xref: /linux/fs/btrfs/disk-io.h (revision dbcedec3a31119d7594baacc743300d127c99c56)
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(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,
56 	       struct btrfs_fs_devices *fs_devices,
57 	       char *options);
58 void __cold close_ctree(struct btrfs_fs_info *fs_info);
59 int btrfs_validate_super(struct btrfs_fs_info *fs_info,
60 			 struct btrfs_super_block *sb, int mirror_num);
61 int btrfs_check_features(struct btrfs_fs_info *fs_info, bool is_rw_mount);
62 int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors);
63 struct btrfs_super_block *btrfs_read_dev_super(struct block_device *bdev);
64 struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
65 						   int copy_num, bool drop_cache);
66 int btrfs_commit_super(struct btrfs_fs_info *fs_info);
67 struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
68 					struct btrfs_key *key);
69 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
70 			 struct btrfs_root *root);
71 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info);
72 
73 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
74 				     u64 objectid, bool check_ref);
75 struct btrfs_root *btrfs_get_new_fs_root(struct btrfs_fs_info *fs_info,
76 					 u64 objectid, dev_t *anon_dev);
77 struct btrfs_root *btrfs_get_fs_root_commit_root(struct btrfs_fs_info *fs_info,
78 						 struct btrfs_path *path,
79 						 u64 objectid);
80 int btrfs_global_root_insert(struct btrfs_root *root);
81 void btrfs_global_root_delete(struct btrfs_root *root);
82 struct btrfs_root *btrfs_global_root(struct btrfs_fs_info *fs_info,
83 				     struct btrfs_key *key);
84 struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info, u64 bytenr);
85 struct btrfs_root *btrfs_extent_root(struct btrfs_fs_info *fs_info, u64 bytenr);
86 struct btrfs_root *btrfs_block_group_root(struct btrfs_fs_info *fs_info);
87 
88 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info);
89 void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info);
90 void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info);
91 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
92 				 struct btrfs_root *root);
93 int btrfs_validate_extent_buffer(struct extent_buffer *eb,
94 				 struct btrfs_tree_parent_check *check);
95 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
96 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info);
97 #endif
98 
99 /*
100  * This function is used to grab the root, and avoid it is freed when we
101  * access it. But it doesn't ensure that the tree is not dropped.
102  *
103  * If you want to ensure the whole tree is safe, you should use
104  * 	fs_info->subvol_srcu
105  */
106 static inline struct btrfs_root *btrfs_grab_root(struct btrfs_root *root)
107 {
108 	if (!root)
109 		return NULL;
110 	if (refcount_inc_not_zero(&root->refs))
111 		return root;
112 	return NULL;
113 }
114 
115 void btrfs_put_root(struct btrfs_root *root);
116 void btrfs_mark_buffer_dirty(struct btrfs_trans_handle *trans,
117 			     struct extent_buffer *buf);
118 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
119 			  int atomic);
120 int btrfs_read_extent_buffer(struct extent_buffer *buf,
121 			     struct btrfs_tree_parent_check *check);
122 
123 blk_status_t btree_csum_one_bio(struct btrfs_bio *bbio);
124 int btrfs_alloc_log_tree_node(struct btrfs_trans_handle *trans,
125 			      struct btrfs_root *root);
126 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
127 			     struct btrfs_fs_info *fs_info);
128 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
129 		       struct btrfs_root *root);
130 void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *trans,
131 			     struct btrfs_fs_info *fs_info);
132 void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
133 				  struct btrfs_fs_info *fs_info);
134 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
135 				     u64 objectid);
136 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
137 int btrfs_get_free_objectid(struct btrfs_root *root, u64 *objectid);
138 int btrfs_init_root_free_objectid(struct btrfs_root *root);
139 
140 #endif
141