A bug that was first introduced into Linux kernel 3.6.3, and that got backported into 3.4x and 3.5.x branches, causing quite a ruckus because it could have led to some serious data loss, was patched by none other than Theodore Ts'o, a maintainer of the EXT4 file system.
“If the journal's starting block is zero, we fail to truncate the journal when we unmount the file system. This can happen if we mount and then unmount the file system fairly quickly, before the log has a chance to wrap,” explained Theodore Ts'o in the original message.
As we reported a week ago, a patch was already in the works and it seems that the problem has been solved.
“This fixes the root cause of the ext4 data corruption bug. This bug only showed up when non-standard mount options (journal_async_commit and/or journal_checksum) were enabled, and when the file system was not cleanly unmounted, but the root cause was the inode bitmap modifications was not being properly journaled,” stated Theodore Ts'o.
has been pushed in the stable tree of Linux kernel and we’re hoping that it will also be backported to the other kernel it affected.