From 0ae653fbec2b9fbc72c65a0c99528990bfb2136d Mon Sep 17 00:00:00 2001 From: Johannes Thumshirn Date: Tue, 13 Aug 2024 13:36:40 +0200 Subject: [PATCH] btrfs: reduce chunk_map lookups in btrfs_map_block() Currently we're calling btrfs_num_copies() before btrfs_get_chunk_map() in btrfs_map_block(). But btrfs_num_copies() itself does a chunk map lookup to be able to calculate the number of copies. So split out the code getting the number of copies from btrfs_num_copies() into a helper called btrfs_chunk_map_num_copies() and directly call it from btrfs_map_block() and btrfs_num_copies(). This saves us one rbtree lookup per btrfs_map_block() invocation. Reviewed-by: Qu Wenruo Reviewed-by: Filipe Manana Signed-off-by: Johannes Thumshirn Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/volumes.c | 49 +++++++++++++++++++++++++--------------------- 1 file changed, 27 insertions(+), 22 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index e07452207426..8f340ad1d938 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -5781,11 +5781,31 @@ void btrfs_mapping_tree_free(struct btrfs_fs_info *fs_info) write_unlock(&fs_info->mapping_tree_lock); } +static int btrfs_chunk_map_num_copies(const struct btrfs_chunk_map *map) +{ + enum btrfs_raid_types index = btrfs_bg_flags_to_raid_index(map->type); + + if (map->type & BTRFS_BLOCK_GROUP_RAID5) + return 2; + + /* + * There could be two corrupted data stripes, we need to loop retry in + * order to rebuild the correct data. + * + * Fail a stripe at a time on every retry except the stripe under + * reconstruction. + */ + if (map->type & BTRFS_BLOCK_GROUP_RAID6) + return map->num_stripes; + + /* Non-RAID56, use their ncopies from btrfs_raid_array. */ + return btrfs_raid_array[index].ncopies; +} + int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len) { struct btrfs_chunk_map *map; - enum btrfs_raid_types index; - int ret = 1; + int ret; map = btrfs_get_chunk_map(fs_info, logical, len); if (IS_ERR(map)) @@ -5797,22 +5817,7 @@ int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len) */ return 1; - index = btrfs_bg_flags_to_raid_index(map->type); - - /* Non-RAID56, use their ncopies from btrfs_raid_array. */ - if (!(map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)) - ret = btrfs_raid_array[index].ncopies; - else if (map->type & BTRFS_BLOCK_GROUP_RAID5) - ret = 2; - else if (map->type & BTRFS_BLOCK_GROUP_RAID6) - /* - * There could be two corrupted data stripes, we need - * to loop retry in order to rebuild the correct data. - * - * Fail a stripe at a time on every retry except the - * stripe under reconstruction. - */ - ret = map->num_stripes; + ret = btrfs_chunk_map_num_copies(map); btrfs_free_chunk_map(map); return ret; } @@ -6462,14 +6467,14 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op, io_geom.stripe_index = 0; io_geom.op = op; - num_copies = btrfs_num_copies(fs_info, logical, fs_info->sectorsize); - if (io_geom.mirror_num > num_copies) - return -EINVAL; - map = btrfs_get_chunk_map(fs_info, logical, *length); if (IS_ERR(map)) return PTR_ERR(map); + num_copies = btrfs_chunk_map_num_copies(map); + if (io_geom.mirror_num > num_copies) + return -EINVAL; + map_offset = logical - map->start; io_geom.raid56_full_stripe_start = (u64)-1; max_len = btrfs_max_io_len(map, map_offset, &io_geom);