From patchwork Sat Sep 3 17:26:05 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Patrick McHardy X-Patchwork-Id: 113248 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id BD578B6F7B for ; Sun, 4 Sep 2011 03:27:02 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753568Ab1ICR0p (ORCPT ); Sat, 3 Sep 2011 13:26:45 -0400 Received: from stinky.trash.net ([213.144.137.162]:56155 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753298Ab1ICR0S (ORCPT ); Sat, 3 Sep 2011 13:26:18 -0400 Received: from x2.localnet. (localhost [127.0.0.1]) by stinky.trash.net (Postfix) with ESMTP id 27389B2C51; Sat, 3 Sep 2011 19:26:16 +0200 (MEST) From: kaber@trash.net To: davem@davemloft.net Cc: netfilter-devel@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH 05/11] netlink: add netlink_skb_set_owner_r() Date: Sat, 3 Sep 2011 19:26:05 +0200 Message-Id: <1315070771-18576-6-git-send-email-kaber@trash.net> X-Mailer: git-send-email 1.7.2.3 In-Reply-To: <1315070771-18576-1-git-send-email-kaber@trash.net> References: <1315070771-18576-1-git-send-email-kaber@trash.net> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Patrick McHardy For mmap'ed I/O a netlink specific skb destructor needs to be invoked after the final kfree_skb() to clean up state in the memory mapped frames. This doesn t work currently since the skb's ownership is transfered to the receiving socket using skb_set_owner_r(), which orphans the skb, thereby invoking the destructor prematurely. Since netlink doesn't account skbs to the originating socket, there's no need to orphan the skb. Add a netlink specific skb_set_owner_r() variant that does not orphan the skb and use a netlink specific destructor to call sock_rfree(). Signed-off-by: Patrick McHardy --- net/netlink/af_netlink.c | 18 ++++++++++++++++-- 1 files changed, 16 insertions(+), 2 deletions(-) diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 7b9d7d0..1402acf 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -161,6 +161,20 @@ static void netlink_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) sk->sk_data_ready(sk, len); } +static void netlink_skb_destructor(struct sk_buff *skb) +{ + sock_rfree(skb); +} + +static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk) +{ + WARN_ON(skb->sk != NULL); + skb->sk = sk; + skb->destructor = netlink_skb_destructor; + atomic_add(skb->truesize, &sk->sk_rmem_alloc); + sk_mem_charge(sk, skb->truesize); +} + static void netlink_sock_destruct(struct sock *sk) { struct netlink_sock *nlk = nlk_sk(sk); @@ -838,7 +852,7 @@ int netlink_attachskb(struct sock *sk, struct sk_buff *skb, } return 1; } - skb_set_owner_r(skb, sk); + netlink_skb_set_owner_r(skb, sk); return 0; } @@ -900,7 +914,7 @@ static inline int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb) ret = -ECONNREFUSED; if (nlk->netlink_rcv != NULL) { ret = skb->len; - skb_set_owner_r(skb, sk); + netlink_skb_set_owner_r(skb, sk); nlk->netlink_rcv(skb); } kfree_skb(skb);