Comment 8 for bug 1366538

Please remove the "Invalid" status from this ticket. I can confirm that this is a linux kernel issue. This happened to me:

1) Attached a external USB harddrive (an 'oldie': the Lacie 250GB) to PC running Ubuntu 14.04.1 with latest kernel update installed.
2) Formatted the harddrive to ext4, already seeing "end_request: critical target error, dev sdX, sector 0" kernel messages.
3) Installed Ubuntu 14.04.1 to the USB harddrive (by booting the Ubuntu 14.04.1 live installer from a USB stick).
4) Booted from the USB harddrive - no problems at all.
5) Updated ONLY the linux-* packages of the Ubuntu running on the USB harddrive.
6) Rebooted the USB harddrive (which auto-selects the latest kernel version in grub), and the filesystem got completely corruppted.

Please note that a VFAT filesystem doesn't get corrupted, but the "end_request: critical target error, dev sdX, sector 0" messages also appear in the syslog.

Also tested the following:
1) Ubuntu 14.10 - same issue.
2) openSUSE 13.2 Factory (latest live version) - same issue.

Searching the internet showed that other distributions have the same issue, e.g.:
- Raspberry Pi: https://github.com/raspberrypi/linux/issues/703
- Ubuntu 14.04: http://unix.stackexchange.com/questions/156704/cannot-mount-fresh-partition-twice
- Ubuntu 14.04: with kernel version .35: Bug #1368299
- Xubuntu 14.04: http://ubuntuforums.org/showthread.php?t=2243515
- I also came accros Arch-Linux and Debian-Linux pages describing the same error, but can't find them atm, sorry for that.

If you need more details, please let me know, I will be happy to provide them.