Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
[linux-2.6.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 int 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_biovec(int type, struct page **pages_in, u64 disk_start,
34                             struct bio_vec *bvec, int vcnt, size_t srclen);
35 int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
36                      unsigned long start_byte, size_t srclen, size_t destlen);
37 int btrfs_decompress_buf2page(char *buf, unsigned long buf_start,
38                               unsigned long total_out, u64 disk_start,
39                               struct bio_vec *bvec, int vcnt,
40                               unsigned long *page_index,
41                               unsigned long *pg_offset);
42
43 int btrfs_submit_compressed_write(struct inode *inode, u64 start,
44                                   unsigned long len, u64 disk_start,
45                                   unsigned long compressed_len,
46                                   struct page **compressed_pages,
47                                   unsigned long nr_pages);
48 int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
49                                  int mirror_num, unsigned long bio_flags);
50
51 struct btrfs_compress_op {
52         struct list_head *(*alloc_workspace)(void);
53
54         void (*free_workspace)(struct list_head *workspace);
55
56         int (*compress_pages)(struct list_head *workspace,
57                               struct address_space *mapping,
58                               u64 start, unsigned long len,
59                               struct page **pages,
60                               unsigned long nr_dest_pages,
61                               unsigned long *out_pages,
62                               unsigned long *total_in,
63                               unsigned long *total_out,
64                               unsigned long max_out);
65
66         int (*decompress_biovec)(struct list_head *workspace,
67                                  struct page **pages_in,
68                                  u64 disk_start,
69                                  struct bio_vec *bvec,
70                                  int vcnt,
71                                  size_t srclen);
72
73         int (*decompress)(struct list_head *workspace,
74                           unsigned char *data_in,
75                           struct page *dest_page,
76                           unsigned long start_byte,
77                           size_t srclen, size_t destlen);
78 };
79
80 extern struct btrfs_compress_op btrfs_zlib_compress;
81 extern struct btrfs_compress_op btrfs_lzo_compress;
82
83 #endif