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