ab5c3046f2
This patch implements an infrastructure to insert/search/merge an extent range (with variable length). This provides the basis for later extent buffer cache used in btrfs. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Marek Behún <marek.behun@nic.cz>
105 lines
2.8 KiB
C
105 lines
2.8 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Crossported from the same named file of btrfs-progs.
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*
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* Minor modification to include headers.
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*/
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#ifndef __BTRFS_EXTENT_CACHE_H__
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#define __BTRFS_EXTENT_CACHE_H__
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#include <linux/rbtree.h>
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#include <linux/types.h>
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struct cache_tree {
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struct rb_root root;
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};
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struct cache_extent {
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struct rb_node rb_node;
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u64 objectid;
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u64 start;
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u64 size;
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};
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void cache_tree_init(struct cache_tree *tree);
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struct cache_extent *first_cache_extent(struct cache_tree *tree);
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struct cache_extent *last_cache_extent(struct cache_tree *tree);
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struct cache_extent *prev_cache_extent(struct cache_extent *pe);
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struct cache_extent *next_cache_extent(struct cache_extent *pe);
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/*
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* Find a cache_extent which covers start.
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*
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* If not found, return next cache_extent if possible.
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*/
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struct cache_extent *search_cache_extent(struct cache_tree *tree, u64 start);
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/*
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* Find a cache_extent which restrictly covers start.
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*
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* If not found, return NULL.
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*/
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struct cache_extent *lookup_cache_extent(struct cache_tree *tree,
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u64 start, u64 size);
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/*
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* Add an non-overlap extent into cache tree
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*
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* If [start, start+size) overlap with existing one, it will return -EEXIST.
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*/
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int add_cache_extent(struct cache_tree *tree, u64 start, u64 size);
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/*
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* Same with add_cache_extent, but with cache_extent strcut.
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*/
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int insert_cache_extent(struct cache_tree *tree, struct cache_extent *pe);
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void remove_cache_extent(struct cache_tree *tree, struct cache_extent *pe);
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static inline int cache_tree_empty(struct cache_tree *tree)
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{
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return RB_EMPTY_ROOT(&tree->root);
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}
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typedef void (*free_cache_extent)(struct cache_extent *pe);
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void cache_tree_free_extents(struct cache_tree *tree,
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free_cache_extent free_func);
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#define FREE_EXTENT_CACHE_BASED_TREE(name, free_func) \
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static void free_##name##_tree(struct cache_tree *tree) \
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{ \
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cache_tree_free_extents(tree, free_func); \
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}
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void free_extent_cache_tree(struct cache_tree *tree);
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/*
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* Search a cache_extent with same objectid, and covers start.
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*
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* If not found, return next if possible.
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*/
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struct cache_extent *search_cache_extent2(struct cache_tree *tree,
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u64 objectid, u64 start);
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/*
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* Search a cache_extent with same objectid, and covers the range
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* [start, start + size)
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*
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* If not found, return next cache_extent if possible.
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*/
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struct cache_extent *lookup_cache_extent2(struct cache_tree *tree,
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u64 objectid, u64 start, u64 size);
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int insert_cache_extent2(struct cache_tree *tree, struct cache_extent *pe);
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/*
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* Insert a cache_extent range [start, start + size).
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*
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* This function may merge with existing cache_extent.
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* NOTE: caller must ensure the inserted range won't cover with any existing
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* range.
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*/
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int add_merge_cache_extent(struct cache_tree *tree, u64 start, u64 size);
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#endif
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