Btrfs: Tune stripe selection for raid1 and raid10
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 57ab755..6d8dd44 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1509,17 +1509,17 @@
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 @@
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