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 22:10:49 +0200 Message-ID: <55F1E3C9.5080109@gmail.com> References: <55F1D7E9.2000209@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=ccePyRyg8L/Db3nQB0dw1daJrIYS2iEChT8nr/IcCKk=; b=RZOQXSdJR6i4iBR80JgN5NaxV2n17JFa4mebATNU1wfau/wQY6Kjb/xXIunP76aHBf Yx3CK5TPee3wsucm22uiPdUv6RhQoszmPCT+Ijj3QS9ug01xgRjWu0KW2M7qinrivxFf NEPrmhXDJhXA9spAnKmZkMV6fneULqPT0igQ0AGOYEzsxjDJWyd8TEhLHitMHXAtqNcQ utnSdjdrjeIpSvQQd4aciGkEftpfChd/GWx7cDKveiMiDB4bfkkVDO0CXhQADfLwTczK yGSZ9w9ijR9HKv8Ese0gEaWO7tFuy032iNZaMbBxZOO3p6/HF8iP9+TG23uW52GyYFD2 PDMw== In-Reply-To: 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 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 "read= only". >> >> No ideas why accessing /dev/dm-X causes IO error. >> Reiser4 is not the culprit ;) You can narrow down this, if interesti= ng. >> I think that something is wrong with LVM settings... >> > I looked more into this: This test fills up dm snapshot (writes 5MB t= o > 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 dat= a > < 4MB space ;) > xfstests uses compressible data for disk full tests so on ccreg40 the= y > give false positive. Are ccreg40 and reg40 code paths for disk full > situation the same? > 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 an= dm >>> snapshot." >>> >>> Test passes cleanly with ccreg40 but kernel panics with reg40 plugi= n. >>> Picture of the panic, as I had no other means of capturing it, is i= n >>> 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