xref: /openbmc/linux/fs/btrfs/disk-io.h (revision e0d07278)
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 
23 enum btrfs_wq_endio_type {
24 	BTRFS_WQ_ENDIO_DATA,
25 	BTRFS_WQ_ENDIO_METADATA,
26 	BTRFS_WQ_ENDIO_FREE_SPACE,
27 	BTRFS_WQ_ENDIO_RAID56,
28 };
29 
30 static inline u64 btrfs_sb_offset(int mirror)
31 {
32 	u64 start = SZ_16K;
33 	if (mirror)
34 		return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror);
35 	return BTRFS_SUPER_INFO_OFFSET;
36 }
37 
38 struct btrfs_device;
39 struct btrfs_fs_devices;
40 
41 void btrfs_check_leaked_roots(struct btrfs_fs_info *fs_info);
42 void btrfs_init_fs_info(struct btrfs_fs_info *fs_info);
43 int btrfs_verify_level_key(struct extent_buffer *eb, int level,
44 			   struct btrfs_key *first_key, u64 parent_transid);
45 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
46 				      u64 parent_transid, int level,
47 				      struct btrfs_key *first_key);
48 void readahead_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr);
49 struct extent_buffer *btrfs_find_create_tree_block(
50 						struct btrfs_fs_info *fs_info,
51 						u64 bytenr);
52 void btrfs_clean_tree_block(struct extent_buffer *buf);
53 int __cold open_ctree(struct super_block *sb,
54 	       struct btrfs_fs_devices *fs_devices,
55 	       char *options);
56 void __cold close_ctree(struct btrfs_fs_info *fs_info);
57 int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors);
58 struct btrfs_super_block *btrfs_read_dev_super(struct block_device *bdev);
59 struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
60 						   int copy_num);
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 					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 
73 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info);
74 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
75 void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info);
76 void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info);
77 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
78 				 struct btrfs_root *root);
79 
80 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
81 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info);
82 #endif
83 
84 /*
85  * This function is used to grab the root, and avoid it is freed when we
86  * access it. But it doesn't ensure that the tree is not dropped.
87  *
88  * If you want to ensure the whole tree is safe, you should use
89  * 	fs_info->subvol_srcu
90  */
91 static inline struct btrfs_root *btrfs_grab_root(struct btrfs_root *root)
92 {
93 	if (!root)
94 		return NULL;
95 	if (refcount_inc_not_zero(&root->refs))
96 		return root;
97 	return NULL;
98 }
99 
100 void btrfs_put_root(struct btrfs_root *root);
101 void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
102 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
103 			  int atomic);
104 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid, int level,
105 		      struct btrfs_key *first_key);
106 blk_status_t btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
107 			enum btrfs_wq_endio_type metadata);
108 blk_status_t btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
109 			int mirror_num, unsigned long bio_flags,
110 			u64 bio_offset, void *private_data,
111 			extent_submit_bio_start_t *submit_bio_start);
112 blk_status_t btrfs_submit_bio_done(void *private_data, struct bio *bio,
113 			  int mirror_num);
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 btree_lock_page_hook(struct page *page, void *data,
125 				void (*flush_fn)(void *));
126 struct extent_map *btree_get_extent(struct btrfs_inode *inode,
127 				    struct page *page, size_t pg_offset,
128 				    u64 start, u64 len);
129 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
130 int __init btrfs_end_io_wq_init(void);
131 void __cold btrfs_end_io_wq_exit(void);
132 
133 #ifdef CONFIG_DEBUG_LOCK_ALLOC
134 void btrfs_init_lockdep(void);
135 void btrfs_set_buffer_lockdep_class(u64 objectid,
136 			            struct extent_buffer *eb, int level);
137 #else
138 static inline void btrfs_init_lockdep(void)
139 { }
140 static inline void btrfs_set_buffer_lockdep_class(u64 objectid,
141 					struct extent_buffer *eb, int level)
142 {
143 }
144 #endif
145 
146 #endif
147