On Thu, Nov 04, 2021 at 06:14:30AM -0600, Jens Axboe wrote:
> To player it safer, I would suggest we fold in something like the
> below. That keeps the submit_checks() under the queue enter.
Yes, this looks much better. Nit below:
> struct block_device *bdev = bio->bi_bdev;
> struct request_queue *q = bdev_get_queue(bdev);
> @@ -868,14 +868,13 @@ static void __submit_bio(struct bio *bio)
> {
> struct gendisk *disk = bio->bi_bdev->bd_disk;
>
> - if (!submit_bio_checks(bio) || !blk_crypto_bio_prep(&bio))
> - return;
> if (!disk->fops->submit_bio) {
> blk_mq_submit_bio(bio);
> } else {
> if (unlikely(bio_queue_enter(bio) != 0))
> return;
> - disk->fops->submit_bio(bio);
> + if (submit_bio_checks(bio) && blk_crypto_bio_prep(&bio))
> + disk->fops->submit_bio(bio);
> blk_queue_exit(disk->queue);
> }
A this point moving the whole ->submit_bio based branch into a
helper probably makes sense as well.
> + if (unlikely(!blk_crypto_bio_prep(&bio)))
> + return;
> +
> blk_queue_bounce(q, &bio);
> if (blk_may_split(q, bio))
> __blk_queue_split(q, &bio, &nr_segs);
> @@ -2551,6 +2554,8 @@ void blk_mq_submit_bio(struct bio *bio)
>
> if (unlikely(!blk_mq_queue_enter(q, bio)))
> return;
> + if (unlikely(!submit_bio_checks(bio)))
> + goto put_exit;
This now skips the checks for the cached request case, doesn't it?
