block: don't call rq_qos_ops->done_bio if the bio isn't tracked
commit a647a524 upstream. 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> [ Shivani: Modified to apply on 5.10.y ] Signed-off-by:
Shivani Agarwal <shivani.agarwal@broadcom.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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