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Diffstat (limited to 'find-root.h')
| -rw-r--r-- | find-root.h | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/find-root.h b/find-root.h new file mode 100644 index 00000000..60d1111d --- /dev/null +++ b/find-root.h @@ -0,0 +1,87 @@ +/* + * 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 "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 |