[SCSI] Shorten the path length of scsi_cmd_to_driver()
This patch tries to shorten the path length of scsi_cmd_to_driver(). As only
REQ_TYPE_BLOCK_PC commands can be submitted without a driver, so we could
avoid the related NULL checking, as long as we make sure we don't use it for
REQ_TYPE_BLOCK_PC type commands. Plus, this fixes a bug where you get
different behaviors from REQ_TYPE_BLOCK_PC commands when a driver is and isn't
attached.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index ac06cc5..de5f5d8 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -132,18 +132,10 @@
unsigned char tag; /* SCSI-II queued command tag */
};
+/* make sure not to use it with REQ_TYPE_BLOCK_PC commands */
static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
{
- struct scsi_driver **sdp;
-
- if (!cmd->request->rq_disk)
- return NULL;
-
- sdp = (struct scsi_driver **)cmd->request->rq_disk->private_data;
- if (!sdp)
- return NULL;
-
- return *sdp;
+ return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
}
extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);