ((bfqq->last_serv_time_ns == 0 && bfqd->rq_in_driver == 1) ||
tot_time_ns < bfqq->last_serv_time_ns) {
+ if (bfqq->last_serv_time_ns == 0) {
+ /*
+ * Now we certainly have a base value: make sure we
+ * start trying injection.
+ */
+ bfqq->inject_limit = max_t(unsigned int, 1, old_limit);
+ }
bfqq->last_serv_time_ns = tot_time_ns;
- /*
- * Now we certainly have a base value: make sure we
- * start trying injection.
- */
- bfqq->inject_limit = max_t(unsigned int, 1, old_limit);
} else if (!bfqd->rqs_injected && bfqd->rq_in_driver == 1)
/*
* No I/O injected and no request still in service in
--
2.20.1