From 2fff734fafa742236aecbdcdc8b1ff4d221cbaca Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Tue, 29 Apr 2008 14:12:09 -0400 Subject: [PATCH] Btrfs: Tune stripe selection for raid1 and raid10 Signed-off-by: Chris Mason --- fs/btrfs/volumes.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 57ab755aca76..6d8dd4438c76 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1509,17 +1509,17 @@ static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw, 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 @@ static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw, 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 -- GitLab