xref: /openbmc/linux/fs/btrfs/compression.h (revision ee89bd6b)
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 
49 struct btrfs_compress_op {
50 	struct list_head *(*alloc_workspace)(void);
51 
52 	void (*free_workspace)(struct list_head *workspace);
53 
54 	int (*compress_pages)(struct list_head *workspace,
55 			      struct address_space *mapping,
56 			      u64 start, unsigned long len,
57 			      struct page **pages,
58 			      unsigned long nr_dest_pages,
59 			      unsigned long *out_pages,
60 			      unsigned long *total_in,
61 			      unsigned long *total_out,
62 			      unsigned long max_out);
63 
64 	int (*decompress_biovec)(struct list_head *workspace,
65 				 struct page **pages_in,
66 				 u64 disk_start,
67 				 struct bio_vec *bvec,
68 				 int vcnt,
69 				 size_t srclen);
70 
71 	int (*decompress)(struct list_head *workspace,
72 			  unsigned char *data_in,
73 			  struct page *dest_page,
74 			  unsigned long start_byte,
75 			  size_t srclen, size_t destlen);
76 };
77 
78 extern struct btrfs_compress_op btrfs_zlib_compress;
79 extern struct btrfs_compress_op btrfs_lzo_compress;
80 
81 #endif
82