Linux 6.16-rc6
[linux-2.6-block.git] / fs / btrfs / extent_map.h
CommitLineData
b2441318 1/* SPDX-License-Identifier: GPL-2.0 */
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DS
2
3#ifndef BTRFS_EXTENT_MAP_H
4#define BTRFS_EXTENT_MAP_H
a52d9a80 5
602035d7 6#include <linux/compiler_types.h>
c27b1dbb 7#include <linux/spinlock_types.h>
a52d9a80 8#include <linux/rbtree.h>
602035d7 9#include <linux/list.h>
490b54d6 10#include <linux/refcount.h>
22b46bdc 11#include "misc.h"
f86f7a75 12#include "compression.h"
a52d9a80 13
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14struct btrfs_inode;
15struct btrfs_fs_info;
16
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17#define EXTENT_MAP_LAST_BYTE ((u64)-4)
18#define EXTENT_MAP_HOLE ((u64)-3)
19#define EXTENT_MAP_INLINE ((u64)-2)
a52d9a80 20
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21/* bits for the extent_map::flags field */
22enum {
23 /* this entry not yet on disk, don't free it */
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24 ENUM_BIT(EXTENT_FLAG_PINNED),
25 ENUM_BIT(EXTENT_FLAG_COMPRESS_ZLIB),
26 ENUM_BIT(EXTENT_FLAG_COMPRESS_LZO),
27 ENUM_BIT(EXTENT_FLAG_COMPRESS_ZSTD),
50b5b602 28 /* pre-allocated extent */
f86f7a75 29 ENUM_BIT(EXTENT_FLAG_PREALLOC),
50b5b602 30 /* Logging this extent */
f86f7a75 31 ENUM_BIT(EXTENT_FLAG_LOGGING),
199257a7 32 /* This em is merged from two or more physically adjacent ems */
f86f7a75 33 ENUM_BIT(EXTENT_FLAG_MERGED),
50b5b602 34};
7f3c74fb 35
f86f7a75 36/*
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37 * This structure represents file extents and holes.
38 *
39 * Unlike on-disk file extent items, extent maps can be merged to save memory.
40 * This means members only match file extent items before any merging.
41 *
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42 * Keep this structure as compact as possible, as we can have really large
43 * amounts of allocated extent maps at any time.
44 */
a52d9a80 45struct extent_map {
a52d9a80 46 struct rb_node rb_node;
d1310b2e 47
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48 /* All of these are in bytes. */
49
50 /* File offset matching the offset of a BTRFS_EXTENT_ITEM_KEY key. */
d1310b2e 51 u64 start;
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52
53 /*
54 * Length of the file extent.
55 *
56 * For non-inlined file extents it's btrfs_file_extent_item::num_bytes.
57 * For inline extents it's sectorsize, since inline data starts at
58 * offsetof(struct btrfs_file_extent_item, disk_bytenr) thus
59 * btrfs_file_extent_item::num_bytes is not valid.
60 */
d1310b2e 61 u64 len;
319d91ee 62
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63 /*
64 * The bytenr of the full on-disk extent.
65 *
66 * For regular extents it's btrfs_file_extent_item::disk_bytenr.
67 * For holes it's EXTENT_MAP_HOLE and for inline extents it's
68 * EXTENT_MAP_INLINE.
69 */
70 u64 disk_bytenr;
71
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72 /*
73 * The full on-disk extent length, matching
74 * btrfs_file_extent_item::disk_num_bytes.
75 */
e8fe524d 76 u64 disk_num_bytes;
319d91ee 77
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78 /*
79 * Offset inside the decompressed extent.
80 *
81 * For regular extents it's btrfs_file_extent_item::offset.
82 * For holes and inline extents it's 0.
83 */
84 u64 offset;
85
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86 /*
87 * The decompressed size of the whole on-disk extent, matching
88 * btrfs_file_extent_item::ram_bytes.
89 */
cc95bef6 90 u64 ram_bytes;
319d91ee 91
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92 /*
93 * Generation of the extent map, for merged em it's the highest
94 * generation of all merged ems.
95 * For non-merged extents, it's from btrfs_file_extent_item::generation.
96 */
5dc562c5 97 u64 generation;
f86f7a75 98 u32 flags;
490b54d6 99 refcount_t refs;
5dc562c5 100 struct list_head list;
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101};
102
d1310b2e 103struct extent_map_tree {
4e660ca3 104 struct rb_root root;
5dc562c5 105 struct list_head modified_extents;
890871be 106 rwlock_t lock;
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107};
108
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109struct btrfs_inode;
110
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111static inline void btrfs_extent_map_set_compression(struct extent_map *em,
112 enum btrfs_compression_type type)
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113{
114 if (type == BTRFS_COMPRESS_ZLIB)
115 em->flags |= EXTENT_FLAG_COMPRESS_ZLIB;
116 else if (type == BTRFS_COMPRESS_LZO)
117 em->flags |= EXTENT_FLAG_COMPRESS_LZO;
118 else if (type == BTRFS_COMPRESS_ZSTD)
119 em->flags |= EXTENT_FLAG_COMPRESS_ZSTD;
120}
121
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122static inline enum btrfs_compression_type btrfs_extent_map_compression(
123 const struct extent_map *em)
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124{
125 if (em->flags & EXTENT_FLAG_COMPRESS_ZLIB)
126 return BTRFS_COMPRESS_ZLIB;
127
128 if (em->flags & EXTENT_FLAG_COMPRESS_LZO)
129 return BTRFS_COMPRESS_LZO;
130
131 if (em->flags & EXTENT_FLAG_COMPRESS_ZSTD)
132 return BTRFS_COMPRESS_ZSTD;
133
134 return BTRFS_COMPRESS_NONE;
135}
136
137/*
138 * More efficient way to determine if extent is compressed, instead of using
139 * 'extent_map_compression() != BTRFS_COMPRESS_NONE'.
140 */
962162ff 141static inline bool btrfs_extent_map_is_compressed(const struct extent_map *em)
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142{
143 return (em->flags & (EXTENT_FLAG_COMPRESS_ZLIB |
144 EXTENT_FLAG_COMPRESS_LZO |
145 EXTENT_FLAG_COMPRESS_ZSTD)) != 0;
146}
147
2e871330 148static inline int btrfs_extent_map_in_tree(const struct extent_map *em)
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149{
150 return !RB_EMPTY_NODE(&em->rb_node);
151}
152
2e871330 153static inline u64 btrfs_extent_map_block_start(const struct extent_map *em)
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154{
155 if (em->disk_bytenr < EXTENT_MAP_LAST_BYTE) {
962162ff 156 if (btrfs_extent_map_is_compressed(em))
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157 return em->disk_bytenr;
158 return em->disk_bytenr + em->offset;
159 }
160 return em->disk_bytenr;
161}
162
2e871330 163static inline u64 btrfs_extent_map_end(const struct extent_map *em)
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164{
165 if (em->start + em->len < em->start)
166 return (u64)-1;
167 return em->start + em->len;
168}
169
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170void btrfs_extent_map_tree_init(struct extent_map_tree *tree);
171struct extent_map *btrfs_lookup_extent_mapping(struct extent_map_tree *tree,
172 u64 start, u64 len);
173void btrfs_remove_extent_mapping(struct btrfs_inode *inode, struct extent_map *em);
174int btrfs_split_extent_map(struct btrfs_inode *inode, u64 start, u64 len, u64 pre,
175 u64 new_logical);
d1310b2e 176
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177struct extent_map *btrfs_alloc_extent_map(void);
178void btrfs_free_extent_map(struct extent_map *em);
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179int __init btrfs_extent_map_init(void);
180void __cold btrfs_extent_map_exit(void);
181int btrfs_unpin_extent_cache(struct btrfs_inode *inode, u64 start, u64 len, u64 gen);
182void btrfs_clear_em_logging(struct btrfs_inode *inode, struct extent_map *em);
183struct extent_map *btrfs_search_extent_mapping(struct extent_map_tree *tree,
184 u64 start, u64 len);
0a308f80 185int btrfs_add_extent_mapping(struct btrfs_inode *inode,
c04e61b5 186 struct extent_map **em_in, u64 start, u64 len);
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187void btrfs_drop_extent_map_range(struct btrfs_inode *inode,
188 u64 start, u64 end,
189 bool skip_pinned);
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190int btrfs_replace_extent_map_range(struct btrfs_inode *inode,
191 struct extent_map *new_em,
192 bool modified);
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193void btrfs_free_extent_maps(struct btrfs_fs_info *fs_info, long nr_to_scan);
194void btrfs_init_extent_map_shrinker_work(struct btrfs_fs_info *fs_info);
9888c340 195
a52d9a80 196#endif