xref: /openbmc/linux/fs/btrfs/disk-io.h (revision bc5aa3a0)
1 /*
2  * Copyright (C) 2007 Oracle.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public
6  * License v2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public
14  * License along with this program; if not, write to the
15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16  * Boston, MA 021110-1307, USA.
17  */
18 
19 #ifndef __DISKIO__
20 #define __DISKIO__
21 
22 #define BTRFS_SUPER_INFO_OFFSET SZ_64K
23 #define BTRFS_SUPER_INFO_SIZE 4096
24 
25 #define BTRFS_SUPER_MIRROR_MAX	 3
26 #define BTRFS_SUPER_MIRROR_SHIFT 12
27 
28 enum btrfs_wq_endio_type {
29 	BTRFS_WQ_ENDIO_DATA = 0,
30 	BTRFS_WQ_ENDIO_METADATA = 1,
31 	BTRFS_WQ_ENDIO_FREE_SPACE = 2,
32 	BTRFS_WQ_ENDIO_RAID56 = 3,
33 	BTRFS_WQ_ENDIO_DIO_REPAIR = 4,
34 };
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 struct btrfs_device;
45 struct btrfs_fs_devices;
46 
47 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
48 				      u64 parent_transid);
49 void readahead_tree_block(struct btrfs_root *root, u64 bytenr);
50 int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr,
51 			 int mirror_num, struct extent_buffer **eb);
52 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
53 						   u64 bytenr);
54 void clean_tree_block(struct btrfs_trans_handle *trans,
55 		      struct btrfs_fs_info *fs_info, struct extent_buffer *buf);
56 int open_ctree(struct super_block *sb,
57 	       struct btrfs_fs_devices *fs_devices,
58 	       char *options);
59 void close_ctree(struct btrfs_root *root);
60 int write_ctree_super(struct btrfs_trans_handle *trans,
61 		      struct btrfs_root *root, int max_mirrors);
62 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev);
63 int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
64 			struct buffer_head **bh_ret);
65 int btrfs_commit_super(struct btrfs_root *root);
66 struct extent_buffer *btrfs_find_tree_block(struct btrfs_fs_info *fs_info,
67 					    u64 bytenr);
68 struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
69 				      struct btrfs_key *location);
70 int btrfs_init_fs_root(struct btrfs_root *root);
71 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
72 					u64 root_id);
73 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
74 			 struct btrfs_root *root);
75 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info);
76 
77 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
78 				     struct btrfs_key *key,
79 				     bool check_ref);
80 static inline struct btrfs_root *
81 btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
82 			   struct btrfs_key *location)
83 {
84 	return btrfs_get_fs_root(fs_info, location, true);
85 }
86 
87 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
88 void btrfs_btree_balance_dirty(struct btrfs_root *root);
89 void btrfs_btree_balance_dirty_nodelay(struct btrfs_root *root);
90 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
91 				 struct btrfs_root *root);
92 void btrfs_free_fs_root(struct btrfs_root *root);
93 
94 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
95 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info,
96 					  u32 sectorsize, u32 nodesize);
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_fs_root(struct btrfs_root *root)
107 {
108 	if (atomic_inc_not_zero(&root->refs))
109 		return root;
110 	return NULL;
111 }
112 
113 static inline void btrfs_put_fs_root(struct btrfs_root *root)
114 {
115 	if (atomic_dec_and_test(&root->refs))
116 		kfree(root);
117 }
118 
119 void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
120 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
121 			  int atomic);
122 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid);
123 u32 btrfs_csum_data(char *data, u32 seed, size_t len);
124 void btrfs_csum_final(u32 crc, char *result);
125 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
126 			enum btrfs_wq_endio_type metadata);
127 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
128 			struct bio *bio, int mirror_num,
129 			unsigned long bio_flags, u64 bio_offset,
130 			extent_submit_bio_hook_t *submit_bio_start,
131 			extent_submit_bio_hook_t *submit_bio_done);
132 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info);
133 int btrfs_write_tree_block(struct extent_buffer *buf);
134 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf);
135 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
136 			     struct btrfs_fs_info *fs_info);
137 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
138 		       struct btrfs_root *root);
139 void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
140 				  struct btrfs_root *root);
141 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
142 				     struct btrfs_fs_info *fs_info,
143 				     u64 objectid);
144 int btree_lock_page_hook(struct page *page, void *data,
145 				void (*flush_fn)(void *));
146 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
147 int btrfs_calc_num_tolerated_disk_barrier_failures(
148 	struct btrfs_fs_info *fs_info);
149 int __init btrfs_end_io_wq_init(void);
150 void btrfs_end_io_wq_exit(void);
151 
152 #ifdef CONFIG_DEBUG_LOCK_ALLOC
153 void btrfs_init_lockdep(void);
154 void btrfs_set_buffer_lockdep_class(u64 objectid,
155 			            struct extent_buffer *eb, int level);
156 #else
157 static inline void btrfs_init_lockdep(void)
158 { }
159 static inline void btrfs_set_buffer_lockdep_class(u64 objectid,
160 					struct extent_buffer *eb, int level)
161 {
162 }
163 #endif
164 #endif
165