From: Jan Kara Subject: Re: xfstests generic/130 hang with non-4k block size ext4 on 4.7-rc1 kernel Date: Thu, 16 Jun 2016 15:26:20 +0200 Message-ID: <20160616132620.GA2106@quack2.suse.cz> References: <20160601165800.GI10350@eguan.usersys.redhat.com> <20160602085840.GH19636@quack2.suse.cz> <20160602121750.GC32574@quack2.suse.cz> <20160603101612.GJ10350@eguan.usersys.redhat.com> <20160603115844.GB2470@quack2.suse.cz> <20160608125631.GA19589@quack2.suse.cz> <87oa7a6d1q.fsf@gooddata.com> <20160609150405.GB19882@quack2.suse.cz> <87oa79h9on.fsf@gooddata.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Jan Kara , Holger =?iso-8859-1?Q?Hoffst=E4tte?= , linux-ext4@vger.kernel.org, Jan Kara To: Nikola Pajkovsky Return-path: Received: from mx2.suse.de ([195.135.220.15]:39036 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753861AbcFPN0X (ORCPT ); Thu, 16 Jun 2016 09:26:23 -0400 Content-Disposition: inline In-Reply-To: <87oa79h9on.fsf@gooddata.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Fri 10-06-16 07:52:56, Nikola Pajkovsky wrote: > Jan Kara writes: > > On Thu 09-06-16 09:23:29, Nikola Pajkovsky wrote: > >> Holger Hoffst=E4tte writes: > >>=20 > >> > On Wed, 08 Jun 2016 14:56:31 +0200, Jan Kara wrote: > >> > (snip) > >> >> Attached patch fixes the issue for me. I'll submit it once a fu= ll xfstests > >> >> run finishes for it (which may take a while as our server room = is currently > >> >> moving to a different place). > >> >>=20 > >> >> Honza > >> >> --=20 > >> >> Jan Kara > >> >> SUSE Labs, CR > >> >> From 3a120841a5d9a6c42bf196389467e9e663cf1cf8 Mon Sep 17 00:00:= 00 2001 > >> >> From: Jan Kara > >> >> Date: Wed, 8 Jun 2016 10:01:45 +0200 > >> >> Subject: [PATCH] ext4: Fix deadlock during page writeback > >> >>=20 > >> >> Commit 06bd3c36a733 (ext4: fix data exposure after a crash) unc= overed a > >> >> deadlock in ext4_writepages() which was previously much harder = to hit. > >> >> After this commit xfstest generic/130 reproduces the deadlock o= n small > >> >> filesystems. > >> > > >> > Since you marked this for -stable, just a heads-up that the prev= ious patch > >> > for the data exposure was rejected from -stable (see [1]) becaus= e it > >> > has the mismatching "!IS_NOQUOTA(inode) &&" line, which didn't e= xist > >> > until 4.6. I removed it locally but Greg probably wants an offic= ial patch. > >> > > >> > So both this and the previous patch need to be submitted. > >> > > >> > [1] http://permalink.gmane.org/gmane.linux.kernel.stable/18074{4= ,5,6} > >>=20 > >> I'm just wondering if the Jan's patch is not related to blocked > >> processes in following trace. It very hard to hit it and I don't h= ave > >> any reproducer. > > > > This looks like a different issue. Does the machine recover itself = or is it > > a hard hang and you have to press a reset button? >=20 > The machine is bit bigger than I have pretend. It's 18 vcpu with 160 = GB > ram and machine has dedicated mount point only for PostgreSQL data. >=20 > Nevertheless, I was able always to ssh to the machine, so machine its= elf > was not in hard hang and ext4 mostly gets recover by itself (it took > 30min). But I have seen situation, were every process who 'touch' the= ext4 > goes immediately to D state and does not recover even after hour. If such situation happens, can you run 'echo w >/proc/sysrq-trigger' to dump stuck processes and also run 'iostat -x 1' for a while to see how = much IO is happening in the system? That should tell us more. Honza --=20 Jan Kara SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html