[PATCH] md: remove arbitrary limit on chunk size

The largest chunk size the code can support without substantial surgery is
2^30 bytes, so make that the limit instead of an arbitrary 4Meg.  Some day,
the 'chunksize' should change to a sector-shift instead of a byte-count.  Then
no limit would be needed.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 3184360..122e64e 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2382,8 +2382,8 @@
 	 * 2 * (n-1) * chunksize where 'n' is the number of raid devices
 	 */
 	{
-		int stripe = (mddev->raid_disks-1) * mddev->chunk_size
-			/ PAGE_SIZE;
+		int stripe = (mddev->raid_disks-1) *
+			(mddev->chunk_size / PAGE_SIZE);
 		if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
 			mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
 	}