btrfs: factor out RAID1 block mapping

Now that we have a container for the I/O geometry that has all the needed
information for the block mappings of RAID1, factor out a helper calculating
this information.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 21a53acd52ac21d678b491d6ae6ae5d119e717dc..2d25e82f24a4158c843e39a710d572b0333b5560 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6371,6 +6371,26 @@ static void map_blocks_raid0(const struct btrfs_chunk_map *map,
                io_geom->mirror_num = 1;
 }
 
+static void map_blocks_raid1(struct btrfs_fs_info *fs_info,
+                            struct btrfs_chunk_map *map,
+                            struct btrfs_io_geometry *io_geom,
+                            bool dev_replace_is_ongoing)
+{
+       if (io_geom->op != BTRFS_MAP_READ) {
+               io_geom->num_stripes = map->num_stripes;
+               return;
+       }
+
+       if (io_geom->mirror_num) {
+               io_geom->stripe_index = io_geom->mirror_num - 1;
+               return;
+       }
+
+       io_geom->stripe_index = find_live_mirror(fs_info, map, 0,
+                                                dev_replace_is_ongoing);
+       io_geom->mirror_num = io_geom->stripe_index + 1;
+}
+
 /*
  * Map one logical range to one or more physical ranges.
  *
@@ -6460,16 +6480,7 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
        if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
                map_blocks_raid0(map, &io_geom);
        } else if (map->type & BTRFS_BLOCK_GROUP_RAID1_MASK) {
-               if (op != BTRFS_MAP_READ) {
-                       io_geom.num_stripes = map->num_stripes;
-               } else if (io_geom.mirror_num) {
-                       io_geom.stripe_index = io_geom.mirror_num - 1;
-               } else {
-                       io_geom.stripe_index = find_live_mirror(fs_info, map, 0,
-                                           dev_replace_is_ongoing);
-                       io_geom.mirror_num = io_geom.stripe_index + 1;
-               }
-
+               map_blocks_raid1(fs_info, map, &io_geom, dev_replace_is_ongoing);
        } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
                if (op != BTRFS_MAP_READ) {
                        io_geom.num_stripes = map->num_stripes;