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);
  71struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
  72                                        u64 root_id);
  73int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
  74                         struct btrfs_root *root);
  75void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info);
  76
  77struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
  78                                     struct btrfs_key *key,
  79                                     bool check_ref);
  80static inline struct btrfs_root *
  81btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
  82                           struct btrfs_key *location)
  83{
  84        return btrfs_get_fs_root(fs_info, location, true);
  85}
  86
  87int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
  88void btrfs_btree_balance_dirty(struct btrfs_root *root);
  89void btrfs_btree_balance_dirty_nodelay(struct btrfs_root *root);
  90void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
  91                                 struct btrfs_root *root);
  92void btrfs_free_fs_root(struct btrfs_root *root);
  93
  94#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
  95struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info,
  96                                          u32 sectorsize, u32 nodesize);
  97#endif
  98
  99/*
 100 * This function is used to grab the root, and avoid it is freed when we
 101 * access it. But it doesn't ensure that the tree is not dropped.
 102 *
 103 * If you want to ensure the whole tree is safe, you should use
 104 *      fs_info->subvol_srcu
 105 */
 106static inline struct btrfs_root *btrfs_grab_fs_root(struct btrfs_root *root)
 107{
 108        if (atomic_inc_not_zero(&root->refs))
 109                return root;
 110        return NULL;
 111}
 112
 113static inline void btrfs_put_fs_root(struct btrfs_root *root)
 114{
 115        if (atomic_dec_and_test(&root->refs))
 116                kfree(root);
 117}
 118
 119void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
 120int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
 121                          int atomic);
 122int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid);
 123u32 btrfs_csum_data(char *data, u32 seed, size_t len);
 124void btrfs_csum_final(u32 crc, char *result);
 125int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 126                        enum btrfs_wq_endio_type metadata);
 127int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 128                        int rw, struct bio *bio, int mirror_num,
 129                        unsigned long bio_flags, u64 bio_offset,
 130                        extent_submit_bio_hook_t *submit_bio_start,
 131                        extent_submit_bio_hook_t *submit_bio_done);
 132unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info);
 133int btrfs_write_tree_block(struct extent_buffer *buf);
 134int btrfs_wait_tree_block_writeback(struct extent_buffer *buf);
 135int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 136                             struct btrfs_fs_info *fs_info);
 137int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
 138                       struct btrfs_root *root);
 139void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *trans,
 140                             struct btrfs_root *root);
 141void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
 142                                  struct btrfs_root *root);
 143struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 144                                     struct btrfs_fs_info *fs_info,
 145                                     u64 objectid);
 146int btree_lock_page_hook(struct page *page, void *data,
 147                                void (*flush_fn)(void *));
 148int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
 149int btrfs_calc_num_tolerated_disk_barrier_failures(
 150        struct btrfs_fs_info *fs_info);
 151int __init btrfs_end_io_wq_init(void);
 152void btrfs_end_io_wq_exit(void);
 153
 154#ifdef CONFIG_DEBUG_LOCK_ALLOC
 155void btrfs_init_lockdep(void);
 156void btrfs_set_buffer_lockdep_class(u64 objectid,
 157                                    struct extent_buffer *eb, int level);
 158#else
 159static inline void btrfs_init_lockdep(void)
 160{ }
 161static inline void btrfs_set_buffer_lockdep_class(u64 objectid,
 162                                        struct extent_buffer *eb, int level)
 163{
 164}
 165#endif
 166#endif
 167