xref: /linux/fs/nilfs2/page.h (revision b6ebbac51bedf9e98e837688bc838f400196da5e)
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  * Written by Ryusuke Konishi and Seiji Kihara.
17  */
18 
19 #ifndef _NILFS_PAGE_H
20 #define _NILFS_PAGE_H
21 
22 #include <linux/buffer_head.h>
23 #include "nilfs.h"
24 
25 /*
26  * Extended buffer state bits
27  */
28 enum {
29 	BH_NILFS_Allocated = BH_PrivateStart,
30 	BH_NILFS_Node,
31 	BH_NILFS_Volatile,
32 	BH_NILFS_Checked,
33 	BH_NILFS_Redirected,
34 };
35 
36 BUFFER_FNS(NILFS_Node, nilfs_node)		/* nilfs node buffers */
37 BUFFER_FNS(NILFS_Volatile, nilfs_volatile)
38 BUFFER_FNS(NILFS_Checked, nilfs_checked)	/* buffer is verified */
39 BUFFER_FNS(NILFS_Redirected, nilfs_redirected)	/* redirected to a copy */
40 
41 
42 int __nilfs_clear_page_dirty(struct page *);
43 
44 struct buffer_head *nilfs_grab_buffer(struct inode *, struct address_space *,
45 				      unsigned long, unsigned long);
46 void nilfs_forget_buffer(struct buffer_head *);
47 void nilfs_copy_buffer(struct buffer_head *, struct buffer_head *);
48 int nilfs_page_buffers_clean(struct page *);
49 void nilfs_page_bug(struct page *);
50 
51 int nilfs_copy_dirty_pages(struct address_space *, struct address_space *);
52 void nilfs_copy_back_pages(struct address_space *, struct address_space *);
53 void nilfs_clear_dirty_page(struct page *, bool);
54 void nilfs_clear_dirty_pages(struct address_space *, bool);
55 void nilfs_mapping_init(struct address_space *mapping, struct inode *inode);
56 unsigned int nilfs_page_count_clean_buffers(struct page *, unsigned int,
57 					    unsigned int);
58 unsigned long nilfs_find_uncommitted_extent(struct inode *inode,
59 					    sector_t start_blk,
60 					    sector_t *blkoff);
61 
62 #define NILFS_PAGE_BUG(page, m, a...) \
63 	do { nilfs_page_bug(page); BUG(); } while (0)
64 
65 static inline struct buffer_head *
66 nilfs_page_get_nth_block(struct page *page, unsigned int count)
67 {
68 	struct buffer_head *bh = page_buffers(page);
69 
70 	while (count-- > 0)
71 		bh = bh->b_this_page;
72 	get_bh(bh);
73 	return bh;
74 }
75 
76 #endif /* _NILFS_PAGE_H */
77