Bug 96251

Summary:	Corrupted log after OOM
Product:	File System	Reporter:	George Shuklin (george.shuklin)
Component:	btrfs	Assignee:	Josef Bacik (josef)
Status:	RESOLVED WILL_NOT_FIX
Severity:	normal	CC:	colin.king, dsterba
Priority:	P1
Hardware:	x86-64
OS:	Linux
Kernel Version:	3.13.0-43-generic	Subsystem:
Regression:	No	Bisected commit-id:

Description George Shuklin 2015-04-07 10:28:42 UTC

We running 3.13 (x86_64) from Ubuntu 12.04. After very bad OOM killer (wiped out most of the processes in the system) btrfs volume become unmountable:

btrfs: device fsid 0520e52d-7681-4156-9061-388e374c4e16 devid 1 transid 407769 /dev/mapper/host-volume
parent transid verify failed on 471304036352 wanted 407770 found 407769
parent transid verify failed on 471304036352 wanted 407770 found 407769
btrfs: failed to read log tree
btrfs: open_ctree failed

btrfsck complaining:

btrfsck --repair /dev/mapper/host-volume
enabling repair mode
parent transid verify failed on 471304036352 wanted 407770 found 407769
parent transid verify failed on 471304036352 wanted 407770 found 407769
parent transid verify failed on 471304036352 wanted 407770 found 407769
parent transid verify failed on 471304036352 wanted 407770 found 407769
Ignoring transid failure
Checking filesystem on /dev/mapper/host-volume
UUID: 0520e52d-7681-4156-9061-388e374c4e16
checking extents
checking free space cache
cache and super generation don't match, space cache will be invalidated
checking fs roots
root 5 inode 407 errors 80, file extent overlap
found 214360836421 bytes used err is 1
total csum bytes: 0
total tree bytes: 10665472000
total fs tree bytes: 5452877824
total extent tree bytes: 5212286976
btree space waste bytes: 843886520
file data blocks allocated: 892593057792
 referenced 890681024512
Btrfs v3.12

And btrfs-zero-log helped.

I've saved image with btrfs-image: (450Mb) http://c2154.eu01.webzillafiles.com/btrfs/btrfs_image.xz

Comment 1 David Sterba 2015-04-07 12:30:30 UTC

> We running 3.13 ...

That's too old sorry. The transid verify problems have been identified and fixed in the meantime. If you really need to use the 3.13 kernel, ask your distro to backport the fixes.

Comment 2 George Shuklin 2015-04-07 12:54:04 UTC

Thank you.

Launchpad's bug: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1441150

Comment 3 Colin Ian King 2015-04-08 12:22:00 UTC

Hints on the appropriate fixes to backport would be useful.

Comment 4 Colin Ian King 2015-04-08 15:52:26 UTC

Actually, I've restored the data and tried to mount it with today's 4.0-rc7 kernel and I still get "transid verify failed" issues, so I'm not sure what to make of that apart from the data can't be recovered at the moment with the latest kernel too.