xref: /kernel/linux/linux-5.10/fs/btrfs/extent_map.h (revision 8c2ecf20)
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/* used only during fiemap calls */
13#define EXTENT_MAP_DELALLOC ((u64)-1)
14
15/* bits for the extent_map::flags field */
16enum {
17	/* this entry not yet on disk, don't free it */
18	EXTENT_FLAG_PINNED,
19	EXTENT_FLAG_COMPRESSED,
20	/* pre-allocated extent */
21	EXTENT_FLAG_PREALLOC,
22	/* Logging this extent */
23	EXTENT_FLAG_LOGGING,
24	/* Filling in a preallocated extent */
25	EXTENT_FLAG_FILLING,
26	/* filesystem extent mapping type */
27	EXTENT_FLAG_FS_MAPPING,
28};
29
30struct extent_map {
31	struct rb_node rb_node;
32
33	/* all of these are in bytes */
34	u64 start;
35	u64 len;
36	u64 mod_start;
37	u64 mod_len;
38	u64 orig_start;
39	u64 orig_block_len;
40	u64 ram_bytes;
41	u64 block_start;
42	u64 block_len;
43	u64 generation;
44	unsigned long flags;
45	/* Used for chunk mappings, flag EXTENT_FLAG_FS_MAPPING must be set */
46	struct map_lookup *map_lookup;
47	refcount_t refs;
48	unsigned int compress_type;
49	struct list_head list;
50};
51
52struct extent_map_tree {
53	struct rb_root_cached map;
54	struct list_head modified_extents;
55	rwlock_t lock;
56};
57
58static inline int extent_map_in_tree(const struct extent_map *em)
59{
60	return !RB_EMPTY_NODE(&em->rb_node);
61}
62
63static inline u64 extent_map_end(struct extent_map *em)
64{
65	if (em->start + em->len < em->start)
66		return (u64)-1;
67	return em->start + em->len;
68}
69
70static inline u64 extent_map_block_end(struct extent_map *em)
71{
72	if (em->block_start + em->block_len < em->block_start)
73		return (u64)-1;
74	return em->block_start + em->block_len;
75}
76
77void extent_map_tree_init(struct extent_map_tree *tree);
78struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
79					 u64 start, u64 len);
80int add_extent_mapping(struct extent_map_tree *tree,
81		       struct extent_map *em, int modified);
82void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
83void replace_extent_mapping(struct extent_map_tree *tree,
84			    struct extent_map *cur,
85			    struct extent_map *new,
86			    int modified);
87
88struct extent_map *alloc_extent_map(void);
89void free_extent_map(struct extent_map *em);
90int __init extent_map_init(void);
91void __cold extent_map_exit(void);
92int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
93void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
94struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
95					 u64 start, u64 len);
96int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info,
97			     struct extent_map_tree *em_tree,
98			     struct extent_map **em_in, u64 start, u64 len);
99
100#endif
101