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1#ifndef __EXTENTMAP__
2#define __EXTENTMAP__
3
4#include <linux/rbtree.h>
5
6#define EXTENT_MAP_LAST_BYTE ((u64)-4)
7#define EXTENT_MAP_HOLE ((u64)-3)
8#define EXTENT_MAP_INLINE ((u64)-2)
9#define EXTENT_MAP_DELALLOC ((u64)-1)
10
11/* bits for the flags field */
12#define EXTENT_FLAG_PINNED 0 /* this entry not yet on disk, don't free it */
13#define EXTENT_FLAG_COMPRESSED 1
14#define EXTENT_FLAG_VACANCY 2 /* no file extent item found */
15#define EXTENT_FLAG_PREALLOC 3 /* pre-allocated extent */
16#define EXTENT_FLAG_LOGGING 4 /* Logging this extent */
17#define EXTENT_FLAG_FILLING 5 /* Filling in a preallocated extent */
18#define EXTENT_FLAG_FS_MAPPING 6 /* filesystem extent mapping type */
19
20struct extent_map {
21 struct rb_node rb_node;
22
23 /* all of these are in bytes */
24 u64 start;
25 u64 len;
26 u64 mod_start;
27 u64 mod_len;
28 u64 orig_start;
29 u64 orig_block_len;
30 u64 ram_bytes;
31 u64 block_start;
32 u64 block_len;
33 u64 generation;
34 unsigned long flags;
35 union {
36 struct block_device *bdev;
37
38 /*
39 * used for chunk mappings
40 * flags & EXTENT_FLAG_FS_MAPPING must be set
41 */
42 struct map_lookup *map_lookup;
43 };
44 atomic_t refs;
45 unsigned int compress_type;
46 struct list_head list;
47};
48
49struct extent_map_tree {
50 struct rb_root map;
51 struct list_head modified_extents;
52 rwlock_t lock;
53};
54
55static inline int extent_map_in_tree(const struct extent_map *em)
56{
57 return !RB_EMPTY_NODE(&em->rb_node);
58}
59
60static inline u64 extent_map_end(struct extent_map *em)
61{
62 if (em->start + em->len < em->start)
63 return (u64)-1;
64 return em->start + em->len;
65}
66
67static inline u64 extent_map_block_end(struct extent_map *em)
68{
69 if (em->block_start + em->block_len < em->block_start)
70 return (u64)-1;
71 return em->block_start + em->block_len;
72}
73
74void extent_map_tree_init(struct extent_map_tree *tree);
75struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
76 u64 start, u64 len);
77int add_extent_mapping(struct extent_map_tree *tree,
78 struct extent_map *em, int modified);
79int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
80void replace_extent_mapping(struct extent_map_tree *tree,
81 struct extent_map *cur,
82 struct extent_map *new,
83 int modified);
84
85struct extent_map *alloc_extent_map(void);
86void free_extent_map(struct extent_map *em);
87int __init extent_map_init(void);
88void extent_map_exit(void);
89int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
90void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
91struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
92 u64 start, u64 len);
93#endif
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