Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753191AbYHHOiA (ORCPT ); Fri, 8 Aug 2008 10:38:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751568AbYHHOht (ORCPT ); Fri, 8 Aug 2008 10:37:49 -0400 Received: from rhun.apana.org.au ([64.62.148.172]:43164 "EHLO arnor.apana.org.au" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751540AbYHHOhs (ORCPT ); Fri, 8 Aug 2008 10:37:48 -0400 Date: Fri, 8 Aug 2008 22:37:42 +0800 From: Herbert Xu To: "Michael S. Tsirkin" Cc: linux-kernel@vger.kernel.org, davem@davemloft.net, yoshfuji@linux-ipv6.org, netdev@vger.kernel.org, haoki@redhat.com Subject: Re: possible recursive locking in udp4_lib_rcv Message-ID: <20080808143741.GA20777@gondor.apana.org.au> References: <20080807234613.GA9598@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1255 Lines: 32 On Fri, Aug 08, 2008 at 10:28:41PM +0800, Herbert Xu wrote: > > @@ -1165,7 +1189,13 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[], > inet_iif(skb), udptable); > > if (sk != NULL) { > - int ret = udp_queue_rcv_skb(sk, skb); > + int ret = 0; > + bh_lock_sock_nested(sk); > + if (!sock_owned_by_user(sk)) > + ret = udp_queue_rcv_skb(sk, skb); > + else > + sk_add_backlog(sk, skb); > + bh_unlock_sock(sk); > > Hmm, what was the reason for that lock? Never mind, I see the reason why it's there. What we should do is drop the lock when we hit an encapsulated socket since they don't need it at all. Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/