xref: /linux/fs/btrfs/disk-io.h (revision a4ff64edf9edc8f05e2183610dc8306d3279c6ac)
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_MIRROR_MAX	 3
10 #define BTRFS_SUPER_MIRROR_SHIFT 12
11 
12 /*
13  * Fixed blocksize for all devices, applies to specific ways of reading
14  * metadata like superblock. Must meet the set_blocksize requirements.
15  *
16  * Do not change.
17  */
18 #define BTRFS_BDEV_BLOCKSIZE	(4096)
19 
20 static inline u64 btrfs_sb_offset(int mirror)
21 {
22 	u64 start = SZ_16K;
23 	if (mirror)
24 		return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror);
25 	return BTRFS_SUPER_INFO_OFFSET;
26 }
27 
28 struct btrfs_device;
29 struct btrfs_fs_devices;
30 struct btrfs_tree_parent_check;
31 
32 void btrfs_check_leaked_roots(struct btrfs_fs_info *fs_info);
33 void btrfs_init_fs_info(struct btrfs_fs_info *fs_info);
34 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
35 				      struct btrfs_tree_parent_check *check);
36 struct extent_buffer *btrfs_find_create_tree_block(
37 						struct btrfs_fs_info *fs_info,
38 						u64 bytenr, u64 owner_root,
39 						int level);
40 void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans,
41 			      struct extent_buffer *buf);
42 void btrfs_clear_oneshot_options(struct btrfs_fs_info *fs_info);
43 int btrfs_start_pre_rw_mount(struct btrfs_fs_info *fs_info);
44 int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
45 			   const struct btrfs_super_block *disk_sb);
46 int __cold open_ctree(struct super_block *sb,
47 	       struct btrfs_fs_devices *fs_devices,
48 	       char *options);
49 void __cold close_ctree(struct btrfs_fs_info *fs_info);
50 int btrfs_validate_super(struct btrfs_fs_info *fs_info,
51 			 struct btrfs_super_block *sb, int mirror_num);
52 int btrfs_check_features(struct btrfs_fs_info *fs_info, bool is_rw_mount);
53 int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors);
54 struct btrfs_super_block *btrfs_read_dev_super(struct block_device *bdev);
55 struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
56 						   int copy_num, bool drop_cache);
57 int btrfs_commit_super(struct btrfs_fs_info *fs_info);
58 struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
59 					struct btrfs_key *key);
60 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
61 			 struct btrfs_root *root);
62 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info);
63 
64 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
65 				     u64 objectid, bool check_ref);
66 struct btrfs_root *btrfs_get_new_fs_root(struct btrfs_fs_info *fs_info,
67 					 u64 objectid, dev_t anon_dev);
68 struct btrfs_root *btrfs_get_fs_root_commit_root(struct btrfs_fs_info *fs_info,
69 						 struct btrfs_path *path,
70 						 u64 objectid);
71 int btrfs_global_root_insert(struct btrfs_root *root);
72 void btrfs_global_root_delete(struct btrfs_root *root);
73 struct btrfs_root *btrfs_global_root(struct btrfs_fs_info *fs_info,
74 				     struct btrfs_key *key);
75 struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info, u64 bytenr);
76 struct btrfs_root *btrfs_extent_root(struct btrfs_fs_info *fs_info, u64 bytenr);
77 struct btrfs_root *btrfs_block_group_root(struct btrfs_fs_info *fs_info);
78 
79 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info);
80 void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info);
81 void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info);
82 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
83 				 struct btrfs_root *root);
84 int btrfs_validate_extent_buffer(struct extent_buffer *eb,
85 				 struct btrfs_tree_parent_check *check);
86 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
87 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info);
88 #endif
89 
90 /*
91  * This function is used to grab the root, and avoid it is freed when we
92  * access it. But it doesn't ensure that the tree is not dropped.
93  *
94  * If you want to ensure the whole tree is safe, you should use
95  * 	fs_info->subvol_srcu
96  */
97 static inline struct btrfs_root *btrfs_grab_root(struct btrfs_root *root)
98 {
99 	if (!root)
100 		return NULL;
101 	if (refcount_inc_not_zero(&root->refs))
102 		return root;
103 	return NULL;
104 }
105 
106 void btrfs_put_root(struct btrfs_root *root);
107 void btrfs_mark_buffer_dirty(struct btrfs_trans_handle *trans,
108 			     struct extent_buffer *buf);
109 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
110 			  int atomic);
111 int btrfs_read_extent_buffer(struct extent_buffer *buf,
112 			     struct btrfs_tree_parent_check *check);
113 
114 blk_status_t btree_csum_one_bio(struct btrfs_bio *bbio);
115 int btrfs_alloc_log_tree_node(struct btrfs_trans_handle *trans,
116 			      struct btrfs_root *root);
117 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
118 			     struct btrfs_fs_info *fs_info);
119 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
120 		       struct btrfs_root *root);
121 void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *trans,
122 			     struct btrfs_fs_info *fs_info);
123 void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
124 				  struct btrfs_fs_info *fs_info);
125 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
126 				     u64 objectid);
127 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
128 int btrfs_get_free_objectid(struct btrfs_root *root, u64 *objectid);
129 int btrfs_init_root_free_objectid(struct btrfs_root *root);
130 
131 #endif
132