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 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info);
 137 int btrfs_write_tree_block(struct extent_buffer *buf);
 138 void btrfs_wait_tree_block_writeback(struct extent_buffer *buf);
 139 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 140                              struct btrfs_fs_info *fs_info);
 141 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
 142                        struct btrfs_root *root);
 143 void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *trans,
 144                              struct btrfs_fs_info *fs_info);
 145 void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
 146                                   struct btrfs_fs_info *fs_info);
 147 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 148                                      struct btrfs_fs_info *fs_info,
 149                                      u64 objectid);
 150 int btree_lock_page_hook(struct page *page, void *data,
 151                                 void (*flush_fn)(void *));
 152 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
 153 int __init btrfs_end_io_wq_init(void);
 154 void btrfs_end_io_wq_exit(void);
 155
 156 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 157 void btrfs_init_lockdep(void);
 158 void btrfs_set_buffer_lockdep_class(u64 objectid,
 159                                     struct extent_buffer *eb, int level);
 160 #else
 161 static inline void btrfs_init_lockdep(void)
 162 { }
 163 static inline void btrfs_set_buffer_lockdep_class(u64 objectid,
 164                                         struct extent_buffer *eb, int level)
 165 {
 166 }
 167 #endif
 168 #endif