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
  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
  36enum 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
  44static 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
  52struct btrfs_device;
  53struct btrfs_fs_devices;
  54
  55struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info,
  56                                      u64 bytenr, u64 parent_transid);
  57void readahead_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr);
  58int reada_tree_block_flagged(struct btrfs_fs_info *fs_info, u64 bytenr,
  59                         int mirror_num, struct extent_buffer **eb);
  60struct extent_buffer *btrfs_find_create_tree_block(
  61                                                struct btrfs_fs_info *fs_info,
  62                                                u64 bytenr);
  63void clean_tree_block(struct btrfs_fs_info *fs_info, struct extent_buffer *buf);
  64int open_ctree(struct super_block *sb,
  65               struct btrfs_fs_devices *fs_devices,
  66               char *options);
  67void close_ctree(struct btrfs_fs_info *fs_info);
  68int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors);
  69struct buffer_head *btrfs_read_dev_super(struct block_device *bdev);
  70int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
  71                        struct buffer_head **bh_ret);
  72int btrfs_commit_super(struct btrfs_fs_info *fs_info);
  73struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
  74                                      struct btrfs_key *location);
  75int btrfs_init_fs_root(struct btrfs_root *root);
  76struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
  77                                        u64 root_id);
  78int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
  79                         struct btrfs_root *root);
  80void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info);
  81
  82struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
  83                                     struct btrfs_key *key,
  84                                     bool check_ref);
  85static inline struct btrfs_root *
  86btrfs_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
  92int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
  93void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info);
  94void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info);
  95void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
  96                                 struct btrfs_root *root);
  97void btrfs_free_fs_root(struct btrfs_root *root);
  98
  99#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 100struct 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 */
 110static 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
 117static inline void btrfs_put_fs_root(struct btrfs_root *root)
 118{
 119        if (refcount_dec_and_test(&root->refs))
 120                kfree(root);
 121}
 122
 123void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
 124int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
 125                          int atomic);
 126int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid);
 127u32 btrfs_csum_data(const char *data, u32 seed, size_t len);
 128void btrfs_csum_final(u32 crc, u8 *result);
 129blk_status_t btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 130                        enum btrfs_wq_endio_type metadata);
 131blk_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);
 136unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info);
 137int btrfs_write_tree_block(struct extent_buffer *buf);
 138void btrfs_wait_tree_block_writeback(struct extent_buffer *buf);
 139int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 140                             struct btrfs_fs_info *fs_info);
 141int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
 142                       struct btrfs_root *root);
 143void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *trans,
 144                             struct btrfs_fs_info *fs_info);
 145void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
 146                                  struct btrfs_fs_info *fs_info);
 147struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 148                                     struct btrfs_fs_info *fs_info,
 149                                     u64 objectid);
 150int btree_lock_page_hook(struct page *page, void *data,
 151                                void (*flush_fn)(void *));
 152int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
 153int __init btrfs_end_io_wq_init(void);
 154void btrfs_end_io_wq_exit(void);
 155
 156#ifdef CONFIG_DEBUG_LOCK_ALLOC
 157void btrfs_init_lockdep(void);
 158void btrfs_set_buffer_lockdep_class(u64 objectid,
 159                                    struct extent_buffer *eb, int level);
 160#else
 161static inline void btrfs_init_lockdep(void)
 162{ }
 163static inline void btrfs_set_buffer_lockdep_class(u64 objectid,
 164                                        struct extent_buffer *eb, int level)
 165{
 166}
 167#endif
 168#endif
 169