scsi: move blk_mq_start_request call earlier

Some ATA drivers need the dma drain size workaround, and thus need to
call blk_mq_start_request before the S/G mapping.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Christoph Hellwig 2014-09-22 15:59:31 +02:00 committed by Jens Axboe
parent 9041583765
commit fe052529e4

View File

@ -1846,6 +1846,8 @@ static int scsi_mq_prep_fn(struct request *req)
next_rq->special = bidi_sdb;
}
blk_mq_start_request(req);
return scsi_setup_cmnd(sdev, req);
}
@ -1880,17 +1882,19 @@ static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req,
if (!scsi_host_queue_ready(q, shost, sdev))
goto out_dec_target_busy;
if (!(req->cmd_flags & REQ_DONTPREP)) {
ret = prep_to_mq(scsi_mq_prep_fn(req));
if (ret)
goto out_dec_host_busy;
req->cmd_flags |= REQ_DONTPREP;
} else {
blk_mq_start_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);