GNU Linux-libre 4.9.304-gnu1
[releases.git] / fs / btrfs / compression.h
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
22 void btrfs_init_compress(void);
23 void btrfs_exit_compress(void);
24
25 int 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);
33 int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
34                      unsigned long start_byte, size_t srclen, size_t destlen);
35 int 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
41 int 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);
46 int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
47                                  int mirror_num, unsigned long bio_flags);
48 void btrfs_clear_biovec_end(struct bio_vec *bvec, int vcnt,
49                                    unsigned long pg_index,
50                                    unsigned long pg_offset);
51
52 enum btrfs_compression_type {
53         BTRFS_COMPRESS_NONE  = 0,
54         BTRFS_COMPRESS_ZLIB  = 1,
55         BTRFS_COMPRESS_LZO   = 2,
56         BTRFS_COMPRESS_TYPES = 2,
57         BTRFS_COMPRESS_LAST  = 3,
58 };
59
60 struct btrfs_compress_op {
61         struct list_head *(*alloc_workspace)(void);
62
63         void (*free_workspace)(struct list_head *workspace);
64
65         int (*compress_pages)(struct list_head *workspace,
66                               struct address_space *mapping,
67                               u64 start, unsigned long len,
68                               struct page **pages,
69                               unsigned long nr_dest_pages,
70                               unsigned long *out_pages,
71                               unsigned long *total_in,
72                               unsigned long *total_out,
73                               unsigned long max_out);
74
75         int (*decompress_biovec)(struct list_head *workspace,
76                                  struct page **pages_in,
77                                  u64 disk_start,
78                                  struct bio_vec *bvec,
79                                  int vcnt,
80                                  size_t srclen);
81
82         int (*decompress)(struct list_head *workspace,
83                           unsigned char *data_in,
84                           struct page *dest_page,
85                           unsigned long start_byte,
86                           size_t srclen, size_t destlen);
87 };
88
89 extern const struct btrfs_compress_op btrfs_zlib_compress;
90 extern const struct btrfs_compress_op btrfs_lzo_compress;
91
92 #endif