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| author | Ming Lei <ming.lei@redhat.com> | 2021-09-24 19:07:04 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-09-24 11:04:39 -0600 |
| commit | a647a524a46736786c95cdb553a070322ca096e3 (patch) | |
| tree | 9e521c7d5b50c6a8f708865d889ce7afc8d16aec /block | |
| parent | 5cad87569164fbdd5279504d7bc089aea51bf0f4 (diff) | |
| download | lwn-a647a524a46736786c95cdb553a070322ca096e3.tar.gz lwn-a647a524a46736786c95cdb553a070322ca096e3.zip | |
block: don't call rq_qos_ops->done_bio if the bio isn't tracked
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>
Diffstat (limited to 'block')
| -rw-r--r-- | block/bio.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/block/bio.c b/block/bio.c index 5df3dd282e40..a6fb6a0b4295 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1466,7 +1466,7 @@ again: 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)) { |