From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753826AbbAMVzJ (ORCPT ); Tue, 13 Jan 2015 16:55:09 -0500 Received: from mga01.intel.com ([192.55.52.88]:20184 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751385AbbAMVzH (ORCPT ); Tue, 13 Jan 2015 16:55:07 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,751,1413270000"; d="scan'208";a="661352545" Date: Tue, 13 Jan 2015 16:55:05 -0500 From: Matthew Wilcox To: Andrew Morton Cc: Matthew Wilcox , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, willy@linux.intel.com Subject: Re: [PATCH v12 09/20] dax,ext2: Replace xip_truncate_page with dax_truncate_page Message-ID: <20150113215505.GL5661@wil.cx> References: <1414185652-28663-1-git-send-email-matthew.r.wilcox@intel.com> <1414185652-28663-10-git-send-email-matthew.r.wilcox@intel.com> <20150112150958.2e6bd85dc3e25b953d28c6cb@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150112150958.2e6bd85dc3e25b953d28c6cb@linux-foundation.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 12, 2015 at 03:09:58PM -0800, Andrew Morton wrote: > > + * Similar to block_truncate_page(), this function can be called by a > > + * filesystem when it is truncating an DAX file to handle the partial page. > > + * > > + * We work in terms of PAGE_CACHE_SIZE here for commonality with > > + * block_truncate_page(), but we could go down to PAGE_SIZE if the filesystem > > + * took care of disposing of the unnecessary blocks. > > But PAGE_SIZE==PAGE_CACHE_SIZE. Unclear what you're saying here. The last I heard, some people were trying to resurrect the PAGE_CACHE_SIZE > PAGE_SIZE patches. I'd be grateful if the distinction between PAGE_SIZE and PAGE_CACHE_SIZE went away, tbh.