1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (C) 2008 Oracle. All rights reserved.
4 */
5
6 #ifndef BTRFS_COMPRESSION_H
7 #define BTRFS_COMPRESSION_H
8
9 #include <linux/sizes.h>
10 #include <linux/mm.h>
11 #include <linux/list.h>
12 #include <linux/workqueue.h>
13 #include <linux/wait.h>
14 #include <linux/pagemap.h>
15 #include "bio.h"
16 #include "fs.h"
17 #include "messages.h"
18
19 struct address_space;
20 struct page;
21 struct inode;
22 struct btrfs_inode;
23 struct btrfs_ordered_extent;
24 struct btrfs_bio;
25
26 /*
27 * We want to make sure that amount of RAM required to uncompress an extent is
28 * reasonable, so we limit the total size in ram of a compressed extent to
29 * 128k. This is a crucial number because it also controls how easily we can
30 * spread reads across cpus for decompression.
31 *
32 * We also want to make sure the amount of IO required to do a random read is
33 * reasonably small, so we limit the size of a compressed extent to 128k.
34 */
35
36 /* Maximum length of compressed data stored on disk */
37 #define BTRFS_MAX_COMPRESSED (SZ_128K)
38 #define BTRFS_MAX_COMPRESSED_PAGES (BTRFS_MAX_COMPRESSED / PAGE_SIZE)
39 static_assert((BTRFS_MAX_COMPRESSED % PAGE_SIZE) == 0);
40
41 /* Maximum size of data before compression */
42 #define BTRFS_MAX_UNCOMPRESSED (SZ_128K)
43
44 #define BTRFS_ZLIB_DEFAULT_LEVEL 3
45
46 struct compressed_bio {
47 /* Number of compressed folios in the array. */
48 unsigned int nr_folios;
49
50 /* The folios with the compressed data on them. */
51 struct folio **compressed_folios;
52
53 /* starting offset in the inode for our pages */
54 u64 start;
55
56 /* Number of bytes in the inode we're working on */
57 unsigned int len;
58
59 /* Number of bytes on disk */
60 unsigned int compressed_len;
61
62 /* The compression algorithm for this bio */
63 u8 compress_type;
64
65 /* Whether this is a write for writeback. */
66 bool writeback;
67
68 union {
69 /* For reads, this is the bio we are copying the data into */
70 struct btrfs_bio *orig_bbio;
71 struct work_struct write_end_work;
72 };
73
74 /* Must be last. */
75 struct btrfs_bio bbio;
76 };
77
78 /* @range_end must be exclusive. */
btrfs_calc_input_length(struct folio * folio,u64 range_end,u64 cur)79 static inline u32 btrfs_calc_input_length(struct folio *folio, u64 range_end, u64 cur)
80 {
81 /* @cur must be inside the folio. */
82 ASSERT(folio_pos(folio) <= cur);
83 ASSERT(cur < folio_end(folio));
84 return min(range_end, folio_end(folio)) - cur;
85 }
86
87 int __init btrfs_init_compress(void);
88 void __cold btrfs_exit_compress(void);
89
90 bool btrfs_compress_level_valid(unsigned int type, int level);
91 int btrfs_compress_folios(unsigned int type, int level, struct address_space *mapping,
92 u64 start, struct folio **folios, unsigned long *out_folios,
93 unsigned long *total_in, unsigned long *total_out);
94 int btrfs_decompress(int type, const u8 *data_in, struct folio *dest_folio,
95 unsigned long start_byte, size_t srclen, size_t destlen);
96 int btrfs_decompress_buf2page(const char *buf, u32 buf_len,
97 struct compressed_bio *cb, u32 decompressed);
98
99 void btrfs_submit_compressed_write(struct btrfs_ordered_extent *ordered,
100 struct folio **compressed_folios,
101 unsigned int nr_folios, blk_opf_t write_flags,
102 bool writeback);
103 void btrfs_submit_compressed_read(struct btrfs_bio *bbio);
104
105 int btrfs_compress_str2level(unsigned int type, const char *str);
106
107 struct folio *btrfs_alloc_compr_folio(void);
108 void btrfs_free_compr_folio(struct folio *folio);
109
110 enum btrfs_compression_type {
111 BTRFS_COMPRESS_NONE = 0,
112 BTRFS_COMPRESS_ZLIB = 1,
113 BTRFS_COMPRESS_LZO = 2,
114 BTRFS_COMPRESS_ZSTD = 3,
115 BTRFS_NR_COMPRESS_TYPES = 4,
116
117 BTRFS_DEFRAG_DONT_COMPRESS,
118 };
119
120 struct workspace_manager {
121 struct list_head idle_ws;
122 spinlock_t ws_lock;
123 /* Number of free workspaces */
124 int free_ws;
125 /* Total number of allocated workspaces */
126 atomic_t total_ws;
127 /* Waiters for a free workspace */
128 wait_queue_head_t ws_wait;
129 };
130
131 struct list_head *btrfs_get_workspace(int type, int level);
132 void btrfs_put_workspace(int type, struct list_head *ws);
133
134 struct btrfs_compress_op {
135 struct workspace_manager *workspace_manager;
136 /* Maximum level supported by the compression algorithm */
137 int min_level;
138 int max_level;
139 int default_level;
140 };
141
142 /* The heuristic workspaces are managed via the 0th workspace manager */
143 #define BTRFS_NR_WORKSPACE_MANAGERS BTRFS_NR_COMPRESS_TYPES
144
145 extern const struct btrfs_compress_op btrfs_heuristic_compress;
146 extern const struct btrfs_compress_op btrfs_zlib_compress;
147 extern const struct btrfs_compress_op btrfs_lzo_compress;
148 extern const struct btrfs_compress_op btrfs_zstd_compress;
149
150 const char* btrfs_compress_type2str(enum btrfs_compression_type type);
151 bool btrfs_compress_is_valid_type(const char *str, size_t len);
152
153 int btrfs_compress_heuristic(struct btrfs_inode *inode, u64 start, u64 end);
154
155 int btrfs_compress_filemap_get_folio(struct address_space *mapping, u64 start,
156 struct folio **in_folio_ret);
157
158 int zlib_compress_folios(struct list_head *ws, struct address_space *mapping,
159 u64 start, struct folio **folios, unsigned long *out_folios,
160 unsigned long *total_in, unsigned long *total_out);
161 int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
162 int zlib_decompress(struct list_head *ws, const u8 *data_in,
163 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen,
164 size_t destlen);
165 struct list_head *zlib_alloc_workspace(unsigned int level);
166 void zlib_free_workspace(struct list_head *ws);
167 struct list_head *zlib_get_workspace(unsigned int level);
168
169 int lzo_compress_folios(struct list_head *ws, struct address_space *mapping,
170 u64 start, struct folio **folios, unsigned long *out_folios,
171 unsigned long *total_in, unsigned long *total_out);
172 int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
173 int lzo_decompress(struct list_head *ws, const u8 *data_in,
174 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen,
175 size_t destlen);
176 struct list_head *lzo_alloc_workspace(void);
177 void lzo_free_workspace(struct list_head *ws);
178
179 int zstd_compress_folios(struct list_head *ws, struct address_space *mapping,
180 u64 start, struct folio **folios, unsigned long *out_folios,
181 unsigned long *total_in, unsigned long *total_out);
182 int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
183 int zstd_decompress(struct list_head *ws, const u8 *data_in,
184 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen,
185 size_t destlen);
186 void zstd_init_workspace_manager(void);
187 void zstd_cleanup_workspace_manager(void);
188 struct list_head *zstd_alloc_workspace(int level);
189 void zstd_free_workspace(struct list_head *ws);
190 struct list_head *zstd_get_workspace(int level);
191 void zstd_put_workspace(struct list_head *ws);
192
193 #endif
194