1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Copyright (C) 2008 Oracle. All rights reserved.
6 #ifndef BTRFS_COMPRESSION_H
7 #define BTRFS_COMPRESSION_H
9 #include <linux/sizes.h>
11 #include <linux/list.h>
12 #include <linux/workqueue.h>
13 #include <linux/wait.h>
20 struct btrfs_ordered_extent;
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.
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.
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);
38 /* Maximum size of data before compression */
39 #define BTRFS_MAX_UNCOMPRESSED (SZ_128K)
41 #define BTRFS_ZLIB_DEFAULT_LEVEL 3
43 struct compressed_bio {
44 /* Number of compressed pages in the array */
45 unsigned int nr_pages;
47 /* the pages with the compressed data on them */
48 struct page **compressed_pages;
50 /* starting offset in the inode for our pages */
53 /* Number of bytes in the inode we're working on */
56 /* Number of bytes on disk */
57 unsigned int compressed_len;
59 /* The compression algorithm for this bio */
62 /* Whether this is a write for writeback. */
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;
72 struct btrfs_bio bbio;
75 static inline unsigned int btrfs_compress_type(unsigned int type_level)
77 return (type_level & 0xF);
80 static inline unsigned int btrfs_compress_level(unsigned int type_level)
82 return ((type_level & 0xF0) >> 4);
85 int __init btrfs_init_compress(void);
86 void __cold btrfs_exit_compress(void);
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);
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,
103 void btrfs_submit_compressed_read(struct btrfs_bio *bbio);
105 unsigned int btrfs_compress_str2level(unsigned int type, const char *str);
107 struct page *btrfs_alloc_compr_page(void);
108 void btrfs_free_compr_page(struct page *page);
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,
118 struct workspace_manager {
119 struct list_head idle_ws;
121 /* Number of free workspaces */
123 /* Total number of allocated workspaces */
125 /* Waiters for a free workspace */
126 wait_queue_head_t ws_wait;
129 struct list_head *btrfs_get_workspace(int type, unsigned int level);
130 void btrfs_put_workspace(int type, struct list_head *ws);
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;
139 /* The heuristic workspaces are managed via the 0th workspace manager */
140 #define BTRFS_NR_WORKSPACE_MANAGERS BTRFS_NR_COMPRESS_TYPES
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;
147 const char* btrfs_compress_type2str(enum btrfs_compression_type type);
148 bool btrfs_compress_is_valid_type(const char *str, size_t len);
150 int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end);
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,
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);
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,
170 struct list_head *lzo_alloc_workspace(unsigned int level);
171 void lzo_free_workspace(struct list_head *ws);
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,
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);