1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * Copyright (C) International Business Machines Corp., 2000-2002
4 * Portions Copyright (C) Christoph Hellwig, 2001-2002
5 */
6 #ifndef _H_JFS_METAPAGE
7 #define _H_JFS_METAPAGE
8
9 #include <linux/pagemap.h>
10
11 struct metapage {
12 /* Common logsyncblk prefix (see jfs_logmgr.h) */
13 u16 xflag;
14 u16 unused;
15 lid_t lid;
16 int lsn;
17 struct list_head synclist;
18 /* End of logsyncblk prefix */
19
20 unsigned long flag; /* See Below */
21 unsigned long count; /* Reference count */
22 void *data; /* Data pointer */
23 sector_t index; /* block address of page */
24 wait_queue_head_t wait;
25
26 /* implementation */
27 struct page *page;
28 struct super_block *sb;
29 unsigned int logical_size;
30
31 /* Journal management */
32 int clsn;
33 int nohomeok;
34 struct jfs_log *log;
35 };
36
37 /* metapage flag */
38 #define META_locked 0
39 #define META_dirty 2
40 #define META_sync 3
41 #define META_discard 4
42 #define META_forcewrite 5
43 #define META_io 6
44
45 #define mark_metapage_dirty(mp) set_bit(META_dirty, &(mp)->flag)
46
47 /* function prototypes */
48 extern int metapage_init(void);
49 extern void metapage_exit(void);
50 extern struct metapage *__get_metapage(struct inode *inode,
51 unsigned long lblock, unsigned int size,
52 int absolute, unsigned long new);
53
54 #define read_metapage(inode, lblock, size, absolute)\
55 __get_metapage(inode, lblock, size, absolute, false)
56
57 #define get_metapage(inode, lblock, size, absolute)\
58 __get_metapage(inode, lblock, size, absolute, true)
59
60 extern void release_metapage(struct metapage *);
61 extern void grab_metapage(struct metapage *);
62 extern void force_metapage(struct metapage *);
63
64 /*
65 * hold_metapage and put_metapage are used in conjunction. The page lock
66 * is not dropped between the two, so no other threads can get or release
67 * the metapage
68 */
69 extern void hold_metapage(struct metapage *);
70 extern void put_metapage(struct metapage *);
71
write_metapage(struct metapage * mp)72 static inline void write_metapage(struct metapage *mp)
73 {
74 set_bit(META_dirty, &mp->flag);
75 release_metapage(mp);
76 }
77
flush_metapage(struct metapage * mp)78 static inline void flush_metapage(struct metapage *mp)
79 {
80 set_bit(META_sync, &mp->flag);
81 write_metapage(mp);
82 }
83
discard_metapage(struct metapage * mp)84 static inline void discard_metapage(struct metapage *mp)
85 {
86 clear_bit(META_dirty, &mp->flag);
87 set_bit(META_discard, &mp->flag);
88 release_metapage(mp);
89 }
90
metapage_nohomeok(struct metapage * mp)91 static inline void metapage_nohomeok(struct metapage *mp)
92 {
93 struct page *page = mp->page;
94 lock_page(page);
95 if (!mp->nohomeok++) {
96 mark_metapage_dirty(mp);
97 get_page(page);
98 wait_on_page_writeback(page);
99 }
100 unlock_page(page);
101 }
102
103 /*
104 * This serializes access to mp->lsn when metapages are added to logsynclist
105 * without setting nohomeok. i.e. updating imap & dmap
106 */
metapage_wait_for_io(struct metapage * mp)107 static inline void metapage_wait_for_io(struct metapage *mp)
108 {
109 if (test_bit(META_io, &mp->flag))
110 wait_on_page_writeback(mp->page);
111 }
112
113 /*
114 * This is called when already holding the metapage
115 */
_metapage_homeok(struct metapage * mp)116 static inline void _metapage_homeok(struct metapage *mp)
117 {
118 if (!--mp->nohomeok)
119 put_page(mp->page);
120 }
121
metapage_homeok(struct metapage * mp)122 static inline void metapage_homeok(struct metapage *mp)
123 {
124 hold_metapage(mp);
125 _metapage_homeok(mp);
126 put_metapage(mp);
127 }
128
129 extern const struct address_space_operations jfs_metapage_aops;
130
131 /*
132 * This routines invalidate all pages for an extent.
133 */
134 extern void __invalidate_metapages(struct inode *, s64, int);
135 #define invalidate_pxd_metapages(ip, pxd) \
136 __invalidate_metapages((ip), addressPXD(&(pxd)), lengthPXD(&(pxd)))
137 #define invalidate_dxd_metapages(ip, dxd) \
138 __invalidate_metapages((ip), addressDXD(&(dxd)), lengthDXD(&(dxd)))
139 #define invalidate_xad_metapages(ip, xad) \
140 __invalidate_metapages((ip), addressXAD(&(xad)), lengthXAD(&(xad)))
141
142 #endif /* _H_JFS_METAPAGE */
143