From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Howells Subject: Re: [rfc][patch 3/5] afs: new aops Date: Tue, 13 Nov 2007 10:56:25 +0000 Message-ID: <18637.1194951385@redhat.com> References: <20071113004459.GE30650@wotan.suse.de> <20071113001548.GA30650@wotan.suse.de> <20071112071448.GE22953@wotan.suse.de> <20071112071245.GB22953@wotan.suse.de> <6161.1194881354@redhat.com> <17445.1194913805@redhat.com> Cc: dhowells@redhat.com, Andrew Morton , linux-fsdevel@vger.kernel.org, mhalcrow@us.ibm.com, phillip@hellewell.homeip.net, sfrench@samba.org To: Nick Piggin Return-path: Received: from mx1.redhat.com ([66.187.233.31]:34039 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751328AbXKMK4f (ORCPT ); Tue, 13 Nov 2007 05:56:35 -0500 In-Reply-To: <20071113004459.GE30650@wotan.suse.de> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Nick Piggin wrote: > It takes a pagecache page, yes. If you follow convention, you use > PAGE_CACHE_SIZE for that guy. You don't have to allow PAGE_CACHE_SIZE != > PAGE_SIZE, and if all the rest of your code is in units of PAGE_SIZE, then > obviously my changing of just the one unit is even more confusing than > the current arrangement ;) The problem is that the code called assumes that the struct page * argument points to a single page, not an array of pages as would presumably be the case if PAGE_CACHE_SIZE > PAGE_SIZE. If I should allow for an array of pages then the lower functions (specifically afs_deliver_fs_fetch_data()) need to change, and until that time occurs, the assertion *must* remain as it is now. It defends the lower functions against being asked to do something they weren't designed to do. So: you may not change the assertion unless you also fix the lower functions. David