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