From fd9c40f64c514bdc585a21e2e33fa5f83ca8811b Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Thu, 4 Apr 2019 10:08:43 -0700 Subject: block: Revert v5.0 blk_mq_request_issue_directly() changes blk_mq_try_issue_directly() can return BLK_STS*_RESOURCE for requests that have been queued. If that happens when blk_mq_try_issue_directly() is called by the dm-mpath driver then dm-mpath will try to resubmit a request that is already queued and a kernel crash follows. Since it is nontrivial to fix blk_mq_request_issue_directly(), revert the blk_mq_request_issue_directly() changes that went into kernel v5.0. This patch reverts the following commits: * d6a51a97c0b2 ("blk-mq: replace and kill blk_mq_request_issue_directly") # v5.0. * 5b7a6f128aad ("blk-mq: issue directly with bypass 'false' in blk_mq_sched_insert_requests") # v5.0. * 7f556a44e61d ("blk-mq: refactor the code of issue request directly") # v5.0. Cc: Christoph Hellwig Cc: Ming Lei Cc: Jianchao Wang Cc: Hannes Reinecke Cc: Johannes Thumshirn Cc: James Smart Cc: Dongli Zhang Cc: Laurence Oberman Cc: Reported-by: Laurence Oberman Tested-by: Laurence Oberman Fixes: 7f556a44e61d ("blk-mq: refactor the code of issue request directly") # v5.0. Signed-off-by: Bart Van Assche Signed-off-by: Jens Axboe --- block/blk-mq.h | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'block/blk-mq.h') diff --git a/block/blk-mq.h b/block/blk-mq.h index d704fc7766f4..423ea88ab6fb 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -70,10 +70,8 @@ void blk_mq_request_bypass_insert(struct request *rq, bool run_queue); void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, struct list_head *list); -blk_status_t blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, - struct request *rq, - blk_qc_t *cookie, - bool bypass, bool last); +/* Used by blk_insert_cloned_request() to issue request directly */ +blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last); void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, struct list_head *list); -- cgit v1.2.3