From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Lehmann Subject: Re: f2fs stability problems keep me from testing Date: Thu, 19 Nov 2015 22:01:30 +0100 Message-ID: <20151119210130.GC2499@schmorp.de> References: <20151119205614.GA10406@jaegeuk.local> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1ZzWKq-0007Oj-3Q for linux-f2fs-devel@lists.sourceforge.net; Thu, 19 Nov 2015 21:01:40 +0000 Received: from mail.nethype.de ([5.9.56.24]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:AES128-SHA:128) (Exim 4.76) id 1ZzWKn-0003CS-Do for linux-f2fs-devel@lists.sourceforge.net; Thu, 19 Nov 2015 21:01:40 +0000 Content-Disposition: inline In-Reply-To: <20151119205614.GA10406@jaegeuk.local> <00a101d122a0$fb9e6ab0$f2db4010$@samsung.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: Chao Yu Cc: linux-f2fs-devel@lists.sourceforge.net On Thu, Nov 19, 2015 at 04:04:21PM +0800, Chao Yu wrote: > > openat(AT_FDCWD, "/cold1", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5 > > fchdir(5) = 0 > > getdents(5, /* 0 entries */, 32768) = 0 > > I found an issue here. > > If the dir entry of '/cold1/var' is removed from dentry page in '/cold1', at > least we should return entries of '.' and '..' for the getdents invoking, but > we didn't. So here it looks like we keep silent about some kind of error (i.e. > ENOMEM/EIO...) when grabing&updating the dentry page of '/cold1', obviously > it's better to report such error to user rather than ignoring it. As for EIO, I would expect the kernel to log something. As for ENOMEM, unless f2fs tries higher order or zone-specific allocations, that's unlikely because the box had over 20GB memory free (according to top). As for other errors, sure, could be. Would that explain the sync lockup though? > I'd like to send a patch to fix this issue, could you include the following > patch in your f2fs module, so when it reproduces we can catch more details > about this problem. I can, but I guess you forgot to attach the patch. On Fri, Nov 20, 2015 at 04:56:14AM +0800, Jaegeuk Kim wrote: > > Ah, sorry if that might not have been clear - after a reboot, fsck showed > > no errors and all files and directories (apparently) were there, i.e. it > > looks like a transient problem, not a problem of the on-disk structure. > > So, it seems that the system suffers from memory pressure significantly, which > can incur ENOMEM, as I guess. > Can you catch /sys/kernel/debug/f2fs/status at that moment? If I can, I will - I didn't attempt to stress the filesystem since then, but will presdumably start doing tests next week again. -- The choice of a Deliantra, the free code+content MORPG -----==- _GNU_ http://www.deliantra.net ----==-- _ generation ---==---(_)__ __ ____ __ Marc Lehmann --==---/ / _ \/ // /\ \/ / schmorp@schmorp.de -=====/_/_//_/\_,_/ /_/\_\ ------------------------------------------------------------------------------