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, addr: &mp->flag);
75 release_metapage(mp);
76}
77
78static inline void flush_metapage(struct metapage *mp)
79{
80 set_bit(META_sync, addr: &mp->flag);
81 write_metapage(mp);
82}
83
84static inline void discard_metapage(struct metapage *mp)
85{
86 clear_bit(META_dirty, addr: &mp->flag);
87 set_bit(META_discard, addr: &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(page: 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(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

source code of linux/fs/jfs/jfs_metapage.h