Re: ext3 badness in 2.6.0-test2

[Neil Brown <neilb@cse.unsw.edu.au>]

On Tuesday August 5, akpm@osdl.org wrote:
> Neil Brown <neilb@cse.unsw.edu.au> wrote:
> > ...
> > Aug  6 15:22:05 adams kernel: EXT3-fs error (device md1): ext3_add_entry: bad entry in directory #41
> > 009295: rec_len is smaller than minimal - offset=0, inode=3265411686, rec_len=0, name_len=0
> 
> It looks like we had a block full of zeroes come back from the device
> driver.  I find it distinctly fishy how this happens so much with
> ext3-on-md, and so little with ext3-on-just-a-disk.

Well, they're not *all* zero.....

I can reproduce this easily with various configurations of ext3 over
raid5, and get a similar problem with ext2 over raid5 (corrupt inodes
rather than directory entries) but ext3 over raid0 is rock-solid.

So I guess the finger points generally in the direction of raid5.
Now I've just got to figure if it is a bug in r5, or some assumption
that it makes that is no longer valid (I was briefly suspicious of
PF_READAHEAD which could have made a real mess of raid5, but that
wouldn't have this symptom)

NeilBrown