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

/*
 * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * 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. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * 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_OSREFERENCE_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_INTERNAL_H_
#define	_SYS_BUF_INTERNAL_H_

#include <sys/appleapiopts.h>

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


#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. */
	int	b_timestamp;		/* timestamp for queuing operation */
	long	b_whichq;		/* the free list the buffer belongs to */
	volatile long	b_flags;	/* B_* flags. */
	volatile long	b_lflags;	/* BL_BUSY | BL_WANTED flags... protected by buf_mtx */
	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. */
        uintptr_t	b_datap;	/* Memory, superblocks, indirect etc.*/
	daddr64_t	b_lblkno;	/* Logical block number. */
	daddr64_t	b_blkno;	/* Underlying physical block number. */
	void	(*b_iodone)(buf_t, void *);	/* Function to call upon completion. */
	vnode_t	b_vp;			/* File vnode for data, device vnode for metadata. */
	kauth_cred_t b_rcred;		/* Read credentials reference. */
	kauth_cred_t b_wcred;		/* Write credentials reference. */
	void *	b_upl;			/* Pointer to UPL */
	buf_t	b_real_bp;		/* used to track bp generated through cluster_bp */
	TAILQ_ENTRY(buf)	b_act;	/* Device driver queue when active */
	void *	b_drvdata;		/* Device driver private use */
        void *  b_fsprivate;		/* filesystem private use */
	void *	b_transaction;		/* journal private use */
	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. */
	proc_t 	b_proc;			/* Associated proc; NULL if kernel. */
#ifdef JOE_DEBUG
        void *	b_owner;
        int     b_tag;
        void *  b_lastbrelse;
        int	b_stackbrelse[6];
        int	b_stackgetblk[6];
#endif
};


/* 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_iostate    b_rcred
#define b_cliodone   b_wcred

/*
 * These flags are kept in b_lflags... 
 * buf_mtxp must be held before examining/updating
 */
#define	BL_BUSY		0x00000001	/* I/O in progress. */
#define	BL_WANTED	0x00000002	/* Process wants this buffer. */
#define BL_IOBUF	0x00000004	/* buffer allocated via 'buf_alloc' */
#define BL_CALLDONE	0x00000008	/* callback routine on B_CALL bp has completed */

/*
 * mask used by buf_flags... these are the readable external flags
 */
#define BUF_X_RDFLAGS (B_PHYS | B_RAW | B_LOCKED | B_ASYNC | B_READ | B_WRITE | B_PAGEIO |\
		       B_META | B_CLUSTER | B_DELWRI | B_FUA | B_PASSIVE)
/*
 * mask used by buf_clearflags/buf_setflags... these are the writable external flags
 */
#define BUF_X_WRFLAGS (B_PHYS | B_RAW | B_LOCKED | B_ASYNC | B_READ | B_WRITE | B_PAGEIO |\
		       B_NOCACHE | B_FUA | B_PASSIVE)

/*
 * These flags are kept in b_flags... access is lockless
 * External flags are defined in buf.h and cannot overlap
 * the internal flags
 * 
 * these flags are internal... there definition may change
 */
#define	B_CACHE		0x00010000	/* getblk found us in the cache. */
#define	B_DONE		0x00020000	/* I/O completed. */
#define	B_INVAL		0x00040000	/* Does not contain valid info. */
#define	B_ERROR		0x00080000	/* I/O error occurred. */
#define	B_EINTR		0x00100000	/* I/O was interrupted */
#define	B_AGE		0x00200000	/* Move to age queue when I/O done. */
#define B_FILTER	0x00400000	/* call b_iodone from biodone as an in-line filter */
#define	B_CALL		0x00800000	/* Call b_iodone from biodone, assumes b_iodone consumes bp */
#define B_EOT		0x01000000	/* last buffer in a transaction list created by cluster_io */
#define	B_WASDIRTY	0x02000000	/* page was found dirty in the VM cache */
#define	B_HDRALLOC	0x04000000	/* zone allocated buffer header */
#define	B_ZALLOC	0x08000000	/* b_datap is zalloc()ed */
/*
 * private flags used by the journal layer
 */
#define	B_NORELSE	0x10000000	/* don't brelse() in bwrite() */
/*
 * private flags used by by the cluster layer
 */
#define B_NEED_IODONE   0x20000000	/* need biodone on the real_bp associated with a cluster_io */
#define B_COMMIT_UPL    0x40000000	/* commit/abort the UPL on I/O success/failure */
/*
 * can we deprecate?
 */
#define	B_TAPE		0x80000000	/* Magnetic tape I/O. */


/* 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 */


extern int niobuf_headers;		/* The number of IO buffer headers for cluster IO */
extern int nbuf_headers;		/* The number of buffer headers */
extern int max_nbuf_headers;		/* The max number of buffer headers */
extern int nbuf_hashelements;		/* The number of elements in bufhash */
extern struct buf *buf_headers;		/* The buffer headers. */


/*
 * 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 */


__BEGIN_DECLS

buf_t	alloc_io_buf(vnode_t, int);
void	free_io_buf(buf_t);

int	allocbuf(struct buf *, int);
void	bufinit(void) __attribute__((section("__TEXT, initcode")));

void	buf_setfilter(buf_t, void (*)(buf_t, void *), void *, void **, void **);

/*
 * Flags for buf_acquire
 */
#define BAC_NOWAIT		0x01	/* Don't wait if buffer is busy */
#define BAC_REMOVE		0x02	/* Remove from free list once buffer is acquired */
#define BAC_SKIP_NONLOCKED	0x04	/* Don't return LOCKED buffers */
#define BAC_SKIP_LOCKED		0x08	/* Only return LOCKED buffers */

void	buf_list_lock(void);
void	buf_list_unlock(void);

void	buf_biowait_callback(buf_t);

void	cluster_init(void) __attribute__((section("__TEXT, initcode")));
void	buf_drop(buf_t);
errno_t	buf_acquire(buf_t, int, int, int);

int	count_busy_buffers(void);
int	count_lock_queue(void);


__END_DECLS


/*
 *	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 /* KERNEL */
#endif /* !_SYS_BUF_H_ */
Commit	Line	Data
91447636	1	/*
2d21ac55	2	* Copyright (c) 2000-2007 Apple Inc. All rights reserved.
5d5c5d0d	3	*
2d21ac55	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
91447636	5	*
2d21ac55 A	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
8f6c56a5	14	*
2d21ac55 A	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
8f6c56a5 A	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
8f6c56a5 A	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
2d21ac55 A	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
8f6c56a5	25	*
2d21ac55	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
91447636 A	27	*/
	28	/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
	29	/*
	30	* Copyright (c) 1982, 1986, 1989, 1993
	31	* The Regents of the University of California. All rights reserved.
	32	* (c) UNIX System Laboratories, Inc.
	33	* All or some portions of this file are derived from material licensed
	34	* to the University of California by American Telephone and Telegraph
	35	* Co. or Unix System Laboratories, Inc. and are reproduced herein with
	36	* the permission of UNIX System Laboratories, Inc.
	37	*
	38	* Redistribution and use in source and binary forms, with or without
	39	* modification, are permitted provided that the following conditions
	40	* are met:
	41	* 1. Redistributions of source code must retain the above copyright
	42	* notice, this list of conditions and the following disclaimer.
	43	* 2. Redistributions in binary form must reproduce the above copyright
	44	* notice, this list of conditions and the following disclaimer in the
	45	* documentation and/or other materials provided with the distribution.
	46	* 3. All advertising materials mentioning features or use of this software
	47	* must display the following acknowledgement:
	48	* This product includes software developed by the University of
	49	* California, Berkeley and its contributors.
	50	* 4. Neither the name of the University nor the names of its contributors
	51	* may be used to endorse or promote products derived from this software
	52	* without specific prior written permission.
	53	*
	54	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	55	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	56	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	57	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	58	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	59	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	60	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	61	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	62	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	63	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	64	* SUCH DAMAGE.
	65	*
	66	* @(#)buf.h 8.9 (Berkeley) 3/30/95
	67	*/
	68
	69	#ifndef _SYS_BUF_INTERNAL_H_
	70	#define _SYS_BUF_INTERNAL_H_
	71
	72	#include <sys/appleapiopts.h>
	73
	74	#ifdef KERNEL
	75	#include <sys/queue.h>
	76	#include <sys/errno.h>
	77	#include <sys/vm.h>
	78	#include <sys/cdefs.h>
	79	#include <sys/buf.h>
	80	#include <sys/lock.h>
	81
	82
91447636 A	83	#define NOLIST ((struct buf *)0x87654321)
	84
	85	/*
	86	* The buffer header describes an I/O operation in the kernel.
	87	*/
	88	struct buf {
	89	LIST_ENTRY(buf) b_hash; /* Hash chain. */
	90	LIST_ENTRY(buf) b_vnbufs; /* Buffer's associated vnode. */
	91	TAILQ_ENTRY(buf) b_freelist; /* Free list position if not active. */
	92	int b_timestamp; /* timestamp for queuing operation */
	93	long b_whichq; /* the free list the buffer belongs to */
	94	volatile long b_flags; /* B_* flags. */
	95	volatile long b_lflags; /* BL_BUSY \| BL_WANTED flags... protected by buf_mtx */
	96	int b_error; /* errno value. */
	97	long b_bufsize; /* Allocated buffer size. */
	98	long b_bcount; /* Valid bytes in buffer. */
	99	long b_resid; /* Remaining I/O. */
	100	dev_t b_dev; /* Device associated with buffer. */
	101	uintptr_t b_datap; /* Memory, superblocks, indirect etc.*/
	102	daddr64_t b_lblkno; /* Logical block number. */
	103	daddr64_t b_blkno; /* Underlying physical block number. */
	104	void (b_iodone)(buf_t, void ); /* Function to call upon completion. */
2d21ac55 A	105	vnode_t b_vp; /* File vnode for data, device vnode for metadata. */
	106	kauth_cred_t b_rcred; /* Read credentials reference. */
	107	kauth_cred_t b_wcred; /* Write credentials reference. */
91447636 A	108	void * b_upl; /* Pointer to UPL */
	109	buf_t b_real_bp; /* used to track bp generated through cluster_bp */
	110	TAILQ_ENTRY(buf) b_act; /* Device driver queue when active */
	111	void * b_drvdata; /* Device driver private use */
	112	void * b_fsprivate; /* filesystem private use */
	113	void * b_transaction; /* journal private use */
	114	int b_dirtyoff; /* Offset in buffer of dirty region. */
	115	int b_dirtyend; /* Offset of end of dirty region. */
	116	int b_validoff; /* Offset in buffer of valid region. */
	117	int b_validend; /* Offset of end of valid region. */
	118	proc_t b_proc; /* Associated proc; NULL if kernel. */
	119	#ifdef JOE_DEBUG
	120	void * b_owner;
	121	int b_tag;
	122	void * b_lastbrelse;
	123	int b_stackbrelse[6];
	124	int b_stackgetblk[6];
	125	#endif
	126	};
	127
	128
	129	/* cluster_io definitions for use with io bufs */
	130	#define b_uploffset b_bufsize
	131	#define b_trans_head b_freelist.tqe_prev
	132	#define b_trans_next b_freelist.tqe_next
	133	#define b_iostate b_rcred
2d21ac55	134	#define b_cliodone b_wcred
91447636 A	135
	136	/*
	137	* These flags are kept in b_lflags...
	138	* buf_mtxp must be held before examining/updating
	139	*/
	140	#define BL_BUSY 0x00000001 /* I/O in progress. */
	141	#define BL_WANTED 0x00000002 /* Process wants this buffer. */
	142	#define BL_IOBUF 0x00000004 /* buffer allocated via 'buf_alloc' */
2d21ac55	143	#define BL_CALLDONE 0x00000008 /* callback routine on B_CALL bp has completed */
91447636 A	144
	145	/*
	146	* mask used by buf_flags... these are the readable external flags
	147	*/
2d21ac55 A	148	#define BUF_X_RDFLAGS (B_PHYS \| B_RAW \| B_LOCKED \| B_ASYNC \| B_READ \| B_WRITE \| B_PAGEIO \|\
2d21ac55 A	149	B_META \| B_CLUSTER \| B_DELWRI \| B_FUA \| B_PASSIVE)
91447636 A	150	/*
	151	* mask used by buf_clearflags/buf_setflags... these are the writable external flags
	152	*/
2d21ac55 A	153	#define BUF_X_WRFLAGS (B_PHYS \| B_RAW \| B_LOCKED \| B_ASYNC \| B_READ \| B_WRITE \| B_PAGEIO \|\
2d21ac55 A	154	B_NOCACHE \| B_FUA \| B_PASSIVE)
91447636 A	155
	156	/*
	157	* These flags are kept in b_flags... access is lockless
	158	* External flags are defined in buf.h and cannot overlap
	159	* the internal flags
	160	*
	161	* these flags are internal... there definition may change
	162	*/
	163	#define B_CACHE 0x00010000 /* getblk found us in the cache. */
	164	#define B_DONE 0x00020000 /* I/O completed. */
	165	#define B_INVAL 0x00040000 /* Does not contain valid info. */
	166	#define B_ERROR 0x00080000 /* I/O error occurred. */
	167	#define B_EINTR 0x00100000 /* I/O was interrupted */
	168	#define B_AGE 0x00200000 /* Move to age queue when I/O done. */
	169	#define B_FILTER 0x00400000 /* call b_iodone from biodone as an in-line filter */
	170	#define B_CALL 0x00800000 /* Call b_iodone from biodone, assumes b_iodone consumes bp */
2d21ac55	171	#define B_EOT 0x01000000 /* last buffer in a transaction list created by cluster_io */
91447636 A	172	#define B_WASDIRTY 0x02000000 /* page was found dirty in the VM cache */
	173	#define B_HDRALLOC 0x04000000 /* zone allocated buffer header */
	174	#define B_ZALLOC 0x08000000 /* b_datap is zalloc()ed */
	175	/*
	176	* private flags used by the journal layer
	177	*/
	178	#define B_NORELSE 0x10000000 /* don't brelse() in bwrite() */
	179	/*
	180	* private flags used by by the cluster layer
	181	*/
	182	#define B_NEED_IODONE 0x20000000 /* need biodone on the real_bp associated with a cluster_io */
	183	#define B_COMMIT_UPL 0x40000000 /* commit/abort the UPL on I/O success/failure */
	184	/*
	185	* can we deprecate?
	186	*/
	187	#define B_TAPE 0x80000000 /* Magnetic tape I/O. */
	188
	189
	190	/* Flags to low-level allocation routines. */
	191	#define B_CLRBUF 0x01 /* Request allocated buffer be cleared. */
	192	#define B_SYNC 0x02 /* Do all allocations synchronously. */
	193	#define B_NOBUFF 0x04 /* Do not allocate struct buf */
	194
	195
2d21ac55 A	196	extern int niobuf_headers; /* The number of IO buffer headers for cluster IO */
2d21ac55 A	197	extern int nbuf_headers; /* The number of buffer headers */
0c530ab8 A	198	extern int max_nbuf_headers; /* The max number of buffer headers */
0c530ab8 A	199	extern int nbuf_hashelements; /* The number of elements in bufhash */
2d21ac55	200	extern struct buf buf_headers; / The buffer headers. */
91447636 A	201
	202
	203	/*
	204	* Definitions for the buffer free lists.
	205	*/
	206	#define BQUEUES 6 /* number of free buffer queues */
	207
	208	#define BQ_LOCKED 0 /* super-blocks &c */
	209	#define BQ_LRU 1 /* lru, useful buffers */
	210	#define BQ_AGE 2 /* rubbish */
	211	#define BQ_EMPTY 3 /* buffer headers with no memory */
	212	#define BQ_META 4 /* buffer containing metadata */
	213	#define BQ_LAUNDRY 5 /* buffers that need cleaning */
	214
	215
	216	__BEGIN_DECLS
	217
	218	buf_t alloc_io_buf(vnode_t, int);
	219	void free_io_buf(buf_t);
	220
	221	int allocbuf(struct buf *, int);
2d21ac55	222	void bufinit(void) __attribute__((section("__TEXT, initcode")));
91447636 A	223
	224	void buf_setfilter(buf_t, void ()(buf_t, void ), void , void , void *);
	225
	226	/*
	227	* Flags for buf_acquire
	228	*/
	229	#define BAC_NOWAIT 0x01 /* Don't wait if buffer is busy */
	230	#define BAC_REMOVE 0x02 /* Remove from free list once buffer is acquired */
	231	#define BAC_SKIP_NONLOCKED 0x04 /* Don't return LOCKED buffers */
	232	#define BAC_SKIP_LOCKED 0x08 /* Only return LOCKED buffers */
	233
2d21ac55 A	234	void buf_list_lock(void);
	235	void buf_list_unlock(void);
	236
	237	void buf_biowait_callback(buf_t);
	238
	239	void cluster_init(void) __attribute__((section("__TEXT, initcode")));
91447636 A	240	void buf_drop(buf_t);
	241	errno_t buf_acquire(buf_t, int, int, int);
	242
	243	int count_busy_buffers(void);
	244	int count_lock_queue(void);
	245
	246
	247	__END_DECLS
	248
	249
	250	/*
	251	* Stats on usefulness of the buffer cache
	252	*/
	253	struct bufstats {
	254	long bufs_incore; /* found incore */
	255	long bufs_busyincore; /* found incore. was busy */
	256	long bufs_vmhits; /* not incore. found in VM */
	257	long bufs_miss; /* not incore. not in VM */
	258	long bufs_sleeps; /* buffer starvation */
	259	long bufs_eblk; /* Calls to geteblk */
	260	long bufs_iobufmax; /* Max. number of IO buffers used */
	261	long bufs_iobufinuse; /* number of IO buffers in use */
	262	long bufs_iobufsleeps; /* IO buffer starvation */
	263	};
	264
	265	#endif /* KERNEL */
	266	#endif /* !_SYS_BUF_H_ */