disk-io.h

   1 /*
   2  * Copyright (C) 2007 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_DISK_IO_H__
  20 #define __BTRFS_DISK_IO_H__
  21
  22 #include "kerncompat.h"
  23 #include "ctree.h"
  24
  25 #define BTRFS_SUPER_INFO_OFFSET (64 * 1024)
  26 #define BTRFS_SUPER_INFO_SIZE 4096
  27
  28 #define BTRFS_SUPER_MIRROR_MAX   3
  29 #define BTRFS_SUPER_MIRROR_SHIFT 12
  30
  31 enum btrfs_open_ctree_flags {
  32         OPEN_CTREE_WRITES               = (1 << 0),
  33         OPEN_CTREE_PARTIAL              = (1 << 1),
  34         OPEN_CTREE_BACKUP_ROOT          = (1 << 2),
  35         OPEN_CTREE_RECOVER_SUPER        = (1 << 3),
  36         OPEN_CTREE_RESTORE              = (1 << 4),
  37         OPEN_CTREE_NO_BLOCK_GROUPS      = (1 << 5),
  38         OPEN_CTREE_EXCLUSIVE            = (1 << 6),
  39         OPEN_CTREE_NO_DEVICES           = (1 << 7),
  40         /*
  41          * Don't print error messages if bytenr or checksums do not match in
  42          * tree block headers. Turn on by OPEN_CTREE_SUPPRESS_ERROR
  43          */
  44         OPEN_CTREE_SUPPRESS_CHECK_BLOCK_ERRORS  = (1 << 8),
  45         /* Return chunk root */
  46         __OPEN_CTREE_RETURN_CHUNK_ROOT  = (1 << 9),
  47         OPEN_CTREE_CHUNK_ROOT_ONLY      = OPEN_CTREE_PARTIAL +
  48                                           OPEN_CTREE_SUPPRESS_CHECK_BLOCK_ERRORS +
  49                                           __OPEN_CTREE_RETURN_CHUNK_ROOT,
  50         /*
  51          * TODO: cleanup: Split the open_ctree_flags into more indepent
  52          * tree bits.
  53          * Like split PARTIAL into SKIP_CSUM/SKIP_EXTENT
  54          */
  55
  56         OPEN_CTREE_IGNORE_FSID_MISMATCH = (1 << 10),
  57
  58         /*
  59          * Allow open_ctree_fs_info() to return a incomplete fs_info with
  60          * system chunks from super block only.
  61          * It's useful for chunk corruption case.
  62          * Makes no sense for open_ctree variants returning btrfs_root.
  63          */
  64         OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR = (1 << 11)
  65 };
  66
  67 static inline u64 btrfs_sb_offset(int mirror)
  68 {
  69         u64 start = 16 * 1024;
  70         if (mirror)
  71                 return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror);
  72         return BTRFS_SUPER_INFO_OFFSET;
  73 }
  74
  75 struct btrfs_device;
  76
  77 int read_whole_eb(struct btrfs_fs_info *info, struct extent_buffer *eb, int mirror);
  78 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
  79                                       u32 blocksize, u64 parent_transid);
  80 int read_extent_data(struct btrfs_root *root, char *data, u64 logical,
  81                      u64 *len, int mirror);
  82 void readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
  83                           u64 parent_transid);
  84 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
  85                                                    u64 bytenr, u32 blocksize);
  86
  87 int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
  88                         u32 stripesize, struct btrfs_root *root,
  89                         struct btrfs_fs_info *fs_info, u64 objectid);
  90 int clean_tree_block(struct btrfs_trans_handle *trans,
  91                      struct btrfs_root *root, struct extent_buffer *buf);
  92
  93 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info);
  94 struct btrfs_fs_info *btrfs_new_fs_info(int writable, u64 sb_bytenr);
  95 int btrfs_check_fs_compatibility(struct btrfs_super_block *sb, int writable);
  96 int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
  97                           enum btrfs_open_ctree_flags flags);
  98 void btrfs_release_all_roots(struct btrfs_fs_info *fs_info);
  99 void btrfs_cleanup_all_caches(struct btrfs_fs_info *fs_info);
 100 int btrfs_scan_fs_devices(int fd, const char *path,
 101                           struct btrfs_fs_devices **fs_devices, u64 sb_bytenr,
 102                           int super_recover, int skip_devices);
 103 int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info);
 104
 105 struct btrfs_root *open_ctree(const char *filename, u64 sb_bytenr,
 106                               enum btrfs_open_ctree_flags flags);
 107 struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr,
 108                                  enum btrfs_open_ctree_flags flags);
 109 struct btrfs_fs_info *open_ctree_fs_info(const char *filename,
 110                                          u64 sb_bytenr, u64 root_tree_bytenr,
 111                                          enum btrfs_open_ctree_flags flags);
 112 int close_ctree_fs_info(struct btrfs_fs_info *fs_info);
 113 static inline int close_ctree(struct btrfs_root *root)
 114 {
 115         BUG_ON(!root);
 116         return close_ctree_fs_info(root->fs_info);
 117 }
 118
 119 int write_all_supers(struct btrfs_root *root);
 120 int write_ctree_super(struct btrfs_trans_handle *trans,
 121                       struct btrfs_root *root);
 122 int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr,
 123                          int super_recover);
 124 int btrfs_map_bh_to_logical(struct btrfs_root *root, struct extent_buffer *bh,
 125                             u64 logical);
 126 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
 127                                             u64 bytenr, u32 blocksize);
 128 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 129                                       struct btrfs_key *location);
 130 struct btrfs_root *btrfs_read_fs_root_no_cache(struct btrfs_fs_info *fs_info,
 131                                                struct btrfs_key *location);
 132 int btrfs_free_fs_root(struct btrfs_root *root);
 133 void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
 134 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid);
 135 int btrfs_set_buffer_uptodate(struct extent_buffer *buf);
 136 int wait_on_tree_block_writeback(struct btrfs_root *root,
 137                                  struct extent_buffer *buf);
 138 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len);
 139 void btrfs_csum_final(u32 crc, char *result);
 140
 141 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 142                              struct btrfs_root *root);
 143 int btrfs_open_device(struct btrfs_device *dev);
 144 int csum_tree_block_size(struct extent_buffer *buf, u16 csum_sectorsize,
 145                          int verify);
 146 int verify_tree_block_csum_silent(struct extent_buffer *buf, u16 csum_size);
 147 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid);
 148 int write_tree_block(struct btrfs_trans_handle *trans,
 149                      struct btrfs_root *root,
 150                      struct extent_buffer *eb);
 151 int write_and_map_eb(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 152                      struct extent_buffer *eb);
 153
 154 /* raid6.c */
 155 void raid6_gen_syndrome(int disks, size_t bytes, void **ptrs);
 156
 157 #endif