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