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1/*
2 * Copyright (C) 2008 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#ifndef __BTRFS_COMPRESSION_
20#define __BTRFS_COMPRESSION_
21
22int btrfs_init_compress(void);
23void btrfs_exit_compress(void);
24
25int btrfs_compress_pages(int type, struct address_space *mapping,
26 u64 start, unsigned long len,
27 struct page **pages,
28 unsigned long nr_dest_pages,
29 unsigned long *out_pages,
30 unsigned long *total_in,
31 unsigned long *total_out,
32 unsigned long max_out);
33int btrfs_decompress_biovec(int type, struct page **pages_in, u64 disk_start,
34 struct bio_vec *bvec, int vcnt, size_t srclen);
35int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
36 unsigned long start_byte, size_t srclen, size_t destlen);
37int btrfs_decompress_buf2page(char *buf, unsigned long buf_start,
38 unsigned long total_out, u64 disk_start,
39 struct bio_vec *bvec, int vcnt,
40 unsigned long *pg_index,
41 unsigned long *pg_offset);
42
43int btrfs_submit_compressed_write(struct inode *inode, u64 start,
44 unsigned long len, u64 disk_start,
45 unsigned long compressed_len,
46 struct page **compressed_pages,
47 unsigned long nr_pages);
48int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
49 int mirror_num, unsigned long bio_flags);
50
51struct btrfs_compress_op {
52 struct list_head *(*alloc_workspace)(void);
53
54 void (*free_workspace)(struct list_head *workspace);
55
56 int (*compress_pages)(struct list_head *workspace,
57 struct address_space *mapping,
58 u64 start, unsigned long len,
59 struct page **pages,
60 unsigned long nr_dest_pages,
61 unsigned long *out_pages,
62 unsigned long *total_in,
63 unsigned long *total_out,
64 unsigned long max_out);
65
66 int (*decompress_biovec)(struct list_head *workspace,
67 struct page **pages_in,
68 u64 disk_start,
69 struct bio_vec *bvec,
70 int vcnt,
71 size_t srclen);
72
73 int (*decompress)(struct list_head *workspace,
74 unsigned char *data_in,
75 struct page *dest_page,
76 unsigned long start_byte,
77 size_t srclen, size_t destlen);
78};
79
80extern struct btrfs_compress_op btrfs_zlib_compress;
81extern struct btrfs_compress_op btrfs_lzo_compress;
82
83#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