From e2490073cd7c3d6f6ef6e029a208edd4d38efac4 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 13 Sep 2014 16:40:09 -0700 Subject: blk-mq: call blk_mq_start_request from ->queue_rq When we call blk_mq_start_request from the core blk-mq code before calling into ->queue_rq there is a racy window where the timeout handler can hit before we've fully set up the driver specific part of the command. Move the call to blk_mq_start_request into the driver so the driver can start the request only once it is fully set up. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/block/mtip32xx/mtip32xx.c | 2 ++ drivers/block/null_blk.c | 2 ++ drivers/block/virtio_blk.c | 2 ++ 3 files changed, 6 insertions(+) (limited to 'drivers/block') diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c index 0e2084f37c67..4042440a0470 100644 --- a/drivers/block/mtip32xx/mtip32xx.c +++ b/drivers/block/mtip32xx/mtip32xx.c @@ -3783,6 +3783,8 @@ static int mtip_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq, if (unlikely(mtip_check_unal_depth(hctx, rq))) return BLK_MQ_RQ_QUEUE_BUSY; + blk_mq_start_request(rq); + ret = mtip_submit_request(hctx, rq); if (likely(!ret)) return BLK_MQ_RQ_QUEUE_OK; diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index c5b7315c2c13..332ce20d45da 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -321,6 +321,8 @@ static int null_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq, cmd->rq = rq; cmd->nq = hctx->driver_data; + blk_mq_start_request(rq); + null_handle_cmd(cmd); return BLK_MQ_RQ_QUEUE_OK; } diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 13756e016797..83816bf6882f 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -205,6 +205,8 @@ static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req, } } + blk_mq_start_request(req); + num = blk_rq_map_sg(hctx->queue, vbr->req, vbr->sg); if (num) { if (rq_data_dir(vbr->req) == WRITE) -- cgit v1.2.3