Duncan <1i5t5.dun...@cox.net> wrote:
> Zach Fuller posted on Thu, 24 Dec 2015 13:15:22 -0600 as excerpted:
>
> > I am currently running btrfs on a 2TB GPT drive. The drive is working
> > fine, still mounts correctly, and I have experienced no data corruption.
> > Whenever I run "btrfs check" on the drive, it returns 100,000+ messages
> > stating "bad extent [###, ###), type mismatch with chunk". Whenever I
> > try to run "btrfs check --repair" it says that it has fixed the errors,
> > but whenever I run "btrfs check" again, the errors return. Should I be
> > worried about data/filesystem corruption,
> > or are these errors meaningless?
>
> > I have my data backed up on 2 different drives, so I can afford to lose
> > the entire btrfs drive temporarily.
> >
> > Here is some info about my system:
> >
> > $ uname -[r]
> > 4.2.5-1-ARCH
> >
> >
> > $ btrfs --version
> > btrfs-progs v4.3.1
>
> While Chris's reply mentioning a patch is correct, that's not the whole
> story and I suspect you have a problem, as the patch is in the userspace
> 4.3.1 you're running.
>
> How long have you had the filesystem? Was it likely created with the
> mkfs.btrfs from btrfs-progs v4.1.1 (July, 2015) as I suspect? If so, you
> have a problem, as that mkfs.btrfs was buggy and created invalid
> filesystems.
>
> As you have two separate backups and you're not experiencing corruption
> or the like so far, you should be fine, but if the filesystem was created
> with that buggy mkfs.btrfs, you need to wipe and recreate it as soon as
> possible, because it's unstable in its current state and could fail, with
> massive corruption, at any point. Unfortunately, the bug created
> filesystems so broken that (last I knew anyway, and your experience
> agrees) there's no way btrfs check --repair can fix them. The only way
> to fix it is to blow away the filesystem and recreate it with a
> mkfs.btrfs that doesn't have the bug that 4.1.1 did. Your 4.3.1 should
> be fine.
>
> (The patch Chris mentioned was to btrfs check, as the first set of
> patches to it to allow it to detect the problem triggered all sorts of
> false-positives and pretty much everybody was flagged as having the
> problem. I believe that was patched in the 4.2 series, however, and
> you're running 4.3.1, so you should have that patch and the reports
> shouldn't be false positives. Tho if you didn't create the filesystem
> with the buggy mkfs.btrfs from v4.1.1, there's likely some other problem
> to root out, but I'm guessing you did, and thus have the bad filesystem
> the patched btrfs check is designed to report, and that report is indeed
> valid.)
Hmmm, I just used the 4.1 mkfs.btrfs to create some of the file systems
I have, because that was on the cd I booted with because I had to do
this offline. So, can I fix things, ro do I have to find a cd with the
4.3.1 programs, or can I put the mkfs.btrfs binary on a USB drive, copy
the files off, recreate the file systems and do a copy back? grrrr!
--
Your life is like a penny. You're going to lose it. The question is:
How do
you spend it?
John Covici
cov...@ccs.covici.com
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