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block, bfq: protect 'bfqd->queued' by 'bfqd->lock' 

commit 181490d532 upstream.

If bfq_schedule_dispatch() is called from bfq_idle_slice_timer_body(),
then 'bfqd->queued' is read without holding 'bfqd->lock'. This is
wrong since it can be wrote concurrently.

Fix the problem by holding 'bfqd->lock' in such case.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220513023507.2625717-2-yukuai3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Cc: Khazhy Kumykov <khazhy@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Yu Kuai 2022-05-13 10:35:06 +08:00 committed by Greg Kroah-Hartman
parent 6949400ec9
commit c494ae1498
1 changed files with 3 additions and 1 deletions
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4
block/bfq-iosched.c
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@ -420,6 +420,8 @@ static struct bfq_io_cq *bfq_bic_lookup(struct bfq_data *bfqd,
*/
void bfq_schedule_dispatch(struct bfq_data *bfqd)
{
lockdep_assert_held(&bfqd->lock);
if (bfqd->queued != 0) {
bfq_log(bfqd, "schedule dispatch");
blk_mq_run_hw_queues(bfqd->queue, true);
@ -6257,8 +6259,8 @@ bfq_idle_slice_timer_body(struct bfq_data *bfqd, struct bfq_queue *bfqq)
bfq_bfqq_expire(bfqd, bfqq, true, reason);
schedule_dispatch:
spin_unlock_irqrestore(&bfqd->lock, flags);
bfq_schedule_dispatch(bfqd);
spin_unlock_irqrestore(&bfqd->lock, flags);
}
/*