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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 "bio.h"
15
16struct address_space;
17struct page;
18struct inode;
19struct btrfs_inode;
20struct btrfs_ordered_extent;
21struct btrfs_bio;
22
23/*
24 * We want to make sure that amount of RAM required to uncompress an extent is
25 * reasonable, so we limit the total size in ram of a compressed extent to
26 * 128k. This is a crucial number because it also controls how easily we can
27 * spread reads across cpus for decompression.
28 *
29 * We also want to make sure the amount of IO required to do a random read is
30 * reasonably small, so we limit the size of a compressed extent to 128k.
31 */
32
33/* Maximum length of compressed data stored on disk */
34#define BTRFS_MAX_COMPRESSED (SZ_128K)
35#define BTRFS_MAX_COMPRESSED_PAGES (BTRFS_MAX_COMPRESSED / PAGE_SIZE)
36static_assert((BTRFS_MAX_COMPRESSED % PAGE_SIZE) == 0);
37
38/* Maximum size of data before compression */
39#define BTRFS_MAX_UNCOMPRESSED (SZ_128K)
40
41#define BTRFS_ZLIB_DEFAULT_LEVEL 3
42
43struct compressed_bio {
44 /* Number of compressed folios in the array. */
45 unsigned int nr_folios;
46
47 /* The folios with the compressed data on them. */
48 struct folio **compressed_folios;
49
50 /* starting offset in the inode for our pages */
51 u64 start;
52
53 /* Number of bytes in the inode we're working on */
54 unsigned int len;
55
56 /* Number of bytes on disk */
57 unsigned int compressed_len;
58
59 /* The compression algorithm for this bio */
60 u8 compress_type;
61
62 /* Whether this is a write for writeback. */
63 bool writeback;
64
65 union {
66 /* For reads, this is the bio we are copying the data into */
67 struct btrfs_bio *orig_bbio;
68 struct work_struct write_end_work;
69 };
70
71 /* Must be last. */
72 struct btrfs_bio bbio;
73};
74
75static inline unsigned int btrfs_compress_type(unsigned int type_level)
76{
77 return (type_level & 0xF);
78}
79
80static inline unsigned int btrfs_compress_level(unsigned int type_level)
81{
82 return ((type_level & 0xF0) >> 4);
83}
84
85/* @range_end must be exclusive. */
86static inline u32 btrfs_calc_input_length(u64 range_end, u64 cur)
87{
88 u64 page_end = round_down(cur, PAGE_SIZE) + PAGE_SIZE;
89
90 return min(range_end, page_end) - cur;
91}
92
93int __init btrfs_init_compress(void);
94void __cold btrfs_exit_compress(void);
95
96int btrfs_compress_folios(unsigned int type_level, struct address_space *mapping,
97 u64 start, struct folio **folios, unsigned long *out_folios,
98 unsigned long *total_in, unsigned long *total_out);
99int btrfs_decompress(int type, const u8 *data_in, struct folio *dest_folio,
100 unsigned long start_byte, size_t srclen, size_t destlen);
101int btrfs_decompress_buf2page(const char *buf, u32 buf_len,
102 struct compressed_bio *cb, u32 decompressed);
103
104void btrfs_submit_compressed_write(struct btrfs_ordered_extent *ordered,
105 struct folio **compressed_folios,
106 unsigned int nr_folios, blk_opf_t write_flags,
107 bool writeback);
108void btrfs_submit_compressed_read(struct btrfs_bio *bbio);
109
110unsigned int btrfs_compress_str2level(unsigned int type, const char *str);
111
112struct folio *btrfs_alloc_compr_folio(void);
113void btrfs_free_compr_folio(struct folio *folio);
114
115enum btrfs_compression_type {
116 BTRFS_COMPRESS_NONE = 0,
117 BTRFS_COMPRESS_ZLIB = 1,
118 BTRFS_COMPRESS_LZO = 2,
119 BTRFS_COMPRESS_ZSTD = 3,
120 BTRFS_NR_COMPRESS_TYPES = 4,
121};
122
123struct workspace_manager {
124 struct list_head idle_ws;
125 spinlock_t ws_lock;
126 /* Number of free workspaces */
127 int free_ws;
128 /* Total number of allocated workspaces */
129 atomic_t total_ws;
130 /* Waiters for a free workspace */
131 wait_queue_head_t ws_wait;
132};
133
134struct list_head *btrfs_get_workspace(int type, unsigned int level);
135void btrfs_put_workspace(int type, struct list_head *ws);
136
137struct btrfs_compress_op {
138 struct workspace_manager *workspace_manager;
139 /* Maximum level supported by the compression algorithm */
140 unsigned int max_level;
141 unsigned int default_level;
142};
143
144/* The heuristic workspaces are managed via the 0th workspace manager */
145#define BTRFS_NR_WORKSPACE_MANAGERS BTRFS_NR_COMPRESS_TYPES
146
147extern const struct btrfs_compress_op btrfs_heuristic_compress;
148extern const struct btrfs_compress_op btrfs_zlib_compress;
149extern const struct btrfs_compress_op btrfs_lzo_compress;
150extern const struct btrfs_compress_op btrfs_zstd_compress;
151
152const char* btrfs_compress_type2str(enum btrfs_compression_type type);
153bool btrfs_compress_is_valid_type(const char *str, size_t len);
154
155int btrfs_compress_heuristic(struct btrfs_inode *inode, u64 start, u64 end);
156
157int btrfs_compress_filemap_get_folio(struct address_space *mapping, u64 start,
158 struct folio **in_folio_ret);
159
160int zlib_compress_folios(struct list_head *ws, struct address_space *mapping,
161 u64 start, struct folio **folios, unsigned long *out_folios,
162 unsigned long *total_in, unsigned long *total_out);
163int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
164int zlib_decompress(struct list_head *ws, const u8 *data_in,
165 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen,
166 size_t destlen);
167struct list_head *zlib_alloc_workspace(unsigned int level);
168void zlib_free_workspace(struct list_head *ws);
169struct list_head *zlib_get_workspace(unsigned int level);
170
171int lzo_compress_folios(struct list_head *ws, struct address_space *mapping,
172 u64 start, struct folio **folios, unsigned long *out_folios,
173 unsigned long *total_in, unsigned long *total_out);
174int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
175int lzo_decompress(struct list_head *ws, const u8 *data_in,
176 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen,
177 size_t destlen);
178struct list_head *lzo_alloc_workspace(void);
179void lzo_free_workspace(struct list_head *ws);
180
181int zstd_compress_folios(struct list_head *ws, struct address_space *mapping,
182 u64 start, struct folio **folios, unsigned long *out_folios,
183 unsigned long *total_in, unsigned long *total_out);
184int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
185int zstd_decompress(struct list_head *ws, const u8 *data_in,
186 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen,
187 size_t destlen);
188void zstd_init_workspace_manager(void);
189void zstd_cleanup_workspace_manager(void);
190struct list_head *zstd_alloc_workspace(unsigned int level);
191void zstd_free_workspace(struct list_head *ws);
192struct list_head *zstd_get_workspace(unsigned int level);
193void zstd_put_workspace(struct list_head *ws);
194
195#endif
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/*
10 * We want to make sure that amount of RAM required to uncompress an extent is
11 * reasonable, so we limit the total size in ram of a compressed extent to
12 * 128k. This is a crucial number because it also controls how easily we can
13 * spread reads across cpus for decompression.
14 *
15 * We also want to make sure the amount of IO required to do a random read is
16 * reasonably small, so we limit the size of a compressed extent to 128k.
17 */
18
19/* Maximum length of compressed data stored on disk */
20#define BTRFS_MAX_COMPRESSED (SZ_128K)
21/* Maximum size of data before compression */
22#define BTRFS_MAX_UNCOMPRESSED (SZ_128K)
23
24#define BTRFS_ZLIB_DEFAULT_LEVEL 3
25
26struct compressed_bio {
27 /* number of bios pending for this compressed extent */
28 refcount_t pending_bios;
29
30 /* the pages with the compressed data on them */
31 struct page **compressed_pages;
32
33 /* inode that owns this data */
34 struct inode *inode;
35
36 /* starting offset in the inode for our pages */
37 u64 start;
38
39 /* number of bytes in the inode we're working on */
40 unsigned long len;
41
42 /* number of bytes on disk */
43 unsigned long compressed_len;
44
45 /* the compression algorithm for this bio */
46 int compress_type;
47
48 /* number of compressed pages in the array */
49 unsigned long nr_pages;
50
51 /* IO errors */
52 int errors;
53 int mirror_num;
54
55 /* for reads, this is the bio we are copying the data into */
56 struct bio *orig_bio;
57
58 /*
59 * the start of a variable length array of checksums only
60 * used by reads
61 */
62 u32 sums;
63};
64
65void __init btrfs_init_compress(void);
66void __cold btrfs_exit_compress(void);
67
68int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping,
69 u64 start, struct page **pages,
70 unsigned long *out_pages,
71 unsigned long *total_in,
72 unsigned long *total_out);
73int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
74 unsigned long start_byte, size_t srclen, size_t destlen);
75int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start,
76 unsigned long total_out, u64 disk_start,
77 struct bio *bio);
78
79blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
80 unsigned long len, u64 disk_start,
81 unsigned long compressed_len,
82 struct page **compressed_pages,
83 unsigned long nr_pages,
84 unsigned int write_flags);
85blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
86 int mirror_num, unsigned long bio_flags);
87
88unsigned btrfs_compress_str2level(const char *str);
89
90enum btrfs_compression_type {
91 BTRFS_COMPRESS_NONE = 0,
92 BTRFS_COMPRESS_ZLIB = 1,
93 BTRFS_COMPRESS_LZO = 2,
94 BTRFS_COMPRESS_ZSTD = 3,
95 BTRFS_COMPRESS_TYPES = 3,
96};
97
98struct btrfs_compress_op {
99 struct list_head *(*alloc_workspace)(void);
100
101 void (*free_workspace)(struct list_head *workspace);
102
103 int (*compress_pages)(struct list_head *workspace,
104 struct address_space *mapping,
105 u64 start,
106 struct page **pages,
107 unsigned long *out_pages,
108 unsigned long *total_in,
109 unsigned long *total_out);
110
111 int (*decompress_bio)(struct list_head *workspace,
112 struct compressed_bio *cb);
113
114 int (*decompress)(struct list_head *workspace,
115 unsigned char *data_in,
116 struct page *dest_page,
117 unsigned long start_byte,
118 size_t srclen, size_t destlen);
119
120 void (*set_level)(struct list_head *ws, unsigned int type);
121};
122
123extern const struct btrfs_compress_op btrfs_zlib_compress;
124extern const struct btrfs_compress_op btrfs_lzo_compress;
125extern const struct btrfs_compress_op btrfs_zstd_compress;
126
127const char* btrfs_compress_type2str(enum btrfs_compression_type type);
128
129int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end);
130
131#endif