Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934567AbaLKKMO (ORCPT ); Thu, 11 Dec 2014 05:12:14 -0500 Received: from mail-pd0-f179.google.com ([209.85.192.179]:64669 "EHLO mail-pd0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933516AbaLKKMM (ORCPT ); Thu, 11 Dec 2014 05:12:12 -0500 Date: Thu, 11 Dec 2014 02:14:34 -0800 From: Kent Overstreet To: Dongsu Park Cc: Ming Lin , linux-fsdevel@vger.kernel.org, lkml , Jens Axboe , Christoph Hellwig Subject: Re: Block layer projects that I haven't had time for Message-ID: <20141211101434.GA12545@kmo-pixel> References: <20141124041629.GA17907@kmo-pixel> <20141204110027.GA28552@gmail.com> <20141206030205.GA22669@kmo-pixel> <20141208114813.GA2724@gmail.com> <20141210225707.GC31102@daterainc.com> <572ec4bea03f28abe72225a053684878.squirrel@minggr.net> <20141211100751.GA2409@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141211100751.GA2409@gmail.com> 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 Thu, Dec 11, 2014 at 11:07:51AM +0100, Dongsu Park wrote: > Hi Ming & Kent, > > On 10.12.2014 23:11, Ming Lin wrote: > > > On Wed, Dec 10, 2014 at 02:42:14PM -0800, Ming Lin wrote: > > > Try this fix: > > Yes, it fixed ext4 problem. > > @kent: Thank you for the patch. Indeed it fixes the ext4 lockup I've seen. > I've applied it to my tree, under the branch block-mpage-bvecs-for-next. > See 0d2e05525a58 ("fs/ext4: fix a lockup when writing blocks into ext4 > rootfs") . > > After that of course, more bugs start to appear, e.g. crash with virtio-blk, > like we'd have opened a can of worms. ;-) Yeah :) You'll need to audit every usage of bio_for_each_segment() to figure out which ones need converting to bio_for_each_page(). I did some of this - but just enough to get it working for me, and I haven't worked on that code since at least 3.14 so really everything needs to be audited. Hopefully in the future a lot of stuff could be converted to bio_for_each_segment() and changed to use more efficient algorithms, but that will be a lot more work. With bio_for_each_page() it shouldn't be too hard to get it stable, though. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/