btrfs-progs/extent-cache.h

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/*
* Copyright (C) 2007 Oracle. 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_EXTENT_CACHE_H__
#define __BTRFS_EXTENT_CACHE_H__
#if BTRFS_FLAT_INCLUDES
#include "kerncompat.h"
#include "rbtree.h"
#else
#include <btrfs/kerncompat.h>
#include <btrfs/rbtree.h>
#endif /* BTRFS_FLAT_INCLUDES */
struct cache_tree {
struct rb_root root;
};
struct cache_extent {
struct rb_node rb_node;
u64 objectid;
u64 start;
u64 size;
};
void cache_tree_init(struct cache_tree *tree);
struct cache_extent *first_cache_extent(struct cache_tree *tree);
struct cache_extent *last_cache_extent(struct cache_tree *tree);
struct cache_extent *prev_cache_extent(struct cache_extent *pe);
struct cache_extent *next_cache_extent(struct cache_extent *pe);
/*
* Find a cache_extent which covers start.
*
* If not found, return next cache_extent if possible.
*/
struct cache_extent *search_cache_extent(struct cache_tree *tree, u64 start);
/*
* Find a cahce_extent which restrictly covers start.
*
* If not found, return NULL.
*/
struct cache_extent *lookup_cache_extent(struct cache_tree *tree,
u64 start, u64 size);
/*
* Add an non-overlap extent into cache tree
*
* If [start, start+size) overlap with existing one, it will return -EEXIST.
*/
int add_cache_extent(struct cache_tree *tree, u64 start, u64 size);
/*
* Same with add_cache_extent, but with cache_extent strcut.
*/
int insert_cache_extent(struct cache_tree *tree, struct cache_extent *pe);
void remove_cache_extent(struct cache_tree *tree, struct cache_extent *pe);
static inline int cache_tree_empty(struct cache_tree *tree)
{
return RB_EMPTY_ROOT(&tree->root);
}
typedef void (*free_cache_extent)(struct cache_extent *pe);
void cache_tree_free_extents(struct cache_tree *tree,
free_cache_extent free_func);
#define FREE_EXTENT_CACHE_BASED_TREE(name, free_func) \
static void free_##name##_tree(struct cache_tree *tree) \
{ \
cache_tree_free_extents(tree, free_func); \
}
void free_extent_cache_tree(struct cache_tree *tree);
/*
* Search a cache_extent with same objectid, and covers start.
*
* If not found, return next if possible.
*/
struct cache_extent *search_cache_extent2(struct cache_tree *tree,
u64 objectid, u64 start);
/*
* Search a cache_extent with same objectid, and covers the range
* [start, start + size)
*
* If not found, return next cache_extent if possible.
*/
struct cache_extent *lookup_cache_extent2(struct cache_tree *tree,
u64 objectid, u64 start, u64 size);
int add_cache_extent2(struct cache_tree *tree,
u64 objectid, u64 start, u64 size);
int insert_cache_extent2(struct cache_tree *tree, struct cache_extent *pe);
/*
* Insert a cache_extent range [start, start + size).
*
* This function may merge with existing cache_extent.
* NOTE: caller must ensure the inserted range won't cover with any existing
* range.
*/
int add_merge_cache_extent(struct cache_tree *tree, u64 start, u64 size);
#endif