ext4 file system corruptions due to a kernel bug

[Huan Zhang]

A problematic kernel patch has been backported to Ubuntu since linux-image-3.5.0-18-generic:
* jbd2: don't write superblock when if its empty (LP: #1066176)

There are a few discussions on this issue:
http://www.phoronix.com/scan.php?page=news_item&px=MTIxNDQ
https://bbs.archlinux.org/viewtopic.php?id=151341&p=1
https://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=8c673cbc7682b3f2862fe42f8069cac20c09e160

"This could potentially lead to minor file system corruptions (pass 5 complaints with the inode allocation bitmap) after an unclean shutdown under the wrong/unlucky workloads, but it turned into major failure if the journal_checksum and/or jouaral_async_commit was enabled."

Another bug Bug #1019347 causing unclean shutdown makes the scenario worse in Ubuntu 12.10. I experienced serious filesystem corruptions twice on a newly installed Ubuntu 12.10 system after upgrading to the latest 3.5.0-21 kernel, especially when I frequently reboot my computer.

[penalvch (penalvch)]

Huan Zhang, thank you for reporting this bug to Ubuntu. linux-lts-quantal reached EOL on August 2014.
See the following documents for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases
https://wiki.ubuntu.com/Kernel/LTSEnablementStack

If this is still reproducible in a supported release, please execute the following in a terminal:
apport-collect 1095220

Otherwise, please mark this as Invalid.

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]