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>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 86b1156..5c5617e 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1846,6 +1846,8 @@
next_rq->special = bidi_sdb;
}
+ blk_mq_start_request(req);
+
return scsi_setup_cmnd(sdev, req);
}
@@ -1880,17 +1882,19 @@
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);