LXR linux/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
  28enum 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
  36static 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
  44struct btrfs_device;
  45struct btrfs_fs_devices;
  46
  47struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
  48                                      u64 parent_transid);
  49void readahead_tree_block(struct btrfs_root *root, u64 bytenr);
  50int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr,
  51                         int mirror_num, struct extent_buffer **eb);
  52struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
  53                                                   u64 bytenr);
  54void clean_tree_block(struct btrfs_trans_handle *trans,
  55                      struct btrfs_fs_info *fs_info, struct extent_buffer *buf);
  56int open_ctree(struct super_block *sb,
  57               struct btrfs_fs_devices *fs_devices,
  58               char *options);
  59void close_ctree(struct btrfs_root *root);
  60int write_ctree_super(struct btrfs_trans_handle *trans,
  61                      struct btrfs_root *root, int max_mirrors);
  62struct buffer_head *btrfs_read_dev_super(struct block_device *bdev);
  63int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
  64                        struct buffer_head **bh_ret);
  65int btrfs_commit_super(struct btrfs_root *root);
  66struct extent_buffer *btrfs_find_tree_block(struct btrfs_fs_info *fs_info,
  67                                            u64 bytenr);
  68struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
  69                                      struct btrfs_key *location);
  70int btrfs_init_fs_root(struct btrfs_root *root);
  71int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
  72                         struct btrfs_root *root);
  73void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info);
  74
  75struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
  76                                     struct btrfs_key *key,
  77                                     bool check_ref);
  78static inline struct btrfs_root *
  79btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
  80                           struct btrfs_key *location)
  81{
  82        return btrfs_get_fs_root(fs_info, location, true);
  83}
  84
  85int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
  86void btrfs_btree_balance_dirty(struct btrfs_root *root);
  87void btrfs_btree_balance_dirty_nodelay(struct btrfs_root *root);
  88void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
  89                                 struct btrfs_root *root);
  90void btrfs_free_fs_root(struct btrfs_root *root);
  91
  92#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
  93struct btrfs_root *btrfs_alloc_dummy_root(void);
  94#endif
  95
  96/*
  97 * This function is used to grab the root, and avoid it is freed when we
  98 * access it. But it doesn't ensure that the tree is not dropped.
  99 *
 100 * If you want to ensure the whole tree is safe, you should use
 101 *      fs_info->subvol_srcu
 102 */
 103static inline struct btrfs_root *btrfs_grab_fs_root(struct btrfs_root *root)
 104{
 105        if (atomic_inc_not_zero(&root->refs))
 106                return root;
 107        return NULL;
 108}
 109
 110static inline void btrfs_put_fs_root(struct btrfs_root *root)
 111{
 112        if (atomic_dec_and_test(&root->refs))
 113                kfree(root);
 114}
 115
 116void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
 117int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
 118                          int atomic);
 119int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid);
 120u32 btrfs_csum_data(char *data, u32 seed, size_t len);
 121void btrfs_csum_final(u32 crc, char *result);
 122int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 123                        enum btrfs_wq_endio_type metadata);
 124int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 125                        int rw, struct bio *bio, int mirror_num,
 126                        unsigned long bio_flags, u64 bio_offset,
 127                        extent_submit_bio_hook_t *submit_bio_start,
 128                        extent_submit_bio_hook_t *submit_bio_done);
 129unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info);
 130int btrfs_write_tree_block(struct extent_buffer *buf);
 131int btrfs_wait_tree_block_writeback(struct extent_buffer *buf);
 132int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 133                             struct btrfs_fs_info *fs_info);
 134int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
 135                       struct btrfs_root *root);
 136void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
 137                                  struct btrfs_root *root);
 138struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 139                                     struct btrfs_fs_info *fs_info,
 140                                     u64 objectid);
 141int btree_lock_page_hook(struct page *page, void *data,
 142                                void (*flush_fn)(void *));
 143int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
 144int btrfs_calc_num_tolerated_disk_barrier_failures(
 145        struct btrfs_fs_info *fs_info);
 146int __init btrfs_end_io_wq_init(void);
 147void btrfs_end_io_wq_exit(void);
 148
 149#ifdef CONFIG_DEBUG_LOCK_ALLOC
 150void btrfs_init_lockdep(void);
 151void btrfs_set_buffer_lockdep_class(u64 objectid,
 152                                    struct extent_buffer *eb, int level);
 153#else
 154static inline void btrfs_init_lockdep(void)
 155{ }
 156static inline void btrfs_set_buffer_lockdep_class(u64 objectid,
 157                                        struct extent_buffer *eb, int level)
 158{
 159}
 160#endif
 161#endif
 162