From: Ming Lei ming.lei@redhat.com

[ Upstream commit a647a524a46736786c95cdb553a070322ca096e3 ]

rq_qos framework is only applied on request based driver, so:

1) rq_qos_done_bio() needn't to be called for bio based driver

2) rq_qos_done_bio() needn't to be called for bio which isn't tracked, such as bios ended from error handling code.

Especially in bio_endio():

1) request queue is referred via bio->bi_bdev->bd_disk->queue, which may be gone since request queue refcount may not be held in above two cases

2) q->rq_qos may be freed in blk_cleanup_queue() when calling into __rq_qos_done_bio()

Fix the potential kernel panic by not calling rq_qos_ops->done_bio if the bio isn't tracked. This way is safe because both ioc_rqos_done_bio() and blkcg_iolatency_done_bio() are nop if the bio isn't tracked.

Reported-by: Yu Kuai yukuai3@huawei.com Cc: tj@kernel.org Signed-off-by: Ming Lei ming.lei@redhat.com Reviewed-by: Christoph Hellwig hch@lst.de Acked-by: Tejun Heo tj@kernel.org Link: https://lore.kernel.org/r/20210924110704.1541818-1-ming.lei@redhat.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org [Shivani: Modified to apply on 5.10.y] Signed-off-by: Shivani Agarwal shivani.agarwal@broadcom.com --- block/bio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/bio.c b/block/bio.c index 88a09c31095f..7851f54edc76 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1430,7 +1430,7 @@ void bio_endio(struct bio *bio) if (!bio_integrity_endio(bio)) return;

- if (bio->bi_disk) + if (bio->bi_disk && bio_flagged(bio, BIO_TRACKED)) rq_qos_done_bio(bio->bi_disk->queue, bio);

/*