[PATCH] md: support md/linear array with components greater than 2 terabytes.

linear currently uses division by the size of the smallest componenet device
to find which device a request goes to.  If that smallest device is larger
than 2 terabytes, then the division will not work on some systems.

So we introduce a pre-shift, and take care not to make the hash table too
large, much like the code in raid0.

Also get rid of conf->nr_zones, which is not needed.

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/raid/linear.h b/include/linux/raid/linear.h
index e04c4fe45b53..7eaf290e10e7 100644
--- a/include/linux/raid/linear.h
+++ b/include/linux/raid/linear.h
@@ -14,8 +14,8 @@ typedef struct dev_info dev_info_t;
 struct linear_private_data
 {
         dev_info_t              **hash_table;
-        dev_info_t              *smallest;
-        int                     nr_zones;
+        sector_t                hash_spacing;
+        int                     preshift; /* shift before dividing by hash_spacing */
         dev_info_t              disks[0];
 };