sd: don't use scsi_setup_blk_pc_cmnd for flush requests
Simplify handling of flush requests by setting up the command directly
instead of initializing request fields and then calling
scsi_setup_blk_pc_cmnd to propagate the information into the command.
Also rename scsi_setup_flush_cmnd to sd_setup_flush_cmnd for consistency.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index e2932ea..18ca21f 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -844,14 +844,20 @@
return ret;
}
-static int scsi_setup_flush_cmnd(struct scsi_device *sdp, struct request *rq)
+static int sd_setup_flush_cmnd(struct scsi_cmnd *cmd)
{
- rq->timeout *= SD_FLUSH_TIMEOUT_MULTIPLIER;
- rq->retries = SD_MAX_RETRIES;
- rq->cmd[0] = SYNCHRONIZE_CACHE;
- rq->cmd_len = 10;
+ struct request *rq = cmd->request;
- return scsi_setup_blk_pc_cmnd(sdp, rq);
+ /* flush requests don't perform I/O, zero the S/G table */
+ memset(&cmd->sdb, 0, sizeof(cmd->sdb));
+
+ cmd->cmnd[0] = SYNCHRONIZE_CACHE;
+ cmd->cmd_len = 10;
+ cmd->transfersize = 0;
+ cmd->allowed = SD_MAX_RETRIES;
+
+ rq->timeout *= SD_FLUSH_TIMEOUT_MULTIPLIER;
+ return BLKPREP_OK;
}
static void sd_uninit_command(struct scsi_cmnd *SCpnt)
@@ -891,7 +897,7 @@
ret = sd_setup_write_same_cmnd(sdp, rq);
goto out;
} else if (rq->cmd_flags & REQ_FLUSH) {
- ret = scsi_setup_flush_cmnd(sdp, rq);
+ ret = sd_setup_flush_cmnd(SCpnt);
goto out;
}
ret = scsi_init_io(SCpnt, GFP_ATOMIC);