From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 0122700014.0.fullrate.dk ([95.166.99.235] helo=kernel.dk) by bombadil.infradead.org with esmtps (Exim 4.69 #1 (Red Hat Linux)) id 1O4tp6-0007sp-3g for linux-mtd@lists.infradead.org; Thu, 22 Apr 2010 10:39:56 +0000 Date: Thu, 22 Apr 2010 12:39:53 +0200 From: Jens Axboe To: =?iso-8859-1?Q?J=F6rn?= Engel Subject: Re: [PATCH] [MTD] Fix JFFS2 sync silent failure Message-ID: <20100422103953.GB27497@kernel.dk> References: <20100417184016.GA17345@logfs.org> <20100419073843.GN27497@kernel.dk> <20100419101559.GA4145@logfs.org> <20100419102056.GS27497@kernel.dk> <20100422055448.GA27309@logfs.org> <20100422090303.GA27497@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20100422090303.GA27497@kernel.dk> Cc: Christoph Hellwig , linux-mtd@lists.infradead.org, David Woodhouse , linux-kernel@vger.kernel.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, Apr 22 2010, Jens Axboe wrote: > On Thu, Apr 22 2010, Jörn Engel wrote: > > On Mon, 19 April 2010 12:20:56 +0200, Jens Axboe wrote: > > > > > > Thanks, we definitely should have put a debug statement to catch this in > > > from day 1, good debugging should be an important part of any new > > > infrastructure. > > > > Woke up early and had another look at this. Looks like a much more > > widespread problem. Based on a quick grep an uncaffeinated brain: > > > > 9p no s_bdi > > afs no s_bdi > > ceph creates its own s_bdi > > cifs no s_bdi > > coda no s_bdi > > ecryptfs no s_bdi > > exofs no s_bdi > > fuse creates its own s_bdi? > > gfs2 creates its own s_bdi? > > jffs2 patch exists > > logfs fixed now > > ncpfs no s_bdi > > nfs creates its own s_bdi > > ocfs2 no s_bdi > > smbfs no s_bdi > > ubifs creates its own s_bdi > > > > I excluded all filesystems that appear to be read-only, block device > > based or lack any sort of backing store. So there is a chance I have > > missed some as well. > > It's funky, I was pretty sure there was/is code to set a default bdi for > non-bdev file systems. It appears to be missing, that's not good. So > options include: > > - Add the appropriate per-sb bdi for these file systems (right fix), or > - Pre-fill default_backing_dev_info as a fallback ->s_bdi to at least > ensure that data gets flushed (quick fix) > > I'll slap together a set of fixes for this. Here's a series for fixing these. At this point they are totally untested except that I did compile them. Note that your analysis appeared correct for all cases but ocfs2, which does use get_sb_bdev() and hence gets ->s_bdi assigned. You can see them here, I'll post the series soon: http://git.kernel.dk/?p=linux-2.6-block.git;a=shortlog;h=refs/heads/for-linus The first patch is a helper addition, the rest are per-fs fixups. -- Jens Axboe