From mboxrd@z Thu Jan 1 00:00:00 1970 From: Edward Shishkin Subject: Re: [xfstests/generic/081] Kernel panic with reg40 plugin and R4-for-4.1.5.patch Date: Thu, 10 Sep 2015 22:24:50 +0200 Message-ID: <55F1E712.80802@gmail.com> References: <55F1D7E9.2000209@gmail.com> <55F1E3C9.5080109@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=WSl/AEyP4tLa2gNy5lzfCxdQJOSrP1pmulRjEylk9HE=; b=hY2jugTiE55BuhDCn0zMIL+DRvXQzjlgKOH0SFV7UKjZo9pcynAeWcIIiNgAQw7X7i EP10x2AFUaOZfCCjKN8DuNzKwXQLgEOBtpg4Y2CybRYB6hCyNpMs1KJnCEaKDmFBHtK+ r8p2tPyzXp5ZeKjKSvDzu5vT/OYrzYI5EPNeHslASQ/j46K69EskJLZBctlcVwS9g0Kl Dr98l6iOX6UWI/osK1AEYB18HGOqHoFSJYGipJWK8bjAFcpBPSYlnbVQCS7UxD8ieJYx zAD30xRRIm5TaDMOekVb4VG7Ds8tBpbcDNJE3bVo6OfmlYzgqMU7DgRMk8vQf+sA88PV firg== In-Reply-To: <55F1E3C9.5080109@gmail.com> Sender: reiserfs-devel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="utf-8"; format="flowed" To: =?UTF-8?B?RHXFoWFuIMSMb2xpxIc=?= Cc: reiserfs-devel On 09/10/2015 10:10 PM, Edward Shishkin wrote: > > > On 09/10/2015 09:42 PM, Du=C5=A1an =C4=8Coli=C4=87 wrote: >> On Thu, Sep 10, 2015 at 9:20 PM, Edward Shishkin >> wrote: >>> Actually, this is not a regression. >>> The attached patch prevents the panic. >>> By default on IO errors reiser4 partition will be remounted as=20 >>> "readonly". >>> >>> No ideas why accessing /dev/dm-X causes IO error. >>> Reiser4 is not the culprit ;) You can narrow down this, if interest= ing. >>> I think that something is wrong with LVM settings... >>> >> I looked more into this: This test fills up dm snapshot (writes 5MB = to >> 4MB snapshot) so we get IO error because it's full. > > > IO error because of no space - it is very strange, > especially when reading the device (as in my case): > > # dd if=3D/dev/dm-3 of=3D/dev/null bs=3D4096 count=3D1 > > >> It doesn't trigger >> on ccreg40 because ccreg40 compresses data so 5MB of compressible da= ta >> < 4MB space ;) >> xfstests uses compressible data for disk full tests so on ccreg40 th= ey >> give false positive. Are ccreg40 and reg40 code paths for disk full >> situation the same? The behavior doesn't depend on file plugin: this is the transaction man= ager who makes the decisions. >> I'll look into fixing xfstetsts. >>> Thanks, >>> Edward. >>> >>> >>> >>> On 09/04/2015 09:35 AM, Du=C5=A1an =C4=8Coli=C4=87 wrote: >>>> Kernel: 4.1.6 >>>> R4 patch: 4.1.5 >>>> Test: xfstests/generic/081 "Test I/O error path by fully filling a= n dm >>>> snapshot." >>>> >>>> Test passes cleanly with ccreg40 but kernel panics with reg40 plug= in. >>>> Picture of the panic, as I had no other means of capturing it, is = in >>>> attachment. >>>> >>>> xfstests local.config section: >>>> >>>> [r4Hybrid] >>>> MKFS_OPTIONS=3D"-o create=3Dreg40" >>>> MOUNT_OPTIONS=3D"-o noatime" >>>> >>>> Have a nice day. >>>> >>>> Dushan >>> > -- To unsubscribe from this list: send the line "unsubscribe reiserfs-deve= l" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html