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 independent
  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         /* Allow to open a partially created filesystem */
  67         OPEN_CTREE_FS_PARTIAL = (1 << 12),
  68 };
  69
  70 /*
  71  * Modes of superblock access
  72  */
  73 enum btrfs_read_sb_flags {
  74         SBREAD_DEFAULT          = 0,
  75         /* Reading superblock during recovery */
  76         SBREAD_RECOVER          = (1 << 0),
  77
  78         /*
  79          * Read superblock with the fake signature, cannot be used with
  80          * SBREAD_RECOVER
  81          */
  82         SBREAD_PARTIAL          = (1 << 1),
  83 };
  84
  85 static inline u64 btrfs_sb_offset(int mirror)
  86 {
  87         u64 start = 16 * 1024;
  88         if (mirror)
  89                 return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror);
  90         return BTRFS_SUPER_INFO_OFFSET;
  91 }
  92
  93 struct btrfs_device;
  94
  95 int read_whole_eb(struct btrfs_fs_info *info, struct extent_buffer *eb, int mirror);
  96 struct extent_buffer* read_tree_block_fs_info(
  97                 struct btrfs_fs_info *fs_info, u64 bytenr, u32 blocksize,
  98                 u64 parent_transid);
  99 static inline struct extent_buffer* read_tree_block(
 100                 struct btrfs_root *root, u64 bytenr, u32 blocksize,
 101                 u64 parent_transid)
 102 {
 103         return read_tree_block_fs_info(root->fs_info, bytenr, blocksize,
 104                         parent_transid);
 105 }
 106
 107 int read_extent_data(struct btrfs_root *root, char *data, u64 logical,
 108                      u64 *len, int mirror);
 109 void readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
 110                           u64 parent_transid);
 111 struct extent_buffer* btrfs_find_create_tree_block(
 112                 struct btrfs_fs_info *fs_info, u64 bytenr, u32 blocksize);
 113
 114 int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 115                         u32 stripesize, struct btrfs_root *root,
 116                         struct btrfs_fs_info *fs_info, u64 objectid);
 117 int clean_tree_block(struct btrfs_trans_handle *trans,
 118                      struct btrfs_root *root, struct extent_buffer *buf);
 119
 120 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info);
 121 struct btrfs_fs_info *btrfs_new_fs_info(int writable, u64 sb_bytenr);
 122 int btrfs_check_fs_compatibility(struct btrfs_super_block *sb, int writable);
 123 int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
 124                           unsigned flags);
 125 void btrfs_release_all_roots(struct btrfs_fs_info *fs_info);
 126 void btrfs_cleanup_all_caches(struct btrfs_fs_info *fs_info);
 127 int btrfs_scan_fs_devices(int fd, const char *path,
 128                           struct btrfs_fs_devices **fs_devices, u64 sb_bytenr,
 129                           unsigned sbflags, int skip_devices);
 130 int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info,
 131                           u64 chunk_root_bytenr);
 132
 133 struct btrfs_root *open_ctree(const char *filename, u64 sb_bytenr,
 134                               unsigned flags);
 135 struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr,
 136                                  unsigned flags);
 137 struct btrfs_fs_info *open_ctree_fs_info(const char *filename,
 138                                          u64 sb_bytenr, u64 root_tree_bytenr,
 139                                          u64 chunk_root_bytenr,
 140                                          unsigned flags);
 141 int close_ctree_fs_info(struct btrfs_fs_info *fs_info);
 142 static inline int close_ctree(struct btrfs_root *root)
 143 {
 144         if (!root)
 145                 return 0;
 146         return close_ctree_fs_info(root->fs_info);
 147 }
 148
 149 int write_all_supers(struct btrfs_root *root);
 150 int write_ctree_super(struct btrfs_trans_handle *trans,
 151                       struct btrfs_root *root);
 152 int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr,
 153                 unsigned sbflags);
 154 int btrfs_map_bh_to_logical(struct btrfs_root *root, struct extent_buffer *bh,
 155                             u64 logical);
 156 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
 157                                             u64 bytenr, u32 blocksize);
 158 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 159                                       struct btrfs_key *location);
 160 struct btrfs_root *btrfs_read_fs_root_no_cache(struct btrfs_fs_info *fs_info,
 161                                                struct btrfs_key *location);
 162 int btrfs_free_fs_root(struct btrfs_root *root);
 163 void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
 164 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid);
 165 int btrfs_set_buffer_uptodate(struct extent_buffer *buf);
 166 int wait_on_tree_block_writeback(struct btrfs_root *root,
 167                                  struct extent_buffer *buf);
 168 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len);
 169 void btrfs_csum_final(u32 crc, char *result);
 170
 171 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 172                              struct btrfs_root *root);
 173 int btrfs_open_device(struct btrfs_device *dev);
 174 int csum_tree_block_size(struct extent_buffer *buf, u16 csum_sectorsize,
 175                          int verify);
 176 int verify_tree_block_csum_silent(struct extent_buffer *buf, u16 csum_size);
 177 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid);
 178 int write_tree_block(struct btrfs_trans_handle *trans,
 179                      struct btrfs_root *root,
 180                      struct extent_buffer *eb);
 181 int write_and_map_eb(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 182                      struct extent_buffer *eb);
 183
 184 /* raid6.c */
 185 void raid6_gen_syndrome(int disks, size_t bytes, void **ptrs);
 186
 187 #endif