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 struct super_block *sb; 42 unsigned int logical_size; 43 44 /* Journal management */ 45 int clsn; 46 int nohomeok; 47 struct jfs_log *log; 48 }; 49 50 /* metapage flag */ 51 #define META_locked 0 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 int metapage_init(void); 62 extern void metapage_exit(void); 63 extern struct metapage *__get_metapage(struct inode *inode, 64 unsigned long lblock, unsigned int size, 65 int absolute, unsigned long new); 66 67 #define read_metapage(inode, lblock, size, absolute)\ 68 __get_metapage(inode, lblock, size, absolute, false) 69 70 #define get_metapage(inode, lblock, size, absolute)\ 71 __get_metapage(inode, lblock, size, absolute, true) 72 73 extern void release_metapage(struct metapage *); 74 extern void grab_metapage(struct metapage *); 75 extern void force_metapage(struct metapage *); 76 77 /* 78 * hold_metapage and put_metapage are used in conjunction. The page lock 79 * is not dropped between the two, so no other threads can get or release 80 * the metapage 81 */ 82 extern void hold_metapage(struct metapage *); 83 extern void put_metapage(struct metapage *); 84 85 static inline void write_metapage(struct metapage *mp) 86 { 87 set_bit(META_dirty, &mp->flag); 88 release_metapage(mp); 89 } 90 91 static inline void flush_metapage(struct metapage *mp) 92 { 93 set_bit(META_sync, &mp->flag); 94 write_metapage(mp); 95 } 96 97 static inline void discard_metapage(struct metapage *mp) 98 { 99 clear_bit(META_dirty, &mp->flag); 100 set_bit(META_discard, &mp->flag); 101 release_metapage(mp); 102 } 103 104 static inline void metapage_nohomeok(struct metapage *mp) 105 { 106 struct page *page = mp->page; 107 lock_page(page); 108 if (!mp->nohomeok++) { 109 mark_metapage_dirty(mp); 110 get_page(page); 111 wait_on_page_writeback(page); 112 } 113 unlock_page(page); 114 } 115 116 /* 117 * This serializes access to mp->lsn when metapages are added to logsynclist 118 * without setting nohomeok. i.e. updating imap & dmap 119 */ 120 static inline void metapage_wait_for_io(struct metapage *mp) 121 { 122 if (test_bit(META_io, &mp->flag)) 123 wait_on_page_writeback(mp->page); 124 } 125 126 /* 127 * This is called when already holding the metapage 128 */ 129 static inline void _metapage_homeok(struct metapage *mp) 130 { 131 if (!--mp->nohomeok) 132 put_page(mp->page); 133 } 134 135 static inline void metapage_homeok(struct metapage *mp) 136 { 137 hold_metapage(mp); 138 _metapage_homeok(mp); 139 put_metapage(mp); 140 } 141 142 extern const struct address_space_operations jfs_metapage_aops; 143 144 /* 145 * This routines invalidate all pages for an extent. 146 */ 147 extern void __invalidate_metapages(struct inode *, s64, int); 148 #define invalidate_pxd_metapages(ip, pxd) \ 149 __invalidate_metapages((ip), addressPXD(&(pxd)), lengthPXD(&(pxd))) 150 #define invalidate_dxd_metapages(ip, dxd) \ 151 __invalidate_metapages((ip), addressDXD(&(dxd)), lengthDXD(&(dxd))) 152 #define invalidate_xad_metapages(ip, xad) \ 153 __invalidate_metapages((ip), addressXAD(&(xad)), lengthXAD(&(xad))) 154 155 #endif /* _H_JFS_METAPAGE */ 156