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
22void 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(int type, unsigned char *data_in, struct page *dest_page,
34		     unsigned long start_byte, size_t srclen, size_t destlen);
35int btrfs_decompress_buf2page(char *buf, unsigned long buf_start,
36			      unsigned long total_out, u64 disk_start,
37			      struct bio_vec *bvec, int vcnt,
38			      unsigned long *pg_index,
39			      unsigned long *pg_offset);
40
41int btrfs_submit_compressed_write(struct inode *inode, u64 start,
42				  unsigned long len, u64 disk_start,
43				  unsigned long compressed_len,
44				  struct page **compressed_pages,
45				  unsigned long nr_pages);
46int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 
47				 int mirror_num, unsigned long bio_flags);
48
 
 
 
 
 
 
 
 
 
 
49struct btrfs_compress_op {
50	struct list_head *(*alloc_workspace)(void);
51
52	void (*free_workspace)(struct list_head *workspace);
53
54	int (*compress_pages)(struct list_head *workspace,
55			      struct address_space *mapping,
56			      u64 start, unsigned long len,
57			      struct page **pages,
58			      unsigned long nr_dest_pages,
59			      unsigned long *out_pages,
60			      unsigned long *total_in,
61			      unsigned long *total_out,
62			      unsigned long max_out);
63
64	int (*decompress_biovec)(struct list_head *workspace,
65				 struct page **pages_in,
66				 u64 disk_start,
67				 struct bio_vec *bvec,
68				 int vcnt,
69				 size_t srclen);
70
71	int (*decompress)(struct list_head *workspace,
72			  unsigned char *data_in,
73			  struct page *dest_page,
74			  unsigned long start_byte,
75			  size_t srclen, size_t destlen);
 
 
76};
77
78extern struct btrfs_compress_op btrfs_zlib_compress;
79extern struct btrfs_compress_op btrfs_lzo_compress;
 
 
 
 
 
80
81#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/*
 10 * We want to make sure that amount of RAM required to uncompress an extent is
 11 * reasonable, so we limit the total size in ram of a compressed extent to
 12 * 128k.  This is a crucial number because it also controls how easily we can
 13 * spread reads across cpus for decompression.
 14 *
 15 * We also want to make sure the amount of IO required to do a random read is
 16 * reasonably small, so we limit the size of a compressed extent to 128k.
 
 
 
 
 
 
 
 
 
 
 
 17 */
 18
 19/* Maximum length of compressed data stored on disk */
 20#define BTRFS_MAX_COMPRESSED		(SZ_128K)
 21/* Maximum size of data before compression */
 22#define BTRFS_MAX_UNCOMPRESSED		(SZ_128K)
 23
 24#define	BTRFS_ZLIB_DEFAULT_LEVEL		3
 25
 26struct compressed_bio {
 27	/* number of bios pending for this compressed extent */
 28	refcount_t pending_bios;
 29
 30	/* the pages with the compressed data on them */
 31	struct page **compressed_pages;
 32
 33	/* inode that owns this data */
 34	struct inode *inode;
 35
 36	/* starting offset in the inode for our pages */
 37	u64 start;
 38
 39	/* number of bytes in the inode we're working on */
 40	unsigned long len;
 41
 42	/* number of bytes on disk */
 43	unsigned long compressed_len;
 44
 45	/* the compression algorithm for this bio */
 46	int compress_type;
 47
 48	/* number of compressed pages in the array */
 49	unsigned long nr_pages;
 50
 51	/* IO errors */
 52	int errors;
 53	int mirror_num;
 54
 55	/* for reads, this is the bio we are copying the data into */
 56	struct bio *orig_bio;
 57
 58	/*
 59	 * the start of a variable length array of checksums only
 60	 * used by reads
 61	 */
 62	u32 sums;
 63};
 64
 65void __init btrfs_init_compress(void);
 66void __cold btrfs_exit_compress(void);
 67
 68int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping,
 69			 u64 start, struct page **pages,
 70			 unsigned long *out_pages,
 71			 unsigned long *total_in,
 72			 unsigned long *total_out);
 
 73int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
 74		     unsigned long start_byte, size_t srclen, size_t destlen);
 75int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start,
 76			      unsigned long total_out, u64 disk_start,
 77			      struct bio *bio);
 
 
 78
 79blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
 80				  unsigned long len, u64 disk_start,
 81				  unsigned long compressed_len,
 82				  struct page **compressed_pages,
 83				  unsigned long nr_pages,
 84				  unsigned int write_flags);
 85blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 86				 int mirror_num, unsigned long bio_flags);
 87
 88unsigned btrfs_compress_str2level(const char *str);
 89
 90enum btrfs_compression_type {
 91	BTRFS_COMPRESS_NONE  = 0,
 92	BTRFS_COMPRESS_ZLIB  = 1,
 93	BTRFS_COMPRESS_LZO   = 2,
 94	BTRFS_COMPRESS_ZSTD  = 3,
 95	BTRFS_COMPRESS_TYPES = 3,
 96};
 97
 98struct btrfs_compress_op {
 99	struct list_head *(*alloc_workspace)(void);
100
101	void (*free_workspace)(struct list_head *workspace);
102
103	int (*compress_pages)(struct list_head *workspace,
104			      struct address_space *mapping,
105			      u64 start,
106			      struct page **pages,
 
107			      unsigned long *out_pages,
108			      unsigned long *total_in,
109			      unsigned long *total_out);
 
110
111	int (*decompress_bio)(struct list_head *workspace,
112				struct compressed_bio *cb);
 
 
 
 
113
114	int (*decompress)(struct list_head *workspace,
115			  unsigned char *data_in,
116			  struct page *dest_page,
117			  unsigned long start_byte,
118			  size_t srclen, size_t destlen);
119
120	void (*set_level)(struct list_head *ws, unsigned int type);
121};
122
123extern const struct btrfs_compress_op btrfs_zlib_compress;
124extern const struct btrfs_compress_op btrfs_lzo_compress;
125extern const struct btrfs_compress_op btrfs_zstd_compress;
126
127const char* btrfs_compress_type2str(enum btrfs_compression_type type);
128
129int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end);
130
131#endif