From 355dfa1bc8026d185678fed4e409719a595b2d39 Mon Sep 17 00:00:00 2001
From: James Bottomley <James.Bottomley@steeleye.com>
Date: Tue, 22 May 2007 14:43:14 -0500
Subject: [PATCH] [SCSI] scsi_error: send the sense buffer down without copying

Now that the block submission path correctly bounces, we can simply
use the command sense_buffer to send to retrieve sense information and
junk the unnecessary page allocation.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
---
 drivers/scsi/scsi_error.c | 26 +++-----------------------
 1 file changed, 3 insertions(+), 23 deletions(-)

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index e8350c562d24..9adb64ac054c 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -18,12 +18,12 @@
 #include <linux/sched.h>
 #include <linux/timer.h>
 #include <linux/string.h>
-#include <linux/slab.h>
 #include <linux/kernel.h>
 #include <linux/kthread.h>
 #include <linux/interrupt.h>
 #include <linux/blkdev.h>
 #include <linux/delay.h>
+#include <linux/scatterlist.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
@@ -640,16 +640,8 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
 	memcpy(scmd->cmnd, cmnd, cmnd_size);
 
 	if (copy_sense) {
-		gfp_t gfp_mask = GFP_ATOMIC;
-
-		if (shost->hostt->unchecked_isa_dma)
-			gfp_mask |= __GFP_DMA;
-
-		sgl.page = alloc_page(gfp_mask);
-		if (!sgl.page)
-			return FAILED;
-		sgl.offset = 0;
-		sgl.length = 252;
+		sg_init_one(&sgl, scmd->sense_buffer,
+			    sizeof(scmd->sense_buffer));
 
 		scmd->sc_data_direction = DMA_FROM_DEVICE;
 		scmd->request_bufflen = sgl.length;
@@ -719,18 +711,6 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
 	}
 
 
-	/*
-	 * Last chance to have valid sense data.
-	 */
-	if (copy_sense) {
-		if (!SCSI_SENSE_VALID(scmd)) {
-			memcpy(scmd->sense_buffer, page_address(sgl.page),
-			       sizeof(scmd->sense_buffer));
-		}
-		__free_page(sgl.page);
-	}
-
-
 	/*
 	 * Restore original data
 	 */
-- 
2.20.1