aaf99529883db2f17ad7fcff20cadb4c1609af49
[sfrench/cifs-2.6.git] / fs / btrfs / disk-io.h
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 /*
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 enum btrfs_wq_endio_type {
37         BTRFS_WQ_ENDIO_DATA = 0,
38         BTRFS_WQ_ENDIO_METADATA = 1,
39         BTRFS_WQ_ENDIO_FREE_SPACE = 2,
40         BTRFS_WQ_ENDIO_RAID56 = 3,
41         BTRFS_WQ_ENDIO_DIO_REPAIR = 4,
42 };
43
44 static inline u64 btrfs_sb_offset(int mirror)
45 {
46         u64 start = SZ_16K;
47         if (mirror)
48                 return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror);
49         return BTRFS_SUPER_INFO_OFFSET;
50 }
51
52 struct btrfs_device;
53 struct btrfs_fs_devices;
54
55 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info,
56                                       u64 bytenr, u64 parent_transid);
57 void readahead_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr);
58 int reada_tree_block_flagged(struct btrfs_fs_info *fs_info, u64 bytenr,
59                          int mirror_num, struct extent_buffer **eb);
60 struct extent_buffer *btrfs_find_create_tree_block(
61                                                 struct btrfs_fs_info *fs_info,
62                                                 u64 bytenr);
63 void clean_tree_block(struct btrfs_fs_info *fs_info, struct extent_buffer *buf);
64 int open_ctree(struct super_block *sb,
65                struct btrfs_fs_devices *fs_devices,
66                char *options);
67 void close_ctree(struct btrfs_fs_info *fs_info);
68 int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors);
69 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev);
70 int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
71                         struct buffer_head **bh_ret);
72 int btrfs_commit_super(struct btrfs_fs_info *fs_info);
73 struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
74                                       struct btrfs_key *location);
75 int btrfs_init_fs_root(struct btrfs_root *root);
76 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
77                                         u64 root_id);
78 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
79                          struct btrfs_root *root);
80 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info);
81
82 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
83                                      struct btrfs_key *key,
84                                      bool check_ref);
85 static inline struct btrfs_root *
86 btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
87                            struct btrfs_key *location)
88 {
89         return btrfs_get_fs_root(fs_info, location, true);
90 }
91
92 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
93 void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info);
94 void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info);
95 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
96                                  struct btrfs_root *root);
97 void btrfs_free_fs_root(struct btrfs_root *root);
98
99 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
100 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info);
101 #endif
102
103 /*
104  * This function is used to grab the root, and avoid it is freed when we
105  * access it. But it doesn't ensure that the tree is not dropped.
106  *
107  * If you want to ensure the whole tree is safe, you should use
108  *      fs_info->subvol_srcu
109  */
110 static inline struct btrfs_root *btrfs_grab_fs_root(struct btrfs_root *root)
111 {
112         if (refcount_inc_not_zero(&root->refs))
113                 return root;
114         return NULL;
115 }
116
117 static inline void btrfs_put_fs_root(struct btrfs_root *root)
118 {
119         if (refcount_dec_and_test(&root->refs))
120                 kfree(root);
121 }
122
123 void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
124 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
125                           int atomic);
126 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid);
127 u32 btrfs_csum_data(const char *data, u32 seed, size_t len);
128 void btrfs_csum_final(u32 crc, u8 *result);
129 blk_status_t btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
130                         enum btrfs_wq_endio_type metadata);
131 blk_status_t btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
132                         int mirror_num, unsigned long bio_flags,
133                         u64 bio_offset, void *private_data,
134                         extent_submit_bio_hook_t *submit_bio_start,
135                         extent_submit_bio_hook_t *submit_bio_done);
136 int btrfs_write_tree_block(struct extent_buffer *buf);
137 void btrfs_wait_tree_block_writeback(struct extent_buffer *buf);
138 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
139                              struct btrfs_fs_info *fs_info);
140 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
141                        struct btrfs_root *root);
142 void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *trans,
143                              struct btrfs_fs_info *fs_info);
144 void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
145                                   struct btrfs_fs_info *fs_info);
146 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
147                                      struct btrfs_fs_info *fs_info,
148                                      u64 objectid);
149 int btree_lock_page_hook(struct page *page, void *data,
150                                 void (*flush_fn)(void *));
151 struct extent_map *btree_get_extent(struct btrfs_inode *inode,
152                 struct page *page, size_t pg_offset, u64 start, u64 len,
153                 int create);
154 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
155 int __init btrfs_end_io_wq_init(void);
156 void __cold btrfs_end_io_wq_exit(void);
157
158 #ifdef CONFIG_DEBUG_LOCK_ALLOC
159 void btrfs_init_lockdep(void);
160 void btrfs_set_buffer_lockdep_class(u64 objectid,
161                                     struct extent_buffer *eb, int level);
162 #else
163 static inline void btrfs_init_lockdep(void)
164 { }
165 static inline void btrfs_set_buffer_lockdep_class(u64 objectid,
166                                         struct extent_buffer *eb, int level)
167 {
168 }
169 #endif
170 #endif