xref: /linux/fs/nilfs2/page.h (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
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 *
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