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 */
16 enum {
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
32 struct 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
60 struct extent_map_tree {
61 struct rb_root_cached map;
62 struct list_head modified_extents;
63 rwlock_t lock;
64 };
65
66 struct btrfs_inode;
67
extent_map_in_tree(const struct extent_map * em)68 static inline int extent_map_in_tree(const struct extent_map *em)
69 {
70 return !RB_EMPTY_NODE(&em->rb_node);
71 }
72
extent_map_end(struct extent_map * em)73 static 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
extent_map_block_end(struct extent_map * em)80 static 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
87 void extent_map_tree_init(struct extent_map_tree *tree);
88 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
89 u64 start, u64 len);
90 int add_extent_mapping(struct extent_map_tree *tree,
91 struct extent_map *em, int modified);
92 void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
93 void replace_extent_mapping(struct extent_map_tree *tree,
94 struct extent_map *cur,
95 struct extent_map *new,
96 int modified);
97
98 struct extent_map *alloc_extent_map(void);
99 void free_extent_map(struct extent_map *em);
100 int __init extent_map_init(void);
101 void __cold extent_map_exit(void);
102 int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
103 void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
104 struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
105 u64 start, u64 len);
106 int 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);
109 void btrfs_drop_extent_map_range(struct btrfs_inode *inode,
110 u64 start, u64 end,
111 bool skip_pinned);
112 int btrfs_replace_extent_map_range(struct btrfs_inode *inode,
113 struct extent_map *new_em,
114 bool modified);
115
116 #endif
117
