Re: corruption

Alexander Viro
2000-11-29T20:27:59Z

On Wed, 29 Nov 2000, Linus Torvalds wrote:

>
>
> On Wed, 29 Nov 2000, Alexander Viro wrote:
> >
> > Problem fixed by Jens' patch had been there since March, so if it's a
> > mix of __make_request() screwing up and something else... Urgh.
>
> No, the bug really got introduced in test11 due to the request merging
> stuff.
>
> The patch may _look_ like it fixed a generic problem that has been there
> forever, but we didn't actually need the spinlock for initializing "head"

Sure.

> at all. It's initialized to a constant offset within the unchaning request
> queue, so we can happily do it outside the spinlock.

Actually, I was not thinking about spinlock. What I missed was the fact
that again: was quite recent. My apologies...

> > I'ld really like to see details on the box with ext2 corruption on SCSI.
> > Tigran, IIRC you had it on SCSI boxen, right? Could you send me relevant
> > part of logs?
>
> I suspect that Tigran may have seen other instability (of which we had
> lots back when he saw it), and that the current rash is for the IDE
> problem only.
>
> Which is not to say that there might not be SCSI issues or other issues
> too, but I'm also not convinced that the SCSI thing might not just be a
> red herring at this point.

There are two quite distinct patterns: duplicated range vs. crap in metadata.
The former looks like a bug caught by Jens. The latter (especially in
bitmaps) seems to be older[1] and independent from elevator stuff. _That_ may
be a fs/buffer.c or fs/ext2/* bug. The former definitely lives below the
fs/buffer.c level.

[1] "older" may mean "shared with 2.2" here - ISTR bug reports looking like
that and IIRC they were never resolved. BTW, if you know some searchable
l-k archive... DN sucks coprolites through the straw these days ;-/