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authorChristoph Hellwig <hch@lst.de>2014-09-13 16:40:09 -0700
committerJens Axboe <axboe@fb.com>2014-09-22 12:00:07 -0600
commite2490073cd7c3d6f6ef6e029a208edd4d38efac4 (patch)
tree48465e67b335f6d696d698641365b4a4d1e89d32 /drivers
parentbf57229745f849e500ba69ff91e35bc8160a7373 (diff)
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 <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/block/mtip32xx/mtip32xx.c2
-rw-r--r--drivers/block/null_blk.c2
-rw-r--r--drivers/block/virtio_blk.c2
-rw-r--r--drivers/scsi/scsi_lib.c1
4 files changed, 7 insertions, 0 deletions
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)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index f1df41168391..2dcd9078de48 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1890,6 +1890,7 @@ static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req,
scsi_init_cmd_errh(cmd);
cmd->scsi_done = scsi_mq_done;
+ blk_mq_start_request(req);
reason = scsi_dispatch_cmd(cmd);
if (reason) {
scsi_set_blocked(cmd, reason);