[apple/xnu.git] / bsd / sys / buf.h

/*
 * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*
 * Copyright (c) 1982, 1986, 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 *	@(#)buf.h	8.9 (Berkeley) 3/30/95
 */

#ifndef _SYS_BUF_H_
#define	_SYS_BUF_H_

#include <sys/appleapiopts.h>

#ifdef KERNEL
#include <sys/queue.h>
#include <sys/errno.h>
#include <sys/vm.h>
#include <sys/cdefs.h>

#ifdef __APPLE_API_PRIVATE

#define NOLIST ((struct buf *)0x87654321)

/*
 * The buffer header describes an I/O operation in the kernel.
 */
struct buf {
	LIST_ENTRY(buf) b_hash;		/* Hash chain. */
	LIST_ENTRY(buf) b_vnbufs;	/* Buffer's associated vnode. */
	TAILQ_ENTRY(buf) b_freelist;	/* Free list position if not active. */
	struct  proc *b_proc;		/* Associated proc; NULL if kernel. */
	volatile long	b_flags;	/* B_* flags. */
	int	b_error;		/* Errno value. */
	long	b_bufsize;		/* Allocated buffer size. */
	long	b_bcount;		/* Valid bytes in buffer. */
	long	b_resid;		/* Remaining I/O. */
	dev_t	b_dev;			/* Device associated with buffer. */
	struct {
		caddr_t	b_addr;		/* Memory, superblocks, indirect etc.*/
	} b_un;
	void	*b_saveaddr;		/* Original b_addr for physio. */
	daddr_t	b_lblkno;		/* Logical block number. */
	daddr_t	b_blkno;		/* Underlying physical block number. */
					/* Function to call upon completion. */
	void	(*b_iodone) __P((struct buf *));
	struct	vnode *b_vp;		/* Device vnode. */
	int	b_dirtyoff;		/* Offset in buffer of dirty region. */
	int	b_dirtyend;		/* Offset of end of dirty region. */
	int	b_validoff;		/* Offset in buffer of valid region. */
	int	b_validend;		/* Offset of end of valid region. */
	struct	ucred *b_rcred;		/* Read credentials reference. */
	struct	ucred *b_wcred;		/* Write credentials reference. */
	int	b_timestamp;		/* timestamp for queuing operation */
	long	b_vectorcount;	/* number of vectors in b_vectorlist */
	void	*b_vectorlist;	/* vector list for I/O */
	void	*b_pagelist;	/* to save pagelist info */
	long	b_vects[2];		/* vectorlist when b_vectorcount is 1 */
	long	b_whichq;		/* the free list the buffer belongs to */
	TAILQ_ENTRY(buf)	b_act;	/* Device driver queue when active */
	void	*b_drvdata;		/* Device driver private use */
};

/*
 * For portability with historic industry practice, the cylinder number has
 * to be maintained in the `b_resid' field.
 */
#define	b_cylinder b_resid		/* Cylinder number for disksort(). */

/* Device driver compatibility definitions. */
#define	b_active b_bcount		/* Driver queue head: drive active. */
#define	b_data	 b_un.b_addr		/* b_un.b_addr is not changeable. */
#define	b_errcnt b_resid		/* Retry count while I/O in progress. */
#define	iodone	 biodone		/* Old name for biodone. */
#define	iowait	 biowait		/* Old name for biowait. */

/* cluster_io definitions for use with io bufs */
#define b_uploffset  b_bufsize
#define b_trans_head b_freelist.tqe_prev
#define b_trans_next b_freelist.tqe_next
#define b_real_bp    b_saveaddr
#define b_iostate    b_rcred

/* journaling uses this cluster i/o field for its own
 * purposes because meta data buf's should never go
 * through the clustering code.
 */
#define b_transaction b_vectorlist

   
/*
 * These flags are kept in b_flags.
 */
#define	B_AGE		0x00000001	/* Move to age queue when I/O done. */
#define	B_NEEDCOMMIT	0x00000002	/* Append-write in progress. */
#define	B_ASYNC		0x00000004	/* Start I/O, do not wait. */
#define	B_BAD		0x00000008	/* Bad block revectoring in progress. */
#define	B_BUSY		0x00000010	/* I/O in progress. */
#define	B_CACHE		0x00000020	/* Bread found us in the cache. */
#define	B_CALL		0x00000040	/* Call b_iodone from biodone. */
#define	B_DELWRI	0x00000080	/* Delay I/O until buffer reused. */
#define	B_DIRTY		0x00000100	/* Dirty page to be pushed out async. */
#define	B_DONE		0x00000200	/* I/O completed. */
#define	B_EINTR		0x00000400	/* I/O was interrupted */
#define	B_ERROR		0x00000800	/* I/O error occurred. */
#define	B_WASDIRTY	0x00001000	/* page was found dirty in the VM cache */
#define	B_INVAL		0x00002000	/* Does not contain valid info. */
#define	B_LOCKED	0x00004000	/* Locked in core (not reusable). */
#define	B_NOCACHE	0x00008000	/* Do not cache block after use. */
#define	B_PAGEOUT	0x00010000	/* Page out indicator... */
#define	B_PGIN		0x00020000	/* Pagein op, so swap() can count it. */
#define	B_PHYS		0x00040000	/* I/O to user memory. */
#define	B_RAW		0x00080000	/* Set by physio for raw transfers. */
#define	B_READ		0x00100000	/* Read buffer. */
#define	B_TAPE		0x00200000	/* Magnetic tape I/O. */
#define	B_PAGELIST	0x00400000	/* Buffer describes pagelist I/O. */
#define	B_WANTED	0x00800000	/* Process wants this buffer. */
#define	B_WRITE		0x00000000	/* Write buffer (pseudo flag). */
#define	B_WRITEINPROG	0x01000000	/* Write in progress. */
#define	B_HDRALLOC	0x02000000	/* zone allocated buffer header */
#define	B_NORELSE	0x04000000	/* don't brelse() in bwrite() */
#define B_NEED_IODONE   0x08000000
								/* need to do a biodone on the */
								/* real_bp associated with a cluster_io */
#define B_COMMIT_UPL    0x10000000
								/* commit pages in upl when */
								/* I/O completes/fails */
#define	B_ZALLOC	0x20000000	/* b_data is zalloc()ed */
#define	B_META		0x40000000	/* buffer contains meta-data. */
#define	B_VECTORLIST	0x80000000	/* Used by device drivers. */


/*
 * Zero out the buffer's data area.
 */
#define	clrbuf(bp) {							\
	bzero((bp)->b_data, (u_int)(bp)->b_bcount);			\
	(bp)->b_resid = 0;						\
}

/* Flags to low-level allocation routines. */
#define B_CLRBUF	0x01	/* Request allocated buffer be cleared. */
#define B_SYNC		0x02	/* Do all allocations synchronously. */
#define B_NOBUFF	0x04	/* Do not allocate struct buf */

/* Flags for operation type in getblk() */
#define	BLK_READ	0x01	/* buffer for read */
#define	BLK_WRITE	0x02	/* buffer for write */
#define	BLK_PAGEIN	0x04	/* buffer for pagein */
#define	BLK_PAGEOUT	0x08	/* buffer for pageout */
#define	BLK_META	0x10	/* buffer for metadata */
#define	BLK_CLREAD	0x20	/* buffer for cluster read */
#define	BLK_CLWRITE	0x40	/* buffer for cluster write */

extern int nbuf;			/* The number of buffer headers */
extern struct buf *buf;		/* The buffer headers. */

#endif /* __APPLE_API_PRIVATE */


#ifdef __APPLE_API_UNSTABLE
/* Macros to clear/set/test flags. */
#define	SET(t, f)	(t) |= (f)
#define	CLR(t, f)	(t) &= ~(f)
#define	ISSET(t, f)	((t) & (f))
#endif /* __APPLE_API_UNSTABLE */

#ifdef __APPLE_API_PRIVATE
/*
 * Definitions for the buffer free lists.
 */
#define	BQUEUES		6		/* number of free buffer queues */

#define	BQ_LOCKED	0		/* super-blocks &c */
#define	BQ_LRU		1		/* lru, useful buffers */
#define	BQ_AGE		2		/* rubbish */
#define	BQ_EMPTY	3		/* buffer headers with no memory */
#define BQ_META		4		/* buffer containing metadata */
#define BQ_LAUNDRY	5		/* buffers that need cleaning */
#endif /* __APPLE_API_PRIVATE */

__BEGIN_DECLS
#ifdef __APPLE_API_UNSTABLE
int	allocbuf __P((struct buf *, int));
void	bawrite __P((struct buf *));
void	bdwrite __P((struct buf *));
void	biodone __P((struct buf *));
int	biowait __P((struct buf *));
int	bread __P((struct vnode *, daddr_t, int,
	    struct ucred *, struct buf **));
int	meta_bread __P((struct vnode *, daddr_t, int,
	    struct ucred *, struct buf **));
int	breada __P((struct vnode *, daddr_t, int, daddr_t, int,
	    struct ucred *, struct buf **));
int	breadn __P((struct vnode *, daddr_t, int, daddr_t *, int *, int,
	    struct ucred *, struct buf **));
void	brelse __P((struct buf *));
void	bremfree __P((struct buf *));
void	bufinit __P((void));
void	bwillwrite __P((void));
int	bwrite __P((struct buf *));
struct buf *getblk __P((struct vnode *, daddr_t, int, int, int, int));
struct buf *geteblk __P((int));
struct buf *incore __P((struct vnode *, daddr_t));
u_int	minphys __P((struct buf *bp));
int physio __P((void (*)(struct buf *), struct buf *, dev_t, int ,  u_int (*)(struct buf *), struct uio *, int ));
int count_busy_buffers __P((void));
struct buf *alloc_io_buf __P((struct vnode *, int));
void free_io_buf __P((struct buf *));
void reassignbuf __P((struct buf *, struct vnode *));
#endif /* __APPLE_API_UNSTABLE */
__END_DECLS

#ifdef __APPLE_API_PRIVATE
/*
 *	Stats on usefulness of the buffer cache
 */
struct bufstats {
	long	bufs_incore;		/* found incore */
	long	bufs_busyincore;	/* found incore. was busy */
	long	bufs_vmhits;		/* not incore. found in VM */
	long	bufs_miss;			/* not incore. not in VM */
	long	bufs_sleeps;		/* buffer starvation */
	long	bufs_eblk;			/* Calls to geteblk */
	long	bufs_iobufmax;		/* Max. number of IO buffers used */
	long	bufs_iobufinuse;	/* number of IO buffers in use */
	long	bufs_iobufsleeps;	/* IO buffer starvation */
};
#endif /* __APPLE_API_PRIVATE */

#endif /* KERNEL */
#endif /* !_SYS_BUF_H_ */
Commit	Line	Data
1c79356b	1	/*
9bccf70c	2	* Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
1c79356b A	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
43866e37	6	* Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
1c79356b	7	*
43866e37 A	8	* This file contains Original Code and/or Modifications of Original Code
	9	* as defined in and that are subject to the Apple Public Source License
	10	* Version 2.0 (the 'License'). You may not use this file except in
	11	* compliance with the License. Please obtain a copy of the License at
	12	* http://www.opensource.apple.com/apsl/ and read it before using this
	13	* file.
	14	*
	15	* The Original Code and all software distributed under the License are
	16	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
1c79356b A	17	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
1c79356b A	18	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
43866e37 A	19	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	20	* Please see the License for the specific language governing rights and
	21	* limitations under the License.
1c79356b A	22	*
	23	* @APPLE_LICENSE_HEADER_END@
	24	*/
	25	/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
	26	/*
	27	* Copyright (c) 1982, 1986, 1989, 1993
	28	* The Regents of the University of California. All rights reserved.
	29	* (c) UNIX System Laboratories, Inc.
	30	* All or some portions of this file are derived from material licensed
	31	* to the University of California by American Telephone and Telegraph
	32	* Co. or Unix System Laboratories, Inc. and are reproduced herein with
	33	* the permission of UNIX System Laboratories, Inc.
	34	*
	35	* Redistribution and use in source and binary forms, with or without
	36	* modification, are permitted provided that the following conditions
	37	* are met:
	38	* 1. Redistributions of source code must retain the above copyright
	39	* notice, this list of conditions and the following disclaimer.
	40	* 2. Redistributions in binary form must reproduce the above copyright
	41	* notice, this list of conditions and the following disclaimer in the
	42	* documentation and/or other materials provided with the distribution.
	43	* 3. All advertising materials mentioning features or use of this software
	44	* must display the following acknowledgement:
	45	* This product includes software developed by the University of
	46	* California, Berkeley and its contributors.
	47	* 4. Neither the name of the University nor the names of its contributors
	48	* may be used to endorse or promote products derived from this software
	49	* without specific prior written permission.
	50	*
	51	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	52	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	53	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	54	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	55	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	56	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	57	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	58	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	59	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	60	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	61	* SUCH DAMAGE.
	62	*
	63	* @(#)buf.h 8.9 (Berkeley) 3/30/95
	64	*/
	65
	66	#ifndef _SYS_BUF_H_
	67	#define _SYS_BUF_H_
9bccf70c A	68
	69	#include <sys/appleapiopts.h>
	70
	71	#ifdef KERNEL
1c79356b A	72	#include <sys/queue.h>
1c79356b A	73	#include <sys/errno.h>
1c79356b	74	#include <sys/vm.h>
9bccf70c	75	#include <sys/cdefs.h>
1c79356b	76
9bccf70c	77	#ifdef __APPLE_API_PRIVATE
1c79356b	78
9bccf70c	79	#define NOLIST ((struct buf *)0x87654321)
1c79356b A	80
	81	/*
	82	* The buffer header describes an I/O operation in the kernel.
	83	*/
	84	struct buf {
	85	LIST_ENTRY(buf) b_hash; /* Hash chain. */
	86	LIST_ENTRY(buf) b_vnbufs; /* Buffer's associated vnode. */
	87	TAILQ_ENTRY(buf) b_freelist; /* Free list position if not active. */
	88	struct proc b_proc; / Associated proc; NULL if kernel. */
	89	volatile long b_flags; /* B_* flags. */
	90	int b_error; /* Errno value. */
	91	long b_bufsize; /* Allocated buffer size. */
	92	long b_bcount; /* Valid bytes in buffer. */
	93	long b_resid; /* Remaining I/O. */
	94	dev_t b_dev; /* Device associated with buffer. */
	95	struct {
	96	caddr_t b_addr; /* Memory, superblocks, indirect etc.*/
	97	} b_un;
	98	void b_saveaddr; / Original b_addr for physio. */
	99	daddr_t b_lblkno; /* Logical block number. */
	100	daddr_t b_blkno; /* Underlying physical block number. */
	101	/* Function to call upon completion. */
	102	void (b_iodone) __P((struct buf ));
	103	struct vnode b_vp; / Device vnode. */
	104	int b_dirtyoff; /* Offset in buffer of dirty region. */
	105	int b_dirtyend; /* Offset of end of dirty region. */
	106	int b_validoff; /* Offset in buffer of valid region. */
	107	int b_validend; /* Offset of end of valid region. */
	108	struct ucred b_rcred; / Read credentials reference. */
	109	struct ucred b_wcred; / Write credentials reference. */
	110	int b_timestamp; /* timestamp for queuing operation */
	111	long b_vectorcount; /* number of vectors in b_vectorlist */
	112	void b_vectorlist; / vector list for I/O */
	113	void b_pagelist; / to save pagelist info */
	114	long b_vects[2]; /* vectorlist when b_vectorcount is 1 */
	115	long b_whichq; /* the free list the buffer belongs to */
	116	TAILQ_ENTRY(buf) b_act; /* Device driver queue when active */
	117	void b_drvdata; / Device driver private use */
	118	};
	119
	120	/*
	121	* For portability with historic industry practice, the cylinder number has
	122	* to be maintained in the `b_resid' field.
	123	*/
	124	#define b_cylinder b_resid /* Cylinder number for disksort(). */
	125
	126	/* Device driver compatibility definitions. */
	127	#define b_active b_bcount /* Driver queue head: drive active. */
	128	#define b_data b_un.b_addr /* b_un.b_addr is not changeable. */
	129	#define b_errcnt b_resid /* Retry count while I/O in progress. */
	130	#define iodone biodone /* Old name for biodone. */
	131	#define iowait biowait /* Old name for biowait. */
	132
	133	/* cluster_io definitions for use with io bufs */
	134	#define b_uploffset b_bufsize
	135	#define b_trans_head b_freelist.tqe_prev
	136	#define b_trans_next b_freelist.tqe_next
	137	#define b_real_bp b_saveaddr
b4c24cb9 A	138	#define b_iostate b_rcred
	139
	140	/* journaling uses this cluster i/o field for its own
	141	* purposes because meta data buf's should never go
	142	* through the clustering code.
	143	*/
	144	#define b_transaction b_vectorlist
	145
	146
1c79356b A	147
	148	/*
	149	* These flags are kept in b_flags.
	150	*/
	151	#define B_AGE 0x00000001 /* Move to age queue when I/O done. */
	152	#define B_NEEDCOMMIT 0x00000002 /* Append-write in progress. */
	153	#define B_ASYNC 0x00000004 /* Start I/O, do not wait. */
	154	#define B_BAD 0x00000008 /* Bad block revectoring in progress. */
	155	#define B_BUSY 0x00000010 /* I/O in progress. */
	156	#define B_CACHE 0x00000020 /* Bread found us in the cache. */
	157	#define B_CALL 0x00000040 /* Call b_iodone from biodone. */
	158	#define B_DELWRI 0x00000080 /* Delay I/O until buffer reused. */
	159	#define B_DIRTY 0x00000100 /* Dirty page to be pushed out async. */
	160	#define B_DONE 0x00000200 /* I/O completed. */
	161	#define B_EINTR 0x00000400 /* I/O was interrupted */
	162	#define B_ERROR 0x00000800 /* I/O error occurred. */
	163	#define B_WASDIRTY 0x00001000 /* page was found dirty in the VM cache */
	164	#define B_INVAL 0x00002000 /* Does not contain valid info. */
	165	#define B_LOCKED 0x00004000 /* Locked in core (not reusable). */
	166	#define B_NOCACHE 0x00008000 /* Do not cache block after use. */
	167	#define B_PAGEOUT 0x00010000 /* Page out indicator... */
	168	#define B_PGIN 0x00020000 /* Pagein op, so swap() can count it. */
	169	#define B_PHYS 0x00040000 /* I/O to user memory. */
	170	#define B_RAW 0x00080000 /* Set by physio for raw transfers. */
	171	#define B_READ 0x00100000 /* Read buffer. */
	172	#define B_TAPE 0x00200000 /* Magnetic tape I/O. */
	173	#define B_PAGELIST 0x00400000 /* Buffer describes pagelist I/O. */
	174	#define B_WANTED 0x00800000 /* Process wants this buffer. */
	175	#define B_WRITE 0x00000000 /* Write buffer (pseudo flag). */
	176	#define B_WRITEINPROG 0x01000000 /* Write in progress. */
765c9de3	177	#define B_HDRALLOC 0x02000000 /* zone allocated buffer header */
b4c24cb9	178	#define B_NORELSE 0x04000000 /* don't brelse() in bwrite() */
1c79356b A	179	#define B_NEED_IODONE 0x08000000
	180	/* need to do a biodone on the */
	181	/* real_bp associated with a cluster_io */
	182	#define B_COMMIT_UPL 0x10000000
	183	/* commit pages in upl when */
	184	/* I/O completes/fails */
	185	#define B_ZALLOC 0x20000000 /* b_data is zalloc()ed */
	186	#define B_META 0x40000000 /* buffer contains meta-data. */
	187	#define B_VECTORLIST 0x80000000 /* Used by device drivers. */
	188
	189
	190	/*
	191	* Zero out the buffer's data area.
	192	*/
	193	#define clrbuf(bp) { \
	194	bzero((bp)->b_data, (u_int)(bp)->b_bcount); \
	195	(bp)->b_resid = 0; \
	196	}
	197
	198	/* Flags to low-level allocation routines. */
	199	#define B_CLRBUF 0x01 /* Request allocated buffer be cleared. */
	200	#define B_SYNC 0x02 /* Do all allocations synchronously. */
	201	#define B_NOBUFF 0x04 /* Do not allocate struct buf */
	202
	203	/* Flags for operation type in getblk() */
	204	#define BLK_READ 0x01 /* buffer for read */
	205	#define BLK_WRITE 0x02 /* buffer for write */
	206	#define BLK_PAGEIN 0x04 /* buffer for pagein */
	207	#define BLK_PAGEOUT 0x08 /* buffer for pageout */
	208	#define BLK_META 0x10 /* buffer for metadata */
	209	#define BLK_CLREAD 0x20 /* buffer for cluster read */
	210	#define BLK_CLWRITE 0x40 /* buffer for cluster write */
	211
1c79356b A	212	extern int nbuf; /* The number of buffer headers */
	213	extern struct buf buf; / The buffer headers. */
	214
9bccf70c A	215	#endif /* __APPLE_API_PRIVATE */
	216
	217
	218	#ifdef __APPLE_API_UNSTABLE
1c79356b A	219	/* Macros to clear/set/test flags. */
	220	#define SET(t, f) (t) \|= (f)
	221	#define CLR(t, f) (t) &= ~(f)
	222	#define ISSET(t, f) ((t) & (f))
9bccf70c	223	#endif /* __APPLE_API_UNSTABLE */
1c79356b	224
9bccf70c	225	#ifdef __APPLE_API_PRIVATE
1c79356b A	226	/*
	227	* Definitions for the buffer free lists.
	228	*/
765c9de3	229	#define BQUEUES 6 /* number of free buffer queues */
1c79356b A	230
	231	#define BQ_LOCKED 0 /* super-blocks &c */
	232	#define BQ_LRU 1 /* lru, useful buffers */
	233	#define BQ_AGE 2 /* rubbish */
	234	#define BQ_EMPTY 3 /* buffer headers with no memory */
	235	#define BQ_META 4 /* buffer containing metadata */
765c9de3	236	#define BQ_LAUNDRY 5 /* buffers that need cleaning */
9bccf70c	237	#endif /* __APPLE_API_PRIVATE */
1c79356b A	238
1c79356b A	239	__BEGIN_DECLS
9bccf70c	240	#ifdef __APPLE_API_UNSTABLE
1c79356b A	241	int allocbuf __P((struct buf *, int));
	242	void bawrite __P((struct buf *));
	243	void bdwrite __P((struct buf *));
	244	void biodone __P((struct buf *));
	245	int biowait __P((struct buf *));
	246	int bread __P((struct vnode *, daddr_t, int,
	247	struct ucred , struct buf *));
	248	int meta_bread __P((struct vnode *, daddr_t, int,
	249	struct ucred , struct buf *));
	250	int breada __P((struct vnode *, daddr_t, int, daddr_t, int,
	251	struct ucred , struct buf *));
	252	int breadn __P((struct vnode , daddr_t, int, daddr_t , int *, int,
	253	struct ucred , struct buf *));
	254	void brelse __P((struct buf *));
	255	void bremfree __P((struct buf *));
	256	void bufinit __P((void));
9bccf70c	257	void bwillwrite __P((void));
1c79356b A	258	int bwrite __P((struct buf *));
	259	struct buf getblk __P((struct vnode , daddr_t, int, int, int, int));
	260	struct buf *geteblk __P((int));
	261	struct buf incore __P((struct vnode , daddr_t));
	262	u_int minphys __P((struct buf *bp));
	263	int physio __P((void ()(struct buf ), struct buf , dev_t, int , u_int ()(struct buf ), struct uio , int ));
	264	int count_busy_buffers __P((void));
0b4e3aa0 A	265	struct buf alloc_io_buf __P((struct vnode , int));
0b4e3aa0 A	266	void free_io_buf __P((struct buf *));
9bccf70c A	267	void reassignbuf __P((struct buf , struct vnode ));
9bccf70c A	268	#endif /* __APPLE_API_UNSTABLE */
1c79356b A	269	__END_DECLS
1c79356b A	270
9bccf70c	271	#ifdef __APPLE_API_PRIVATE
1c79356b A	272	/*
	273	* Stats on usefulness of the buffer cache
	274	*/
	275	struct bufstats {
	276	long bufs_incore; /* found incore */
	277	long bufs_busyincore; /* found incore. was busy */
	278	long bufs_vmhits; /* not incore. found in VM */
	279	long bufs_miss; /* not incore. not in VM */
	280	long bufs_sleeps; /* buffer starvation */
	281	long bufs_eblk; /* Calls to geteblk */
	282	long bufs_iobufmax; /* Max. number of IO buffers used */
	283	long bufs_iobufinuse; /* number of IO buffers in use */
	284	long bufs_iobufsleeps; /* IO buffer starvation */
	285	};
9bccf70c	286	#endif /* __APPLE_API_PRIVATE */
1c79356b A	287
	288	#endif /* KERNEL */
	289	#endif /* !_SYS_BUF_H_ */