Btrfs: fix __btrfs_map_block on 32 bit machines

Recent changes for discard support didn't compile,
this fixes them not to try and % 64 bit numbers.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index c440c89a470ac3b9d265fffc00ef67b3d059149f..8b9fb8c7683da9fc2652281cb21c99bdcbab2f2e 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3126,13 +3126,19 @@ again:
 
                        if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
                                u64 stripes;
-                               int last_stripe = (stripe_nr_end - 1) %
-                                       map->num_stripes;
+                               u32 last_stripe = 0;
                                int j;
 
+                               div_u64_rem(stripe_nr_end - 1,
+                                           map->num_stripes,
+                                           &last_stripe);
+
                                for (j = 0; j < map->num_stripes; j++) {
-                                       if ((stripe_nr_end - 1 - j) %
-                                             map->num_stripes == stripe_index)
+                                       u32 test;
+
+                                       div_u64_rem(stripe_nr_end - 1 - j,
+                                                   map->num_stripes, &test);
+                                       if (test == stripe_index)
                                                break;
                                }
                                stripes = stripe_nr_end - 1 - j;
@@ -3153,11 +3159,19 @@ again:
                                int j;
                                int factor = map->num_stripes /
                                             map->sub_stripes;
-                               int last_stripe = (stripe_nr_end - 1) % factor;
+                               u32 last_stripe = 0;
+
+                               div_u64_rem(stripe_nr_end - 1,
+                                           factor, &last_stripe);
                                last_stripe *= map->sub_stripes;
 
                                for (j = 0; j < factor; j++) {
-                                       if ((stripe_nr_end - 1 - j) % factor ==
+                                       u32 test;
+
+                                       div_u64_rem(stripe_nr_end - 1 - j,
+                                                   factor, &test);
+
+                                       if (test ==
                                            stripe_index / map->sub_stripes)
                                                break;
                                }