| /* |
| * Copyright (C) 2015 Fujitsu. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public |
| * License v2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public |
| * License along with this program; if not, write to the |
| * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| * Boston, MA 021110-1307, USA. |
| */ |
| |
| #ifndef __BTRFS_FIND_ROOT_H__ |
| #define __BTRFS_FIND_ROOT_H__ |
| |
| #include "kerncompat.h" |
| |
| #include "ctree.h" |
| #include "kernel-lib/list.h" |
| #include "extent-cache.h" |
| |
| /* |
| * Find-root will restore the search result in a 2-level trees. |
| * Search result is a cache_tree consisted of generation_cache. |
| * Each generation cache records the highest level of this generation |
| * and all the tree blocks with this generation. |
| * |
| * <result> |
| * cache_tree ----> generation_cache: gen:1 level: 2 eb_tree ----> eb1 |
| * | |-> eb2 |
| * | ...... |
| * |-> generation_cache: gen:2 level: 3 eb_tree ---> eb3 |
| * |
| * In the above example, generation 1's highest level is 2, but have multiple |
| * eb with same generation, so the root of generation 1 must be missing, |
| * possibly has already been overwritten. |
| * On the other hand, generation 2's highest level is 3 and we find only one |
| * eb for it, so it may be the root of generation 2. |
| */ |
| |
| struct btrfs_find_root_gen_cache { |
| struct cache_extent cache; /* cache->start is generation */ |
| u64 highest_level; |
| struct cache_tree eb_tree; |
| }; |
| |
| struct btrfs_find_root_filter { |
| u64 objectid; /* Only search tree with this objectid */ |
| u64 generation; /* Only record tree block with higher or |
| equal generation */ |
| u8 level; /* Only record tree block with higher or |
| equal level */ |
| u8 match_level; |
| u64 match_gen; |
| int search_all; |
| /* |
| * If set search_all, even the tree block matches match_gen |
| * and match_level and objectid, still continue searching |
| * This *WILL* take *TONS* of extra time. |
| */ |
| }; |
| int btrfs_find_root_search(struct btrfs_fs_info *fs_info, |
| struct btrfs_find_root_filter *filter, |
| struct cache_tree *result, |
| struct cache_extent **match); |
| static inline void btrfs_find_root_free(struct cache_tree *result) |
| { |
| struct btrfs_find_root_gen_cache *gen_cache; |
| struct cache_extent *cache; |
| |
| cache = first_cache_extent(result); |
| while (cache) { |
| gen_cache = container_of(cache, |
| struct btrfs_find_root_gen_cache, cache); |
| free_extent_cache_tree(&gen_cache->eb_tree); |
| remove_cache_extent(result, cache); |
| free(gen_cache); |
| cache = first_cache_extent(result); |
| } |
| } |
| #endif |