[SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

ontobelli · 2012-10-24 10:38:21

Be careful

EXT4 Data Corruption Bug Hits Stable Linux Kernels

http://www.phoronix.com/scan.php?page=n … px=MTIxNDQ

https://lkml.org/lkml/2012/10/23/779

Edited: Removed the [ALERT] label.

Last edited by ontobelli (2012-11-01 04:58:43)

headkase · 2012-10-24 11:08:27

As far as how you get hit by this EXT4 bug, Ted says, "Well, the problem won't show up if the journal has wrapped. So it will only show up if the system has been rebooted twice in fairly quick succession.

Don't reboot twice in a row until it's fixed.

technolog · 2012-10-24 11:15:28

What counts as twice in a row? Few secods difference, maybe minutes?

This is better than any horror movie.

Last edited by technolog (2012-10-24 11:18:35)

headkase · 2012-10-24 11:23:57

technolog wrote:

What counts as twice in a row? Few secods difference, maybe minutes?
This is better than any horror movie.

http://www.youtube.com/watch?v=u0-oinyjsk0

I'd say don't suspend/resume/reboot for at least 20 minute intervals just to be safe. That is a scientifically proven guesstimate.

curson · 2012-10-24 11:33:22

This is scary. Coupled with the seemingly overheating problems that 3.6.3 is displaying for i915 users (https://bbs.archlinux.org/viewtopic.php?id=150743) for me, it's not a really good Kernel day

It would be really of great utility to know and find out what is meant by "...don't reboot your system too quickly..." in order to minimize the risk as much as possible until a fix will hit a new stable kernel release.

CTheGreatDevaluation · 2012-10-24 11:52:03

I'm uncomfortably numb

How long does it take till a new fixed release will hit?

hiciu · 2012-10-24 12:04:45

Is it possible to release new kernel package with reverted commit 14b4ed22a6 / eeecef0af5e / "jbd2: don't write superblock when if its empty"?

trapanator · 2012-10-24 12:16:10

hiciu wrote:

Is it possible to release new kernel package with reverted commit 14b4ed22a6 / eeecef0af5e / "jbd2: don't write superblock when if its empty"?

or we wait for 3.6.4, I think it will be released quickly.

Lekensteyn · 2012-10-24 12:30:41

Until then, just use suspend/resume (assuming that works for you).

technolog · 2012-10-24 13:38:18

I still have 3.6.2, despite 3.6.3 being in the repos. Guess the best move is not to upgrade?

Jristz · 2012-10-24 13:45:20

why simply not use other filesystem diferent to ext, like....emh...nilfs or btrfs?
or aboid upgrade, resume or wathever is???

Is not hard to found a patch and update the actual kernel with the patch (if exist)

karol · 2012-10-24 13:51:40

Jristz wrote:

why simply not use other filesystem diferent to ext, like....emh...nilfs or btrfs?

I'm not sure if changing filesystems back and forth is simple.
Does btrfs have the fsck ready? If not, that it's not safe either.

Jristz · 2012-10-24 13:55:03

btrfs filesystem

read the option btrfs have a fsck but isnot standard as any opther fsck.*
alongside btrfs have (too) snapshots possibilities

but I prefer nilfs for the snapshots feature, and I want thest any more exotic (like runing in my toater [arch wiki reference])

oldtimeyjunk · 2012-10-24 14:00:05

I'm so glad I forgot to update my machine. It's thankfully running Kernel 3.6.2!
Is there anyway to update all packages, but leave one out (like Linux, for example)?

Last edited by oldtimeyjunk (2012-10-24 14:05:47)

demaio · 2012-10-24 14:07:16

For those who think they are safe with 3.6.2: please read the topic and the Phoronix post again:

Ted Ts'o wrote:

I think I've found the problem. I believe the commit at fault is commit 14b4ed22a6 (upstream commit eeecef0af5e):
jbd2: don't write superblock when if its empty
which first appeared in v3.6.2.

karol · 2012-10-24 14:08:12

oldtimeyjunk wrote:

Is there anyway to update all packages, but leave one out (like Linux, for example)?

Partial updates are not supported, but sure there is. Read e.g. 'man pacman.conf' for details.

oldtimeyjunk · 2012-10-24 14:09:14

demaio wrote:

For those who think they are safe with 3.6.2: please read the topic and the Phoronix post again:
Ted Ts'o wrote:
I think I've found the problem. I believe the commit at fault is commit 14b4ed22a6 (upstream commit eeecef0af5e):
jbd2: don't write superblock when if its empty
which first appeared in v3.6.2.

My laptop is running 3.6.2, and I've done countless reboots, including having to go through several accidental power outages when I've not had a battery in. Nothing has happened...

demaio · 2012-10-24 14:11:20

oldtimeyjunk wrote:

My laptop is running 3.6.2, and I've done countless reboots, including having to go through several accidental power outages when I've not had a battery in. Nothing has happened...

Just because nothing happened to you doesn't mean Ted Ts'o is wrong ;-)

osoh · 2012-10-24 14:39:01

Hi,

I guess that using linux-lts package (includes kernel version 3.0.48 at this time) could be a safe solution (until the problem get fixed).

Good luck!

89c51 · 2012-10-24 17:22:07

Any guesstimate on when this will hit the arch repos? Are the devs waiting for 3.6.4?

Jristz · 2012-10-24 17:31:12

89c51 wrote:

Any guesstimate on when this will hit the arch repos? Are the devs waiting for 3.6.4?

no, they pull now 3.6.3 to core...

headkase · 2012-10-24 17:33:12

89c51 wrote:

Any guesstimate on when this will hit the arch repos? Are the devs waiting for 3.6.4?

There is no upstream 3.6.4 yet:

http://www.kernel.org/

Have to wait until it is released then it will, hopefully quickly, make it into Arch.

89c51 · 2012-10-24 17:41:20

I meant the fix. Will the devs wait for 3.6.4 which obviously will include the fix or are they going to release a 3.6.3-2 with a patch that fixes this.

headkase · 2012-10-24 17:50:16

Even though it is a severe bug the chances of it happening to you are low. You have to unmount and immediately remount an EXT4 partition twice in a row for it to happen. On a normally operating system that is not a normal thing to happen. Just wait on your desktop for 5 minutes before rebooting again.

Arch, as a general rule, tends to stick as close to upstream as possible. I'm sure the devs are very competent people but a quick hack or branch revert has the possibility of introducing issues of its own. With the chance of the bug occurring low on a normally operating system I think it is better to wait for a fix from upstream.

89c51 · 2012-10-24 18:38:00

headkase wrote:

Even though it is a severe bug the chances of it happening to you are low. You have to unmount and immediately remount an EXT4 partition twice in a row for it to happen. On a normally operating system that is not a normal thing to happen. Just wait on your desktop for 5 minutes before rebooting again.
Arch, as a general rule, tends to stick as close to upstream as possible. I'm sure the devs are very competent people but a quick hack or branch revert has the possibility of introducing issues of its own. With the chance of the bug occurring low on a normally operating system I think it is better to wait for a fix from upstream.

Well maybe i am a bit over stressed about this since with this computer i have quite a lot of troube which i cannot find solutions to. Also a kernel panic after a reboot this morning -probably not related to this- got me in a bad mood.

Anyway.

Arch Linux

#1 2012-10-24 10:38:21

[SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#2 2012-10-24 11:08:27

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#3 2012-10-24 11:15:28

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#4 2012-10-24 11:23:57

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#5 2012-10-24 11:33:22

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#6 2012-10-24 11:52:03

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#7 2012-10-24 12:04:45

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#8 2012-10-24 12:16:10

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#9 2012-10-24 12:30:41

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#10 2012-10-24 13:38:18

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#11 2012-10-24 13:45:20

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#12 2012-10-24 13:51:40

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#13 2012-10-24 13:55:03

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#14 2012-10-24 14:00:05

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#15 2012-10-24 14:07:16

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#16 2012-10-24 14:08:12

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#17 2012-10-24 14:09:14

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#18 2012-10-24 14:11:20

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#19 2012-10-24 14:39:01

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#20 2012-10-24 17:22:07

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#21 2012-10-24 17:31:12

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#22 2012-10-24 17:33:12

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#23 2012-10-24 17:41:20

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#24 2012-10-24 17:50:16

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

#25 2012-10-24 18:38:00

Re: [SOLVED] EXT4 Data Corruption Bug Linux 3.6.2 & 3.6.3

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