]>
Commit | Line | Data |
---|---|---|
c8b97818 CM |
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 | ||
ff763866 DS |
22 | /* |
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 | ||
e1ddce71 AJ |
37 | struct 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 | ||
143bede5 | 76 | void btrfs_init_compress(void); |
261507a0 LZ |
77 | void btrfs_exit_compress(void); |
78 | ||
79 | int btrfs_compress_pages(int type, struct address_space *mapping, | |
38c31464 | 80 | u64 start, struct page **pages, |
261507a0 LZ |
81 | unsigned long *out_pages, |
82 | unsigned long *total_in, | |
e5d74902 | 83 | unsigned long *total_out); |
261507a0 LZ |
84 | int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page, |
85 | unsigned long start_byte, size_t srclen, size_t destlen); | |
14a3357b | 86 | int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start, |
3a39c18d | 87 | unsigned long total_out, u64 disk_start, |
974b1adc | 88 | struct bio *bio); |
261507a0 | 89 | |
4e4cbee9 | 90 | blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start, |
c8b97818 CM |
91 | unsigned long len, u64 disk_start, |
92 | unsigned long compressed_len, | |
93 | struct page **compressed_pages, | |
94 | unsigned long nr_pages); | |
4e4cbee9 | 95 | blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, |
c8b97818 | 96 | int mirror_num, unsigned long bio_flags); |
ebb8765b AJ |
97 | |
98 | enum btrfs_compression_type { | |
99 | BTRFS_COMPRESS_NONE = 0, | |
100 | BTRFS_COMPRESS_ZLIB = 1, | |
101 | BTRFS_COMPRESS_LZO = 2, | |
5c1aab1d NT |
102 | BTRFS_COMPRESS_ZSTD = 3, |
103 | BTRFS_COMPRESS_TYPES = 3, | |
ebb8765b AJ |
104 | }; |
105 | ||
261507a0 LZ |
106 | struct 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, | |
38c31464 | 113 | u64 start, |
261507a0 | 114 | struct page **pages, |
261507a0 LZ |
115 | unsigned long *out_pages, |
116 | unsigned long *total_in, | |
e5d74902 | 117 | unsigned long *total_out); |
261507a0 | 118 | |
974b1adc | 119 | int (*decompress_bio)(struct list_head *workspace, |
e1ddce71 | 120 | struct compressed_bio *cb); |
261507a0 LZ |
121 | |
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 | ||
e8c9f186 DS |
129 | extern const struct btrfs_compress_op btrfs_zlib_compress; |
130 | extern const struct btrfs_compress_op btrfs_lzo_compress; | |
5c1aab1d | 131 | extern const struct btrfs_compress_op btrfs_zstd_compress; |
261507a0 | 132 | |
c2fcdcdf TT |
133 | int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end); |
134 | ||
c8b97818 | 135 | #endif |