linux/fs/btrfs/extent_map.h

/* SPDX-License-Identifier: GPL-2.0 */

#ifndef BTRFS_EXTENT_MAP_H
#define BTRFS_EXTENT_MAP_H

#include <linux/compiler_types.h>
#include <linux/spinlock_types.h>
#include <linux/rbtree.h>
#include <linux/list.h>
#include <linux/refcount.h>
#include "misc.h"
#include "compression.h"

struct btrfs_inode;
struct btrfs_fs_info;

#define EXTENT_MAP_LAST_BYTE …
#define EXTENT_MAP_HOLE …
#define EXTENT_MAP_INLINE …

/* bits for the extent_map::flags field */
enum { … };

/*
 * This structure represents file extents and holes.
 *
 * Unlike on-disk file extent items, extent maps can be merged to save memory.
 * This means members only match file extent items before any merging.
 *
 * Keep this structure as compact as possible, as we can have really large
 * amounts of allocated extent maps at any time.
 */
struct extent_map { … };

struct extent_map_tree { … };

struct btrfs_inode;

static inline void extent_map_set_compression(struct extent_map *em,
					      enum btrfs_compression_type type)
{ … }

static inline enum btrfs_compression_type extent_map_compression(const struct extent_map *em)
{ … }

/*
 * More efficient way to determine if extent is compressed, instead of using
 * 'extent_map_compression() != BTRFS_COMPRESS_NONE'.
 */
static inline bool extent_map_is_compressed(const struct extent_map *em)
{ … }

static inline int extent_map_in_tree(const struct extent_map *em)
{ … }

static inline u64 extent_map_block_start(const struct extent_map *em)
{ … }

static inline u64 extent_map_end(const struct extent_map *em)
{ … }

void extent_map_tree_init(struct extent_map_tree *tree);
struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
					 u64 start, u64 len);
void remove_extent_mapping(struct btrfs_inode *inode, struct extent_map *em);
int split_extent_map(struct btrfs_inode *inode, u64 start, u64 len, u64 pre,
		     u64 new_logical);

struct extent_map *alloc_extent_map(void);
void free_extent_map(struct extent_map *em);
int __init extent_map_init(void);
void __cold extent_map_exit(void);
int unpin_extent_cache(struct btrfs_inode *inode, u64 start, u64 len, u64 gen);
void clear_em_logging(struct btrfs_inode *inode, struct extent_map *em);
struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
					 u64 start, u64 len);
int btrfs_add_extent_mapping(struct btrfs_inode *inode,
			     struct extent_map **em_in, u64 start, u64 len);
void btrfs_drop_extent_map_range(struct btrfs_inode *inode,
				 u64 start, u64 end,
				 bool skip_pinned);
int btrfs_replace_extent_map_range(struct btrfs_inode *inode,
				   struct extent_map *new_em,
				   bool modified);
long btrfs_free_extent_maps(struct btrfs_fs_info *fs_info, long nr_to_scan);

#endif