Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757817AbZFQSpa (ORCPT ); Wed, 17 Jun 2009 14:45:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752714AbZFQSpV (ORCPT ); Wed, 17 Jun 2009 14:45:21 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:54357 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752470AbZFQSpT (ORCPT ); Wed, 17 Jun 2009 14:45:19 -0400 Date: Wed, 17 Jun 2009 11:44:18 -0700 (PDT) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Al Viro cc: Andreas Dilger , David Howells , Alan Cox , akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-afs@lists.infradead.org Subject: Re: [PATCH 00/17] [RFC] AFS: Implement OpenAFS pioctls(version)s In-Reply-To: <20090617183745.GI8633@ZenIV.linux.org.uk> Message-ID: References: <20090617001157.065ee652@lxorguk.ukuu.org.uk> <20090616203845.4526.60013.stgit@warthog.procyon.org.uk> <10437.1245193192@redhat.com> <11650.1245198358@redhat.com> <20090617075502.GB13073@webber.adilger.int> <20090617183745.GI8633@ZenIV.linux.org.uk> User-Agent: Alpine 2.01 (LFD 1184 2008-12-16) 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: 1146 Lines: 29 On Wed, 17 Jun 2009, Al Viro wrote: > On Wed, Jun 17, 2009 at 09:09:47AM -0700, Linus Torvalds wrote: > > We've traditionally had that magic "open with flag=3" to do a magic open > > of device files without waiting, and we have O_NOFOLLOW to open symlinks > > without following them (sadly, it just errors out, rather than opening the > > symlink, but that's another detail). > > > > So I think it should be solvable some way, but not by trying to find the > > mount point. > > O_NOFOLLOW *will* open their mountpoints just fine, without triggering > automount. That's not the problem with O_NOFOLLOW. The problem is that if you want to actually open the symlink itself (say, you do some filesystem cleanup operation on it, like saying "drop the caches of this file"), you can't do it. O_NOFOLLOW won't open the symlink, it will just refuse to follow it, and return an error. 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/