From: Jason Wang <jasowang@redhat.com>
Date: Mon, 17 Jan 2011 08:11:17 +0000 (+0800)
Subject: vhost: lock receive queue, not the socket
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=783e3988544b94ff3918666b9f36866ac547fba1;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git

vhost: lock receive queue, not the socket

vhost takes a sock lock to try and prevent
the skb from being pulled from the receive queue
after skb_peek.  However this is not the right lock to use for that,
sk_receive_queue.lock is. Fix that up.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 0329c411bbf1..57203014c457 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -213,12 +213,13 @@ static int peek_head_len(struct sock *sk)
 {
 	struct sk_buff *head;
 	int len = 0;
+	unsigned long flags;
 
-	lock_sock(sk);
+	spin_lock_irqsave(&sk->sk_receive_queue.lock, flags);
 	head = skb_peek(&sk->sk_receive_queue);
-	if (head)
+	if (likely(head))
 		len = head->len;
-	release_sock(sk);
+	spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags);
 	return len;
 }