From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f175.google.com (mail-pd0-f175.google.com [209.85.192.175]) by kanga.kvack.org (Postfix) with ESMTP id 7885D6B00B0 for ; Sun, 13 Apr 2014 18:37:14 -0400 (EDT) Received: by mail-pd0-f175.google.com with SMTP id x10so7356433pdj.20 for ; Sun, 13 Apr 2014 15:37:11 -0700 (PDT) Received: from mga09.intel.com (mga09.intel.com. [134.134.136.24]) by mx.google.com with ESMTP id s8si7731470pas.303.2014.04.13.15.37.11 for ; Sun, 13 Apr 2014 15:37:11 -0700 (PDT) Date: Sun, 13 Apr 2014 15:07:21 -0400 From: Matthew Wilcox Subject: Re: [PATCH v7 08/22] Replace xip_truncate_page with dax_truncate_page Message-ID: <20140413190721.GA21460@linux.intel.com> References: <20140408221759.GD26019@quack.suse.cz> <20140409092635.GB32103@quack.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140409092635.GB32103@quack.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Jan Kara Cc: Matthew Wilcox , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Wed, Apr 09, 2014 at 11:26:35AM +0200, Jan Kara wrote: > I thought about this for a while and classical IO, truncation etc. could > easily work for blocksize < pagesize. And for mmap() you could just use > pagecache. Not sure if it's worth the complications though. Anyway we > should decide whether we don't care about blocksize < PAGE_CACHE_SIZE at > all, or whether we try to make things which can work reasonably easily > functional. In that case dax_truncate_page() needs some tweaking because it > currently assumes blocksize == PAGE_CACHE_SIZE. I think it actually assumes that blocksize <= PAGE_CACHE_SIZE in that it doesn't contain a loop to iterate over all blocks. It wouldn't be hard to fix but I'll just put in a comment noting what needs to be fixed ... I don't think there's going to be a lot of enthusiasm for adding support for blocksize != PAGE_SIZE / PAGE_CACHE_SIZE. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org