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 | |
16 | struct address_space; |
17 | struct page; |
18 | struct inode; |
19 | struct btrfs_inode; |
20 | struct btrfs_ordered_extent; |
21 | struct 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) |
36 | static_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 | |
43 | struct compressed_bio { |
44 | /* Number of compressed pages in the array */ |
45 | unsigned int nr_pages; |
46 | |
47 | /* the pages with the compressed data on them */ |
48 | struct page **compressed_pages; |
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 | |
75 | static inline unsigned int btrfs_compress_type(unsigned int type_level) |
76 | { |
77 | return (type_level & 0xF); |
78 | } |
79 | |
80 | static inline unsigned int btrfs_compress_level(unsigned int type_level) |
81 | { |
82 | return ((type_level & 0xF0) >> 4); |
83 | } |
84 | |
85 | int __init btrfs_init_compress(void); |
86 | void __cold btrfs_exit_compress(void); |
87 | |
88 | int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping, |
89 | u64 start, struct page **pages, |
90 | unsigned long *out_pages, |
91 | unsigned long *total_in, |
92 | unsigned long *total_out); |
93 | int btrfs_decompress(int type, const u8 *data_in, struct page *dest_page, |
94 | unsigned long start_byte, size_t srclen, size_t destlen); |
95 | int btrfs_decompress_buf2page(const char *buf, u32 buf_len, |
96 | struct compressed_bio *cb, u32 decompressed); |
97 | |
98 | void btrfs_submit_compressed_write(struct btrfs_ordered_extent *ordered, |
99 | struct page **compressed_pages, |
100 | unsigned int nr_pages, |
101 | blk_opf_t write_flags, |
102 | bool writeback); |
103 | void btrfs_submit_compressed_read(struct btrfs_bio *bbio); |
104 | |
105 | unsigned int btrfs_compress_str2level(unsigned int type, const char *str); |
106 | |
107 | struct page *btrfs_alloc_compr_page(void); |
108 | void btrfs_free_compr_page(struct page *page); |
109 | |
110 | enum btrfs_compression_type { |
111 | BTRFS_COMPRESS_NONE = 0, |
112 | BTRFS_COMPRESS_ZLIB = 1, |
113 | BTRFS_COMPRESS_LZO = 2, |
114 | BTRFS_COMPRESS_ZSTD = 3, |
115 | BTRFS_NR_COMPRESS_TYPES = 4, |
116 | }; |
117 | |
118 | struct workspace_manager { |
119 | struct list_head idle_ws; |
120 | spinlock_t ws_lock; |
121 | /* Number of free workspaces */ |
122 | int free_ws; |
123 | /* Total number of allocated workspaces */ |
124 | atomic_t total_ws; |
125 | /* Waiters for a free workspace */ |
126 | wait_queue_head_t ws_wait; |
127 | }; |
128 | |
129 | struct list_head *btrfs_get_workspace(int type, unsigned int level); |
130 | void btrfs_put_workspace(int type, struct list_head *ws); |
131 | |
132 | struct btrfs_compress_op { |
133 | struct workspace_manager *workspace_manager; |
134 | /* Maximum level supported by the compression algorithm */ |
135 | unsigned int max_level; |
136 | unsigned int default_level; |
137 | }; |
138 | |
139 | /* The heuristic workspaces are managed via the 0th workspace manager */ |
140 | #define BTRFS_NR_WORKSPACE_MANAGERS BTRFS_NR_COMPRESS_TYPES |
141 | |
142 | extern const struct btrfs_compress_op btrfs_heuristic_compress; |
143 | extern const struct btrfs_compress_op btrfs_zlib_compress; |
144 | extern const struct btrfs_compress_op btrfs_lzo_compress; |
145 | extern const struct btrfs_compress_op btrfs_zstd_compress; |
146 | |
147 | const char* btrfs_compress_type2str(enum btrfs_compression_type type); |
148 | bool btrfs_compress_is_valid_type(const char *str, size_t len); |
149 | |
150 | int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end); |
151 | |
152 | int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, |
153 | u64 start, struct page **pages, unsigned long *out_pages, |
154 | unsigned long *total_in, unsigned long *total_out); |
155 | int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb); |
156 | int zlib_decompress(struct list_head *ws, const u8 *data_in, |
157 | struct page *dest_page, unsigned long dest_pgoff, size_t srclen, |
158 | size_t destlen); |
159 | struct list_head *zlib_alloc_workspace(unsigned int level); |
160 | void zlib_free_workspace(struct list_head *ws); |
161 | struct list_head *zlib_get_workspace(unsigned int level); |
162 | |
163 | int lzo_compress_pages(struct list_head *ws, struct address_space *mapping, |
164 | u64 start, struct page **pages, unsigned long *out_pages, |
165 | unsigned long *total_in, unsigned long *total_out); |
166 | int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb); |
167 | int lzo_decompress(struct list_head *ws, const u8 *data_in, |
168 | struct page *dest_page, unsigned long dest_pgoff, size_t srclen, |
169 | size_t destlen); |
170 | struct list_head *lzo_alloc_workspace(unsigned int level); |
171 | void lzo_free_workspace(struct list_head *ws); |
172 | |
173 | int zstd_compress_pages(struct list_head *ws, struct address_space *mapping, |
174 | u64 start, struct page **pages, unsigned long *out_pages, |
175 | unsigned long *total_in, unsigned long *total_out); |
176 | int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb); |
177 | int zstd_decompress(struct list_head *ws, const u8 *data_in, |
178 | struct page *dest_page, unsigned long dest_pgoff, size_t srclen, |
179 | size_t destlen); |
180 | void zstd_init_workspace_manager(void); |
181 | void zstd_cleanup_workspace_manager(void); |
182 | struct list_head *zstd_alloc_workspace(unsigned int level); |
183 | void zstd_free_workspace(struct list_head *ws); |
184 | struct list_head *zstd_get_workspace(unsigned int level); |
185 | void zstd_put_workspace(struct list_head *ws); |
186 | |
187 | #endif |
188 | |