[deliverable/linux.git] / fs / jfs / jfs_metapage.h

/*
 *   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_free	1
#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 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 conjuction.  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 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 */
Commit	Line	Data
1da177e4 LT	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 */
7fab479b	36	sector_t index; /* block address of page */
1da177e4 LT	37	wait_queue_head_t wait;
	38
	39	/* implementation */
	40	struct page *page;
7fab479b	41	unsigned int logical_size;
1da177e4 LT	42
	43	/* Journal management */
	44	int clsn;
7fab479b	45	int nohomeok;
1da177e4 LT	46	struct jfs_log *log;
	47	};
	48
	49	/* metapage flag */
	50	#define META_locked 0
7fab479b DK	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
1da177e4 LT	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 *);
7fab479b DK	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 *);
1da177e4 LT	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
7fab479b DK	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
1da177e4 LT	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 */