jfs_metapage.h 4.2 KB

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  1. /*
  2. * Copyright (C) International Business Machines Corp., 2000-2002
  3. * Portions Copyright (C) Christoph Hellwig, 2001-2002
  4. *
  5. * This program is free software; you can redistribute it and/or modify
  6. * it under the terms of the GNU General Public License as published by
  7. * the Free Software Foundation; either version 2 of the License, or
  8. * (at your option) any later version.
  9. *
  10. * This program is distributed in the hope that it will be useful,
  11. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  13. * the GNU General Public License for more details.
  14. *
  15. * You should have received a copy of the GNU General Public License
  16. * along with this program; if not, write to the Free Software
  17. * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  18. */
  19. #ifndef _H_JFS_METAPAGE
  20. #define _H_JFS_METAPAGE
  21. #include <linux/pagemap.h>
  22. struct metapage {
  23. /* Common logsyncblk prefix (see jfs_logmgr.h) */
  24. u16 xflag;
  25. u16 unused;
  26. lid_t lid;
  27. int lsn;
  28. struct list_head synclist;
  29. /* End of logsyncblk prefix */
  30. unsigned long flag; /* See Below */
  31. unsigned long count; /* Reference count */
  32. void *data; /* Data pointer */
  33. sector_t index; /* block address of page */
  34. wait_queue_head_t wait;
  35. /* implementation */
  36. struct page *page;
  37. unsigned int logical_size;
  38. /* Journal management */
  39. int clsn;
  40. int nohomeok;
  41. struct jfs_log *log;
  42. };
  43. /* metapage flag */
  44. #define META_locked 0
  45. #define META_free 1
  46. #define META_dirty 2
  47. #define META_sync 3
  48. #define META_discard 4
  49. #define META_forcewrite 5
  50. #define META_io 6
  51. #define mark_metapage_dirty(mp) set_bit(META_dirty, &(mp)->flag)
  52. /* function prototypes */
  53. extern int metapage_init(void);
  54. extern void metapage_exit(void);
  55. extern struct metapage *__get_metapage(struct inode *inode,
  56. unsigned long lblock, unsigned int size,
  57. int absolute, unsigned long new);
  58. #define read_metapage(inode, lblock, size, absolute)\
  59. __get_metapage(inode, lblock, size, absolute, false)
  60. #define get_metapage(inode, lblock, size, absolute)\
  61. __get_metapage(inode, lblock, size, absolute, true)
  62. extern void release_metapage(struct metapage *);
  63. extern void grab_metapage(struct metapage *);
  64. extern void force_metapage(struct metapage *);
  65. /*
  66. * hold_metapage and put_metapage are used in conjuction. The page lock
  67. * is not dropped between the two, so no other threads can get or release
  68. * the metapage
  69. */
  70. extern void hold_metapage(struct metapage *);
  71. extern void put_metapage(struct metapage *);
  72. static inline void write_metapage(struct metapage *mp)
  73. {
  74. set_bit(META_dirty, &mp->flag);
  75. release_metapage(mp);
  76. }
  77. static inline void flush_metapage(struct metapage *mp)
  78. {
  79. set_bit(META_sync, &mp->flag);
  80. write_metapage(mp);
  81. }
  82. static inline void discard_metapage(struct metapage *mp)
  83. {
  84. clear_bit(META_dirty, &mp->flag);
  85. set_bit(META_discard, &mp->flag);
  86. release_metapage(mp);
  87. }
  88. static inline void metapage_nohomeok(struct metapage *mp)
  89. {
  90. struct page *page = mp->page;
  91. lock_page(page);
  92. if (!mp->nohomeok++) {
  93. mark_metapage_dirty(mp);
  94. page_cache_get(page);
  95. wait_on_page_writeback(page);
  96. }
  97. unlock_page(page);
  98. }
  99. /*
  100. * This serializes access to mp->lsn when metapages are added to logsynclist
  101. * without setting nohomeok. i.e. updating imap & dmap
  102. */
  103. static inline void metapage_wait_for_io(struct metapage *mp)
  104. {
  105. if (test_bit(META_io, &mp->flag))
  106. wait_on_page_writeback(mp->page);
  107. }
  108. /*
  109. * This is called when already holding the metapage
  110. */
  111. static inline void _metapage_homeok(struct metapage *mp)
  112. {
  113. if (!--mp->nohomeok)
  114. page_cache_release(mp->page);
  115. }
  116. static inline void metapage_homeok(struct metapage *mp)
  117. {
  118. hold_metapage(mp);
  119. _metapage_homeok(mp);
  120. put_metapage(mp);
  121. }
  122. extern const struct address_space_operations jfs_metapage_aops;
  123. /*
  124. * This routines invalidate all pages for an extent.
  125. */
  126. extern void __invalidate_metapages(struct inode *, s64, int);
  127. #define invalidate_pxd_metapages(ip, pxd) \
  128. __invalidate_metapages((ip), addressPXD(&(pxd)), lengthPXD(&(pxd)))
  129. #define invalidate_dxd_metapages(ip, dxd) \
  130. __invalidate_metapages((ip), addressDXD(&(dxd)), lengthDXD(&(dxd)))
  131. #define invalidate_xad_metapages(ip, xad) \
  132. __invalidate_metapages((ip), addressXAD(&(xad)), lengthXAD(&(xad)))
  133. #endif /* _H_JFS_METAPAGE */