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 22 #include <linux/pagemap.h> 23 24 struct metapage { 25 /* Common logsyncblk prefix (see jfs_logmgr.h) */ 26 u16 xflag; 27 u16 unused; 28 lid_t lid; 29 int lsn; 30 struct list_head synclist; 31 /* End of logsyncblk prefix */ 32 33 unsigned long flag; /* See Below */ 34 unsigned long count; /* Reference count */ 35 void *data; /* Data pointer */ 36 sector_t index; /* block address of page */ 37 wait_queue_head_t wait; 38 39 /* implementation */ 40 struct page *page; 41 unsigned int logical_size; 42 43 /* Journal management */ 44 int clsn; 45 int nohomeok; 46 struct jfs_log *log; 47 }; 48 49 /* metapage flag */ 50 #define META_locked 0 51 #define META_free 1 52 #define META_dirty 2 53 #define META_sync 3 54 #define META_discard 4 55 #define META_forcewrite 5 56 #define META_io 6 57 58 #define mark_metapage_dirty(mp) set_bit(META_dirty, &(mp)->flag) 59 60 /* function prototypes */ 61 extern struct metapage *__get_metapage(struct inode *inode, 62 unsigned long lblock, unsigned int size, 63 int absolute, unsigned long new); 64 65 #define read_metapage(inode, lblock, size, absolute)\ 66 __get_metapage(inode, lblock, size, absolute, FALSE) 67 68 #define get_metapage(inode, lblock, size, absolute)\ 69 __get_metapage(inode, lblock, size, absolute, TRUE) 70 71 extern void release_metapage(struct metapage *); 72 extern void grab_metapage(struct metapage *); 73 extern void force_metapage(struct metapage *); 74 75 /* 76 * hold_metapage and put_metapage are used in conjuction. The page lock 77 * is not dropped between the two, so no other threads can get or release 78 * the metapage 79 */ 80 extern void hold_metapage(struct metapage *); 81 extern void put_metapage(struct metapage *); 82 83 static inline void write_metapage(struct metapage *mp) 84 { 85 set_bit(META_dirty, &mp->flag); 86 release_metapage(mp); 87 } 88 89 static inline void flush_metapage(struct metapage *mp) 90 { 91 set_bit(META_sync, &mp->flag); 92 write_metapage(mp); 93 } 94 95 static inline void discard_metapage(struct metapage *mp) 96 { 97 clear_bit(META_dirty, &mp->flag); 98 set_bit(META_discard, &mp->flag); 99 release_metapage(mp); 100 } 101 102 static inline void metapage_nohomeok(struct metapage *mp) 103 { 104 struct page *page = mp->page; 105 lock_page(page); 106 if (!mp->nohomeok++) { 107 mark_metapage_dirty(mp); 108 page_cache_get(page); 109 wait_on_page_writeback(page); 110 } 111 unlock_page(page); 112 } 113 114 /* 115 * This serializes access to mp->lsn when metapages are added to logsynclist 116 * without setting nohomeok. i.e. updating imap & dmap 117 */ 118 static inline void metapage_wait_for_io(struct metapage *mp) 119 { 120 if (test_bit(META_io, &mp->flag)) 121 wait_on_page_writeback(mp->page); 122 } 123 124 /* 125 * This is called when already holding the metapage 126 */ 127 static inline void _metapage_homeok(struct metapage *mp) 128 { 129 if (!--mp->nohomeok) 130 page_cache_release(mp->page); 131 } 132 133 static inline void metapage_homeok(struct metapage *mp) 134 { 135 hold_metapage(mp); 136 _metapage_homeok(mp); 137 put_metapage(mp); 138 } 139 140 extern struct address_space_operations jfs_metapage_aops; 141 142 /* 143 * This routines invalidate all pages for an extent. 144 */ 145 extern void __invalidate_metapages(struct inode *, s64, int); 146 #define invalidate_pxd_metapages(ip, pxd) \ 147 __invalidate_metapages((ip), addressPXD(&(pxd)), lengthPXD(&(pxd))) 148 #define invalidate_dxd_metapages(ip, dxd) \ 149 __invalidate_metapages((ip), addressDXD(&(dxd)), lengthDXD(&(dxd))) 150 #define invalidate_xad_metapages(ip, xad) \ 151 __invalidate_metapages((ip), addressXAD(&(xad)), lengthXAD(&(xad))) 152 153 #endif /* _H_JFS_METAPAGE */ 154