From: Jason Wang <jasowang@redhat.com>
Date: Sat, 8 Jun 2013 06:17:41 +0000 (+0800)
Subject: tuntap: set SOCK_ZEROCOPY flag during open
X-Git-Tag: v3.10-rc6~18^2~4
X-Git-Url: http://pileus.org/git/?p=~andy%2Flinux;a=commitdiff_plain;h=19a6afb23e5d323e1245baa4e62755492b2f1200

tuntap: set SOCK_ZEROCOPY flag during open

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@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index b1cbfbcff78..bfa9bb48e42 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -2159,6 +2159,8 @@ 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;
 }