buf.h

微内核软实时操作系统

/*
 * Copyright (c) 2005-2007, Kohsuke Ohtani
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the author nor the names of any co-contributors 
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef _SYS_BUF_H
#define _SYS_BUF_H

#include <prex/prex.h>
#include <sys/cdefs.h>
#include <sys/list.h>

/*
 * Buffer header
 */
struct buf {
	struct list	b_link;		/* Link to block list */
	int		b_flags;	/* Buffer flag */
	dev_t		b_dev;		/* Device number */
	int		b_blkno;	/* Block number */
	mutex_t		b_lock;		/* Lock */
	char		*b_data;	/* Pointer to data buffer */
};

/* Buffer flag */
#define	B_BUSY		0x00000001	/* I/O in progress. */
#define	B_DELWRI	0x00000002	/* Delay I/O until buffer reused. */
#define	B_INVAL		0x00000004	/* Does not contain valid info. */
#define	B_READ		0x00000008	/* Read buffer. */
#define	B_DONE		0x00000010	/* I/O completed. */

__BEGIN_DECLS
struct buf *getblk(dev_t dev, int blkno);
int	bread(dev_t dev, int blkno, struct buf **bpp);
int	bwrite(struct buf *bp);
void	bdwrite(struct buf *bp);
void	binval(dev_t dev);
void	bdirty(struct buf *);
void	brelse(struct buf *);
void	clrbuf(struct buf *);
void	bio_init(void);
__END_DECLS

#endif /* !_SYS_BUF_H */