1/*
2 * page.h - buffer/page management specific to NILFS
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
19 *
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>,
21 *            Seiji Kihara <kihara@osrg.net>.
22 */
23
24#ifndef _NILFS_PAGE_H
25#define _NILFS_PAGE_H
26
27#include <linux/buffer_head.h>
28#include "nilfs.h"
29
30/*
31 * Extended buffer state bits
32 */
33enum {
34	BH_NILFS_Allocated = BH_PrivateStart,
35	BH_NILFS_Node,
36	BH_NILFS_Volatile,
37	BH_NILFS_Checked,
38};
39
40BUFFER_FNS(NILFS_Allocated, nilfs_allocated)	/* nilfs private buffers */
41BUFFER_FNS(NILFS_Node, nilfs_node)		/* nilfs node buffers */
42BUFFER_FNS(NILFS_Volatile, nilfs_volatile)
43BUFFER_FNS(NILFS_Checked, nilfs_checked)	/* buffer is verified */
44
45
46void nilfs_mark_buffer_dirty(struct buffer_head *bh);
47int __nilfs_clear_page_dirty(struct page *);
48
49struct buffer_head *nilfs_grab_buffer(struct inode *, struct address_space *,
50				      unsigned long, unsigned long);
51void nilfs_forget_buffer(struct buffer_head *);
52void nilfs_copy_buffer(struct buffer_head *, struct buffer_head *);
53int nilfs_page_buffers_clean(struct page *);
54void nilfs_page_bug(struct page *);
55struct page *nilfs_alloc_private_page(struct block_device *, int,
56				      unsigned long);
57void nilfs_free_private_page(struct page *);
58
59int nilfs_copy_dirty_pages(struct address_space *, struct address_space *);
60void nilfs_copy_back_pages(struct address_space *, struct address_space *);
61void nilfs_clear_dirty_pages(struct address_space *);
62unsigned nilfs_page_count_clean_buffers(struct page *, unsigned, unsigned);
63
64#define NILFS_PAGE_BUG(page, m, a...) \
65	do { nilfs_page_bug(page); BUG(); } while (0)
66
67static inline struct buffer_head *
68nilfs_page_get_nth_block(struct page *page, unsigned int count)
69{
70	struct buffer_head *bh = page_buffers(page);
71
72	while (count-- > 0)
73		bh = bh->b_this_page;
74	get_bh(bh);
75	return bh;
76}
77
78#endif /* _NILFS_PAGE_H */
79