From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id 4ABDA6B0069 for ; Sat, 10 Sep 2016 03:52:56 -0400 (EDT) Received: by mail-pf0-f198.google.com with SMTP id 128so7711347pfb.2 for ; Sat, 10 Sep 2016 00:52:56 -0700 (PDT) Received: from NAM03-DM3-obe.outbound.protection.outlook.com (mail-dm3nam03on0108.outbound.protection.outlook.com. [104.47.41.108]) by mx.google.com with ESMTPS id x9si8474437pff.84.2016.09.10.00.52.55 for (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Sat, 10 Sep 2016 00:52:55 -0700 (PDT) From: Matthew Wilcox Subject: RE: [PATCH v2 2/9] ext2: tell DAX the size of allocation holes Date: Sat, 10 Sep 2016 07:52:53 +0000 Message-ID: References: <20160823220419.11717-1-ross.zwisler@linux.intel.com> <20160823220419.11717-3-ross.zwisler@linux.intel.com> <20160825075728.GA11235@infradead.org> <20160826212934.GA11265@linux.intel.com> <20160829074116.GA16491@infradead.org> <20160829125741.cdnbb2uaditcmnw2@thunk.org> <20160909164808.GC18554@linux.intel.com> <20160910073012.GA5295@infradead.org> <20160910074228.GA23749@infradead.org> In-Reply-To: <20160910074228.GA23749@infradead.org> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Hellwig Cc: Ross Zwisler , Theodore Ts'o , "linux-kernel@vger.kernel.org" , Andrew Morton , "linux-nvdimm@ml01.01.org" , Dave Chinner , "linux-mm@kvack.org" , Andreas Dilger , Alexander Viro , Jan Kara , "linux-fsdevel@vger.kernel.org" , "linux-ext4@vger.kernel.org" From: Christoph Hellwig [mailto:hch@infradead.org] > On Sat, Sep 10, 2016 at 07:33:18AM +0000, Matthew Wilcox wrote: > > > caller specific is unaceptable. That being said your idea doesn't > > > sounds unreasonable, but will require a bit more work and has no > > > real short-term need. > > > > So your proposal is to remove buffer_heads from ext2? >=20 > No, the proposal is to remove buffer_heads from XFS first, then GFS2 and = then > maybe others like ext4. I'd like to remove buffer_heads from the DAX pat= h for > ext2 and ext4 entitrely for sure (and direct I/O next). That's ... what I propose. The only use of buffer_head in my proposal is t= o communicate a single extent from the filesystem to the DAX core, and that can equally well use an iomap. Ross seems to think that converting the cur= rent DAX code over to using iomap requires converting all of ext2 away from buffer_head; are you saying he's wrong? -- 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