fs/btrfs/disk-io.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (C) 2007 Oracle.  All rights reserved.
   4  */
   5
   6 #ifndef BTRFS_DISK_IO_H
   7 #define BTRFS_DISK_IO_H
   8
   9 #define BTRFS_SUPER_INFO_OFFSET SZ_64K
  10 #define BTRFS_SUPER_INFO_SIZE 4096
  11
  12 #define BTRFS_SUPER_MIRROR_MAX   3
  13 #define BTRFS_SUPER_MIRROR_SHIFT 12
  14
  15 /*
  16  * Fixed blocksize for all devices, applies to specific ways of reading
  17  * metadata like superblock. Must meet the set_blocksize requirements.
  18  *
  19  * Do not change.
  20  */
  21 #define BTRFS_BDEV_BLOCKSIZE    (4096)
  22
  23 enum btrfs_wq_endio_type {
  24         BTRFS_WQ_ENDIO_DATA,
  25         BTRFS_WQ_ENDIO_METADATA,
  26         BTRFS_WQ_ENDIO_FREE_SPACE,
  27         BTRFS_WQ_ENDIO_RAID56,
  28         BTRFS_WQ_ENDIO_DIO_REPAIR,
  29 };
  30
  31 static inline u64 btrfs_sb_offset(int mirror)
  32 {
  33         u64 start = SZ_16K;
  34         if (mirror)
  35                 return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror);
  36         return BTRFS_SUPER_INFO_OFFSET;
  37 }
  38
  39 struct btrfs_device;
  40 struct btrfs_fs_devices;
  41
  42 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
  43                                       u64 parent_transid, int level,
  44                                       struct btrfs_key *first_key);
  45 void readahead_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr);
  46 int reada_tree_block_flagged(struct btrfs_fs_info *fs_info, u64 bytenr,
  47                          int mirror_num, struct extent_buffer **eb);
  48 struct extent_buffer *btrfs_find_create_tree_block(
  49                                                 struct btrfs_fs_info *fs_info,
  50                                                 u64 bytenr);
  51 void clean_tree_block(struct btrfs_fs_info *fs_info, struct extent_buffer *buf);
  52 int open_ctree(struct super_block *sb,
  53                struct btrfs_fs_devices *fs_devices,
  54                char *options);
  55 void close_ctree(struct btrfs_fs_info *fs_info);
  56 int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors);
  57 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev);
  58 int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
  59                         struct buffer_head **bh_ret);
  60 int btrfs_commit_super(struct btrfs_fs_info *fs_info);
  61 struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
  62                                       struct btrfs_key *location);
  63 int btrfs_init_fs_root(struct btrfs_root *root);
  64 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
  65                                         u64 root_id);
  66 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
  67                          struct btrfs_root *root);
  68 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info);
  69
  70 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
  71                                      struct btrfs_key *key,
  72                                      bool check_ref);
  73 static inline struct btrfs_root *
  74 btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
  75                            struct btrfs_key *location)
  76 {
  77         return btrfs_get_fs_root(fs_info, location, true);
  78 }
  79
  80 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
  81 void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info);
  82 void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info);
  83 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
  84                                  struct btrfs_root *root);
  85 void btrfs_free_fs_root(struct btrfs_root *root);
  86
  87 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
  88 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info);
  89 #endif
  90
  91 /*
  92  * This function is used to grab the root, and avoid it is freed when we
  93  * access it. But it doesn't ensure that the tree is not dropped.
  94  *
  95  * If you want to ensure the whole tree is safe, you should use
  96  *      fs_info->subvol_srcu
  97  */
  98 static inline struct btrfs_root *btrfs_grab_fs_root(struct btrfs_root *root)
  99 {
 100         if (refcount_inc_not_zero(&root->refs))
 101                 return root;
 102         return NULL;
 103 }
 104
 105 static inline void btrfs_put_fs_root(struct btrfs_root *root)
 106 {
 107         if (refcount_dec_and_test(&root->refs))
 108                 kfree(root);
 109 }
 110
 111 void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
 112 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
 113                           int atomic);
 114 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid, int level,
 115                       struct btrfs_key *first_key);
 116 u32 btrfs_csum_data(const char *data, u32 seed, size_t len);
 117 void btrfs_csum_final(u32 crc, u8 *result);
 118 blk_status_t btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 119                         enum btrfs_wq_endio_type metadata);
 120 blk_status_t btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 121                         int mirror_num, unsigned long bio_flags,
 122                         u64 bio_offset, void *private_data,
 123                         extent_submit_bio_start_t *submit_bio_start);
 124 blk_status_t btrfs_submit_bio_done(void *private_data, struct bio *bio,
 125                           int mirror_num);
 126 int btrfs_write_tree_block(struct extent_buffer *buf);
 127 void btrfs_wait_tree_block_writeback(struct extent_buffer *buf);
 128 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 129                              struct btrfs_fs_info *fs_info);
 130 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
 131                        struct btrfs_root *root);
 132 void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *trans,
 133                              struct btrfs_fs_info *fs_info);
 134 void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
 135                                   struct btrfs_fs_info *fs_info);
 136 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 137                                      struct btrfs_fs_info *fs_info,
 138                                      u64 objectid);
 139 int btree_lock_page_hook(struct page *page, void *data,
 140                                 void (*flush_fn)(void *));
 141 struct extent_map *btree_get_extent(struct btrfs_inode *inode,
 142                 struct page *page, size_t pg_offset, u64 start, u64 len,
 143                 int create);
 144 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
 145 int __init btrfs_end_io_wq_init(void);
 146 void __cold btrfs_end_io_wq_exit(void);
 147
 148 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 149 void btrfs_init_lockdep(void);
 150 void btrfs_set_buffer_lockdep_class(u64 objectid,
 151                                     struct extent_buffer *eb, int level);
 152 #else
 153 static inline void btrfs_init_lockdep(void)
 154 { }
 155 static inline void btrfs_set_buffer_lockdep_class(u64 objectid,
 156                                         struct extent_buffer *eb, int level)
 157 {
 158 }
 159 #endif
 160
 161 #endif