From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757071Ab3ILSMo (ORCPT ); Thu, 12 Sep 2013 14:12:44 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57107 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755704Ab3ILR7W (ORCPT ); Thu, 12 Sep 2013 13:59:22 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Graf , Eric Dumazet , Hannes Frederic Sowa , Stephen Warren , Fabio Estevam , Fabio Estevam , Stephen Warren , "David S. Miller" Subject: [ 32/46] ipv6: Dont depend on per socket memory for neighbour discovery messages Date: Thu, 12 Sep 2013 10:58:43 -0700 Message-Id: <20130912175724.492578856@linuxfoundation.org> X-Mailer: git-send-email 1.8.4.3.gca3854a In-Reply-To: <20130912175721.001906199@linuxfoundation.org> References: <20130912175721.001906199@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Graf [ Upstream commit 25a6e6b84fba601eff7c28d30da8ad7cfbef0d43 ] Allocating skbs when sending out neighbour discovery messages currently uses sock_alloc_send_skb() based on a per net namespace socket and thus share a socket wmem buffer space. If a netdevice is temporarily unable to transmit due to carrier loss or for other reasons, the queued up ndisc messages will cosnume all of the wmem space and will thus prevent from any more skbs to be allocated even for netdevices that are able to transmit packets. The number of neighbour discovery messages sent is very limited, use of alloc_skb() bypasses the socket wmem buffer size enforcement while the manual call to skb_set_owner_w() maintains the socket reference needed for the IPv6 output path. This patch has orginally been posted by Eric Dumazet in a modified form. Signed-off-by: Thomas Graf Cc: Eric Dumazet Cc: Hannes Frederic Sowa Cc: Stephen Warren Cc: Fabio Estevam Tested-by: Fabio Estevam Tested-by: Stephen Warren Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/ndisc.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -372,14 +372,11 @@ static struct sk_buff *ndisc_alloc_skb(s int tlen = dev->needed_tailroom; struct sock *sk = dev_net(dev)->ipv6.ndisc_sk; struct sk_buff *skb; - int err; - skb = sock_alloc_send_skb(sk, - hlen + sizeof(struct ipv6hdr) + len + tlen, - 1, &err); + skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC); if (!skb) { - ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb, err=%d\n", - __func__, err); + ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n", + __func__); return NULL; } @@ -389,6 +386,11 @@ static struct sk_buff *ndisc_alloc_skb(s skb_reserve(skb, hlen + sizeof(struct ipv6hdr)); skb_reset_transport_header(skb); + /* Manually assign socket ownership as we avoid calling + * sock_alloc_send_pskb() to bypass wmem buffer limits + */ + skb_set_owner_w(skb, sk); + return skb; }