[net-next-2.6.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 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 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 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 */
Commit	Line	Data
1da177e4	1	/*
1868f4aa DK	2	* Copyright (C) International Business Machines Corp., 2000-2002
1868f4aa DK	3	* Portions Copyright (C) Christoph Hellwig, 2001-2002
1da177e4 LT	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
63f83c9f	7	* the Free Software Foundation; either version 2 of the License, or
1da177e4	8	* (at your option) any later version.
63f83c9f	9	*
1da177e4 LT	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
63f83c9f	16	* along with this program; if not, write to the Free Software
1da177e4 LT	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 */
63f83c9f	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 */
1868f4aa DK	61	extern int metapage_init(void);
1868f4aa DK	62	extern void metapage_exit(void);
1da177e4 LT	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)\
4d81715f	68	__get_metapage(inode, lblock, size, absolute, false)
1da177e4 LT	69
1da177e4 LT	70	#define get_metapage(inode, lblock, size, absolute)\
4d81715f	71	__get_metapage(inode, lblock, size, absolute, true)
1da177e4 LT	72
1da177e4 LT	73	extern void release_metapage(struct metapage *);
7fab479b DK	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 conjuction. 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 *);
1da177e4 LT	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
7fab479b DK	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	page_cache_get(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	page_cache_release(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
f5e54d6e	142	extern const struct address_space_operations jfs_metapage_aops;
7fab479b	143
1da177e4 LT	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 */