From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752496AbaKDJIX (ORCPT ); Tue, 4 Nov 2014 04:08:23 -0500 Received: from cantor2.suse.de ([195.135.220.15]:40286 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751647AbaKDJIT (ORCPT ); Tue, 4 Nov 2014 04:08:19 -0500 Date: Tue, 4 Nov 2014 10:08:14 +0100 From: Jan Kara To: Jan Beulich Cc: Dave Chinner , xfs@oss.sgi.com, Jan Kara , linux-kernel@vger.kernel.org Subject: Re: your patch "mm: Remove false WARN_ON from pagecache_isize_extended()" Message-ID: <20141104090814.GA2953@quack.suse.cz> References: <5457BE390200007800044838@mail.emea.novell.com> <20141103221849.GB23575@dastard> <545890F40200007800044A31@mail.emea.novell.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <545890F40200007800044A31@mail.emea.novell.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 04-11-14 07:40:20, Jan Beulich wrote: > >>> On 03.11.14 at 23:18, wrote: > > On Mon, Nov 03, 2014 at 04:41:13PM +0000, Jan Beulich wrote: > >> having run into that warning too, I looked into it a little, and now > >> having found that patch am pretty uncertain: Both truncate_setsize() > >> and pagecache_isize_extended() document that they want to be > >> called with i_mutex held, so removing the WARN_ON() alone seems > >> either incomplete or wrong. What I found to work without violating > >> this documented requirement is the patch below. > > > > Or, just perhaps, the comments are wrong.... > > Right - that's what I was suggesting with the option of the patch > being incomplete (rather than just removing the WARN_ON() it > should also remove the respective comments then). Yeah, I'll update the comments to mention there are filesystem which use serialization different from i_mutex. Thanks for catching this. Honza -- Jan Kara SUSE Labs, CR