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 filesystem for writes */
  33         OPEN_CTREE_WRITES               = (1U << 0),
  34         /* Allow to open filesystem with some broken tree roots (eg log root) */
  35         OPEN_CTREE_PARTIAL              = (1U << 1),
  36         /* If primary root pinters are invalid, try backup copies */
  37         OPEN_CTREE_BACKUP_ROOT          = (1U << 2),
  38         /* Allow reading all superblock sopies if the primary is damaged */
  39         OPEN_CTREE_RECOVER_SUPER        = (1U << 3),
  40         /* Restoring filesystem image */
  41         OPEN_CTREE_RESTORE              = (1U << 4),
  42         /* Do not read block groups (extent tree) */
  43         OPEN_CTREE_NO_BLOCK_GROUPS      = (1U << 5),
  44         /* Open all devices in O_EXCL mode */
  45         OPEN_CTREE_EXCLUSIVE            = (1U << 6),
  46         /* Do not scan devices */
  47         OPEN_CTREE_NO_DEVICES           = (1U << 7),
  48         /*
  49          * Don't print error messages if bytenr or checksums do not match in
  50          * tree block headers. Turn on by OPEN_CTREE_SUPPRESS_ERROR
  51          */
  52         OPEN_CTREE_SUPPRESS_CHECK_BLOCK_ERRORS  = (1U << 8),
  53         /* Return the chunk root */
  54         __OPEN_CTREE_RETURN_CHUNK_ROOT  = (1U << 9),
  55         OPEN_CTREE_CHUNK_ROOT_ONLY      = OPEN_CTREE_PARTIAL +
  56                                           OPEN_CTREE_SUPPRESS_CHECK_BLOCK_ERRORS +
  57                                           __OPEN_CTREE_RETURN_CHUNK_ROOT,
  58         /*
  59          * TODO: cleanup: Split the open_ctree_flags into more independent
  60          * Tree bits.
  61          * Like split PARTIAL into SKIP_CSUM/SKIP_EXTENT
  62          */
  63
  64         /* Ignore UUID mismatches */
  65         OPEN_CTREE_IGNORE_FSID_MISMATCH = (1U << 10),
  66
  67         /*
  68          * Allow open_ctree_fs_info() to return an incomplete fs_info with
  69          * system chunks from super block only.
  70          * It's useful when chunks are corrupted.
  71          * Makes no sense for open_ctree variants returning btrfs_root.
  72          */
  73         OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR = (1U << 11),
  74
  75         /* Allow to open a partially created filesystem */
  76         OPEN_CTREE_FS_PARTIAL = (1U << 12),
  77
  78         /*
  79          * Invalidate the free space tree (i.e., clear the FREE_SPACE_TREE_VALID
  80          * compat_ro bit).
  81          */
  82         OPEN_CTREE_INVALIDATE_FST = (1U << 13),
  83 };
  84
  85 /*
  86  * Modes of superblock access
  87  */
  88 enum btrfs_read_sb_flags {
  89         SBREAD_DEFAULT          = 0,
  90         /* Reading superblock during recovery */
  91         SBREAD_RECOVER          = (1 << 0),
  92
  93         /*
  94          * Read superblock with the fake signature, cannot be used with
  95          * SBREAD_RECOVER
  96          */
  97         SBREAD_PARTIAL          = (1 << 1),
  98 };
  99
 100 static inline u64 btrfs_sb_offset(int mirror)
 101 {
 102         u64 start = 16 * 1024;
 103         if (mirror)
 104                 return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror);
 105         return BTRFS_SUPER_INFO_OFFSET;
 106 }
 107
 108 struct btrfs_device;
 109
 110 int read_whole_eb(struct btrfs_fs_info *info, struct extent_buffer *eb, int mirror);
 111 struct extent_buffer* read_tree_block_fs_info(
 112                 struct btrfs_fs_info *fs_info, u64 bytenr, u32 blocksize,
 113                 u64 parent_transid);
 114 static inline struct extent_buffer* read_tree_block(
 115                 struct btrfs_root *root, u64 bytenr, u32 blocksize,
 116                 u64 parent_transid)
 117 {
 118         return read_tree_block_fs_info(root->fs_info, bytenr, blocksize,
 119                         parent_transid);
 120 }
 121
 122 int read_extent_data(struct btrfs_root *root, char *data, u64 logical,
 123                      u64 *len, int mirror);
 124 void readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
 125                           u64 parent_transid);
 126 struct extent_buffer* btrfs_find_create_tree_block(
 127                 struct btrfs_fs_info *fs_info, u64 bytenr, u32 blocksize);
 128
 129 void btrfs_setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 130                         u32 stripesize, struct btrfs_root *root,
 131                         struct btrfs_fs_info *fs_info, u64 objectid);
 132 int clean_tree_block(struct btrfs_trans_handle *trans,
 133                      struct btrfs_root *root, struct extent_buffer *buf);
 134
 135 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info);
 136 struct btrfs_fs_info *btrfs_new_fs_info(int writable, u64 sb_bytenr);
 137 int btrfs_check_fs_compatibility(struct btrfs_super_block *sb,
 138                                  unsigned int flags);
 139 int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
 140                           unsigned flags);
 141 void btrfs_release_all_roots(struct btrfs_fs_info *fs_info);
 142 void btrfs_cleanup_all_caches(struct btrfs_fs_info *fs_info);
 143 int btrfs_scan_fs_devices(int fd, const char *path,
 144                           struct btrfs_fs_devices **fs_devices, u64 sb_bytenr,
 145                           unsigned sbflags, int skip_devices);
 146 int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info,
 147                           u64 chunk_root_bytenr);
 148
 149 struct btrfs_root *open_ctree(const char *filename, u64 sb_bytenr,
 150                               unsigned flags);
 151 struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr,
 152                                  unsigned flags);
 153 struct btrfs_fs_info *open_ctree_fs_info(const char *filename,
 154                                          u64 sb_bytenr, u64 root_tree_bytenr,
 155                                          u64 chunk_root_bytenr,
 156                                          unsigned flags);
 157 int close_ctree_fs_info(struct btrfs_fs_info *fs_info);
 158 static inline int close_ctree(struct btrfs_root *root)
 159 {
 160         if (!root)
 161                 return 0;
 162         return close_ctree_fs_info(root->fs_info);
 163 }
 164
 165 int write_all_supers(struct btrfs_root *root);
 166 int write_ctree_super(struct btrfs_trans_handle *trans,
 167                       struct btrfs_root *root);
 168 int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr,
 169                 unsigned sbflags);
 170 int btrfs_map_bh_to_logical(struct btrfs_root *root, struct extent_buffer *bh,
 171                             u64 logical);
 172 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
 173                                             u64 bytenr, u32 blocksize);
 174 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 175                                       struct btrfs_key *location);
 176 struct btrfs_root *btrfs_read_fs_root_no_cache(struct btrfs_fs_info *fs_info,
 177                                                struct btrfs_key *location);
 178 int btrfs_free_fs_root(struct btrfs_root *root);
 179 void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
 180 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid);
 181 int btrfs_set_buffer_uptodate(struct extent_buffer *buf);
 182 int wait_on_tree_block_writeback(struct btrfs_root *root,
 183                                  struct extent_buffer *buf);
 184 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len);
 185 void btrfs_csum_final(u32 crc, u8 *result);
 186
 187 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 188                              struct btrfs_root *root);
 189 int btrfs_open_device(struct btrfs_device *dev);
 190 int csum_tree_block_size(struct extent_buffer *buf, u16 csum_sectorsize,
 191                          int verify);
 192 int verify_tree_block_csum_silent(struct extent_buffer *buf, u16 csum_size);
 193 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid);
 194 int write_tree_block(struct btrfs_trans_handle *trans,
 195                      struct btrfs_root *root,
 196                      struct extent_buffer *eb);
 197 int write_and_map_eb(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 198                      struct extent_buffer *eb);
 199
 200 /* raid56.c */
 201 void raid6_gen_syndrome(int disks, size_t bytes, void **ptrs);
 202
 203 #endif