1/* SPDX-License-Identifier: GPL-2.0 */
2
3#ifndef BTRFS_EXTENT_MAP_H
4#define BTRFS_EXTENT_MAP_H
5
6#include <linux/compiler_types.h>
7#include <linux/rwlock_types.h>
8#include <linux/rbtree.h>
9#include <linux/list.h>
10#include <linux/refcount.h>
11#include "misc.h"
12#include "extent_map.h"
13#include "compression.h"
14
15struct btrfs_inode;
16struct btrfs_fs_info;
17
18#define EXTENT_MAP_LAST_BYTE ((u64)-4)
19#define EXTENT_MAP_HOLE ((u64)-3)
20#define EXTENT_MAP_INLINE ((u64)-2)
21
22/* bits for the extent_map::flags field */
23enum {
24	/* this entry not yet on disk, don't free it */
25	ENUM_BIT(EXTENT_FLAG_PINNED),
26	ENUM_BIT(EXTENT_FLAG_COMPRESS_ZLIB),
27	ENUM_BIT(EXTENT_FLAG_COMPRESS_LZO),
28	ENUM_BIT(EXTENT_FLAG_COMPRESS_ZSTD),
29	/* pre-allocated extent */
30	ENUM_BIT(EXTENT_FLAG_PREALLOC),
31	/* Logging this extent */
32	ENUM_BIT(EXTENT_FLAG_LOGGING),
33	/* Filling in a preallocated extent */
34	ENUM_BIT(EXTENT_FLAG_FILLING),
35	/* This em is merged from two or more physically adjacent ems */
36	ENUM_BIT(EXTENT_FLAG_MERGED),
37};
38
39/*
40 * Keep this structure as compact as possible, as we can have really large
41 * amounts of allocated extent maps at any time.
42 */
43struct extent_map {
44	struct rb_node rb_node;
45
46	/* all of these are in bytes */
47	u64 start;
48	u64 len;
49	u64 mod_start;
50	u64 mod_len;
51	u64 orig_start;
52	u64 orig_block_len;
53	u64 ram_bytes;
54	u64 block_start;
55	u64 block_len;
56
57	/*
58	 * Generation of the extent map, for merged em it's the highest
59	 * generation of all merged ems.
60	 * For non-merged extents, it's from btrfs_file_extent_item::generation.
61	 */
62	u64 generation;
63	u32 flags;
64	refcount_t refs;
65	struct list_head list;
66};
67
68struct extent_map_tree {
69	struct rb_root_cached map;
70	struct list_head modified_extents;
71	rwlock_t lock;
72};
73
74struct btrfs_inode;
75
76static inline void extent_map_set_compression(struct extent_map *em,
77					      enum btrfs_compression_type type)
78{
79	if (type == BTRFS_COMPRESS_ZLIB)
80		em->flags |= EXTENT_FLAG_COMPRESS_ZLIB;
81	else if (type == BTRFS_COMPRESS_LZO)
82		em->flags |= EXTENT_FLAG_COMPRESS_LZO;
83	else if (type == BTRFS_COMPRESS_ZSTD)
84		em->flags |= EXTENT_FLAG_COMPRESS_ZSTD;
85}
86
87static inline enum btrfs_compression_type extent_map_compression(const struct extent_map *em)
88{
89	if (em->flags & EXTENT_FLAG_COMPRESS_ZLIB)
90		return BTRFS_COMPRESS_ZLIB;
91
92	if (em->flags & EXTENT_FLAG_COMPRESS_LZO)
93		return BTRFS_COMPRESS_LZO;
94
95	if (em->flags & EXTENT_FLAG_COMPRESS_ZSTD)
96		return BTRFS_COMPRESS_ZSTD;
97
98	return BTRFS_COMPRESS_NONE;
99}
100
101/*
102 * More efficient way to determine if extent is compressed, instead of using
103 * 'extent_map_compression() != BTRFS_COMPRESS_NONE'.
104 */
105static inline bool extent_map_is_compressed(const struct extent_map *em)
106{
107	return (em->flags & (EXTENT_FLAG_COMPRESS_ZLIB |
108			     EXTENT_FLAG_COMPRESS_LZO |
109			     EXTENT_FLAG_COMPRESS_ZSTD)) != 0;
110}
111
112static inline int extent_map_in_tree(const struct extent_map *em)
113{
114	return !RB_EMPTY_NODE(&em->rb_node);
115}
116
117static inline u64 extent_map_end(const struct extent_map *em)
118{
119	if (em->start + em->len < em->start)
120		return (u64)-1;
121	return em->start + em->len;
122}
123
124void extent_map_tree_init(struct extent_map_tree *tree);
125struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
126					 u64 start, u64 len);
127void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
128int split_extent_map(struct btrfs_inode *inode, u64 start, u64 len, u64 pre,
129		     u64 new_logical);
130
131struct extent_map *alloc_extent_map(void);
132void free_extent_map(struct extent_map *em);
133int __init extent_map_init(void);
134void __cold extent_map_exit(void);
135int unpin_extent_cache(struct btrfs_inode *inode, u64 start, u64 len, u64 gen);
136void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
137struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
138					 u64 start, u64 len);
139int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info,
140			     struct extent_map_tree *em_tree,
141			     struct extent_map **em_in, u64 start, u64 len);
142void btrfs_drop_extent_map_range(struct btrfs_inode *inode,
143				 u64 start, u64 end,
144				 bool skip_pinned);
145int btrfs_replace_extent_map_range(struct btrfs_inode *inode,
146				   struct extent_map *new_em,
147				   bool modified);
148
149#endif
150