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 #define EXTENT_MAP_DELALLOC ((u64)-1)
13
14 /* bits for the flags field */
15 #define EXTENT_FLAG_PINNED 0 /* this entry not yet on disk, don't free it */
16 #define EXTENT_FLAG_COMPRESSED 1
17 #define EXTENT_FLAG_PREALLOC 3 /* pre-allocated extent */
18 #define EXTENT_FLAG_LOGGING 4 /* Logging this extent */
19 #define EXTENT_FLAG_FILLING 5 /* Filling in a preallocated extent */
20 #define EXTENT_FLAG_FS_MAPPING 6 /* filesystem extent mapping type */
21
22 struct extent_map {
23 struct rb_node rb_node;
24
25 /* all of these are in bytes */
26 u64 start;
27 u64 len;
28 u64 mod_start;
29 u64 mod_len;
30 u64 orig_start;
31 u64 orig_block_len;
32 u64 ram_bytes;
33 u64 block_start;
34 u64 block_len;
35 u64 generation;
36 unsigned long flags;
37 union {
38 struct block_device *bdev;
39
40 /*
41 * used for chunk mappings
42 * flags & EXTENT_FLAG_FS_MAPPING must be set
43 */
44 struct map_lookup *map_lookup;
45 };
46 refcount_t refs;
47 unsigned int compress_type;
48 struct list_head list;
49 };
50
51 struct extent_map_tree {
52 struct rb_root map;
53 struct list_head modified_extents;
54 rwlock_t lock;
55 };
56
extent_map_in_tree(const struct extent_map * em)57 static inline int extent_map_in_tree(const struct extent_map *em)
58 {
59 return !RB_EMPTY_NODE(&em->rb_node);
60 }
61
extent_map_end(struct extent_map * em)62 static inline u64 extent_map_end(struct extent_map *em)
63 {
64 if (em->start + em->len < em->start)
65 return (u64)-1;
66 return em->start + em->len;
67 }
68
extent_map_block_end(struct extent_map * em)69 static inline u64 extent_map_block_end(struct extent_map *em)
70 {
71 if (em->block_start + em->block_len < em->block_start)
72 return (u64)-1;
73 return em->block_start + em->block_len;
74 }
75
76 void extent_map_tree_init(struct extent_map_tree *tree);
77 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
78 u64 start, u64 len);
79 int add_extent_mapping(struct extent_map_tree *tree,
80 struct extent_map *em, int modified);
81 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
82 void replace_extent_mapping(struct extent_map_tree *tree,
83 struct extent_map *cur,
84 struct extent_map *new,
85 int modified);
86
87 struct extent_map *alloc_extent_map(void);
88 void free_extent_map(struct extent_map *em);
89 int __init extent_map_init(void);
90 void __cold extent_map_exit(void);
91 int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
92 void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
93 struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
94 u64 start, u64 len);
95 int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info,
96 struct extent_map_tree *em_tree,
97 struct extent_map **em_in, u64 start, u64 len);
98
99 #endif
100