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 */
33 enum {
34 BH_NILFS_Allocated = BH_PrivateStart,
35 BH_NILFS_Node,
36 BH_NILFS_Volatile,
37 BH_NILFS_Checked,
38 BH_NILFS_Redirected,
39 };
40
41 BUFFER_FNS(NILFS_Node, nilfs_node) /* nilfs node buffers */
42 BUFFER_FNS(NILFS_Volatile, nilfs_volatile)
43 BUFFER_FNS(NILFS_Checked, nilfs_checked) /* buffer is verified */
44 BUFFER_FNS(NILFS_Redirected, nilfs_redirected) /* redirected to a copy */
45
46
47 int __nilfs_clear_page_dirty(struct page *);
48
49 struct buffer_head *nilfs_grab_buffer(struct inode *, struct address_space *,
50 unsigned long, unsigned long);
51 void nilfs_forget_buffer(struct buffer_head *);
52 void nilfs_copy_buffer(struct buffer_head *, struct buffer_head *);
53 int nilfs_page_buffers_clean(struct page *);
54 void nilfs_page_bug(struct page *);
55
56 int nilfs_copy_dirty_pages(struct address_space *, struct address_space *);
57 void nilfs_copy_back_pages(struct address_space *, struct address_space *);
58 void nilfs_clear_dirty_pages(struct address_space *);
59 void nilfs_mapping_init(struct address_space *mapping, struct inode *inode,
60 struct backing_dev_info *bdi);
61 unsigned nilfs_page_count_clean_buffers(struct page *, unsigned, unsigned);
62 unsigned long nilfs_find_uncommitted_extent(struct inode *inode,
63 sector_t start_blk,
64 sector_t *blkoff);
65
66 #define NILFS_PAGE_BUG(page, m, a...) \
67 do { nilfs_page_bug(page); BUG(); } while (0)
68
69 static inline struct buffer_head *
nilfs_page_get_nth_block(struct page * page,unsigned int count)70 nilfs_page_get_nth_block(struct page *page, unsigned int count)
71 {
72 struct buffer_head *bh = page_buffers(page);
73
74 while (count-- > 0)
75 bh = bh->b_this_page;
76 get_bh(bh);
77 return bh;
78 }
79
80 #endif /* _NILFS_PAGE_H */
81