fs/btrfs/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 __DISKIO__
  20 #define __DISKIO__
  21
  22 #define BTRFS_SUPER_INFO_OFFSET SZ_64K
  23 #define BTRFS_SUPER_INFO_SIZE 4096
  24
  25 #define BTRFS_SUPER_MIRROR_MAX   3
  26 #define BTRFS_SUPER_MIRROR_SHIFT 12
  27
  28 /*
  29  * Fixed blocksize for all devices, applies to specific ways of reading
  30  * metadata like superblock. Must meet the set_blocksize requirements.
  31  *
  32  * Do not change.
  33  */
  34 #define BTRFS_BDEV_BLOCKSIZE    (4096)
  35
  36 enum btrfs_wq_endio_type {
  37         BTRFS_WQ_ENDIO_DATA = 0,
  38         BTRFS_WQ_ENDIO_METADATA = 1,
  39         BTRFS_WQ_ENDIO_FREE_SPACE = 2,
  40         BTRFS_WQ_ENDIO_RAID56 = 3,
  41         BTRFS_WQ_ENDIO_DIO_REPAIR = 4,
  42 };
  43
  44 static inline u64 btrfs_sb_offset(int mirror)
  45 {
  46         u64 start = SZ_16K;
  47         if (mirror)
  48                 return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror);
  49         return BTRFS_SUPER_INFO_OFFSET;
  50 }
  51
  52 struct btrfs_device;
  53 struct btrfs_fs_devices;
  54
  55 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
  56                                       u64 parent_transid, int level,
  57                                       struct btrfs_key *first_key);
  58 void readahead_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr);
  59 int reada_tree_block_flagged(struct btrfs_fs_info *fs_info, u64 bytenr,
  60                          int mirror_num, struct extent_buffer **eb);
  61 struct extent_buffer *btrfs_find_create_tree_block(
  62                                                 struct btrfs_fs_info *fs_info,
  63                                                 u64 bytenr);
  64 void clean_tree_block(struct btrfs_fs_info *fs_info, struct extent_buffer *buf);
  65 int open_ctree(struct super_block *sb,
  66                struct btrfs_fs_devices *fs_devices,
  67                char *options);
  68 void close_ctree(struct btrfs_fs_info *fs_info);
  69 int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors);
  70 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev);
  71 int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
  72                         struct buffer_head **bh_ret);
  73 int btrfs_commit_super(struct btrfs_fs_info *fs_info);
  74 struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
  75                                       struct btrfs_key *location);
  76 int btrfs_init_fs_root(struct btrfs_root *root);
  77 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
  78                                         u64 root_id);
  79 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
  80                          struct btrfs_root *root);
  81 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info);
  82
  83 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
  84                                      struct btrfs_key *key,
  85                                      bool check_ref);
  86 static inline struct btrfs_root *
  87 btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
  88                            struct btrfs_key *location)
  89 {
  90         return btrfs_get_fs_root(fs_info, location, true);
  91 }
  92
  93 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
  94 void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info);
  95 void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info);
  96 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
  97                                  struct btrfs_root *root);
  98 void btrfs_free_fs_root(struct btrfs_root *root);
  99
 100 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 101 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info);
 102 #endif
 103
 104 /*
 105  * This function is used to grab the root, and avoid it is freed when we
 106  * access it. But it doesn't ensure that the tree is not dropped.
 107  *
 108  * If you want to ensure the whole tree is safe, you should use
 109  *      fs_info->subvol_srcu
 110  */
 111 static inline struct btrfs_root *btrfs_grab_fs_root(struct btrfs_root *root)
 112 {
 113         if (refcount_inc_not_zero(&root->refs))
 114                 return root;
 115         return NULL;
 116 }
 117
 118 static inline void btrfs_put_fs_root(struct btrfs_root *root)
 119 {
 120         if (refcount_dec_and_test(&root->refs))
 121                 kfree(root);
 122 }
 123
 124 void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
 125 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
 126                           int atomic);
 127 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid, int level,
 128                       struct btrfs_key *first_key);
 129 u32 btrfs_csum_data(const char *data, u32 seed, size_t len);
 130 void btrfs_csum_final(u32 crc, u8 *result);
 131 blk_status_t btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 132                         enum btrfs_wq_endio_type metadata);
 133 blk_status_t btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 134                         int mirror_num, unsigned long bio_flags,
 135                         u64 bio_offset, void *private_data,
 136                         extent_submit_bio_start_t *submit_bio_start,
 137                         extent_submit_bio_done_t *submit_bio_done);
 138 int btrfs_write_tree_block(struct extent_buffer *buf);
 139 void btrfs_wait_tree_block_writeback(struct extent_buffer *buf);
 140 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 141                              struct btrfs_fs_info *fs_info);
 142 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
 143                        struct btrfs_root *root);
 144 void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *trans,
 145                              struct btrfs_fs_info *fs_info);
 146 void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
 147                                   struct btrfs_fs_info *fs_info);
 148 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 149                                      struct btrfs_fs_info *fs_info,
 150                                      u64 objectid);
 151 int btree_lock_page_hook(struct page *page, void *data,
 152                                 void (*flush_fn)(void *));
 153 struct extent_map *btree_get_extent(struct btrfs_inode *inode,
 154                 struct page *page, size_t pg_offset, u64 start, u64 len,
 155                 int create);
 156 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
 157 int __init btrfs_end_io_wq_init(void);
 158 void __cold btrfs_end_io_wq_exit(void);
 159
 160 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 161 void btrfs_init_lockdep(void);
 162 void btrfs_set_buffer_lockdep_class(u64 objectid,
 163                                     struct extent_buffer *eb, int level);
 164 #else
 165 static inline void btrfs_init_lockdep(void)
 166 { }
 167 static inline void btrfs_set_buffer_lockdep_class(u64 objectid,
 168                                         struct extent_buffer *eb, int level)
 169 {
 170 }
 171 #endif
 172 #endif