Re: Another checksum error bugreport

[Lubos Kolouch <lubos.kolouch@gmail.com>]

Sebastian 'gonX' Jensen, Wed, 29 Sep 2010 12:48:56 +0200:

> Hey guys,
> 
> Today I experienced my first checksum error just out of the blue - and
> it's not just the 'csum + 1 = private' issue, it's a completely
> different one. Because of this, I am unable to retrieve the data off the
> drive, even with nodatasum enabled - I simply get an I/O error. Here's
> the dmesg output:
> 
> [149423.845177] btrfs: setting nodatasum [149423.850339] Btrfs detected
> SSD devices, enabling SSD mode [149432.094728] btrfs csum failed ino 259
> off 26701824 csum 3875867041 private 371726550
> [149432.117938] btrfs csum failed ino 259 off 26701824 csum 3875867041
> private 371726550
> [149432.118340] btrfs csum failed ino 259 off 26701824 csum 3875867041
> private 371726550
> [149432.125671] btrfs csum failed ino 259 off 26701824 csum 3875867041
> private 371726550
> [149432.126075] btrfs csum failed ino 259 off 26701824 csum 3875867041
> private 371726550
> [149432.135671] btrfs csum failed ino 259 off 26701824 csum 3875867041
> private 371726550
> 
> I would really like to have the files on the drive retrieved in their
> entirety, but if that is not possible then that is also OK. Consider
> this a bugreport and a question on how to retrieve the data now.
> 
> Thanks,
> Sebastian J.

I have seen this now too, on a usb flash drive (yes, with LUKS on it) that
has been always correctly unmounted and luksClosed. In facts I created 
the fs on it couple of days ago and now I cannot read one file with the 
same error.

I do not need to recover the file, it's just that you are not the only 
with this error.

Lubos