[SCSI] qla2xxx: Micro optimization in queuecommand handler

Optimized queuecommand handler's to eliminate double head-room checks.
The checks are moved inside the 1st if-loop otherwise you would end up checking twice when there is
enough head room.

Signed-off-by: Chetan Loke <loke.chetan@gmail.com>
Reviewed-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Reviewed-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 9 insertions, 10 deletions

diff --git a/drivers/scsi/qla2xxx/qla_iocb.c b/drivers/scsi/qla2xxx/qla_iocb.c
index eac950924497..1ae0d1dbbdb4 100644
--- a/drivers/scsi/qla2xxx/qla_iocb.c
+++ b/drivers/scsi/qla2xxx/qla_iocb.c
@@ -385,9 +385,10 @@ qla2x00_start_scsi(srb_t *sp)
                 else
                         req->cnt = req->length -
                             (req->ring_index - cnt);
+                /* If still no head room then bail out */
+                if (req->cnt < (req_cnt + 2))
+                        goto queuing_error;
         }
-        if (req->cnt < (req_cnt + 2))
-                goto queuing_error;
 
         /* Build command packet */
         req->current_outstanding_cmd = handle;
@@ -1502,9 +1503,9 @@ qla24xx_start_scsi(srb_t *sp)
                 else
                         req->cnt = req->length -
                                 (req->ring_index - cnt);
+                if (req->cnt < (req_cnt + 2))
+                        goto queuing_error;
         }
-        if (req->cnt < (req_cnt + 2))
-                goto queuing_error;
 
         /* Build command packet. */
         req->current_outstanding_cmd = handle;
@@ -1717,11 +1718,10 @@ qla24xx_dif_start_scsi(srb_t *sp)
                 else
                         req->cnt = req->length -
                                 (req->ring_index - cnt);
+                if (req->cnt < (req_cnt + 2))
+                        goto queuing_error;
         }
 
-        if (req->cnt < (req_cnt + 2))
-                goto queuing_error;
-
         status |= QDSS_GOT_Q_SPACE;
 
         /* Build header part of command packet (excluding the OPCODE). */
@@ -2343,11 +2343,10 @@ sufficient_dsds:
                         else
                                 req->cnt = req->length -
                                         (req->ring_index - cnt);
+                        if (req->cnt < (req_cnt + 2))
+                                goto queuing_error;
                 }
 
-                if (req->cnt < (req_cnt + 2))
-                        goto queuing_error;
-
                 ctx = sp->u.scmd.ctx =
                     mempool_alloc(ha->ctx_mempool, GFP_ATOMIC);
                 if (!ctx) {