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
11struct 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 */
48extern int metapage_init(void);
49extern void metapage_exit(void);
50extern 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
60extern void release_metapage(struct metapage *);
61extern void grab_metapage(struct metapage *);
62extern 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 */
69extern void hold_metapage(struct metapage *);
70extern void put_metapage(struct metapage *);
71
72static inline void write_metapage(struct metapage *mp)
73{
74	set_bit(META_dirty, &mp->flag);
75	release_metapage(mp);
76}
77
78static inline void flush_metapage(struct metapage *mp)
79{
80	set_bit(META_sync, &mp->flag);
81	write_metapage(mp);
82}
83
84static 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
91static 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 */
107static 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 */
116static inline void _metapage_homeok(struct metapage *mp)
117{
118	if (!--mp->nohomeok)
119		put_page(mp->page);
120}
121
122static inline void metapage_homeok(struct metapage *mp)
123{
124	hold_metapage(mp);
125	_metapage_homeok(mp);
126	put_metapage(mp);
127}
128
129extern const struct address_space_operations jfs_metapage_aops;
130
131/*
132 * This routines invalidate all pages for an extent.
133 */
134extern 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