xref: /openbmc/linux/fs/btrfs/extent_map.h (revision 4f3db074)
1 #ifndef __EXTENTMAP__
2 #define __EXTENTMAP__
3 
4 #include <linux/rbtree.h>
5 
6 #define EXTENT_MAP_LAST_BYTE ((u64)-4)
7 #define EXTENT_MAP_HOLE ((u64)-3)
8 #define EXTENT_MAP_INLINE ((u64)-2)
9 #define EXTENT_MAP_DELALLOC ((u64)-1)
10 
11 /* bits for the flags field */
12 #define EXTENT_FLAG_PINNED 0 /* this entry not yet on disk, don't free it */
13 #define EXTENT_FLAG_COMPRESSED 1
14 #define EXTENT_FLAG_VACANCY 2 /* no file extent item found */
15 #define EXTENT_FLAG_PREALLOC 3 /* pre-allocated extent */
16 #define EXTENT_FLAG_LOGGING 4 /* Logging this extent */
17 #define EXTENT_FLAG_FILLING 5 /* Filling in a preallocated extent */
18 #define EXTENT_FLAG_FS_MAPPING 6 /* filesystem extent mapping type */
19 
20 struct extent_map {
21 	struct rb_node rb_node;
22 
23 	/* all of these are in bytes */
24 	u64 start;
25 	u64 len;
26 	u64 mod_start;
27 	u64 mod_len;
28 	u64 orig_start;
29 	u64 orig_block_len;
30 	u64 ram_bytes;
31 	u64 block_start;
32 	u64 block_len;
33 	u64 generation;
34 	unsigned long flags;
35 	struct block_device *bdev;
36 	atomic_t refs;
37 	unsigned int compress_type;
38 	struct list_head list;
39 };
40 
41 struct extent_map_tree {
42 	struct rb_root map;
43 	struct list_head modified_extents;
44 	rwlock_t lock;
45 };
46 
47 static inline int extent_map_in_tree(const struct extent_map *em)
48 {
49 	return !RB_EMPTY_NODE(&em->rb_node);
50 }
51 
52 static inline u64 extent_map_end(struct extent_map *em)
53 {
54 	if (em->start + em->len < em->start)
55 		return (u64)-1;
56 	return em->start + em->len;
57 }
58 
59 static inline u64 extent_map_block_end(struct extent_map *em)
60 {
61 	if (em->block_start + em->block_len < em->block_start)
62 		return (u64)-1;
63 	return em->block_start + em->block_len;
64 }
65 
66 void extent_map_tree_init(struct extent_map_tree *tree);
67 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
68 					 u64 start, u64 len);
69 int add_extent_mapping(struct extent_map_tree *tree,
70 		       struct extent_map *em, int modified);
71 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
72 void replace_extent_mapping(struct extent_map_tree *tree,
73 			    struct extent_map *cur,
74 			    struct extent_map *new,
75 			    int modified);
76 
77 struct extent_map *alloc_extent_map(void);
78 void free_extent_map(struct extent_map *em);
79 int __init extent_map_init(void);
80 void extent_map_exit(void);
81 int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
82 void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
83 struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
84 					 u64 start, u64 len);
85 #endif
86