tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 extent_map::flags field */
15enum {
16 /* this entry not yet on disk, don't free it */
17 EXTENT_FLAG_PINNED,
18 EXTENT_FLAG_COMPRESSED,
19 /* pre-allocated extent */
20 EXTENT_FLAG_PREALLOC,
21 /* Logging this extent */
22 EXTENT_FLAG_LOGGING,
23 /* Filling in a preallocated extent */
24 EXTENT_FLAG_FILLING,
25 /* filesystem extent mapping type */
26 EXTENT_FLAG_FS_MAPPING,
27};
28
29struct extent_map {
30 struct rb_node rb_node;
31
32 /* all of these are in bytes */
33 u64 start;
34 u64 len;
35 u64 mod_start;
36 u64 mod_len;
37 u64 orig_start;
38 u64 orig_block_len;
39 u64 ram_bytes;
40 u64 block_start;
41 u64 block_len;
42 u64 generation;
43 unsigned long flags;
44 union {
45 struct block_device *bdev;
46
47 /*
48 * used for chunk mappings
49 * flags & EXTENT_FLAG_FS_MAPPING must be set
50 */
51 struct map_lookup *map_lookup;
52 };
53 refcount_t refs;
54 unsigned int compress_type;
55 struct list_head list;
56};
57
58struct extent_map_tree {
59 struct rb_root_cached map;
60 struct list_head modified_extents;
61 rwlock_t lock;
62};
63
64static inline int extent_map_in_tree(const struct extent_map *em)
65{
66 return !RB_EMPTY_NODE(&em->rb_node);
67}
68
69static inline u64 extent_map_end(struct extent_map *em)
70{
71 if (em->start + em->len < em->start)
72 return (u64)-1;
73 return em->start + em->len;
74}
75
76static inline u64 extent_map_block_end(struct extent_map *em)
77{
78 if (em->block_start + em->block_len < em->block_start)
79 return (u64)-1;
80 return em->block_start + em->block_len;
81}
82
83void extent_map_tree_init(struct extent_map_tree *tree);
84struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
85 u64 start, u64 len);
86int add_extent_mapping(struct extent_map_tree *tree,
87 struct extent_map *em, int modified);
88void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
89void replace_extent_mapping(struct extent_map_tree *tree,
90 struct extent_map *cur,
91 struct extent_map *new,
92 int modified);
93
94struct extent_map *alloc_extent_map(void);
95void free_extent_map(struct extent_map *em);
96int __init extent_map_init(void);
97void __cold extent_map_exit(void);
98int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
99void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
100struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
101 u64 start, u64 len);
102int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info,
103 struct extent_map_tree *em_tree,
104 struct extent_map **em_in, u64 start, u64 len);
105
106#endif