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
20struct 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
41struct extent_map_tree {
42	struct rb_root map;
43	struct list_head modified_extents;
44	rwlock_t lock;
45};
46
47static inline int extent_map_in_tree(const struct extent_map *em)
48{
49	return !RB_EMPTY_NODE(&em->rb_node);
50}
51
52static 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
59static 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
66void extent_map_tree_init(struct extent_map_tree *tree);
67struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
68					 u64 start, u64 len);
69int add_extent_mapping(struct extent_map_tree *tree,
70		       struct extent_map *em, int modified);
71int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
72void replace_extent_mapping(struct extent_map_tree *tree,
73			    struct extent_map *cur,
74			    struct extent_map *new,
75			    int modified);
76
77struct extent_map *alloc_extent_map(void);
78void free_extent_map(struct extent_map *em);
79int __init extent_map_init(void);
80void extent_map_exit(void);
81int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
82void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
83struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
84					 u64 start, u64 len);
85#endif
86