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 (64 * 1024)
  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 {
  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 };
  34
  35 static inline u64 btrfs_sb_offset(int mirror)
  36 {
  37         u64 start = 16 * 1024;
  38         if (mirror)
  39                 return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror);
  40         return BTRFS_SUPER_INFO_OFFSET;
  41 }
  42
  43 struct btrfs_device;
  44 struct btrfs_fs_devices;
  45
  46 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
  47                                       u32 blocksize, u64 parent_transid);
  48 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
  49                          u64 parent_transid);
  50 int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr, u32 blocksize,
  51                          int mirror_num, struct extent_buffer **eb);
  52 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
  53                                                    u64 bytenr, u32 blocksize);
  54 void clean_tree_block(struct btrfs_trans_handle *trans,
  55                       struct btrfs_root *root, struct extent_buffer *buf);
  56 int open_ctree(struct super_block *sb,
  57                struct btrfs_fs_devices *fs_devices,
  58                char *options);
  59 int 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_commit_super(struct btrfs_root *root);
  64 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
  65                                             u64 bytenr, u32 blocksize);
  66 struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
  67                                       struct btrfs_key *location);
  68 int btrfs_init_fs_root(struct btrfs_root *root);
  69 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
  70                          struct btrfs_root *root);
  71
  72 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
  73                                      struct btrfs_key *key,
  74                                      bool check_ref);
  75 static inline struct btrfs_root *
  76 btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
  77                            struct btrfs_key *location)
  78 {
  79         return btrfs_get_fs_root(fs_info, location, true);
  80 }
  81
  82 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
  83 void btrfs_btree_balance_dirty(struct btrfs_root *root);
  84 void btrfs_btree_balance_dirty_nodelay(struct btrfs_root *root);
  85 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
  86                                  struct btrfs_root *root);
  87 void btrfs_free_fs_root(struct btrfs_root *root);
  88
  89 /*
  90  * This function is used to grab the root, and avoid it is freed when we
  91  * access it. But it doesn't ensure that the tree is not dropped.
  92  *
  93  * If you want to ensure the whole tree is safe, you should use
  94  *      fs_info->subvol_srcu
  95  */
  96 static inline struct btrfs_root *btrfs_grab_fs_root(struct btrfs_root *root)
  97 {
  98         if (atomic_inc_not_zero(&root->refs))
  99                 return root;
 100         return NULL;
 101 }
 102
 103 static inline void btrfs_put_fs_root(struct btrfs_root *root)
 104 {
 105         if (atomic_dec_and_test(&root->refs))
 106                 kfree(root);
 107 }
 108
 109 void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
 110 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
 111                           int atomic);
 112 int btrfs_set_buffer_uptodate(struct extent_buffer *buf);
 113 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid);
 114 u32 btrfs_csum_data(char *data, u32 seed, size_t len);
 115 void btrfs_csum_final(u32 crc, char *result);
 116 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 117                         int metadata);
 118 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 119                         int rw, struct bio *bio, int mirror_num,
 120                         unsigned long bio_flags, u64 bio_offset,
 121                         extent_submit_bio_hook_t *submit_bio_start,
 122                         extent_submit_bio_hook_t *submit_bio_done);
 123 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info);
 124 int btrfs_write_tree_block(struct extent_buffer *buf);
 125 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf);
 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_one_transaction(struct btrfs_transaction *trans,
 131                                   struct btrfs_root *root);
 132 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 133                                      struct btrfs_fs_info *fs_info,
 134                                      u64 objectid);
 135 int btree_lock_page_hook(struct page *page, void *data,
 136                                 void (*flush_fn)(void *));
 137 int btrfs_calc_num_tolerated_disk_barrier_failures(
 138         struct btrfs_fs_info *fs_info);
 139
 140 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 141 void btrfs_init_lockdep(void);
 142 void btrfs_set_buffer_lockdep_class(u64 objectid,
 143                                     struct extent_buffer *eb, int level);
 144 #else
 145 static inline void btrfs_init_lockdep(void)
 146 { }
 147 static inline void btrfs_set_buffer_lockdep_class(u64 objectid,
 148                                         struct extent_buffer *eb, int level)
 149 {
 150 }
 151 #endif
 152 #endif