Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755176AbZDURo0 (ORCPT ); Tue, 21 Apr 2009 13:44:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751272AbZDURoO (ORCPT ); Tue, 21 Apr 2009 13:44:14 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:53933 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754152AbZDURoM (ORCPT ); Tue, 21 Apr 2009 13:44:12 -0400 Date: Tue, 21 Apr 2009 10:35:58 -0700 (PDT) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Oleg Nesterov cc: Hugh Dickins , Al Viro , Andrew Morton , Joe Malicki , Michael Itz , Kenneth Baker , Chris Wright , David Howells , Alexey Dobriyan , Greg Kroah-Hartman , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: Q: check_unsafe_exec() races (Was: [PATCH 2/4] fix setuid sometimes doesn't) In-Reply-To: <20090421171530.GA12014@redhat.com> Message-ID: References: <20090330123101.GQ28946@ZenIV.linux.org.uk> <20090331061615.GS28946@ZenIV.linux.org.uk> <20090401023849.GW28946@ZenIV.linux.org.uk> <20090401030339.GX28946@ZenIV.linux.org.uk> <20090406153127.GA21220@redhat.com> <20090421161006.GC5402@redhat.com> <20090421171530.GA12014@redhat.com> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 832 Lines: 23 On Tue, 21 Apr 2009, Oleg Nesterov wrote: > > OK, I agree, it doesn't really matter from latency/etc pov. > > But still I can't understand why it is better to take fs->lock under > RCU lock. I mean, "fs->lock is the innermost lock" should not apply > to rcu_read_lock(). Because the latter is a bit special, no? Oh, I don't think it matters. If you want to put the RCU read-lock innermost, that's fine by me. I just reacted to your latency argument as not being very strong :) All I personally want is a patch that everybody can agree on, and that has sane semantics. Linus -- 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/