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 <linux/pagemap.h>
15 #include "bio.h"
16 #include "fs.h"
17 #include "btrfs_inode.h"
18
19 struct address_space;
20 struct inode;
21 struct btrfs_inode;
22 struct btrfs_ordered_extent;
23
24 /*
25 * We want to make sure that amount of RAM required to uncompress an extent is
26 * reasonable, so we limit the total size in ram of a compressed extent to
27 * 128k. This is a crucial number because it also controls how easily we can
28 * spread reads across cpus for decompression.
29 *
30 * We also want to make sure the amount of IO required to do a random read is
31 * reasonably small, so we limit the size of a compressed extent to 128k.
32 */
33
34 /* Maximum length of compressed data stored on disk */
35 #define BTRFS_MAX_COMPRESSED (SZ_128K)
36 #define BTRFS_MAX_COMPRESSED_PAGES (BTRFS_MAX_COMPRESSED / PAGE_SIZE)
37 static_assert((BTRFS_MAX_COMPRESSED % PAGE_SIZE) == 0);
38
39 /* Maximum size of data before compression */
40 #define BTRFS_MAX_UNCOMPRESSED (SZ_128K)
41
42 #define BTRFS_ZLIB_DEFAULT_LEVEL 3
43
44 struct compressed_bio {
45 /* starting offset in the inode for our pages */
46 u64 start;
47
48 /* Number of bytes in the inode we're working on */
49 unsigned int len;
50
51 /* Number of bytes on disk */
52 unsigned int compressed_len;
53
54 /* The compression algorithm for this bio */
55 u8 compress_type;
56
57 /* Whether this is a write for writeback. */
58 bool writeback;
59
60 /* For reads, this is the bio we are copying the data into. */
61 struct btrfs_bio *orig_bbio;
62
63 /* Must be last. */
64 struct btrfs_bio bbio;
65 };
66
cb_to_fs_info(const struct compressed_bio * cb)67 static inline struct btrfs_fs_info *cb_to_fs_info(const struct compressed_bio *cb)
68 {
69 return cb->bbio.inode->root->fs_info;
70 }
71
72 /* @range_end must be exclusive. */
btrfs_calc_input_length(struct folio * folio,u64 range_end,u64 cur)73 static inline u32 btrfs_calc_input_length(struct folio *folio, u64 range_end, u64 cur)
74 {
75 /* @cur must be inside the folio. */
76 ASSERT(folio_pos(folio) <= cur);
77 ASSERT(cur < folio_next_pos(folio));
78 return umin(range_end, folio_next_pos(folio)) - cur;
79 }
80
81 int btrfs_alloc_compress_wsm(struct btrfs_fs_info *fs_info);
82 void btrfs_free_compress_wsm(struct btrfs_fs_info *fs_info);
83
84 int __init btrfs_init_compress(void);
85 void __cold btrfs_exit_compress(void);
86
87 bool btrfs_compress_level_valid(unsigned int type, int level);
88 int btrfs_decompress(int type, const u8 *data_in, struct folio *dest_folio,
89 unsigned long dest_pgoff, size_t srclen, size_t destlen);
90 int btrfs_decompress_buf2page(const char *buf, u32 buf_len,
91 struct compressed_bio *cb, u32 decompressed);
92
93 struct compressed_bio *btrfs_alloc_compressed_write(struct btrfs_inode *inode,
94 u64 start, u64 len);
95 void btrfs_submit_compressed_write(struct btrfs_ordered_extent *ordered,
96 struct compressed_bio *cb);
97 void btrfs_submit_compressed_read(struct btrfs_bio *bbio);
98
99 int btrfs_compress_str2level(unsigned int type, const char *str, int *level_ret);
100
101 struct folio *btrfs_alloc_compr_folio(struct btrfs_fs_info *fs_info);
102 void btrfs_free_compr_folio(struct folio *folio);
103
104 struct workspace_manager {
105 struct list_head idle_ws;
106 spinlock_t ws_lock;
107 /* Number of free workspaces */
108 int free_ws;
109 /* Total number of allocated workspaces */
110 atomic_t total_ws;
111 /* Waiters for a free workspace */
112 wait_queue_head_t ws_wait;
113 };
114
115 struct list_head *btrfs_get_workspace(struct btrfs_fs_info *fs_info, int type, int level);
116 void btrfs_put_workspace(struct btrfs_fs_info *fs_info, int type, struct list_head *ws);
117
118 struct btrfs_compress_levels {
119 /* Maximum level supported by the compression algorithm */
120 int min_level;
121 int max_level;
122 int default_level;
123 };
124
125 /* The heuristic workspaces are managed via the 0th workspace manager */
126 #define BTRFS_NR_WORKSPACE_MANAGERS BTRFS_NR_COMPRESS_TYPES
127
128 extern const struct btrfs_compress_levels btrfs_heuristic_compress;
129 extern const struct btrfs_compress_levels btrfs_zlib_compress;
130 extern const struct btrfs_compress_levels btrfs_lzo_compress;
131 extern const struct btrfs_compress_levels btrfs_zstd_compress;
132
133 const char* btrfs_compress_type2str(enum btrfs_compression_type type);
134 bool btrfs_compress_is_valid_type(const char *str, size_t len);
135
136 int btrfs_compress_heuristic(struct btrfs_inode *inode, u64 start, u64 end);
137
138 int btrfs_compress_filemap_get_folio(struct address_space *mapping, u64 start,
139 struct folio **in_folio_ret);
140 struct compressed_bio *btrfs_compress_bio(struct btrfs_inode *inode,
141 u64 start, u32 len, unsigned int type,
142 int level, blk_opf_t write_flags);
143
cleanup_compressed_bio(struct compressed_bio * cb)144 static inline void cleanup_compressed_bio(struct compressed_bio *cb)
145 {
146 struct bio *bio = &cb->bbio.bio;
147 struct folio_iter fi;
148
149 bio_for_each_folio_all(fi, bio)
150 btrfs_free_compr_folio(fi.folio);
151 bio_put(bio);
152 }
153
154 int zlib_compress_bio(struct list_head *ws, struct compressed_bio *cb);
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 folio *dest_folio, unsigned long dest_pgoff, size_t srclen,
158 size_t destlen);
159 struct list_head *zlib_alloc_workspace(struct btrfs_fs_info *fs_info, unsigned int level);
160 void zlib_free_workspace(struct list_head *ws);
161 struct list_head *zlib_get_workspace(struct btrfs_fs_info *fs_info, unsigned int level);
162
163 int lzo_compress_bio(struct list_head *ws, struct compressed_bio *cb);
164 int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
165 int lzo_decompress(struct list_head *ws, const u8 *data_in,
166 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen,
167 size_t destlen);
168 struct list_head *lzo_alloc_workspace(struct btrfs_fs_info *fs_info);
169 void lzo_free_workspace(struct list_head *ws);
170
171 int zstd_compress_bio(struct list_head *ws, struct compressed_bio *cb);
172 int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
173 int zstd_decompress(struct list_head *ws, const u8 *data_in,
174 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen,
175 size_t destlen);
176 int zstd_alloc_workspace_manager(struct btrfs_fs_info *fs_info);
177 void zstd_free_workspace_manager(struct btrfs_fs_info *fs_info);
178 struct list_head *zstd_alloc_workspace(struct btrfs_fs_info *fs_info, int level);
179 void zstd_free_workspace(struct list_head *ws);
180 struct list_head *zstd_get_workspace(struct btrfs_fs_info *fs_info, int level);
181 void zstd_put_workspace(struct btrfs_fs_info *fs_info, struct list_head *ws);
182
183 #endif
184