LXR linux/fs/jfs/jfs

   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