From: K. Y. Srinivasan <kys@microsoft.com>
Date: Sat, 27 Aug 2011 18:31:21 +0000 (-0700)
Subject: Staging: hv: storvsc: Optimize the bounce buffer handling in the "read" case
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=fa23b8c78fefae4e8033a28e685673c35ff10789;p=deliverable%2Flinux.git

Staging: hv: storvsc: Optimize the bounce buffer handling in the "read" case

Optimize the bounce buffer handling in the "read" case.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/staging/hv/storvsc_drv.c b/drivers/staging/hv/storvsc_drv.c
index 90b91ade825a..3e00e70c945d 100644
--- a/drivers/staging/hv/storvsc_drv.c
+++ b/drivers/staging/hv/storvsc_drv.c
@@ -560,12 +560,10 @@ static int storvsc_queuecommand_lck(struct scsi_cmnd *scmnd,
 				ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
 					PAGE_SHIFT;
 
-			/*
-			 * FIXME: We can optimize on reads by just skipping
-			 * this
-			 */
-			copy_to_bounce_buffer(sgl, cmd_request->bounce_sgl,
-					      scsi_sg_count(scmnd));
+			if (vm_srb->data_in == WRITE_TYPE)
+				copy_to_bounce_buffer(sgl,
+					cmd_request->bounce_sgl,
+					scsi_sg_count(scmnd));
 
 			sgl = cmd_request->bounce_sgl;
 			sg_count = cmd_request->bounce_sgl_count;