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" <[EMAIL PROTECTED]>
Signed-off-by: Neil Brown <[EMAIL PROTECTED]>
Signed-off-by: Chris Wright <[EMAIL PROTECTED]>
Signed-off-by: Greg Kroah-Hartman <[EMAIL PROTECTED]>
---
 drivers/md/raid0.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index dfe3214..2c404f7 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -415,7 +415,7 @@ static int raid0_make_request (request_queue_t *q, struct 
bio *bio)
        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_queue_t *q, struct 
bio *bio)
 
                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)];
-- 
1.5.2.4

-- 
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