[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>

diff --git a/drivers/scsi/qla2xxx/qla_iocb.c b/drivers/scsi/qla2xxx/qla_iocb.c
index eac9509244971ba9e324803ca531014e3f917dad..1ae0d1dbbdb450807138abd48a980f0f5780db0f 100644 (file)
--- 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) {