ebdfed4dc5
This adds optional function to metadata files which makes a copy of bmap, page caches, and b-tree node cache, and rolls back to the copy as needed. This enhancement is intended to displace gcdat inode that provides a similar function in a different way. In this patch, nilfs_shadow_map structure is added to store a copy of the foregoing states. nilfs_mdt_setup_shadow_map relates this structure to a metadata file. And, nilfs_mdt_save_to_shadow_map() and nilfs_mdt_restore_from_shadow_map() provides save and restore functions respectively. Finally, nilfs_mdt_clear_shadow_map() clears states of nilfs_shadow_map. The copy of b-tree node cache and page cache is made by duplicating only dirty pages into corresponding caches in nilfs_shadow_map. Their restoration is done by clearing dirty pages from original caches and by copying dirty pages back from nilfs_shadow_map. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
83 lines
2.7 KiB
C
83 lines
2.7 KiB
C
/*
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* page.h - buffer/page management specific to NILFS
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*
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* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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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
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* GNU 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 License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* Written by Ryusuke Konishi <ryusuke@osrg.net>,
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* Seiji Kihara <kihara@osrg.net>.
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*/
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#ifndef _NILFS_PAGE_H
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#define _NILFS_PAGE_H
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#include <linux/buffer_head.h>
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#include "nilfs.h"
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/*
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* Extended buffer state bits
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*/
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enum {
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BH_NILFS_Allocated = BH_PrivateStart,
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BH_NILFS_Node,
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BH_NILFS_Volatile,
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BH_NILFS_Checked,
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};
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BUFFER_FNS(NILFS_Allocated, nilfs_allocated) /* nilfs private buffers */
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BUFFER_FNS(NILFS_Node, nilfs_node) /* nilfs node buffers */
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BUFFER_FNS(NILFS_Volatile, nilfs_volatile)
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BUFFER_FNS(NILFS_Checked, nilfs_checked) /* buffer is verified */
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void nilfs_mark_buffer_dirty(struct buffer_head *bh);
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int __nilfs_clear_page_dirty(struct page *);
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struct buffer_head *nilfs_grab_buffer(struct inode *, struct address_space *,
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unsigned long, unsigned long);
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void nilfs_forget_buffer(struct buffer_head *);
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void nilfs_copy_buffer(struct buffer_head *, struct buffer_head *);
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int nilfs_page_buffers_clean(struct page *);
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void nilfs_page_bug(struct page *);
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struct page *nilfs_alloc_private_page(struct block_device *, int,
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unsigned long);
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void nilfs_free_private_page(struct page *);
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int nilfs_copy_dirty_pages(struct address_space *, struct address_space *);
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void nilfs_copy_back_pages(struct address_space *, struct address_space *);
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void nilfs_clear_dirty_pages(struct address_space *);
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void nilfs_mapping_init_once(struct address_space *mapping);
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void nilfs_mapping_init(struct address_space *mapping,
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struct backing_dev_info *bdi,
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const struct address_space_operations *aops);
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unsigned nilfs_page_count_clean_buffers(struct page *, unsigned, unsigned);
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#define NILFS_PAGE_BUG(page, m, a...) \
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do { nilfs_page_bug(page); BUG(); } while (0)
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static inline struct buffer_head *
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nilfs_page_get_nth_block(struct page *page, unsigned int count)
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{
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struct buffer_head *bh = page_buffers(page);
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while (count-- > 0)
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bh = bh->b_this_page;
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get_bh(bh);
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return bh;
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}
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#endif /* _NILFS_PAGE_H */
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