Btrfs: Tune stripe selection for raid1 and raid10

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

1 files changed, 7 insertions, 10 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 57ab755aca7..6d8dd4438c7 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1509,17 +1509,17 @@ again:
         if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
                 if (unplug_page || (rw & (1 << BIO_RW)))
                         num_stripes = map->num_stripes;
-                else if (mirror_num) {
+                else if (mirror_num)
                         stripe_index = mirror_num - 1;
-                } else {
-                        u64 orig_stripe_nr = stripe_nr;
-                        stripe_index = do_div(orig_stripe_nr, num_stripes);
-                }
+                else
+                        stripe_index = current->pid % map->num_stripes;
+
         } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
                 if (rw & (1 << BIO_RW))
                         num_stripes = map->num_stripes;
                 else if (mirror_num)
                         stripe_index = mirror_num - 1;
+
         } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
                 int factor = map->num_stripes / map->sub_stripes;
 
@@ -1530,11 +1530,8 @@ again:
                         num_stripes = map->sub_stripes;
                 else if (mirror_num)
                         stripe_index += mirror_num - 1;
-                else {
-                        u64 orig_stripe_nr = stripe_nr;
-                        stripe_index += do_div(orig_stripe_nr,
-                                               map->sub_stripes);
-                }
+                else
+                        stripe_index += current->pid % map->sub_stripes;
         } else {
                 /*
                  * after this do_div call, stripe_nr is the number of stripes