| Message ID | 20240813113641.26579-1-jth@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] btrfs: reduce chunk_map lookups in btrfs_map_block | expand |
On Tue, Aug 13, 2024 at 12:37 PM Johannes Thumshirn <jth@kernel.org> wrote: > > From: Johannes Thumshirn <johannes.thumshirn@wdc.com> > > 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 <wqu@suse.com> > Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Looks good, thanks. > --- > Changes in v2: > - Added Reviewed-bys > - Reflowed comments > - Moved non RAID56 cases to the end without an if > Link to v1: > https://lore.kernel.org/all/20240812165931.9106-1-jth@kernel.org/ > > Changes in v3: > - constified btrfs_chunk_map_num_copies() parameter > - fixed accidentially changed comment > Link to v2: > https://lore.kernel.org/all/bc73d318c7f24196cdc7305b6a6ce516fb4fc81d.1723546054.git.jth@kernel.org/ > > 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..4b9b647a7e29 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); > -- > 2.43.0 > >
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index e07452207426..4b9b647a7e29 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);