mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-11 04:18:39 +08:00
block, bfq: move forward the getting of an extra ref in bfq_bfqq_move
Commitecedd3d7e1
("block, bfq: get extra ref to prevent a queue from being freed during a group move") gets an extra reference to a bfq_queue before possibly deactivating it (temporarily), in bfq_bfqq_move(). This prevents the bfq_queue from disappearing before being reactivated in its new group. Yet, the bfq_queue may also be expired (i.e., its service may be stopped) before the bfq_queue is deactivated. And also an expiration may lead to a premature freeing. This commit fixes this issue by simply moving forward the getting of the extra reference already introduced by commitecedd3d7e1
("block, bfq: get extra ref to prevent a queue from being freed during a group move"). Reported-by: cki-project@redhat.com Tested-by: cki-project@redhat.com Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
parent
2f95fa5c95
commit
fd1bb3ae54
@ -642,6 +642,12 @@ void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
|
||||
{
|
||||
struct bfq_entity *entity = &bfqq->entity;
|
||||
|
||||
/*
|
||||
* Get extra reference to prevent bfqq from being freed in
|
||||
* next possible expire or deactivate.
|
||||
*/
|
||||
bfqq->ref++;
|
||||
|
||||
/* If bfqq is empty, then bfq_bfqq_expire also invokes
|
||||
* bfq_del_bfqq_busy, thereby removing bfqq and its entity
|
||||
* from data structures related to current group. Otherwise we
|
||||
@ -652,12 +658,6 @@ void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
|
||||
bfq_bfqq_expire(bfqd, bfqd->in_service_queue,
|
||||
false, BFQQE_PREEMPTED);
|
||||
|
||||
/*
|
||||
* get extra reference to prevent bfqq from being freed in
|
||||
* next possible deactivate
|
||||
*/
|
||||
bfqq->ref++;
|
||||
|
||||
if (bfq_bfqq_busy(bfqq))
|
||||
bfq_deactivate_bfqq(bfqd, bfqq, false, false);
|
||||
else if (entity->on_st_or_in_serv)
|
||||
@ -677,7 +677,7 @@ void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
|
||||
|
||||
if (!bfqd->in_service_queue && !bfqd->rq_in_driver)
|
||||
bfq_schedule_dispatch(bfqd);
|
||||
/* release extra ref taken above */
|
||||
/* release extra ref taken above, bfqq may happen to be freed now */
|
||||
bfq_put_queue(bfqq);
|
||||
}
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user