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_fs_info *fs_info,
  48                                      u64 bytenr, u64 parent_transid);
  49void readahead_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr);
  50int reada_tree_block_flagged(struct btrfs_fs_info *fs_info, u64 bytenr,
  51                         int mirror_num, struct extent_buffer **eb);
  52struct extent_buffer *btrfs_find_create_tree_block(
  53                                                struct btrfs_fs_info *fs_info,
  54                                                u64 bytenr);
  55void clean_tree_block(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_fs_info *fs_info);
  60int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors);
  61struct buffer_head *btrfs_read_dev_super(struct block_device *bdev);
  62int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
  63                        struct buffer_head **bh_ret);
  64int btrfs_commit_super(struct btrfs_fs_info *fs_info);
  65struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
  66                                      struct btrfs_key *location);
  67int btrfs_init_fs_root(struct btrfs_root *root);
  68struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
  69                                        u64 root_id);
  70int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
  71                         struct btrfs_root *root);
  72void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info);
  73
  74struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
  75                                     struct btrfs_key *key,
  76                                     bool check_ref);
  77static inline struct btrfs_root *
  78btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
  79                           struct btrfs_key *location)
  80{
  81        return btrfs_get_fs_root(fs_info, location, true);
  82}
  83
  84int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
  85void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info);
  86void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info);
  87void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
  88                                 struct btrfs_root *root);
  89void btrfs_free_fs_root(struct btrfs_root *root);
  90
  91#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
  92struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info);
  93#endif
  94
  95/*
  96 * This function is used to grab the root, and avoid it is freed when we
  97 * access it. But it doesn't ensure that the tree is not dropped.
  98 *
  99 * If you want to ensure the whole tree is safe, you should use
 100 *      fs_info->subvol_srcu
 101 */
 102static inline struct btrfs_root *btrfs_grab_fs_root(struct btrfs_root *root)
 103{
 104        if (atomic_inc_not_zero(&root->refs))
 105                return root;
 106        return NULL;
 107}
 108
 109static inline void btrfs_put_fs_root(struct btrfs_root *root)
 110{
 111        if (atomic_dec_and_test(&root->refs))
 112                kfree(root);
 113}
 114
 115void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
 116int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
 117                          int atomic);
 118int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid);
 119u32 btrfs_csum_data(const char *data, u32 seed, size_t len);
 120void btrfs_csum_final(u32 crc, u8 *result);
 121int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 122                        enum btrfs_wq_endio_type metadata);
 123int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 124                        struct bio *bio, int mirror_num,
 125                        unsigned long bio_flags, u64 bio_offset,
 126                        extent_submit_bio_hook_t *submit_bio_start,
 127                        extent_submit_bio_hook_t *submit_bio_done);
 128unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info);
 129int btrfs_write_tree_block(struct extent_buffer *buf);
 130int btrfs_wait_tree_block_writeback(struct extent_buffer *buf);
 131int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 132                             struct btrfs_fs_info *fs_info);
 133int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
 134                       struct btrfs_root *root);
 135void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *trans,
 136                             struct btrfs_fs_info *fs_info);
 137void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
 138                                  struct btrfs_fs_info *fs_info);
 139struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 140                                     struct btrfs_fs_info *fs_info,
 141                                     u64 objectid);
 142int btree_lock_page_hook(struct page *page, void *data,
 143                                void (*flush_fn)(void *));
 144int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
 145int btrfs_calc_num_tolerated_disk_barrier_failures(
 146        struct btrfs_fs_info *fs_info);
 147int __init btrfs_end_io_wq_init(void);
 148void btrfs_end_io_wq_exit(void);
 149
 150#ifdef CONFIG_DEBUG_LOCK_ALLOC
 151void btrfs_init_lockdep(void);
 152void btrfs_set_buffer_lockdep_class(u64 objectid,
 153                                    struct extent_buffer *eb, int level);
 154#else
 155static inline void btrfs_init_lockdep(void)
 156{ }
 157static inline void btrfs_set_buffer_lockdep_class(u64 objectid,
 158                                        struct extent_buffer *eb, int level)
 159{
 160}
 161#endif
 162#endif
 163