linux/fs/btrfs/disk-io.h
<<
>>
Prefs
   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
  23enum btrfs_wq_endio_type {
  24        BTRFS_WQ_ENDIO_DATA = 0,
  25        BTRFS_WQ_ENDIO_METADATA = 1,
  26        BTRFS_WQ_ENDIO_FREE_SPACE = 2,
  27        BTRFS_WQ_ENDIO_RAID56 = 3,
  28        BTRFS_WQ_ENDIO_DIO_REPAIR = 4,
  29};
  30
  31static 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
  39struct btrfs_device;
  40struct btrfs_fs_devices;
  41
  42struct 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);
  45void readahead_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr);
  46int reada_tree_block_flagged(struct btrfs_fs_info *fs_info, u64 bytenr,
  47                         int mirror_num, struct extent_buffer **eb);
  48struct extent_buffer *btrfs_find_create_tree_block(
  49                                                struct btrfs_fs_info *fs_info,
  50                                                u64 bytenr);
  51void clean_tree_block(struct btrfs_fs_info *fs_info, struct extent_buffer *buf);
  52int open_ctree(struct super_block *sb,
  53               struct btrfs_fs_devices *fs_devices,
  54               char *options);
  55void close_ctree(struct btrfs_fs_info *fs_info);
  56int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors);
  57struct buffer_head *btrfs_read_dev_super(struct block_device *bdev);
  58int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
  59                        struct buffer_head **bh_ret);
  60int btrfs_commit_super(struct btrfs_fs_info *fs_info);
  61struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
  62                                      struct btrfs_key *location);
  63int btrfs_init_fs_root(struct btrfs_root *root);
  64struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
  65                                        u64 root_id);
  66int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
  67                         struct btrfs_root *root);
  68void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info);
  69
  70struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
  71                                     struct btrfs_key *key,
  72                                     bool check_ref);
  73static inline struct btrfs_root *
  74btrfs_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
  80int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
  81void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info);
  82void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info);
  83void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
  84                                 struct btrfs_root *root);
  85void btrfs_free_fs_root(struct btrfs_root *root);
  86
  87#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
  88struct 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 */
  98static 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
 105static inline void btrfs_put_fs_root(struct btrfs_root *root)
 106{
 107        if (refcount_dec_and_test(&root->refs))
 108                kfree(root);
 109}
 110
 111void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
 112int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
 113                          int atomic);
 114int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid, int level,
 115                      struct btrfs_key *first_key);
 116u32 btrfs_csum_data(const char *data, u32 seed, size_t len);
 117void btrfs_csum_final(u32 crc, u8 *result);
 118blk_status_t btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 119                        enum btrfs_wq_endio_type metadata);
 120blk_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                        extent_submit_bio_done_t *submit_bio_done);
 125int btrfs_write_tree_block(struct extent_buffer *buf);
 126void btrfs_wait_tree_block_writeback(struct extent_buffer *buf);
 127int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 128                             struct btrfs_fs_info *fs_info);
 129int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
 130                       struct btrfs_root *root);
 131void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *trans,
 132                             struct btrfs_fs_info *fs_info);
 133void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
 134                                  struct btrfs_fs_info *fs_info);
 135struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 136                                     struct btrfs_fs_info *fs_info,
 137                                     u64 objectid);
 138int btree_lock_page_hook(struct page *page, void *data,
 139                                void (*flush_fn)(void *));
 140struct extent_map *btree_get_extent(struct btrfs_inode *inode,
 141                struct page *page, size_t pg_offset, u64 start, u64 len,
 142                int create);
 143int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
 144int __init btrfs_end_io_wq_init(void);
 145void __cold btrfs_end_io_wq_exit(void);
 146
 147#ifdef CONFIG_DEBUG_LOCK_ALLOC
 148void btrfs_init_lockdep(void);
 149void btrfs_set_buffer_lockdep_class(u64 objectid,
 150                                    struct extent_buffer *eb, int level);
 151#else
 152static inline void btrfs_init_lockdep(void)
 153{ }
 154static inline void btrfs_set_buffer_lockdep_class(u64 objectid,
 155                                        struct extent_buffer *eb, int level)
 156{
 157}
 158#endif
 159
 160#endif
 161