scsi: add scsi_setup_cmnd helper

Factor out command setup code that will be shared with the blk-mq code path.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Webb Scales <webbnh@hp.com>

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 85cf0ef..04c3684 100644 (file)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1092,6 +1092,27 @@ static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
        return scsi_cmd_to_driver(cmd)->init_command(cmd);
 }
 
+static int scsi_setup_cmnd(struct scsi_device *sdev, struct request *req)
+{
+       struct scsi_cmnd *cmd = req->special;
+
+       if (!blk_rq_bytes(req))
+               cmd->sc_data_direction = DMA_NONE;
+       else if (rq_data_dir(req) == WRITE)
+               cmd->sc_data_direction = DMA_TO_DEVICE;
+       else
+               cmd->sc_data_direction = DMA_FROM_DEVICE;
+
+       switch (req->cmd_type) {
+       case REQ_TYPE_FS:
+               return scsi_setup_fs_cmnd(sdev, req);
+       case REQ_TYPE_BLOCK_PC:
+               return scsi_setup_blk_pc_cmnd(sdev, req);
+       default:
+               return BLKPREP_KILL;
+       }
+}
+
 static int
 scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
 {
@@ -1195,24 +1216,7 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req)
                goto out;
        }
 
-       if (!blk_rq_bytes(req))
-               cmd->sc_data_direction = DMA_NONE;
-       else if (rq_data_dir(req) == WRITE)
-               cmd->sc_data_direction = DMA_TO_DEVICE;
-       else
-               cmd->sc_data_direction = DMA_FROM_DEVICE;
-
-       switch (req->cmd_type) {
-       case REQ_TYPE_FS:
-               ret = scsi_setup_fs_cmnd(sdev, req);
-               break;
-       case REQ_TYPE_BLOCK_PC:
-               ret = scsi_setup_blk_pc_cmnd(sdev, req);
-               break;
-       default:
-               ret = BLKPREP_KILL;
-       }
-
+       ret = scsi_setup_cmnd(sdev, req);
 out:
        return scsi_prep_return(q, req, ret);
 }