Re: new Areca driver in 2.6.16-rc6-mm2 appears to be broken

[Jens Axboe <axboe@suse.de>]

(don't top post!)

On Thu, Apr 20 2006, erich wrote:
> Dear Dear Jens Axboe,
> 
> Thanks for your notification and advice.
> Areca's firmware has max sg entries of 38 limit.
> In my debug driver I had add this condition check.
> But no one request more than 38 sg.
> Both transfer length all have a lot of requests equal with 38 sg.
> But why it ocur only at 4096 sectors?
> If the /sys/block/sda/queue/max_sectors_kb equal 256 all operation running 
> well.
> But if I modify it more than 256, the bug appeared.
> I  will do more research about why there were a lot of requests equal with 
> 38 sg in all file system.

It was just a suggestion, the bug might very well be just the size of
the transfer itself and nothing SG related. All I can say for sure is
that I'd be very surprised if this fs corruption isn't due to the
hardware mangling the data for large transfers.

> And only it ocur at the volume that format with mkfs.ext2.

Most likely a coincidence, try running eg dbench or other stress tests
on the fs with larger xfer size and I'm sure it'll corrupt eventually as
well.


-- 
Jens Axboe