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