From mboxrd@z Thu Jan 1 00:00:00 1970 From: ming.lei@redhat.com (Ming Lei) Date: Wed, 17 Apr 2019 11:44:03 +0800 Subject: [PATCH V6 2/9] blk-mq: move cancel of requeue_work into blk_mq_release In-Reply-To: <20190417034410.31957-1-ming.lei@redhat.com> References: <20190417034410.31957-1-ming.lei@redhat.com> Message-ID: <20190417034410.31957-3-ming.lei@redhat.com> With holding queue's kobject refcount, it is safe for driver to schedule requeue. However, blk_mq_kick_requeue_list() may be called after blk_sync_queue() is done because of concurrent requeue activities, then requeue work may not be completed when freeing queue, and kernel oops is triggered. So moving the cancel of requeue_work into blk_mq_release() for avoiding race between requeue and freeing queue. Cc: Dongli Zhang Cc: James Smart Cc: Bart Van Assche Cc: linux-scsi at vger.kernel.org, Cc: Martin K . Petersen , Cc: Christoph Hellwig , Cc: James E . J . Bottomley , Cc: jianchao wang Reviewed-by: Bart Van Assche Reviewed-by: Johannes Thumshirn Signed-off-by: Ming Lei --- block/blk-core.c | 1 - block/blk-mq.c | 2 ++ 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/block/blk-core.c b/block/blk-core.c index a55389ba8779..93dc588fabe2 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -237,7 +237,6 @@ void blk_sync_queue(struct request_queue *q) struct blk_mq_hw_ctx *hctx; int i; - cancel_delayed_work_sync(&q->requeue_work); queue_for_each_hw_ctx(q, hctx, i) cancel_delayed_work_sync(&hctx->run_work); } diff --git a/block/blk-mq.c b/block/blk-mq.c index ef5a16a2d6fb..55776a6e2586 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2640,6 +2640,8 @@ void blk_mq_release(struct request_queue *q) struct blk_mq_hw_ctx *hctx; unsigned int i; + cancel_delayed_work_sync(&q->requeue_work); + /* hctx kobj stays in hctx */ queue_for_each_hw_ctx(q, hctx, i) { if (!hctx) -- 2.9.5