linux-kernel - RE: Software raid0 will crash the file-system, when each disk is 5TB

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <17995.57891.56738.592100@notabene.brown>
Date:	Thu, 17 May 2007 15:03:31 +1000
From:	Neil Brown <neilb@...e.de>
To:	david@...g.hm
Cc:	Jeff Zheng <Jeff.Zheng@...ace.com>,
	Michal Piotrowski <michal.k.k.piotrowski@...il.com>,
	Ingo Molnar <mingo@...e.hu>, linux-raid@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org
Subject: RE: Software raid0 will crash the file-system, when each disk is
 5TB

On Wednesday May 16, david@...g.hm wrote:
> On Thu, 17 May 2007, Neil Brown wrote:
> 
> > On Thursday May 17, Jeff.Zheng@...ace.com wrote:
> >>
> >>> The only difference of any significance between the working
> >>> and non-working configurations is that in the non-working,
> >>> the component devices are larger than 2Gig, and hence have
> >>> sector offsets greater than 32 bits.
> >>
> >> Do u mean 2T here?, but in both configuartion, the component devices are
> >> larger than 2T (2.25T&5.5T).
> >
> > Yes, I meant 2T, and yes, the components are always over 2T.
> 
> 2T decimal or 2T binary?
> 

Either.  The smallest as actually 2.75T (typo above).
Precisely it was
  2929641472  kilobytes
or 
  5859282944 sectors
or 
  0x15D3D9000 sectors.

So it is over 32bits already...

Uhm, I just noticed something.
'chunk' is unsigned long, and when it gets shifted up, we might lose
bits.  That could still happen with the 4*2.75T arrangement, but is
much more likely in the 2*5.5T arrangement.

Jeff, can you try this patch?

Thanks.
NeilBrown


Signed-off-by: Neil Brown <neilb@...e.de>

### 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
+++ ./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;
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/