[3.8.y.z extended stable] Patch "xen-netback: remove pointless clause from if statement" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    xen-netback: remove pointless clause from if statement

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.22.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 5546c76b35a6eb705979609d0c80013c843fdaad Mon Sep 17 00:00:00 2001
From: Paul Durrant <Paul.Durrant at citrix.com>
Date: Fri, 28 Mar 2014 11:39:05 +0000
Subject: xen-netback: remove pointless clause from if statement

[ Upstream commit 0576eddf24df716d8570ef8ca11452a9f98eaab2 ]

This patch removes a test in start_new_rx_buffer() that checks whether
a copy operation is less than MAX_BUFFER_OFFSET in length, since
MAX_BUFFER_OFFSET is defined to be PAGE_SIZE and the only caller of
start_new_rx_buffer() already limits copy operations to PAGE_SIZE or less.

Signed-off-by: Paul Durrant <paul.durrant at citrix.com>
Cc: Ian Campbell <ian.campbell at citrix.com>
Cc: Wei Liu <wei.liu2 at citrix.com>
Cc: Sander Eikelenboom <linux at eikelenboom.it>
Reported-By: Sander Eikelenboom <linux at eikelenboom.it>
Tested-By: Sander Eikelenboom <linux at eikelenboom.it>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/net/xen-netback/netback.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index d56fe61..6468d55 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -347,8 +347,8 @@ static bool start_new_rx_buffer(int offset, unsigned long size, int head)
 	 * into multiple copies tend to give large frags their
 	 * own buffers as before.
 	 */
-	if ((offset + size > MAX_BUFFER_OFFSET) &&
-	    (size <= MAX_BUFFER_OFFSET) && offset && !head)
+	BUG_ON(size > MAX_BUFFER_OFFSET);
+	if ((offset + size > MAX_BUFFER_OFFSET) && offset && !head)
 		return true;

 	return false;
--
1.8.3.2