From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755613AbZHEOBr (ORCPT ); Wed, 5 Aug 2009 10:01:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933270AbZHEOBr (ORCPT ); Wed, 5 Aug 2009 10:01:47 -0400 Received: from cantor2.suse.de ([195.135.220.15]:49020 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752239AbZHEOBq (ORCPT ); Wed, 5 Aug 2009 10:01:46 -0400 Date: Wed, 5 Aug 2009 16:01:45 +0200 From: Nick Piggin To: Andi Kleen Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, fengguang.wu@intel.com, hidehiro.kawai.ez@hitachi.com Subject: Re: [PATCH] [11/19] HWPOISON: Refactor truncate to allow direct truncating of page v2 Message-ID: <20090805140145.GB28563@wotan.suse.de> References: <200908051136.682859934@firstfloor.org> <20090805093638.D3754B15D8@basil.firstfloor.org> <20090805102008.GB17190@wotan.suse.de> <20090805134607.GH11385@basil.fritz.box> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090805134607.GH11385@basil.fritz.box> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 05, 2009 at 03:46:08PM +0200, Andi Kleen wrote: > On Wed, Aug 05, 2009 at 12:20:08PM +0200, Nick Piggin wrote: > > > truncate_complete_page(struct address_space *mapping, struct page *page) > > > { > > > if (page->mapping != mapping) > > > - return; > > > + return -EIO; > > > > Hmm, at this point, the page must have been removed from pagecache, > > so I don't know if you need to pass an error back? > > It could be reused, which would be bad for us? I haven't brought up the caller at this point, but IIRC you had the page locked and mapping confirmed at this point anyway so it would never be an error for your code. Probably it would be nice to just force callers to verify the page. Normally IMO it is much nicer and clearer to do it at the time the page gets locked, unless there is good reason otherwise.