xref: /kernel/linux/linux-6.6/fs/btrfs/extent_map.h (revision 62306a36)
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	/* This em is merged from two or more physically adjacent ems */
29	EXTENT_FLAG_MERGED,
30};
31
32struct extent_map {
33	struct rb_node rb_node;
34
35	/* all of these are in bytes */
36	u64 start;
37	u64 len;
38	u64 mod_start;
39	u64 mod_len;
40	u64 orig_start;
41	u64 orig_block_len;
42	u64 ram_bytes;
43	u64 block_start;
44	u64 block_len;
45
46	/*
47	 * Generation of the extent map, for merged em it's the highest
48	 * generation of all merged ems.
49	 * For non-merged extents, it's from btrfs_file_extent_item::generation.
50	 */
51	u64 generation;
52	unsigned long flags;
53	/* Used for chunk mappings, flag EXTENT_FLAG_FS_MAPPING must be set */
54	struct map_lookup *map_lookup;
55	refcount_t refs;
56	unsigned int compress_type;
57	struct list_head list;
58};
59
60struct extent_map_tree {
61	struct rb_root_cached map;
62	struct list_head modified_extents;
63	rwlock_t lock;
64};
65
66struct btrfs_inode;
67
68static inline int extent_map_in_tree(const struct extent_map *em)
69{
70	return !RB_EMPTY_NODE(&em->rb_node);
71}
72
73static inline u64 extent_map_end(struct extent_map *em)
74{
75	if (em->start + em->len < em->start)
76		return (u64)-1;
77	return em->start + em->len;
78}
79
80static inline u64 extent_map_block_end(struct extent_map *em)
81{
82	if (em->block_start + em->block_len < em->block_start)
83		return (u64)-1;
84	return em->block_start + em->block_len;
85}
86
87void extent_map_tree_init(struct extent_map_tree *tree);
88struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
89					 u64 start, u64 len);
90int add_extent_mapping(struct extent_map_tree *tree,
91		       struct extent_map *em, int modified);
92void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
93int split_extent_map(struct btrfs_inode *inode, u64 start, u64 len, u64 pre,
94		     u64 new_logical);
95
96struct extent_map *alloc_extent_map(void);
97void free_extent_map(struct extent_map *em);
98int __init extent_map_init(void);
99void __cold extent_map_exit(void);
100int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen);
101void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
102struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
103					 u64 start, u64 len);
104int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info,
105			     struct extent_map_tree *em_tree,
106			     struct extent_map **em_in, u64 start, u64 len);
107void btrfs_drop_extent_map_range(struct btrfs_inode *inode,
108				 u64 start, u64 end,
109				 bool skip_pinned);
110int btrfs_replace_extent_map_range(struct btrfs_inode *inode,
111				   struct extent_map *new_em,
112				   bool modified);
113
114#endif
115