On Fri, Jun 5, 2009 at 11:01 AM, Theodore Tso<tytso@xxxxxxx> wrote: > On Fri, Jun 05, 2009 at 05:40:33PM +0300, Aioanei Rares wrote: >>> When I upgrade libc from 2.7 (debian stable) to 2.9 (debian unstable), >>> the locale breaks every reboot, and I have to repair it by running >>> locale-gen. This happened now when I only upgraded libc, in order to >>> play with signalfd(). It also happened before, when I upgraded the >>> entire machine to debian unstable (which I later reverted). >>> >>> The problem is that /usr/lib/locale/locale-archive gets corrupted when >>> I reboot. The exact corruption differs with each reboot (i.e. the >>> md5sum differs). Last time, the first ~70K was overwritten with data >>> from xorg.log and my web browsing history. I have copies of the >>> original and corrupted state which I can send, the full file is 1.3 >>> megs, but I can limit it to the first 70K, since that's all that was >>> corrupted. > >> I suspect, although I might be wrong, that this is not a kernel-related >> problem. > > Actually, I suspect it is indeed a kernel-related problem. The > problem has been reported before, with a repeatable test case: > > http://bugzilla.kernel.org/show_bug.cgi?id=13292 > > The problem shows up after you unmount and remount the filesystem. > Before you the filesystem is unmounted, the locale-archive file has > the correct md5sum. After you unmount and remount the filesystem, the > filesystem is corrupted. I'm guessing that some data blocks aren't > getting marked as needing writeback, so the previous contents on disk > aren't written back. I was able to show that even though the mounted > filesystem had the correct information, direct access to the disk > using debugfs showed the blocks on disk had the contents that would be > revealed after the filesystem was unmounted and remounted. > > The problem only shows up when using ext4 without a journal, and I was > never able to create a simpler reproduction case. The last time I > tried to work on this bug was approximately a month ago. About two > weeks ago Frank from Google tried reproducing it, but he wasn't able > to do so using his 2.6.26-based kernel plus an updated ext4. > Unfortunately, I haven't had time to look at it since then, or to > check to see if some of the more recent patches scheduled for the > 2.6.31 merge window might have changed the behaviour of this bug. Just FYI: Frank Mayhar has recreated this issue in a recent kernel (though we're not seeing it with our 2.6.26 kernel + ext4 patches), and is actively working on it. Curt > > - Ted > > > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
