1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2008 Oracle. All rights reserved.
*/
#ifndef BTRFS_COMPRESSION_H
#define BTRFS_COMPRESSION_H
#include <linux/sizes.h>
#include "bio.h"
struct btrfs_inode;
struct btrfs_ordered_extent;
/*
* We want to make sure that amount of RAM required to uncompress an extent is
* reasonable, so we limit the total size in ram of a compressed extent to
* 128k. This is a crucial number because it also controls how easily we can
* spread reads across cpus for decompression.
*
* We also want to make sure the amount of IO required to do a random read is
* reasonably small, so we limit the size of a compressed extent to 128k.
*/
/* Maximum length of compressed data stored on disk */
#define BTRFS_MAX_COMPRESSED (SZ_128K)
#define BTRFS_MAX_COMPRESSED_PAGES (BTRFS_MAX_COMPRESSED / PAGE_SIZE)
static_assert((BTRFS_MAX_COMPRESSED % PAGE_SIZE) == 0);
/* Maximum size of data before compression */
#define BTRFS_MAX_UNCOMPRESSED (SZ_128K)
#define BTRFS_ZLIB_DEFAULT_LEVEL 3
struct page;
struct compressed_bio {
/* Number of compressed pages in the array */
unsigned int nr_pages;
/* the pages with the compressed data on them */
struct page **compressed_pages;
/* starting offset in the inode for our pages */
u64 start;
/* Number of bytes in the inode we're working on */
unsigned int len;
/* Number of bytes on disk */
unsigned int compressed_len;
/* The compression algorithm for this bio */
u8 compress_type;
/* Whether this is a write for writeback. */
bool writeback;
union {
/* For reads, this is the bio we are copying the data into */
struct btrfs_bio *orig_bbio;
struct work_struct write_end_work;
};
/* Must be last. */
struct btrfs_bio bbio;
};
static inline unsigned int btrfs_compress_type(unsigned int type_level)
{
return (type_level & 0xF);
}
static inline unsigned int btrfs_compress_level(unsigned int type_level)
{
return ((type_level & 0xF0) >> 4);
}
int __init btrfs_init_compress(void);
void __cold btrfs_exit_compress(void);
int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping,
u64 start, struct page **pages,
unsigned long *out_pages,
unsigned long *total_in,
unsigned long *total_out);
int btrfs_decompress(int type, const u8 *data_in, struct page *dest_page,
unsigned long start_byte, size_t srclen, size_t destlen);
int btrfs_decompress_buf2page(const char *buf, u32 buf_len,
struct compressed_bio *cb, u32 decompressed);
void btrfs_submit_compressed_write(struct btrfs_ordered_extent *ordered,
struct page **compressed_pages,
unsigned int nr_pages,
blk_opf_t write_flags,
bool writeback);
void btrfs_submit_compressed_read(struct btrfs_bio *bbio);
unsigned int btrfs_compress_str2level(unsigned int type, const char *str);
struct page *btrfs_alloc_compr_page(void);
void btrfs_free_compr_page(struct page *page);
enum btrfs_compression_type {
BTRFS_COMPRESS_NONE = 0,
BTRFS_COMPRESS_ZLIB = 1,
BTRFS_COMPRESS_LZO = 2,
BTRFS_COMPRESS_ZSTD = 3,
BTRFS_NR_COMPRESS_TYPES = 4,
};
struct workspace_manager {
struct list_head idle_ws;
spinlock_t ws_lock;
/* Number of free workspaces */
int free_ws;
/* Total number of allocated workspaces */
atomic_t total_ws;
/* Waiters for a free workspace */
wait_queue_head_t ws_wait;
};
struct list_head *btrfs_get_workspace(int type, unsigned int level);
void btrfs_put_workspace(int type, struct list_head *ws);
struct btrfs_compress_op {
struct workspace_manager *workspace_manager;
/* Maximum level supported by the compression algorithm */
unsigned int max_level;
unsigned int default_level;
};
/* The heuristic workspaces are managed via the 0th workspace manager */
#define BTRFS_NR_WORKSPACE_MANAGERS BTRFS_NR_COMPRESS_TYPES
extern const struct btrfs_compress_op btrfs_heuristic_compress;
extern const struct btrfs_compress_op btrfs_zlib_compress;
extern const struct btrfs_compress_op btrfs_lzo_compress;
extern const struct btrfs_compress_op btrfs_zstd_compress;
const char* btrfs_compress_type2str(enum btrfs_compression_type type);
bool btrfs_compress_is_valid_type(const char *str, size_t len);
int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end);
int zlib_compress_pages(struct list_head *ws, struct address_space *mapping,
u64 start, struct page **pages, unsigned long *out_pages,
unsigned long *total_in, unsigned long *total_out);
int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
int zlib_decompress(struct list_head *ws, const u8 *data_in,
struct page *dest_page, unsigned long start_byte, size_t srclen,
size_t destlen);
struct list_head *zlib_alloc_workspace(unsigned int level);
void zlib_free_workspace(struct list_head *ws);
struct list_head *zlib_get_workspace(unsigned int level);
int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
u64 start, struct page **pages, unsigned long *out_pages,
unsigned long *total_in, unsigned long *total_out);
int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
int lzo_decompress(struct list_head *ws, const u8 *data_in,
struct page *dest_page, unsigned long start_byte, size_t srclen,
size_t destlen);
struct list_head *lzo_alloc_workspace(unsigned int level);
void lzo_free_workspace(struct list_head *ws);
int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
u64 start, struct page **pages, unsigned long *out_pages,
unsigned long *total_in, unsigned long *total_out);
int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
int zstd_decompress(struct list_head *ws, const u8 *data_in,
struct page *dest_page, unsigned long start_byte, size_t srclen,
size_t destlen);
void zstd_init_workspace_manager(void);
void zstd_cleanup_workspace_manager(void);
struct list_head *zstd_alloc_workspace(unsigned int level);
void zstd_free_workspace(struct list_head *ws);
struct list_head *zstd_get_workspace(unsigned int level);
void zstd_put_workspace(struct list_head *ws);
#endif
|
