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![David Woodhouse](/assets/img/avatar_default.png)
This builds on David Woodhouse's original Btrfs raid5/6 implementation. The code has changed quite a bit, blame Chris Mason for any bugs. Read/modify/write is done after the higher levels of the filesystem have prepared a given bio. This means the higher layers are not responsible for building full stripes, and they don't need to query for the topology of the extents that may get allocated during delayed allocation runs. It also means different files can easily share the same stripe. But, it does expose us to incorrect parity if we crash or lose power while doing a read/modify/write cycle. This will be addressed in a later commit. Scrub is unable to repair crc errors on raid5/6 chunks. Discard does not work on raid5/6 (yet) The stripe size is fixed at 64KiB per disk. This will be tunable in a later commit. Signed-off-by: Chris Mason <chris.mason@fusionio.com>
120 lines
4.7 KiB
C
120 lines
4.7 KiB
C
/*
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* Copyright (C) 2007 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#ifndef __DISKIO__
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#define __DISKIO__
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#define BTRFS_SUPER_INFO_OFFSET (64 * 1024)
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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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enum {
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BTRFS_WQ_ENDIO_DATA = 0,
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BTRFS_WQ_ENDIO_METADATA = 1,
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BTRFS_WQ_ENDIO_FREE_SPACE = 2,
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BTRFS_WQ_ENDIO_RAID56 = 3,
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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 = 16 * 1024;
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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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struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
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u32 blocksize, u64 parent_transid);
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int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
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u64 parent_transid);
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int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr, u32 blocksize,
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int mirror_num, struct extent_buffer **eb);
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struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
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u64 bytenr, u32 blocksize);
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void clean_tree_block(struct btrfs_trans_handle *trans,
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struct btrfs_root *root, struct extent_buffer *buf);
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int 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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int close_ctree(struct btrfs_root *root);
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int write_ctree_super(struct btrfs_trans_handle *trans,
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struct btrfs_root *root, int max_mirrors);
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struct buffer_head *btrfs_read_dev_super(struct block_device *bdev);
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int btrfs_commit_super(struct btrfs_root *root);
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void btrfs_error_commit_super(struct btrfs_root *root);
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struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
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u64 bytenr, u32 blocksize);
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struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
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struct btrfs_key *location);
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struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
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struct btrfs_key *location);
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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_root *root);
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void btrfs_btree_balance_dirty_nodelay(struct btrfs_root *root);
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void btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root);
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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_set_buffer_uptodate(struct extent_buffer *buf);
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int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid);
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u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len);
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void btrfs_csum_final(u32 crc, char *result);
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int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
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int metadata);
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int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
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int rw, struct bio *bio, int mirror_num,
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unsigned long bio_flags, u64 bio_offset,
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extent_submit_bio_hook_t *submit_bio_start,
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extent_submit_bio_hook_t *submit_bio_done);
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unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info);
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int btrfs_write_tree_block(struct extent_buffer *buf);
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int btrfs_wait_tree_block_writeback(struct extent_buffer *buf);
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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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int btrfs_cleanup_transaction(struct btrfs_root *root);
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void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
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struct btrfs_root *root);
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void btrfs_abort_devices(struct btrfs_root *root);
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struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
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struct btrfs_fs_info *fs_info,
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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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int btrfs_calc_num_tolerated_disk_barrier_failures(
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struct btrfs_fs_info *fs_info);
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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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