From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Mason Subject: Re: [PATCH] Fix ext2 error reporting on fsync Date: Thu, 12 Jan 2006 21:08:54 -0500 Message-ID: <200601122108.55103.mason@suse.com> References: <20060111174302.GD16728@atrey.karlin.mff.cuni.cz> <20060112142656.GB14235@atrey.karlin.mff.cuni.cz> <20060112124717.6e242802.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: Jan Kara , linux-fsdevel@vger.kernel.org Return-path: Received: from ns1.suse.de ([195.135.220.2]:24557 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1161264AbWAMCJJ (ORCPT ); Thu, 12 Jan 2006 21:09:09 -0500 To: Andrew Morton In-Reply-To: <20060112124717.6e242802.akpm@osdl.org> Content-Disposition: inline Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Thursday 12 January 2006 15:47, Andrew Morton wrote: > Jan Kara wrote: > > > Jan Kara wrote: > > > > > > hm, yes, try_to_free_buffers() against a blockdev page is a problem. > > > But I think it's fixable. > > > > > > In the second loop of drop_buffers(), if we find a bh which had a write > > > error we need to set AS_EIO on the address_space which is interested in > > > this buffer. > > > > > > That address_space is pinned by a) the fact that it has buffers at > > > ->private_list and b) we hold the blockdev mapping's private_lock. > > > > > > The only problem is actually _finding_ the address_space which is > > > interested in this buffer_head. Looks like we'd need a backpointer in > > > the buffer_head. > > > > Yes, the pointer seems to be inevitable in this solution. If you think > > the improvement is worth adding 4 bytes to each buffer_head, then I can > > write the patch. > > hm. It only affects what are now rarely-used filesystems like ext2, minix, > etc. Not sure about reiser3. But it is a strict correctness issue. I > suppose we should do it. It'd be nice to find a way to avoid increasing > the bh size.. > I know my patch is pretty nasty, but is it really worth adding complexity to the base code for this corner case? > It'll be a hard patch to test. I'll dig up $partner. They had a nasty test suite for that kind of thing. -chris