Chris Mason | c8b9781 | 2008-10-29 14:49:59 -0400 | [diff] [blame] | 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 | |
David Sterba | ff76386 | 2017-02-14 19:30:39 +0100 | [diff] [blame] | 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 | |
Anand Jain | e1ddce7 | 2017-05-26 15:44:59 +0800 | [diff] [blame] | 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 | |
Jeff Mahoney | 143bede | 2012-03-01 14:56:26 +0100 | [diff] [blame] | 76 | void btrfs_init_compress(void); |
Li Zefan | 261507a0 | 2010-12-17 14:21:50 +0800 | [diff] [blame] | 77 | void btrfs_exit_compress(void); |
| 78 | |
| 79 | int btrfs_compress_pages(int type, struct address_space *mapping, |
David Sterba | 38c3146 | 2017-02-14 19:04:07 +0100 | [diff] [blame] | 80 | u64 start, struct page **pages, |
Li Zefan | 261507a0 | 2010-12-17 14:21:50 +0800 | [diff] [blame] | 81 | unsigned long *out_pages, |
| 82 | unsigned long *total_in, |
David Sterba | e5d7490 | 2017-02-14 19:45:05 +0100 | [diff] [blame] | 83 | unsigned long *total_out); |
Li Zefan | 261507a0 | 2010-12-17 14:21:50 +0800 | [diff] [blame] | 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); |
David Sterba | 14a3357 | 2017-02-14 17:58:04 +0100 | [diff] [blame] | 86 | int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start, |
Li Zefan | 3a39c18 | 2010-11-08 15:22:19 +0800 | [diff] [blame] | 87 | unsigned long total_out, u64 disk_start, |
Christoph Hellwig | 974b1ad | 2016-11-25 09:07:46 +0100 | [diff] [blame] | 88 | struct bio *bio); |
Li Zefan | 261507a0 | 2010-12-17 14:21:50 +0800 | [diff] [blame] | 89 | |
Christoph Hellwig | 4e4cbee | 2017-06-03 09:38:06 +0200 | [diff] [blame] | 90 | blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start, |
Chris Mason | c8b9781 | 2008-10-29 14:49:59 -0400 | [diff] [blame] | 91 | unsigned long len, u64 disk_start, |
| 92 | unsigned long compressed_len, |
| 93 | struct page **compressed_pages, |
| 94 | unsigned long nr_pages); |
Christoph Hellwig | 4e4cbee | 2017-06-03 09:38:06 +0200 | [diff] [blame] | 95 | blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, |
Chris Mason | c8b9781 | 2008-10-29 14:49:59 -0400 | [diff] [blame] | 96 | int mirror_num, unsigned long bio_flags); |
Anand Jain | ebb8765 | 2016-03-10 17:26:59 +0800 | [diff] [blame] | 97 | |
| 98 | enum btrfs_compression_type { |
| 99 | BTRFS_COMPRESS_NONE = 0, |
| 100 | BTRFS_COMPRESS_ZLIB = 1, |
| 101 | BTRFS_COMPRESS_LZO = 2, |
Nick Terrell | 5c1aab1 | 2017-08-09 19:39:02 -0700 | [diff] [blame] | 102 | BTRFS_COMPRESS_ZSTD = 3, |
| 103 | BTRFS_COMPRESS_TYPES = 3, |
Anand Jain | ebb8765 | 2016-03-10 17:26:59 +0800 | [diff] [blame] | 104 | }; |
| 105 | |
Li Zefan | 261507a0 | 2010-12-17 14:21:50 +0800 | [diff] [blame] | 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, |
David Sterba | 38c3146 | 2017-02-14 19:04:07 +0100 | [diff] [blame] | 113 | u64 start, |
Li Zefan | 261507a0 | 2010-12-17 14:21:50 +0800 | [diff] [blame] | 114 | struct page **pages, |
Li Zefan | 261507a0 | 2010-12-17 14:21:50 +0800 | [diff] [blame] | 115 | unsigned long *out_pages, |
| 116 | unsigned long *total_in, |
David Sterba | e5d7490 | 2017-02-14 19:45:05 +0100 | [diff] [blame] | 117 | unsigned long *total_out); |
Li Zefan | 261507a0 | 2010-12-17 14:21:50 +0800 | [diff] [blame] | 118 | |
Christoph Hellwig | 974b1ad | 2016-11-25 09:07:46 +0100 | [diff] [blame] | 119 | int (*decompress_bio)(struct list_head *workspace, |
Anand Jain | e1ddce7 | 2017-05-26 15:44:59 +0800 | [diff] [blame] | 120 | struct compressed_bio *cb); |
Li Zefan | 261507a0 | 2010-12-17 14:21:50 +0800 | [diff] [blame] | 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 | |
David Sterba | e8c9f18 | 2015-01-02 18:23:10 +0100 | [diff] [blame] | 129 | extern const struct btrfs_compress_op btrfs_zlib_compress; |
| 130 | extern const struct btrfs_compress_op btrfs_lzo_compress; |
Nick Terrell | 5c1aab1 | 2017-08-09 19:39:02 -0700 | [diff] [blame] | 131 | extern const struct btrfs_compress_op btrfs_zstd_compress; |
Li Zefan | 261507a0 | 2010-12-17 14:21:50 +0800 | [diff] [blame] | 132 | |
Timofey Titovets | c2fcdcd | 2017-07-17 16:52:58 +0300 | [diff] [blame] | 133 | int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end); |
| 134 | |
Chris Mason | c8b9781 | 2008-10-29 14:49:59 -0400 | [diff] [blame] | 135 | #endif |