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>

1 files changed, 20 insertions, 6 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index c440c89a470a..8b9fb8c7683d 100644
--- 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;
                                 }