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