u-boot/fs/btrfs/extent-cache.h
Qu Wenruo ab5c3046f2 fs: btrfs: Crossport extent-cache.[ch] from btrfs-progs
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>
2020-09-07 20:57:27 -04:00

104 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Crossported from the same named file of btrfs-progs.
*
* Minor modification to include headers.
*/
#ifndef __BTRFS_EXTENT_CACHE_H__
#define __BTRFS_EXTENT_CACHE_H__
#include <linux/rbtree.h>
#include <linux/types.h>
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 cache_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 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