[PATCH 5.4 029/118] block, bfq: turn put_queue into release_process_ref in __bfq_bic_change_cgroup

From: Greg Kroah-Hartman
Date: Wed Apr 22 2020 - 06:18:10 EST


From: Paolo Valente <paolo.valente@xxxxxxxxxx>

commit c8997736650060594845e42c5d01d3118aec8d25 upstream.

A bfq_put_queue() may be invoked in __bfq_bic_change_cgroup(). The
goal of this put is to release a process reference to a bfq_queue. But
process-reference releases may trigger also some extra operation, and,
to this goal, are handled through bfq_release_process_ref(). So, turn
the invocation of bfq_put_queue() into an invocation of
bfq_release_process_ref().

Tested-by: cki-project@xxxxxxxxxx
Signed-off-by: Paolo Valente <paolo.valente@xxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
block/bfq-cgroup.c | 5 +----
block/bfq-iosched.c | 2 --
block/bfq-iosched.h | 1 +
3 files changed, 2 insertions(+), 6 deletions(-)

--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -697,10 +697,7 @@ static struct bfq_group *__bfq_bic_chang

if (entity->sched_data != &bfqg->sched_data) {
bic_set_bfqq(bic, NULL, 0);
- bfq_log_bfqq(bfqd, async_bfqq,
- "bic_change_group: %p %d",
- async_bfqq, async_bfqq->ref);
- bfq_put_queue(async_bfqq);
+ bfq_release_process_ref(bfqd, async_bfqq);
}
}

--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -2717,8 +2717,6 @@ static void bfq_bfqq_save_state(struct b
}
}

-
-static
void bfq_release_process_ref(struct bfq_data *bfqd, struct bfq_queue *bfqq)
{
/*
--- a/block/bfq-iosched.h
+++ b/block/bfq-iosched.h
@@ -950,6 +950,7 @@ void bfq_bfqq_expire(struct bfq_data *bf
bool compensate, enum bfqq_expiration reason);
void bfq_put_queue(struct bfq_queue *bfqq);
void bfq_end_wr_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg);
+void bfq_release_process_ref(struct bfq_data *bfqd, struct bfq_queue *bfqq);
void bfq_schedule_dispatch(struct bfq_data *bfqd);
void bfq_put_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg);