[ 3.8.y.z extended stable ] Patch "tuntap: set SOCK_ZEROCOPY flag during open" has been added to staging queue

[Kamal Mostafa]

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

    tuntap: set SOCK_ZEROCOPY flag during open

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 3.8.13.4.

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 f4d8e13a462e4711025ffbdf61ab502d568d75b9 Mon Sep 17 00:00:00 2001
From: Jason Wang <jasowang at redhat.com>
Date: Sat, 8 Jun 2013 14:17:41 +0800
Subject: tuntap: set SOCK_ZEROCOPY flag during open

[ Upstream commit 19a6afb23e5d323e1245baa4e62755492b2f1200 ]

Commit 54f968d6efdbf7dec36faa44fc11f01b0e4d1990
(tuntap: move socket to tun_file) forgets to set SOCK_ZEROCOPY flag, which will
prevent vhost_net from doing zercopy w/ tap. This patch fixes this by setting
it during file open.

Cc: Michael S. Tsirkin <mst at redhat.com>
Signed-off-by: Jason Wang <jasowang at redhat.com>
Acked-by: Michael S. Tsirkin <mst at redhat.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/net/tun.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 2129cf90..2a56317 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -2154,6 +2154,8 @@ static int tun_chr_open(struct inode *inode, struct file * file)
 	set_bit(SOCK_EXTERNALLY_ALLOCATED, &tfile->socket.flags);
 	INIT_LIST_HEAD(&tfile->next);

+	sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
+
 	return 0;
 }

--
1.8.1.2