8f32380d3f
Super-block reading in BTRFS is done using buffer_heads. Buffer_heads
have some drawbacks, like not being able to propagate errors from the
lower layers.
Directly use the page cache for reading the super blocks from disk or
invalidating an on-disk super block. We have to use the page cache so to
avoid races between mkfs and udev. See also 6f60cbd3ae ("btrfs: access
superblock via pagecache in scan_one_device").
This patch unwraps the buffer head API and does not change the way the
super block is actually read.
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
161 lines
5.4 KiB
C
161 lines
5.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (C) 2007 Oracle. All rights reserved.
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*/
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#ifndef BTRFS_DISK_IO_H
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#define BTRFS_DISK_IO_H
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#define BTRFS_SUPER_INFO_OFFSET SZ_64K
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#define BTRFS_SUPER_INFO_SIZE 4096
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#define BTRFS_SUPER_MIRROR_MAX 3
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#define BTRFS_SUPER_MIRROR_SHIFT 12
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/*
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* Fixed blocksize for all devices, applies to specific ways of reading
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* metadata like superblock. Must meet the set_blocksize requirements.
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*
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* Do not change.
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*/
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#define BTRFS_BDEV_BLOCKSIZE (4096)
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enum btrfs_wq_endio_type {
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BTRFS_WQ_ENDIO_DATA,
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BTRFS_WQ_ENDIO_METADATA,
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BTRFS_WQ_ENDIO_FREE_SPACE,
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BTRFS_WQ_ENDIO_RAID56,
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BTRFS_WQ_ENDIO_DIO_REPAIR,
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};
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static inline u64 btrfs_sb_offset(int mirror)
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{
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u64 start = SZ_16K;
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if (mirror)
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return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror);
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return BTRFS_SUPER_INFO_OFFSET;
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}
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struct btrfs_device;
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struct btrfs_fs_devices;
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void btrfs_check_leaked_roots(struct btrfs_fs_info *fs_info);
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void btrfs_init_fs_info(struct btrfs_fs_info *fs_info);
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int btrfs_verify_level_key(struct extent_buffer *eb, int level,
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struct btrfs_key *first_key, u64 parent_transid);
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struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
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u64 parent_transid, int level,
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struct btrfs_key *first_key);
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void readahead_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr);
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struct extent_buffer *btrfs_find_create_tree_block(
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struct btrfs_fs_info *fs_info,
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u64 bytenr);
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void btrfs_clean_tree_block(struct extent_buffer *buf);
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int __cold open_ctree(struct super_block *sb,
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struct btrfs_fs_devices *fs_devices,
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char *options);
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void __cold close_ctree(struct btrfs_fs_info *fs_info);
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int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors);
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struct btrfs_super_block *btrfs_read_dev_super(struct block_device *bdev);
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struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
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int copy_num);
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int btrfs_commit_super(struct btrfs_fs_info *fs_info);
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struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
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struct btrfs_key *key);
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int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
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struct btrfs_root *root);
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void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info);
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struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
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struct btrfs_key *key,
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bool check_ref);
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void btrfs_free_fs_info(struct btrfs_fs_info *fs_info);
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int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
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void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info);
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void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info);
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void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
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struct btrfs_root *root);
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void btrfs_free_fs_root(struct btrfs_root *root);
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#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
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struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info);
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#endif
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/*
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* This function is used to grab the root, and avoid it is freed when we
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* access it. But it doesn't ensure that the tree is not dropped.
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*
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* If you want to ensure the whole tree is safe, you should use
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* fs_info->subvol_srcu
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*/
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static inline struct btrfs_root *btrfs_grab_root(struct btrfs_root *root)
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{
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if (!root)
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return NULL;
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if (refcount_inc_not_zero(&root->refs))
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return root;
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return NULL;
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}
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static inline void btrfs_put_root(struct btrfs_root *root)
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{
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if (!root)
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return;
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if (refcount_dec_and_test(&root->refs)) {
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#ifdef CONFIG_BTRFS_DEBUG
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spin_lock(&root->fs_info->fs_roots_radix_lock);
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list_del_init(&root->leak_list);
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spin_unlock(&root->fs_info->fs_roots_radix_lock);
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#endif
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kfree(root);
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}
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}
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void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
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int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
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int atomic);
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int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid, int level,
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struct btrfs_key *first_key);
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blk_status_t btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
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enum btrfs_wq_endio_type metadata);
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blk_status_t btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
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int mirror_num, unsigned long bio_flags,
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u64 bio_offset, void *private_data,
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extent_submit_bio_start_t *submit_bio_start);
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blk_status_t btrfs_submit_bio_done(void *private_data, struct bio *bio,
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int mirror_num);
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int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
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struct btrfs_fs_info *fs_info);
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int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
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struct btrfs_root *root);
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void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *trans,
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struct btrfs_fs_info *fs_info);
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void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
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struct btrfs_fs_info *fs_info);
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struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
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u64 objectid);
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int btree_lock_page_hook(struct page *page, void *data,
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void (*flush_fn)(void *));
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struct extent_map *btree_get_extent(struct btrfs_inode *inode,
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struct page *page, size_t pg_offset,
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u64 start, u64 len);
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int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
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int __init btrfs_end_io_wq_init(void);
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void __cold btrfs_end_io_wq_exit(void);
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
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void btrfs_init_lockdep(void);
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void btrfs_set_buffer_lockdep_class(u64 objectid,
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struct extent_buffer *eb, int level);
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#else
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static inline void btrfs_init_lockdep(void)
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{ }
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static inline void btrfs_set_buffer_lockdep_class(u64 objectid,
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struct extent_buffer *eb, int level)
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{
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}
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#endif
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#endif
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