From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: RE: Software raid0 will crash the file-system, when each disk is 5TB Date: Fri, 18 May 2007 10:21:53 +1000 Message-ID: <17996.61857.486525.172950@notabene.brown> References: <659F626D666070439A4A5965CD6EBF406836C6@gazelle.ad.endace.com> <6bffcb0e0705151629j78920ca2r9337dccdfc1bb6a9@mail.gmail.com> <17994.19043.771733.453896@notabene.brown> <659F626D666070439A4A5965CD6EBF406B31C5@gazelle.ad.endace.com> <17995.42562.870806.396617@notabene.brown> <659F626D666070439A4A5965CD6EBF406B33ED@gazelle.ad.endace.com> <17995.49602.427417.500049@notabene.brown> <17995.57891.56738.592100@notabene.brown> <17995.59547.368508.202596@notabene.brown> <659F626D666070439A4A5965CD6EBF406B348A@gazelle.ad.endace.com> <659F626D666070439A4A5965CD6EBF406B352A@gazelle.ad.endace.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: message from Jeff Zheng on Friday May 18 Sender: linux-raid-owner@vger.kernel.org To: Jeff Zheng Cc: david@lang.hm, Michal Piotrowski , Ingo Molnar , linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org List-Id: linux-raid.ids On Friday May 18, Jeff.Zheng@endace.com wrote: > Fix confirmed, filled the whole 11T hard disk, without crashing. > I presume this would go into 2.6.22 Yes, and probably 2.6.21.y, though the patch will be slightly different, see below. > > Thanks again. And thank-you for pursuing this with me. NeilBrown --------------------------- Avoid overflow in raid0 calculation with large components. If a raid0 has a component device larger than 4TB, and is accessed on a 32bit machines, then as 'chunk' is unsigned lock, chunk << chunksize_bits can overflow (this can be as high as the size of the device in KB). chunk itself will not overflow (without triggering a BUG). So change 'chunk' to be 'sector_t, and get rid of the 'BUG' as it becomes impossible to hit. Cc: "Jeff Zheng" Signed-off-by: Neil Brown ### Diffstat output ./drivers/md/raid0.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) 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 16:14:12.000000000 +1000 @@ -415,7 +415,7 @@ static int raid0_make_request (request_q raid0_conf_t *conf = mddev_to_conf(mddev); struct strip_zone *zone; mdk_rdev_t *tmp_dev; - unsigned long chunk; + sector_t chunk; sector_t block, rsect; const int rw = bio_data_dir(bio); @@ -470,7 +470,6 @@ static int raid0_make_request (request_q sector_div(x, zone->nb_dev); chunk = x; - BUG_ON(x != (sector_t)chunk); x = block >> chunksize_bits; tmp_dev = zone->dev[sector_div(x, zone->nb_dev)];