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 #include <linux/sizes.h>
10 #include <linux/compiler_types.h>
11 #include "ctree.h"
12 #include "fs.h"
13 
14 struct block_device;
15 struct super_block;
16 struct extent_buffer;
17 struct btrfs_device;
18 struct btrfs_fs_devices;
19 struct btrfs_fs_info;
20 struct btrfs_super_block;
21 struct btrfs_trans_handle;
22 struct btrfs_tree_parent_check;
23 struct btrfs_transaction;
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 static inline u64 btrfs_sb_offset(int mirror)
37 {
38 	u64 start = SZ_16K;
39 	if (mirror)
40 		return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror);
41 	return BTRFS_SUPER_INFO_OFFSET;
42 }
43 
44 void btrfs_check_leaked_roots(const struct btrfs_fs_info *fs_info);
45 void btrfs_init_fs_info(struct btrfs_fs_info *fs_info);
46 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
47 				      struct btrfs_tree_parent_check *check);
48 struct extent_buffer *btrfs_find_create_tree_block(
49 						struct btrfs_fs_info *fs_info,
50 						u64 bytenr, u64 owner_root,
51 						int level);
52 int btrfs_start_pre_rw_mount(struct btrfs_fs_info *fs_info);
53 int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
54 			   const struct btrfs_super_block *disk_sb);
55 int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_devices);
56 void __cold close_ctree(struct btrfs_fs_info *fs_info);
57 int btrfs_validate_super(const struct btrfs_fs_info *fs_info,
58 			 const struct btrfs_super_block *sb, int mirror_num);
59 int btrfs_check_features(struct btrfs_fs_info *fs_info, bool is_rw_mount);
60 int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors);
61 int btrfs_commit_super(struct btrfs_fs_info *fs_info);
62 struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
63 					const struct btrfs_key *key);
64 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
65 			 struct btrfs_root *root);
66 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info);
67 
68 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
69 				     u64 objectid, bool check_ref);
70 struct btrfs_root *btrfs_get_new_fs_root(struct btrfs_fs_info *fs_info,
71 					 u64 objectid, dev_t *anon_dev);
72 struct btrfs_root *btrfs_get_fs_root_commit_root(struct btrfs_fs_info *fs_info,
73 						 struct btrfs_path *path,
74 						 u64 objectid);
75 int btrfs_global_root_insert(struct btrfs_root *root);
76 void btrfs_global_root_delete(struct btrfs_root *root);
77 struct btrfs_root *btrfs_global_root(struct btrfs_fs_info *fs_info,
78 				     struct btrfs_key *key);
79 struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info, u64 bytenr);
80 struct btrfs_root *btrfs_extent_root(struct btrfs_fs_info *fs_info, u64 bytenr);
81 
82 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info);
83 void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info);
84 void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info);
85 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
86 				 struct btrfs_root *root);
87 int btrfs_validate_extent_buffer(struct extent_buffer *eb,
88 				 const struct btrfs_tree_parent_check *check);
89 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
90 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info);
91 #endif
92 
93 /*
94  * This function is used to grab the root, and avoid it is freed when we
95  * access it. But it doesn't ensure that the tree is not dropped.
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 			     const struct btrfs_tree_parent_check *check);
113 
114 int 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_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
125 				     u64 objectid);
126 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
127 int btrfs_get_free_objectid(struct btrfs_root *root, u64 *objectid);
128 int btrfs_init_root_free_objectid(struct btrfs_root *root);
129 
130 #endif
131