--- /dev/null
+From 35f2a591192d0a5d9f7fc696869c76f0b8e49c3d Mon Sep 17 00:00:00 2001
+From: NeilBrown <neilb@suse.de>
+Date: Tue, 20 Apr 2010 14:13:34 +1000
+Subject: md/raid5: allow for more than 2^31 chunks.
+
+From: NeilBrown <neilb@suse.de>
+
+commit 35f2a591192d0a5d9f7fc696869c76f0b8e49c3d upstream.
+
+With many large drives and small chunk sizes it is possible
+to create a RAID5 with more than 2^31 chunks. Make sure this
+works.
+
+Reported-by: Brett King <king.br@gmail.com>
+Signed-off-by: NeilBrown <neilb@suse.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
+
+---
+ drivers/md/raid5.c | 19 +++++++------------
+ 1 file changed, 7 insertions(+), 12 deletions(-)
+
+--- a/drivers/md/raid5.c
++++ b/drivers/md/raid5.c
+@@ -1649,8 +1649,8 @@ static sector_t raid5_compute_sector(rai
+ int previous, int *dd_idx,
+ struct stripe_head *sh)
+ {
+- long stripe;
+- unsigned long chunk_number;
++ sector_t stripe;
++ sector_t chunk_number;
+ unsigned int chunk_offset;
+ int pd_idx, qd_idx;
+ int ddf_layout = 0;
+@@ -1670,17 +1670,12 @@ static sector_t raid5_compute_sector(rai
+ */
+ chunk_offset = sector_div(r_sector, sectors_per_chunk);
+ chunk_number = r_sector;
+- BUG_ON(r_sector != chunk_number);
+
+ /*
+ * Compute the stripe number
+ */
+- stripe = chunk_number / data_disks;
+-
+- /*
+- * Compute the data disk and parity disk indexes inside the stripe
+- */
+- *dd_idx = chunk_number % data_disks;
++ stripe = chunk_number;
++ *dd_idx = sector_div(stripe, data_disks);
+
+ /*
+ * Select the parity disk based on the user selected algorithm.
+@@ -1869,14 +1864,14 @@ static sector_t compute_blocknr(struct s
+ : conf->algorithm;
+ sector_t stripe;
+ int chunk_offset;
+- int chunk_number, dummy1, dd_idx = i;
++ sector_t chunk_number;
++ int dummy1, dd_idx = i;
+ sector_t r_sector;
+ struct stripe_head sh2;
+
+
+ chunk_offset = sector_div(new_sector, sectors_per_chunk);
+ stripe = new_sector;
+- BUG_ON(new_sector != stripe);
+
+ if (i == sh->pd_idx)
+ return 0;
+@@ -1969,7 +1964,7 @@ static sector_t compute_blocknr(struct s
+ }
+
+ chunk_number = stripe * data_disks + i;
+- r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset;
++ r_sector = chunk_number * sectors_per_chunk + chunk_offset;
+
+ check = raid5_compute_sector(conf, r_sector,
+ previous, &dummy1, &sh2);