Re: Rampant ext3/4 corruption on 2.6.34-rc7 with VIVT ARM (Marvell 88f5182)

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

>   Could you get the filesystem image with: e2image -r /dev/sdb2 buggy-image
> bzip2 it and make it available somewhere? Maybe I could guess something
> from the way the filesystem gets corrupted.
>   Oh, and also overwrite the partition with zeros before calling mkfs to make
> the analysis simpler.

Will do asap.

> > In fact, if I do ls /mnt/test/usr/bin/ I see debconf but if I do
> > ls /mnt/test/usr/bin/chrt then I get No such file or directory.
> > 
> > So something is badly wrong :-)
> > 
> > Now, trying without the dir_index feature (mkfs.ext3 -O ^dir_index)
> > and it works fine. All my md5sum's are correct and fsck passes.
>   Funny. Not sure how that could happen...

Yeah, strange. I looked at the code a bit and I don't see anything
obvious, ext3 seems to be using the same standard buffer head access
methods for the htree as for the rest of the metadata, and I see no
fancy playing with virtual addresses that could explain a VIVT problem.

I could be an issue with the SATA controller that gets more easily
triggered by the access patterns caused by htree, though that's a bit
strange.

I'll let you know when I have something to look at.

Cheers,
Ben.