From 004b8f8a691205a93d9e80d98b786b2b97424d6e Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@redhat.com>
Date: Fri, 24 Sep 2021 19:07:04 +0800
Subject: [PATCH] block: don't call rq_qos_ops->done_bio if the bio isn't tracked
Git-commit: a647a524a46736786c95cdb553a070322ca096e3
Patch-mainline: v5.15-rc3
References: stable-5.14.11
[ 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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
block/bio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/bio.c b/block/bio.c
index d95e3456ba0c..52548c487883 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1396,7 +1396,7 @@ void bio_endio(struct bio *bio)
if (!bio_integrity_endio(bio))
return;
- if (bio->bi_bdev)
+ if (bio->bi_bdev && bio_flagged(bio, BIO_TRACKED))
rq_qos_done_bio(bio->bi_bdev->bd_disk->queue, bio);
if (bio->bi_bdev && bio_flagged(bio, BIO_TRACE_COMPLETION)) {
--
2.26.2