Fix confirmed, filled the whole 11T hard disk, without crashing.
I presume this would go into 2.6.22

Thanks again.

Jeff

-----Original Message-----
From: linux-raid-owner@vger.kernel.org 
[mailto:linux-raid-owner@vger.kernel.org] On Behalf Of Jeff Zheng
Sent: Thursday, 17 May 2007 5:39 p.m.
To: Neil Brown; david@lang.hm; Michal Piotrowski; Ingo 
Molnar; linux-raid@vger.kernel.org; 
linux-kernel@vger.kernel.org; linux-fsdevel@vger.kernel.org
Subject: RE: Software raid0 will crash the file-system, when 
each disk is 5TB


Yeah, seems you've locked it down, :D. I've written 600GB of 
data now, and anything is still fine.
Will let it run overnight, and fill the whole 11T. I'll post 
the result tomorrow

Thanks a lot though.

Jeff 

quoted

-----Original Message-----
From: Neil Brown [mailto:neilb@suse.de]
Sent: Thursday, 17 May 2007 5:31 p.m.
To: david@lang.hm; Jeff Zheng; Michal Piotrowski; Ingo Molnar; 
linux-raid@vger.kernel.org; linux-kernel@vger.kernel.org; 
linux-fsdevel@vger.kernel.org
Subject: RE: Software raid0 will crash the file-system, 

when each disk 

quoted

is 5TB

On Thursday May 17, neilb@suse.de wrote:

quoted

Uhm, I just noticed something.
'chunk' is unsigned long, and when it gets shifted up, we

might lose

quoted

bits.  That could still happen with the 4*2.75T 

arrangement, but is 

quoted

quoted

much more likely in the 2*5.5T arrangement.

Actually, it cannot be a problem with the 4*2.75T arrangement.
  chuck << chunksize_bits

will not exceed the size of the underlying device *in*kilobytes*.
In that case that is 0xAE9EC800 which will git in a 32bit long.
We don't double it to make sectors until after we add
zone->dev_offset, which is "sector_t" and so 64bit 

arithmetic is used.

quoted

So I'm quite certain this bug will cause exactly the problems 
experienced!!

quoted

Jeff, can you try this patch?

Don't bother about the other tests I mentioned, just try this one.
Thanks.

NeilBrown

quoted

Signed-off-by: Neil Brown <redacted>

### Diffstat output
 ./drivers/md/raid0.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff .prev/drivers/md/raid0.c ./drivers/md/raid0.c

--- .prev/drivers/md/raid0.c	2007-05-17 

10:33:30.000000000 +1000

quoted

+++ ./drivers/md/raid0.c	2007-05-17 15:02:15.000000000 +1000

@@ -475,7 +475,7 @@ static int raid0_make_request (request_q
 		x = block >> chunksize_bits;
 		tmp_dev = zone->dev[sector_div(x, zone->nb_dev)];
 	}
-	rsect = (((chunk << chunksize_bits) + zone->dev_offset)<<1)
+	rsect = ((((sector_t)chunk << chunksize_bits) +
+zone->dev_offset)<<1)
 		+ sect_in_chunk;
  
 	bio->bi_bdev = tmp_dev->bdev;

-
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