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 sector_t index; /* block address of page */
37 wait_queue_head_t wait;
38
39 /* implementation */
40 struct page *page;
41 unsigned int logical_size;
42
43 /* Journal management */
44 int clsn;
45 int nohomeok;
46 struct jfs_log *log;
47 };
48
49 /* metapage flag */
50 #define META_locked 0
51 #define META_free 1
52 #define META_dirty 2
53 #define META_sync 3
54 #define META_discard 4
55 #define META_forcewrite 5
56 #define META_io 6
57
58 #define mark_metapage_dirty(mp) set_bit(META_dirty, &(mp)->flag)
59
60 /* function prototypes */
61 extern int metapage_init(void);
62 extern void metapage_exit(void);
63 extern struct metapage *__get_metapage(struct inode *inode,
64 unsigned long lblock, unsigned int size,
65 int absolute, unsigned long new);
66
67 #define read_metapage(inode, lblock, size, absolute)\
68 __get_metapage(inode, lblock, size, absolute, false)
69
70 #define get_metapage(inode, lblock, size, absolute)\
71 __get_metapage(inode, lblock, size, absolute, true)
72
73 extern void release_metapage(struct metapage *);
74 extern void grab_metapage(struct metapage *);
75 extern void force_metapage(struct metapage *);
76
77 /*
78 * hold_metapage and put_metapage are used in conjuction. The page lock
79 * is not dropped between the two, so no other threads can get or release
80 * the metapage
81 */
82 extern void hold_metapage(struct metapage *);
83 extern void put_metapage(struct metapage *);
84
85 static inline void write_metapage(struct metapage *mp)
86 {
87 set_bit(META_dirty, &mp->flag);
88 release_metapage(mp);
89 }
90
91 static inline void flush_metapage(struct metapage *mp)
92 {
93 set_bit(META_sync, &mp->flag);
94 write_metapage(mp);
95 }
96
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 static inline void metapage_nohomeok(struct metapage *mp)
105 {
106 struct page *page = mp->page;
107 lock_page(page);
108 if (!mp->nohomeok++) {
109 mark_metapage_dirty(mp);
110 page_cache_get(page);
111 wait_on_page_writeback(page);
112 }
113 unlock_page(page);
114 }
115
116 /*
117 * This serializes access to mp->lsn when metapages are added to logsynclist
118 * without setting nohomeok. i.e. updating imap & dmap
119 */
120 static inline void metapage_wait_for_io(struct metapage *mp)
121 {
122 if (test_bit(META_io, &mp->flag))
123 wait_on_page_writeback(mp->page);
124 }
125
126 /*
127 * This is called when already holding the metapage
128 */
129 static inline void _metapage_homeok(struct metapage *mp)
130 {
131 if (!--mp->nohomeok)
132 page_cache_release(mp->page);
133 }
134
135 static inline void metapage_homeok(struct metapage *mp)
136 {
137 hold_metapage(mp);
138 _metapage_homeok(mp);
139 put_metapage(mp);
140 }
141
142 extern const struct address_space_operations jfs_metapage_aops;
143
144 /*
145 * This routines invalidate all pages for an extent.
146 */
147 extern void __invalidate_metapages(struct inode *, s64, int);
148 #define invalidate_pxd_metapages(ip, pxd) \
149 __invalidate_metapages((ip), addressPXD(&(pxd)), lengthPXD(&(pxd)))
150 #define invalidate_dxd_metapages(ip, dxd) \
151 __invalidate_metapages((ip), addressDXD(&(dxd)), lengthDXD(&(dxd)))
152 #define invalidate_xad_metapages(ip, xad) \
153 __invalidate_metapages((ip), addressXAD(&(xad)), lengthXAD(&(xad)))
154
155 #endif /* _H_JFS_METAPAGE */
156
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