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 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
  72                                               struct btrfs_key *location);
  73 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
  74 void btrfs_btree_balance_dirty(struct btrfs_root *root);
  75 void btrfs_btree_balance_dirty_nodelay(struct btrfs_root *root);
  76 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
  77                                  struct btrfs_root *root);
  78 void btrfs_free_fs_root(struct btrfs_root *root);
  79
  80 /*
  81  * This function is used to grab the root, and avoid it is freed when we
  82  * access it. But it doesn't ensure that the tree is not dropped.
  83  *
  84  * If you want to ensure the whole tree is safe, you should use
  85  *      fs_info->subvol_srcu
  86  */
  87 static inline struct btrfs_root *btrfs_grab_fs_root(struct btrfs_root *root)
  88 {
  89         if (atomic_inc_not_zero(&root->refs))
  90                 return root;
  91         return NULL;
  92 }
  93
  94 static inline void btrfs_put_fs_root(struct btrfs_root *root)
  95 {
  96         if (atomic_dec_and_test(&root->refs))
  97                 kfree(root);
  98 }
  99
 100 void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
 101 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
 102                           int atomic);
 103 int btrfs_set_buffer_uptodate(struct extent_buffer *buf);
 104 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid);
 105 u32 btrfs_csum_data(char *data, u32 seed, size_t len);
 106 void btrfs_csum_final(u32 crc, char *result);
 107 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 108                         int metadata);
 109 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 110                         int rw, struct bio *bio, int mirror_num,
 111                         unsigned long bio_flags, u64 bio_offset,
 112                         extent_submit_bio_hook_t *submit_bio_start,
 113                         extent_submit_bio_hook_t *submit_bio_done);
 114 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info);
 115 int btrfs_write_tree_block(struct extent_buffer *buf);
 116 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf);
 117 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 118                              struct btrfs_fs_info *fs_info);
 119 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
 120                        struct btrfs_root *root);
 121 void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
 122                                   struct btrfs_root *root);
 123 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 124                                      struct btrfs_fs_info *fs_info,
 125                                      u64 objectid);
 126 int btree_lock_page_hook(struct page *page, void *data,
 127                                 void (*flush_fn)(void *));
 128 int btrfs_calc_num_tolerated_disk_barrier_failures(
 129         struct btrfs_fs_info *fs_info);
 130
 131 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 132 void btrfs_init_lockdep(void);
 133 void btrfs_set_buffer_lockdep_class(u64 objectid,
 134                                     struct extent_buffer *eb, int level);
 135 #else
 136 static inline void btrfs_init_lockdep(void)
 137 { }
 138 static inline void btrfs_set_buffer_lockdep_class(u64 objectid,
 139                                         struct extent_buffer *eb, int level)
 140 {
 141 }
 142 #endif
 143 #endif