xref: /openbmc/linux/fs/btrfs/extent_map.h (revision 4da722ca)
1 #ifndef __EXTENTMAP__
2 #define __EXTENTMAP__
3 
4 #include <linux/rbtree.h>
5 #include <linux/refcount.h>
6 
7 #define EXTENT_MAP_LAST_BYTE ((u64)-4)
8 #define EXTENT_MAP_HOLE ((u64)-3)
9 #define EXTENT_MAP_INLINE ((u64)-2)
10 #define EXTENT_MAP_DELALLOC ((u64)-1)
11 
12 /* bits for the flags field */
13 #define EXTENT_FLAG_PINNED 0 /* this entry not yet on disk, don't free it */
14 #define EXTENT_FLAG_COMPRESSED 1
15 #define EXTENT_FLAG_VACANCY 2 /* no file extent item found */
16 #define EXTENT_FLAG_PREALLOC 3 /* pre-allocated extent */
17 #define EXTENT_FLAG_LOGGING 4 /* Logging this extent */
18 #define EXTENT_FLAG_FILLING 5 /* Filling in a preallocated extent */
19 #define EXTENT_FLAG_FS_MAPPING 6 /* filesystem extent mapping type */
20 
21 struct extent_map {
22 	struct rb_node rb_node;
23 
24 	/* all of these are in bytes */
25 	u64 start;
26 	u64 len;
27 	u64 mod_start;
28 	u64 mod_len;
29 	u64 orig_start;
30 	u64 orig_block_len;
31 	u64 ram_bytes;
32 	u64 block_start;
33 	u64 block_len;
34 	u64 generation;
35 	unsigned long flags;
36 	union {
37 		struct block_device *bdev;
38 
39 		/*
40 		 * used for chunk mappings
41 		 * flags & EXTENT_FLAG_FS_MAPPING must be set
42 		 */
43 		struct map_lookup *map_lookup;
44 	};
45 	refcount_t refs;
46 	unsigned int compress_type;
47 	struct list_head list;
48 };
49 
50 struct extent_map_tree {
51 	struct rb_root map;
52 	struct list_head modified_extents;
53 	rwlock_t lock;
54 };
55 
56 static inline int extent_map_in_tree(const struct extent_map *em)
57 {
58 	return !RB_EMPTY_NODE(&em->rb_node);
59 }
60 
61 static inline u64 extent_map_end(struct extent_map *em)
62 {
63 	if (em->start + em->len < em->start)
64 		return (u64)-1;
65 	return em->start + em->len;
66 }
67 
68 static inline u64 extent_map_block_end(struct extent_map *em)
69 {
70 	if (em->block_start + em->block_len < em->block_start)
71 		return (u64)-1;
72 	return em->block_start + em->block_len;
73 }
74 
75 void extent_map_tree_init(struct extent_map_tree *tree);
76 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
77 					 u64 start, u64 len);
78 int add_extent_mapping(struct extent_map_tree *tree,
79 		       struct extent_map *em, int modified);
80 int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
81 void replace_extent_mapping(struct extent_map_tree *tree,
82 			    struct extent_map *cur,
83 			    struct extent_map *new,
84 			    int modified);
85 
86 struct extent_map *alloc_extent_map(void);
87 void free_extent_map(struct extent_map *em);
88 int __init extent_map_init(void);
89 void extent_map_exit(void);
90 int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
91 void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
92 struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
93 					 u64 start, u64 len);
94 #endif
95