1 /* SPDX-License-Identifier: GPL-2.0 */
3 #ifndef BTRFS_EXTENT_MAP_H
4 #define BTRFS_EXTENT_MAP_H
6 #include <linux/compiler_types.h>
7 #include <linux/rwlock_types.h>
8 #include <linux/rbtree.h>
9 #include <linux/list.h>
10 #include <linux/refcount.h>
12 #include "extent_map.h"
13 #include "compression.h"
18 #define EXTENT_MAP_LAST_BYTE ((u64)-4)
19 #define EXTENT_MAP_HOLE ((u64)-3)
20 #define EXTENT_MAP_INLINE ((u64)-2)
22 /* bits for the extent_map::flags field */
24 /* this entry not yet on disk, don't free it */
25 ENUM_BIT(EXTENT_FLAG_PINNED),
26 ENUM_BIT(EXTENT_FLAG_COMPRESS_ZLIB),
27 ENUM_BIT(EXTENT_FLAG_COMPRESS_LZO),
28 ENUM_BIT(EXTENT_FLAG_COMPRESS_ZSTD),
29 /* pre-allocated extent */
30 ENUM_BIT(EXTENT_FLAG_PREALLOC),
31 /* Logging this extent */
32 ENUM_BIT(EXTENT_FLAG_LOGGING),
33 /* Filling in a preallocated extent */
34 ENUM_BIT(EXTENT_FLAG_FILLING),
35 /* This em is merged from two or more physically adjacent ems */
36 ENUM_BIT(EXTENT_FLAG_MERGED),
40 * Keep this structure as compact as possible, as we can have really large
41 * amounts of allocated extent maps at any time.
44 struct rb_node rb_node;
46 /* all of these are in bytes */
58 * Generation of the extent map, for merged em it's the highest
59 * generation of all merged ems.
60 * For non-merged extents, it's from btrfs_file_extent_item::generation.
65 struct list_head list;
68 struct extent_map_tree {
69 struct rb_root_cached map;
70 struct list_head modified_extents;
76 static inline void extent_map_set_compression(struct extent_map *em,
77 enum btrfs_compression_type type)
79 if (type == BTRFS_COMPRESS_ZLIB)
80 em->flags |= EXTENT_FLAG_COMPRESS_ZLIB;
81 else if (type == BTRFS_COMPRESS_LZO)
82 em->flags |= EXTENT_FLAG_COMPRESS_LZO;
83 else if (type == BTRFS_COMPRESS_ZSTD)
84 em->flags |= EXTENT_FLAG_COMPRESS_ZSTD;
87 static inline enum btrfs_compression_type extent_map_compression(const struct extent_map *em)
89 if (em->flags & EXTENT_FLAG_COMPRESS_ZLIB)
90 return BTRFS_COMPRESS_ZLIB;
92 if (em->flags & EXTENT_FLAG_COMPRESS_LZO)
93 return BTRFS_COMPRESS_LZO;
95 if (em->flags & EXTENT_FLAG_COMPRESS_ZSTD)
96 return BTRFS_COMPRESS_ZSTD;
98 return BTRFS_COMPRESS_NONE;
102 * More efficient way to determine if extent is compressed, instead of using
103 * 'extent_map_compression() != BTRFS_COMPRESS_NONE'.
105 static inline bool extent_map_is_compressed(const struct extent_map *em)
107 return (em->flags & (EXTENT_FLAG_COMPRESS_ZLIB |
108 EXTENT_FLAG_COMPRESS_LZO |
109 EXTENT_FLAG_COMPRESS_ZSTD)) != 0;
112 static inline int extent_map_in_tree(const struct extent_map *em)
114 return !RB_EMPTY_NODE(&em->rb_node);
117 static inline u64 extent_map_end(const struct extent_map *em)
119 if (em->start + em->len < em->start)
121 return em->start + em->len;
124 void extent_map_tree_init(struct extent_map_tree *tree);
125 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
127 void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
128 int split_extent_map(struct btrfs_inode *inode, u64 start, u64 len, u64 pre,
131 struct extent_map *alloc_extent_map(void);
132 void free_extent_map(struct extent_map *em);
133 int __init extent_map_init(void);
134 void __cold extent_map_exit(void);
135 int unpin_extent_cache(struct btrfs_inode *inode, u64 start, u64 len, u64 gen);
136 void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
137 struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
139 int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info,
140 struct extent_map_tree *em_tree,
141 struct extent_map **em_in, u64 start, u64 len);
142 void btrfs_drop_extent_map_range(struct btrfs_inode *inode,
145 int btrfs_replace_extent_map_range(struct btrfs_inode *inode,
146 struct extent_map *new_em,