jfs_metapage.h
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/*
* Copyright (C) International Business Machines Corp., 2000-2002
* Portions Copyright (C) Christoph Hellwig, 2001-2002
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _H_JFS_METAPAGE
#define _H_JFS_METAPAGE
#include <linux/pagemap.h>
struct metapage {
/* Common logsyncblk prefix (see jfs_logmgr.h) */
u16 xflag;
u16 unused;
lid_t lid;
int lsn;
struct list_head synclist;
/* End of logsyncblk prefix */
unsigned long flag; /* See Below */
unsigned long count; /* Reference count */
void *data; /* Data pointer */
sector_t index; /* block address of page */
wait_queue_head_t wait;
/* implementation */
struct page *page;
unsigned int logical_size;
/* Journal management */
int clsn;
int nohomeok;
struct jfs_log *log;
};
/* metapage flag */
#define META_locked 0
#define META_dirty 2
#define META_sync 3
#define META_discard 4
#define META_forcewrite 5
#define META_io 6
#define mark_metapage_dirty(mp) set_bit(META_dirty, &(mp)->flag)
/* function prototypes */
extern int metapage_init(void);
extern void metapage_exit(void);
extern struct metapage *__get_metapage(struct inode *inode,
unsigned long lblock, unsigned int size,
int absolute, unsigned long new);
#define read_metapage(inode, lblock, size, absolute)\
__get_metapage(inode, lblock, size, absolute, false)
#define get_metapage(inode, lblock, size, absolute)\
__get_metapage(inode, lblock, size, absolute, true)
extern void release_metapage(struct metapage *);
extern void grab_metapage(struct metapage *);
extern void force_metapage(struct metapage *);
/*
* hold_metapage and put_metapage are used in conjunction. The page lock
* is not dropped between the two, so no other threads can get or release
* the metapage
*/
extern void hold_metapage(struct metapage *);
extern void put_metapage(struct metapage *);
static inline void write_metapage(struct metapage *mp)
{
set_bit(META_dirty, &mp->flag);
release_metapage(mp);
}
static inline void flush_metapage(struct metapage *mp)
{
set_bit(META_sync, &mp->flag);
write_metapage(mp);
}
static inline void discard_metapage(struct metapage *mp)
{
clear_bit(META_dirty, &mp->flag);
set_bit(META_discard, &mp->flag);
release_metapage(mp);
}
static inline void metapage_nohomeok(struct metapage *mp)
{
struct page *page = mp->page;
lock_page(page);
if (!mp->nohomeok++) {
mark_metapage_dirty(mp);
page_cache_get(page);
wait_on_page_writeback(page);
}
unlock_page(page);
}
/*
* This serializes access to mp->lsn when metapages are added to logsynclist
* without setting nohomeok. i.e. updating imap & dmap
*/
static inline void metapage_wait_for_io(struct metapage *mp)
{
if (test_bit(META_io, &mp->flag))
wait_on_page_writeback(mp->page);
}
/*
* This is called when already holding the metapage
*/
static inline void _metapage_homeok(struct metapage *mp)
{
if (!--mp->nohomeok)
page_cache_release(mp->page);
}
static inline void metapage_homeok(struct metapage *mp)
{
hold_metapage(mp);
_metapage_homeok(mp);
put_metapage(mp);
}
extern const struct address_space_operations jfs_metapage_aops;
/*
* This routines invalidate all pages for an extent.
*/
extern void __invalidate_metapages(struct inode *, s64, int);
#define invalidate_pxd_metapages(ip, pxd) \
__invalidate_metapages((ip), addressPXD(&(pxd)), lengthPXD(&(pxd)))
#define invalidate_dxd_metapages(ip, dxd) \
__invalidate_metapages((ip), addressDXD(&(dxd)), lengthDXD(&(dxd)))
#define invalidate_xad_metapages(ip, xad) \
__invalidate_metapages((ip), addressXAD(&(xad)), lengthXAD(&(xad)))
#endif /* _H_JFS_METAPAGE */