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 };
29
30 struct extent_map {
31 struct rb_node rb_node;
32
33 /* all of these are in bytes */
34 u64 start;
35 u64 len;
36 u64 mod_start;
37 u64 mod_len;
38 u64 orig_start;
39 u64 orig_block_len;
40 u64 ram_bytes;
41 u64 block_start;
42 u64 block_len;
43 u64 generation;
44 unsigned long flags;
45 /* Used for chunk mappings, flag EXTENT_FLAG_FS_MAPPING must be set */
46 struct map_lookup *map_lookup;
47 refcount_t refs;
48 unsigned int compress_type;
49 struct list_head list;
50 };
51
52 struct extent_map_tree {
53 struct rb_root_cached map;
54 struct list_head modified_extents;
55 rwlock_t lock;
56 };
57
extent_map_in_tree(const struct extent_map * em)58 static inline int extent_map_in_tree(const struct extent_map *em)
59 {
60 return !RB_EMPTY_NODE(&em->rb_node);
61 }
62
extent_map_end(struct extent_map * em)63 static inline u64 extent_map_end(struct extent_map *em)
64 {
65 if (em->start + em->len < em->start)
66 return (u64)-1;
67 return em->start + em->len;
68 }
69
extent_map_block_end(struct extent_map * em)70 static inline u64 extent_map_block_end(struct extent_map *em)
71 {
72 if (em->block_start + em->block_len < em->block_start)
73 return (u64)-1;
74 return em->block_start + em->block_len;
75 }
76
77 void extent_map_tree_init(struct extent_map_tree *tree);
78 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
79 u64 start, u64 len);
80 int add_extent_mapping(struct extent_map_tree *tree,
81 struct extent_map *em, int modified);
82 void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
83 void replace_extent_mapping(struct extent_map_tree *tree,
84 struct extent_map *cur,
85 struct extent_map *new,
86 int modified);
87
88 struct extent_map *alloc_extent_map(void);
89 void free_extent_map(struct extent_map *em);
90 int __init extent_map_init(void);
91 void __cold extent_map_exit(void);
92 int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
93 void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
94 struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
95 u64 start, u64 len);
96 int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info,
97 struct extent_map_tree *em_tree,
98 struct extent_map **em_in, u64 start, u64 len);
99
100 #endif
101