From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: Re: Regression: Disk corruption with dm-crypt and kernels >= 4.0 Date: Fri, 1 May 2015 17:17:03 -0400 Message-ID: <20150501211703.GA15030@redhat.com> References: <1430455027.7012.32.camel@memnix.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <1430455027.7012.32.camel@memnix.com> Sender: linux-kernel-owner@vger.kernel.org To: Abelardo Ricart III Cc: dm-devel@redhat.com, mpatocka@redhat.com, linux-kernel@vger.kernel.org List-Id: dm-devel.ids On Fri, May 01 2015 at 12:37am -0400, Abelardo Ricart III wrote: > I made sure to run a completely vanilla kernel when testing why I was= suddenly > seeing some nasty libata errors with all kernels >=3D v4.0. Here's a = snippet: >=20 > -------------------->8-------------------- > [ 165.592136] ata5.00: exception Emask 0x60 SAct 0x7000 SErr 0x800 a= ction 0x6 > frozen > [ 165.592140] ata5.00: irq_stat 0x20000000, host bus error > [ 165.592143] ata5: SError: { HostInt } > [ 165.592145] ata5.00: failed command: READ FPDMA QUEUED > [ 165.592149] ata5.00: cmd 60/08:60:a0:0d:89/00:00:07:00:00/40 tag 1= 2 ncq 4096 > in > res 40/00:74:40:58:5d/00:00:00:00:00/40 Emask= 0x60 > (host bus error) > [ 165.592151] ata5.00: status: { DRDY } > -------------------->8-------------------- >=20 > After a few dozen of these errors, I'd suddenly find my system in rea= d-only > mode with corrupted files throughout my encrypted filesystems (seemed= like > either a read or a write would corrupt a file, though I could be mist= aken). I > decided to do a git bisect with a random read-write-sync test to narr= ow down > the culprit, which turned out to be this commit (part of a series): >=20 > # first bad commit: [cf2f1abfbd0dba701f7f16ef619e4d2485de3366] dm cry= pt: don't > allocate pages for a partial request >=20 > Just to be sure, I created a patch to revert the entire nine patch se= ries that > commit belonged to... and the bad behavior disappeared. I've now been= running > kernel 4.0 for a few days without issue, and went so far as to stress= test my > poor SSD for a few hours to be 100% positive. >=20 > Here's some more info on my setup. >=20 > -------------------->8-------------------- > $ lsblk -f > NAME FSTYPE LABEL MOUNTPOINT > sda =20 > =E2=94=9C=E2=94=80sda1 vfat /boot/EFI > =E2=94=9C=E2=94=80sda2 ext4 /boot > =E2=94=94=E2=94=80sda3 LVM2_member > =E2=94=9C=E2=94=80SSD-root crypto_LUKS > =E2=94=82 =E2=94=94=E2=94=80root f2fs / > =E2=94=94=E2=94=80SSD-home crypto_LUKS > =E2=94=94=E2=94=80home f2fs /home >=20 > $ cat /proc/cmdline > BOOT_IMAGE=3D/vmlinuz-linux-memnix cryptdevice=3D/dev/SSD/root:root:a= llow-discards > root=3D/dev/mapper/root acpi_osi=3DLinux security=3Dtomoyo > TOMOYO_trigger=3D/usr/lib/systemd/systemd intel_iommu=3Don > modprobe.blacklist=3Dnouveau rw quiet >=20 > $ cat /etc/lvm/lvm.conf | grep "issue_discards" > issue_discards =3D 1 > -------------------->8-------------------- >=20 > If there's anything else I can do to help diagnose the underlying pro= blem, I'm > more than willing. The patchset in question was tested quite heavily so this is a surprising report. I'm noticing you are opting in to dm-crypt discard support. Have you tested without discards enabled?