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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#include <linux/sizes.h>
10
11struct btrfs_inode;
12
13/*
14 * We want to make sure that amount of RAM required to uncompress an extent is
15 * reasonable, so we limit the total size in ram of a compressed extent to
16 * 128k. This is a crucial number because it also controls how easily we can
17 * spread reads across cpus for decompression.
18 *
19 * We also want to make sure the amount of IO required to do a random read is
20 * reasonably small, so we limit the size of a compressed extent to 128k.
21 */
22
23/* Maximum length of compressed data stored on disk */
24#define BTRFS_MAX_COMPRESSED (SZ_128K)
25/* Maximum size of data before compression */
26#define BTRFS_MAX_UNCOMPRESSED (SZ_128K)
27
28#define BTRFS_ZLIB_DEFAULT_LEVEL 3
29
30struct compressed_bio {
31 /* number of bios pending for this compressed extent */
32 refcount_t pending_bios;
33
34 /* the pages with the compressed data on them */
35 struct page **compressed_pages;
36
37 /* inode that owns this data */
38 struct inode *inode;
39
40 /* starting offset in the inode for our pages */
41 u64 start;
42
43 /* number of bytes in the inode we're working on */
44 unsigned long len;
45
46 /* number of bytes on disk */
47 unsigned long compressed_len;
48
49 /* the compression algorithm for this bio */
50 int compress_type;
51
52 /* number of compressed pages in the array */
53 unsigned long nr_pages;
54
55 /* IO errors */
56 int errors;
57 int mirror_num;
58
59 /* for reads, this is the bio we are copying the data into */
60 struct bio *orig_bio;
61
62 /*
63 * the start of a variable length array of checksums only
64 * used by reads
65 */
66 u8 sums[];
67};
68
69static inline unsigned int btrfs_compress_type(unsigned int type_level)
70{
71 return (type_level & 0xF);
72}
73
74static inline unsigned int btrfs_compress_level(unsigned int type_level)
75{
76 return ((type_level & 0xF0) >> 4);
77}
78
79void __init btrfs_init_compress(void);
80void __cold btrfs_exit_compress(void);
81
82int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping,
83 u64 start, struct page **pages,
84 unsigned long *out_pages,
85 unsigned long *total_in,
86 unsigned long *total_out);
87int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
88 unsigned long start_byte, size_t srclen, size_t destlen);
89int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start,
90 unsigned long total_out, u64 disk_start,
91 struct bio *bio);
92
93blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
94 unsigned long len, u64 disk_start,
95 unsigned long compressed_len,
96 struct page **compressed_pages,
97 unsigned long nr_pages,
98 unsigned int write_flags,
99 struct cgroup_subsys_state *blkcg_css);
100blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
101 int mirror_num, unsigned long bio_flags);
102
103unsigned int btrfs_compress_str2level(unsigned int type, const char *str);
104
105enum btrfs_compression_type {
106 BTRFS_COMPRESS_NONE = 0,
107 BTRFS_COMPRESS_ZLIB = 1,
108 BTRFS_COMPRESS_LZO = 2,
109 BTRFS_COMPRESS_ZSTD = 3,
110 BTRFS_NR_COMPRESS_TYPES = 4,
111};
112
113struct workspace_manager {
114 struct list_head idle_ws;
115 spinlock_t ws_lock;
116 /* Number of free workspaces */
117 int free_ws;
118 /* Total number of allocated workspaces */
119 atomic_t total_ws;
120 /* Waiters for a free workspace */
121 wait_queue_head_t ws_wait;
122};
123
124struct list_head *btrfs_get_workspace(int type, unsigned int level);
125void btrfs_put_workspace(int type, struct list_head *ws);
126
127struct btrfs_compress_op {
128 struct workspace_manager *workspace_manager;
129 /* Maximum level supported by the compression algorithm */
130 unsigned int max_level;
131 unsigned int default_level;
132};
133
134/* The heuristic workspaces are managed via the 0th workspace manager */
135#define BTRFS_NR_WORKSPACE_MANAGERS BTRFS_NR_COMPRESS_TYPES
136
137extern const struct btrfs_compress_op btrfs_heuristic_compress;
138extern const struct btrfs_compress_op btrfs_zlib_compress;
139extern const struct btrfs_compress_op btrfs_lzo_compress;
140extern const struct btrfs_compress_op btrfs_zstd_compress;
141
142const char* btrfs_compress_type2str(enum btrfs_compression_type type);
143bool btrfs_compress_is_valid_type(const char *str, size_t len);
144
145int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end);
146
147#endif