LXR linux/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
  22void btrfs_init_compress(void);
  23void btrfs_exit_compress(void);
  24
  25int 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);
  33int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
  34                     unsigned long start_byte, size_t srclen, size_t destlen);
  35int 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
  41int 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);
  46int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
  47                                 int mirror_num, unsigned long bio_flags);
  48
  49struct 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
  78extern struct btrfs_compress_op btrfs_zlib_compress;
  79extern struct btrfs_compress_op btrfs_lzo_compress;
  80
  81#endif
  82