[PATCH 06/13] btrfs: factor out block mapping for RAID10

Johannes Thumshirn
2023-12-12T12:38:23Z

Now that we have a container for the I/O geometry that has all the needed
information for the block mappings of RAID10, factor out a helper calculating
this information.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
fs/btrfs/volumes.c | 48 +++++++++++++++++++++++++++++++-----------------
1 file changed, 31 insertions(+), 17 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index b0a5c53fba51..9090bfc4fe38 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6408,6 +6408,35 @@ static void map_blocks_for_dup(struct btrfs_chunk_map *map,
io_geom->mirror_num = 1;
}

+static void map_blocks_for_raid10(struct btrfs_fs_info *fs_info,
+ struct btrfs_chunk_map *map,
+ enum btrfs_map_op op,
+ struct btrfs_io_geometry *io_geom,
+ int replace)
+{
+ u32 factor = map->num_stripes / map->sub_stripes;
+ int old_stripe_index;
+
+ io_geom->stripe_index =
+ (io_geom->stripe_nr % factor) * map->sub_stripes;
+ io_geom->stripe_nr /= factor;
+
+ if (op != BTRFS_MAP_READ) {
+ io_geom->num_stripes = map->sub_stripes;
+ return;
+ }
+
+ if (io_geom->mirror_num) {
+ io_geom->stripe_index += io_geom->mirror_num - 1;
+ return;
+ }
+
+ old_stripe_index = io_geom->stripe_index;
+ io_geom->stripe_index =
+ find_live_mirror(fs_info, map, io_geom->stripe_index, replace);
+ io_geom->mirror_num = io_geom->stripe_index - old_stripe_index + 1;
+}
+
/*
* Map one logical range to one or more physical ranges.
*
@@ -6500,23 +6529,8 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
map_blocks_for_dup(map, op, &io_geom);
} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
- u32 factor = map->num_stripes / map->sub_stripes;
-
- io_geom.stripe_index = (io_geom.stripe_nr % factor) * map->sub_stripes;
- io_geom.stripe_nr /= factor;
-
- if (op != BTRFS_MAP_READ)
- io_geom.num_stripes = map->sub_stripes;
- else if (io_geom.mirror_num)
- io_geom.stripe_index += io_geom.mirror_num - 1;
- else {
- int old_stripe_index = io_geom.stripe_index;
- io_geom.stripe_index = find_live_mirror(fs_info, map,
- io_geom.stripe_index,
- dev_replace_is_ongoing);
- io_geom.mirror_num = io_geom.stripe_index - old_stripe_index + 1;
- }
-
+ map_blocks_for_raid10(fs_info, map, op, &io_geom,
+ dev_replace_is_ongoing);
} else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
if (op != BTRFS_MAP_READ || io_geom.mirror_num > 1) {
/*

--
2.43.0