1 /*
2  *   Copyright (c) International Business Machines Corp., 2000-2002
3  *   Portions Copyright (c) Christoph Hellwig, 2001-2002
4  *
5  *   This program is free software;  you can redistribute it and/or modify
6  *   it under the terms of the GNU General Public License as published by
7  *   the Free Software Foundation; either version 2 of the License, or
8  *   (at your option) any later version.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13  *   the GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License
16  *   along with this program;  if not, write to the Free Software
17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  */
19 #ifndef	_H_JFS_METAPAGE
20 #define _H_JFS_METAPAGE
21 
22 #include <linux/pagemap.h>
23 
24 struct metapage {
25 	/* Common logsyncblk prefix (see jfs_logmgr.h) */
26 	u16 xflag;
27 	u16 unused;
28 	lid_t lid;
29 	int lsn;
30 	struct list_head synclist;
31 	/* End of logsyncblk prefix */
32 
33 	unsigned long flag;	/* See Below */
34 	unsigned long count;	/* Reference count */
35 	void *data;		/* Data pointer */
36 
37 	/* list management stuff */
38 	struct metapage *hash_prev;
39 	struct metapage *hash_next;	/* Also used for free list */
40 
41 	/*
42 	 * mapping & index become redundant, but we need these here to
43 	 * add the metapage to the hash before we have the real page
44 	 */
45 	struct address_space *mapping;
46 	unsigned long index;
47 	wait_queue_head_t wait;
48 
49 	/* implementation */
50 	struct page *page;
51 	unsigned long logical_size;
52 
53 	/* Journal management */
54 	int clsn;
55 	atomic_t nohomeok;
56 	struct jfs_log *log;
57 };
58 
59 /* metapage flag */
60 #define META_locked	0
61 #define META_absolute	1
62 #define META_free	2
63 #define META_dirty	3
64 #define META_sync	4
65 #define META_discard	5
66 #define META_forced	6
67 #define META_stale	7
68 
69 #define mark_metapage_dirty(mp) set_bit(META_dirty, &(mp)->flag)
70 
71 /* function prototypes */
72 extern struct metapage *__get_metapage(struct inode *inode,
73 				  unsigned long lblock, unsigned int size,
74 				  int absolute, unsigned long new);
75 
76 #define read_metapage(inode, lblock, size, absolute)\
77 	 __get_metapage(inode, lblock, size, absolute, FALSE)
78 
79 #define get_metapage(inode, lblock, size, absolute)\
80 	 __get_metapage(inode, lblock, size, absolute, TRUE)
81 
82 extern void release_metapage(struct metapage *);
83 extern void hold_metapage(struct metapage *, int);
84 
write_metapage(struct metapage * mp)85 static inline void write_metapage(struct metapage *mp)
86 {
87 	set_bit(META_dirty, &mp->flag);
88 	release_metapage(mp);
89 }
90 
flush_metapage(struct metapage * mp)91 static inline void flush_metapage(struct metapage *mp)
92 {
93 	set_bit(META_sync, &mp->flag);
94 	write_metapage(mp);
95 }
96 
discard_metapage(struct metapage * mp)97 static inline void discard_metapage(struct metapage *mp)
98 {
99 	clear_bit(META_dirty, &mp->flag);
100 	set_bit(META_discard, &mp->flag);
101 	release_metapage(mp);
102 }
103 
104 /*
105  * This routines invalidate all pages for an extent.
106  */
107 extern void __invalidate_metapages(struct inode *, s64, int);
108 #define invalidate_pxd_metapages(ip, pxd) \
109 	__invalidate_metapages((ip), addressPXD(&(pxd)), lengthPXD(&(pxd)))
110 #define invalidate_dxd_metapages(ip, dxd) \
111 	__invalidate_metapages((ip), addressDXD(&(dxd)), lengthDXD(&(dxd)))
112 #define invalidate_xad_metapages(ip, xad) \
113 	__invalidate_metapages((ip), addressXAD(&(xad)), lengthXAD(&(xad)))
114 
115 #endif				/* _H_JFS_METAPAGE */
116