aboutsummaryrefslogtreecommitdiffstats
path: root/fs/btrfs/extent_map.h
blob: 56314217cfc0639aee6d40906df6523a3ac43563 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
#ifndef __EXTENTMAP__
#define __EXTENTMAP__

#include <linux/rbtree.h>

#define EXTENT_MAP_LAST_BYTE (u64)-4
#define EXTENT_MAP_HOLE (u64)-3
#define EXTENT_MAP_INLINE (u64)-2
#define EXTENT_MAP_DELALLOC (u64)-1

struct extent_map {
	struct rb_node rb_node;

	/* all of these are in bytes */
	u64 start;
	u64 len;
	u64 block_start;
	unsigned long flags;
	struct block_device *bdev;
	atomic_t refs;
	int in_tree;
};

struct extent_map_tree {
	struct rb_root map;
	struct extent_map *last;
	spinlock_t lock;
};

static inline u64 extent_map_end(struct extent_map *em)
{
	if (em->start + em->len < em->start)
		return (u64)-1;
	return em->start + em->len;
}

static inline u64 extent_map_block_end(struct extent_map *em)
{
	if (em->block_start + em->len < em->block_start)
		return (u64)-1;
	return em->block_start + em->len;
}

void extent_map_tree_init(struct extent_map_tree *tree, gfp_t mask);
struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
					 u64 start, u64 len);
int add_extent_mapping(struct extent_map_tree *tree,
		       struct extent_map *em);
int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);

struct extent_map *alloc_extent_map(gfp_t mask);
void free_extent_map(struct extent_map *em);
int __init extent_map_init(void);
void extent_map_exit(void);
#endif