fs/jfs/jfs_metapage.h

   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
  72 static inline void write_metapage(struct metapage *mp)
  73 {
  74         set_bit(META_dirty, &mp->flag);
  75         release_metapage(mp);
  76 }
  77
  78 static inline void flush_metapage(struct metapage *mp)
  79 {
  80         set_bit(META_sync, &mp->flag);
  81         write_metapage(mp);
  82 }
  83
  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
  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  */
 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  */
 116 static inline void _metapage_homeok(struct metapage *mp)
 117 {
 118         if (!--mp->nohomeok)
 119                 put_page(mp->page);
 120 }
 121
 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 */