From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc MERLIN Subject: Re: BUG: drivers/md/bcache/writeback.c:237 Date: Thu, 25 Feb 2016 07:20:53 -0800 Message-ID: <20160225152053.GC15421@merlins.org> References: <56C1F2A4.4090208@evilazrael.de> <20160224204530.GA13079@merlins.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from magic.merlins.org ([209.81.13.136]:42419 "EHLO mail1.merlins.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932337AbcBYPUz (ORCPT ); Thu, 25 Feb 2016 10:20:55 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: Zhu Yanhai Cc: Christoph Nelles , Eric Wheeler , linux-bcache@vger.kernel.org On Thu, Feb 25, 2016 at 06:18:03PM +0800, Zhu Yanhai wrote: > Marc, > When did you *first* see this BUG_ON? During boot up or far after the > whole system is up? I setup bcache, had it work a bit. During shutdown, it crapped out when syncing/unmounting After each subsequent boot, the system crashed as soon as the module loaded and scanned my disks. While I understand I did hit a bug, I've been on a cruisade to get BUG_ON removed from btrfs code and replaced with warns/abort/remount read only. On a production system, BUG_ON really sucks, especially if it happens as soon as the kernel loads and before you can even do anything to fix the issue :) If there is any chance this can be changed into some kind of abort that disables bcache or just prevents bcache from making damaging writes to the backing device, by simply disabling the cache, that would be much better :) In the meantime, I've stopped using writeback since it seems that it's been the reason why I hit this problem. Thanks, Marc -- "A mouse is a device used to point at the xterm you want to type in" - A.S.R. Microsoft is to operating systems .... .... what McDonalds is to gourmet cooking Home page: http://marc.merlins.org/