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Chris Masonc8b97812008-10-29 14:49:59 -04001/*
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
David Sterbaff763862017-02-14 19:30:39 +010022/*
23 * We want to make sure that amount of RAM required to uncompress an extent is
24 * reasonable, so we limit the total size in ram of a compressed extent to
25 * 128k. This is a crucial number because it also controls how easily we can
26 * spread reads across cpus for decompression.
27 *
28 * We also want to make sure the amount of IO required to do a random read is
29 * reasonably small, so we limit the size of a compressed extent to 128k.
30 */
31
32/* Maximum length of compressed data stored on disk */
33#define BTRFS_MAX_COMPRESSED (SZ_128K)
34/* Maximum size of data before compression */
35#define BTRFS_MAX_UNCOMPRESSED (SZ_128K)
36
Anand Jaine1ddce72017-05-26 15:44:59 +080037struct compressed_bio {
38 /* number of bios pending for this compressed extent */
39 refcount_t pending_bios;
40
41 /* the pages with the compressed data on them */
42 struct page **compressed_pages;
43
44 /* inode that owns this data */
45 struct inode *inode;
46
47 /* starting offset in the inode for our pages */
48 u64 start;
49
50 /* number of bytes in the inode we're working on */
51 unsigned long len;
52
53 /* number of bytes on disk */
54 unsigned long compressed_len;
55
56 /* the compression algorithm for this bio */
57 int compress_type;
58
59 /* number of compressed pages in the array */
60 unsigned long nr_pages;
61
62 /* IO errors */
63 int errors;
64 int mirror_num;
65
66 /* for reads, this is the bio we are copying the data into */
67 struct bio *orig_bio;
68
69 /*
70 * the start of a variable length array of checksums only
71 * used by reads
72 */
73 u32 sums;
74};
75
Jeff Mahoney143bede2012-03-01 14:56:26 +010076void btrfs_init_compress(void);
Li Zefan261507a02010-12-17 14:21:50 +080077void btrfs_exit_compress(void);
78
79int btrfs_compress_pages(int type, struct address_space *mapping,
David Sterba38c31462017-02-14 19:04:07 +010080 u64 start, struct page **pages,
Li Zefan261507a02010-12-17 14:21:50 +080081 unsigned long *out_pages,
82 unsigned long *total_in,
David Sterbae5d74902017-02-14 19:45:05 +010083 unsigned long *total_out);
Li Zefan261507a02010-12-17 14:21:50 +080084int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
85 unsigned long start_byte, size_t srclen, size_t destlen);
David Sterba14a33572017-02-14 17:58:04 +010086int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start,
Li Zefan3a39c182010-11-08 15:22:19 +080087 unsigned long total_out, u64 disk_start,
Christoph Hellwig974b1ad2016-11-25 09:07:46 +010088 struct bio *bio);
Li Zefan261507a02010-12-17 14:21:50 +080089
Christoph Hellwig4e4cbee2017-06-03 09:38:06 +020090blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
Chris Masonc8b97812008-10-29 14:49:59 -040091 unsigned long len, u64 disk_start,
92 unsigned long compressed_len,
93 struct page **compressed_pages,
94 unsigned long nr_pages);
Christoph Hellwig4e4cbee2017-06-03 09:38:06 +020095blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
Chris Masonc8b97812008-10-29 14:49:59 -040096 int mirror_num, unsigned long bio_flags);
Anand Jainebb87652016-03-10 17:26:59 +080097
98enum btrfs_compression_type {
99 BTRFS_COMPRESS_NONE = 0,
100 BTRFS_COMPRESS_ZLIB = 1,
101 BTRFS_COMPRESS_LZO = 2,
Nick Terrell5c1aab12017-08-09 19:39:02 -0700102 BTRFS_COMPRESS_ZSTD = 3,
103 BTRFS_COMPRESS_TYPES = 3,
Anand Jainebb87652016-03-10 17:26:59 +0800104};
105
Li Zefan261507a02010-12-17 14:21:50 +0800106struct btrfs_compress_op {
107 struct list_head *(*alloc_workspace)(void);
108
109 void (*free_workspace)(struct list_head *workspace);
110
111 int (*compress_pages)(struct list_head *workspace,
112 struct address_space *mapping,
David Sterba38c31462017-02-14 19:04:07 +0100113 u64 start,
Li Zefan261507a02010-12-17 14:21:50 +0800114 struct page **pages,
Li Zefan261507a02010-12-17 14:21:50 +0800115 unsigned long *out_pages,
116 unsigned long *total_in,
David Sterbae5d74902017-02-14 19:45:05 +0100117 unsigned long *total_out);
Li Zefan261507a02010-12-17 14:21:50 +0800118
Christoph Hellwig974b1ad2016-11-25 09:07:46 +0100119 int (*decompress_bio)(struct list_head *workspace,
Anand Jaine1ddce72017-05-26 15:44:59 +0800120 struct compressed_bio *cb);
Li Zefan261507a02010-12-17 14:21:50 +0800121
122 int (*decompress)(struct list_head *workspace,
123 unsigned char *data_in,
124 struct page *dest_page,
125 unsigned long start_byte,
126 size_t srclen, size_t destlen);
127};
128
David Sterbae8c9f182015-01-02 18:23:10 +0100129extern const struct btrfs_compress_op btrfs_zlib_compress;
130extern const struct btrfs_compress_op btrfs_lzo_compress;
Nick Terrell5c1aab12017-08-09 19:39:02 -0700131extern const struct btrfs_compress_op btrfs_zstd_compress;
Li Zefan261507a02010-12-17 14:21:50 +0800132
Timofey Titovetsc2fcdcd2017-07-17 16:52:58 +0300133int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end);
134
Chris Masonc8b97812008-10-29 14:49:59 -0400135#endif