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_dirty 2 52 #define META_sync 3 53 #define META_discard 4 54 #define META_forcewrite 5 55 #define META_io 6 56 57 #define mark_metapage_dirty(mp) set_bit(META_dirty, &(mp)->flag) 58 59 /* function prototypes */ 60 extern int metapage_init(void); 61 extern void metapage_exit(void); 62 extern struct metapage *__get_metapage(struct inode *inode, 63 unsigned long lblock, unsigned int size, 64 int absolute, unsigned long new); 65 66 #define read_metapage(inode, lblock, size, absolute)\ 67 __get_metapage(inode, lblock, size, absolute, false) 68 69 #define get_metapage(inode, lblock, size, absolute)\ 70 __get_metapage(inode, lblock, size, absolute, true) 71 72 extern void release_metapage(struct metapage *); 73 extern void grab_metapage(struct metapage *); 74 extern void force_metapage(struct metapage *); 75 76 /* 77 * hold_metapage and put_metapage are used in conjunction. The page lock 78 * is not dropped between the two, so no other threads can get or release 79 * the metapage 80 */ 81 extern void hold_metapage(struct metapage *); 82 extern void put_metapage(struct metapage *); 83 84 static inline void write_metapage(struct metapage *mp) 85 { 86 set_bit(META_dirty, &mp->flag); 87 release_metapage(mp); 88 } 89 90 static inline void flush_metapage(struct metapage *mp) 91 { 92 set_bit(META_sync, &mp->flag); 93 write_metapage(mp); 94 } 95 96 static inline void discard_metapage(struct metapage *mp) 97 { 98 clear_bit(META_dirty, &mp->flag); 99 set_bit(META_discard, &mp->flag); 100 release_metapage(mp); 101 } 102 103 static inline void metapage_nohomeok(struct metapage *mp) 104 { 105 struct page *page = mp->page; 106 lock_page(page); 107 if (!mp->nohomeok++) { 108 mark_metapage_dirty(mp); 109 page_cache_get(page); 110 wait_on_page_writeback(page); 111 } 112 unlock_page(page); 113 } 114 115 /* 116 * This serializes access to mp->lsn when metapages are added to logsynclist 117 * without setting nohomeok. i.e. updating imap & dmap 118 */ 119 static inline void metapage_wait_for_io(struct metapage *mp) 120 { 121 if (test_bit(META_io, &mp->flag)) 122 wait_on_page_writeback(mp->page); 123 } 124 125 /* 126 * This is called when already holding the metapage 127 */ 128 static inline void _metapage_homeok(struct metapage *mp) 129 { 130 if (!--mp->nohomeok) 131 page_cache_release(mp->page); 132 } 133 134 static inline void metapage_homeok(struct metapage *mp) 135 { 136 hold_metapage(mp); 137 _metapage_homeok(mp); 138 put_metapage(mp); 139 } 140 141 extern const struct address_space_operations jfs_metapage_aops; 142 143 /* 144 * This routines invalidate all pages for an extent. 145 */ 146 extern void __invalidate_metapages(struct inode *, s64, int); 147 #define invalidate_pxd_metapages(ip, pxd) \ 148 __invalidate_metapages((ip), addressPXD(&(pxd)), lengthPXD(&(pxd))) 149 #define invalidate_dxd_metapages(ip, dxd) \ 150 __invalidate_metapages((ip), addressDXD(&(dxd)), lengthDXD(&(dxd))) 151 #define invalidate_xad_metapages(ip, xad) \ 152 __invalidate_metapages((ip), addressXAD(&(xad)), lengthXAD(&(xad))) 153 154 #endif /* _H_JFS_METAPAGE */ 155