1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * page.h - buffer/page management specific to NILFS
4  *
5  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6  *
7  * Written by Ryusuke Konishi and Seiji Kihara.
8  */
9 
10 #ifndef _NILFS_PAGE_H
11 #define _NILFS_PAGE_H
12 
13 #include <linux/buffer_head.h>
14 #include "nilfs.h"
15 
16 /*
17  * Extended buffer state bits
18  */
19 enum {
20 	BH_NILFS_Allocated = BH_PrivateStart,
21 	BH_NILFS_Node,
22 	BH_NILFS_Volatile,
23 	BH_NILFS_Checked,
24 	BH_NILFS_Redirected,
25 };
26 
27 BUFFER_FNS(NILFS_Node, nilfs_node)		/* nilfs node buffers */
28 BUFFER_FNS(NILFS_Volatile, nilfs_volatile)
29 BUFFER_FNS(NILFS_Checked, nilfs_checked)	/* buffer is verified */
30 BUFFER_FNS(NILFS_Redirected, nilfs_redirected)	/* redirected to a copy */
31 
32 
33 int __nilfs_clear_page_dirty(struct page *);
34 
35 struct buffer_head *nilfs_grab_buffer(struct inode *, struct address_space *,
36 				      unsigned long, unsigned long);
37 void nilfs_forget_buffer(struct buffer_head *);
38 void nilfs_copy_buffer(struct buffer_head *, struct buffer_head *);
39 int nilfs_page_buffers_clean(struct page *);
40 void nilfs_page_bug(struct page *);
41 
42 int nilfs_copy_dirty_pages(struct address_space *, struct address_space *);
43 void nilfs_copy_back_pages(struct address_space *, struct address_space *);
44 void nilfs_clear_dirty_page(struct page *, bool);
45 void nilfs_clear_dirty_pages(struct address_space *, bool);
46 void nilfs_mapping_init(struct address_space *mapping, struct inode *inode);
47 unsigned int nilfs_page_count_clean_buffers(struct page *, unsigned int,
48 					    unsigned int);
49 unsigned long nilfs_find_uncommitted_extent(struct inode *inode,
50 					    sector_t start_blk,
51 					    sector_t *blkoff);
52 
53 #define NILFS_PAGE_BUG(page, m, a...) \
54 	do { nilfs_page_bug(page); BUG(); } while (0)
55 
56 static inline struct buffer_head *
nilfs_page_get_nth_block(struct page * page,unsigned int count)57 nilfs_page_get_nth_block(struct page *page, unsigned int count)
58 {
59 	struct buffer_head *bh = page_buffers(page);
60 
61 	while (count-- > 0)
62 		bh = bh->b_this_page;
63 	get_bh(bh);
64 	return bh;
65 }
66 
67 #endif /* _NILFS_PAGE_H */
68