From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: [dm-devel] [PATCH] Fix over-zealous flush_disk when changing device size. Date: Mon, 07 Mar 2011 10:46:58 -0600 Message-ID: <1299516418.15258.4.camel@mulgrave.site> References: <20110217165057.5c50e566@notabene.brown> <20110303143120.GA8134@infradead.org> <20110304111624.4be27aaf@notabene.brown> <1299259506.2118.24.camel@grinch> <20110306174755.49404c8e@notabene.brown> <1299471771.2228.11.camel@grinch> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1299471771.2228.11.camel@grinch> Sender: linux-kernel-owner@vger.kernel.org To: device-mapper development Cc: NeilBrown , Jens Axboe , linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, Christoph Hellwig List-Id: linux-raid.ids On Sun, 2011-03-06 at 21:22 -0700, Andrew Patterson wrote: > On Sun, 2011-03-06 at 17:47 +1100, NeilBrown wrote: > > Would you be uncomfortable if I asked Linus to revert both my fix and your > > original patch?? > > James Bottomley wanted me to put this functionality in. I have no > problem with reverting it myself, especially if it is causing other > problems. I would have to say that you need to ask him (or rather, I am > not qualified to render an opinion here). So it seems we have a couple of problems: the first being that flush_disk() doesn't actually do what it says (flush the disk). If it's just discarding all data, dirty or clean, then its use in the grow/shrink interface is definitely wrong. The idea is that before we complete the grow/shrink, we make sure that the device doesn't have any errors, so we want to try to write out all dirty buffers to make sure they still have a home. If flush_disk() doesn't do that, then we need to use a different interface ... what's the interface to flush a disk? James