xref: /linux/fs/btrfs/disk-io.h (revision c4101e55974cc7d835fbd2d8e01553a3f61e9e75)
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 int btrfs_start_pre_rw_mount(struct btrfs_fs_info *fs_info);
41 int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
42 			   const struct btrfs_super_block *disk_sb);
43 int __cold open_ctree(struct super_block *sb,
44 	       struct btrfs_fs_devices *fs_devices,
45 	       char *options);
46 void __cold close_ctree(struct btrfs_fs_info *fs_info);
47 int btrfs_validate_super(struct btrfs_fs_info *fs_info,
48 			 struct btrfs_super_block *sb, int mirror_num);
49 int btrfs_check_features(struct btrfs_fs_info *fs_info, bool is_rw_mount);
50 int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors);
51 struct btrfs_super_block *btrfs_read_dev_super(struct block_device *bdev);
52 struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
53 						   int copy_num, bool drop_cache);
54 int btrfs_commit_super(struct btrfs_fs_info *fs_info);
55 struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
56 					struct btrfs_key *key);
57 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
58 			 struct btrfs_root *root);
59 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info);
60 
61 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
62 				     u64 objectid, bool check_ref);
63 struct btrfs_root *btrfs_get_new_fs_root(struct btrfs_fs_info *fs_info,
64 					 u64 objectid, dev_t anon_dev);
65 struct btrfs_root *btrfs_get_fs_root_commit_root(struct btrfs_fs_info *fs_info,
66 						 struct btrfs_path *path,
67 						 u64 objectid);
68 int btrfs_global_root_insert(struct btrfs_root *root);
69 void btrfs_global_root_delete(struct btrfs_root *root);
70 struct btrfs_root *btrfs_global_root(struct btrfs_fs_info *fs_info,
71 				     struct btrfs_key *key);
72 struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info, u64 bytenr);
73 struct btrfs_root *btrfs_extent_root(struct btrfs_fs_info *fs_info, u64 bytenr);
74 struct btrfs_root *btrfs_block_group_root(struct btrfs_fs_info *fs_info);
75 
76 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info);
77 void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info);
78 void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info);
79 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
80 				 struct btrfs_root *root);
81 int btrfs_validate_extent_buffer(struct extent_buffer *eb,
82 				 struct btrfs_tree_parent_check *check);
83 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
84 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info);
85 #endif
86 
87 /*
88  * This function is used to grab the root, and avoid it is freed when we
89  * access it. But it doesn't ensure that the tree is not dropped.
90  *
91  * If you want to ensure the whole tree is safe, you should use
92  * 	fs_info->subvol_srcu
93  */
94 static inline struct btrfs_root *btrfs_grab_root(struct btrfs_root *root)
95 {
96 	if (!root)
97 		return NULL;
98 	if (refcount_inc_not_zero(&root->refs))
99 		return root;
100 	return NULL;
101 }
102 
103 void btrfs_put_root(struct btrfs_root *root);
104 void btrfs_mark_buffer_dirty(struct btrfs_trans_handle *trans,
105 			     struct extent_buffer *buf);
106 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
107 			  int atomic);
108 int btrfs_read_extent_buffer(struct extent_buffer *buf,
109 			     struct btrfs_tree_parent_check *check);
110 
111 blk_status_t btree_csum_one_bio(struct btrfs_bio *bbio);
112 int btrfs_alloc_log_tree_node(struct btrfs_trans_handle *trans,
113 			      struct btrfs_root *root);
114 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
115 			     struct btrfs_fs_info *fs_info);
116 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
117 		       struct btrfs_root *root);
118 void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *trans,
119 			     struct btrfs_fs_info *fs_info);
120 void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
121 				  struct btrfs_fs_info *fs_info);
122 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
123 				     u64 objectid);
124 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
125 int btrfs_get_free_objectid(struct btrfs_root *root, u64 *objectid);
126 int btrfs_init_root_free_objectid(struct btrfs_root *root);
127 
128 #endif
129