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

/*
 * Copyright (c) 2004-2006 Apple Computer, 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) 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Scooter Morris at Genentech 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.
 * 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.
 *
 *	@(#)lockf.h	8.1 (Berkeley) 6/11/93
 * $FreeBSD: src/sys/sys/lockf.h,v 1.16 2004/04/07 04:19:49 imp Exp $
 */

#ifndef _SYS_LOCKF_H_
#define	_SYS_LOCKF_H_

#include <sys/queue.h>
#include <sys/cdefs.h>

struct vnop_advlock_args;
struct vnode;

#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_LOCKF);
#endif

/*
 * The lockf structure is a kernel structure which contains the information
 * associated with a byte range lock.  The lockf structures are linked into
 * the vnode structure.  Locks are sorted by the starting byte of the lock for
 * efficiency after they have been committed; uncommitted locks are on the list
 * head so they may quickly be accessed, and are both short lived and transient.
 */
TAILQ_HEAD(locklist, lockf);

#pragma pack(4)

struct lockf {
	short	lf_flags;	    /* Semantics: F_POSIX, F_FLOCK, F_WAIT */
	short	lf_type;	 /* Lock type: F_RDLCK, F_WRLCK */
	off_t	lf_start;	    /* Byte # of the start of the lock */
	off_t	lf_end;		    /* Byte # of the end of the lock (-1=EOF) */
	caddr_t	lf_id;		    /* Id of the resource holding the lock */
	struct	lockf **lf_head;    /* Back pointer to the head of the locf list */
	struct vnode *lf_vnode;	    /* Back pointer to the inode */
	struct	lockf *lf_next;	    /* Pointer to the next lock on this inode */
	struct	locklist lf_blkhd;  /* List of requests blocked on this lock */
	TAILQ_ENTRY(lockf) lf_block;/* A request waiting for a lock */
};

#pragma pack()

/* Maximum length of sleep chains to traverse to try and detect deadlock. */
#define MAXDEPTH 50

__BEGIN_DECLS

#ifdef KERNEL_PRIVATE
int	lf_advlock(struct vnop_advlock_args *);
int	lf_assert(struct vnop_advlock_args *, void **);
void	lf_commit(void *, int);

#ifdef LOCKF_DEBUG
void	lf_print(char *, struct lockf *);
void	lf_printlist(char *, struct lockf *);
#endif
#endif /* KERNEL_PRIVATE */

__END_DECLS

#endif /* !_SYS_LOCKF_H_ */
Commit	Line	Data
1c79356b	1	/*
2d21ac55	2	* Copyright (c) 2004-2006 Apple Computer, Inc. All rights reserved.
1c79356b	3	*
2d21ac55	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b	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@
1c79356b	27	*/
1c79356b A	28	/*
	29	* Copyright (c) 1991, 1993
	30	* The Regents of the University of California. All rights reserved.
	31	*
	32	* This code is derived from software contributed to Berkeley by
	33	* Scooter Morris at Genentech 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.
1c79356b A	43	* 4. Neither the name of the University nor the names of its contributors
	44	* may be used to endorse or promote products derived from this software
	45	* without specific prior written permission.
	46	*
	47	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	48	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	49	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	50	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	51	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	52	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	53	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	54	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	55	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	56	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	57	* SUCH DAMAGE.
	58	*
	59	* @(#)lockf.h 8.1 (Berkeley) 6/11/93
91447636	60	* $FreeBSD: src/sys/sys/lockf.h,v 1.16 2004/04/07 04:19:49 imp Exp $
1c79356b A	61	*/
	62
	63	#ifndef _SYS_LOCKF_H_
	64	#define _SYS_LOCKF_H_
	65
91447636 A	66	#include <sys/queue.h>
	67	#include <sys/cdefs.h>
	68
	69	struct vnop_advlock_args;
	70	struct vnode;
	71
	72	#ifdef MALLOC_DECLARE
	73	MALLOC_DECLARE(M_LOCKF);
	74	#endif
9bccf70c	75
1c79356b A	76	/*
	77	* The lockf structure is a kernel structure which contains the information
	78	* associated with a byte range lock. The lockf structures are linked into
2d21ac55 A	79	* the vnode structure. Locks are sorted by the starting byte of the lock for
	80	* efficiency after they have been committed; uncommitted locks are on the list
	81	* head so they may quickly be accessed, and are both short lived and transient.
1c79356b	82	*/
91447636 A	83	TAILQ_HEAD(locklist, lockf);
91447636 A	84
0c530ab8	85	#pragma pack(4)
91447636	86
1c79356b	87	struct lockf {
91447636	88	short lf_flags; /* Semantics: F_POSIX, F_FLOCK, F_WAIT */
1c79356b	89	short lf_type; /* Lock type: F_RDLCK, F_WRLCK */
91447636 A	90	off_t lf_start; /* Byte # of the start of the lock */
	91	off_t lf_end; /* Byte # of the end of the lock (-1=EOF) */
	92	caddr_t lf_id; /* Id of the resource holding the lock */
	93	struct lockf *lf_head; / Back pointer to the head of the locf list */
	94	struct vnode lf_vnode; / Back pointer to the inode */
	95	struct lockf lf_next; / Pointer to the next lock on this inode */
	96	struct locklist lf_blkhd; /* List of requests blocked on this lock */
	97	TAILQ_ENTRY(lockf) lf_block;/* A request waiting for a lock */
1c79356b A	98	};
1c79356b A	99
0c530ab8	100	#pragma pack()
91447636	101
1c79356b A	102	/* Maximum length of sleep chains to traverse to try and detect deadlock. */
	103	#define MAXDEPTH 50
	104
	105	__BEGIN_DECLS
1c79356b	106
b0d623f7	107	#ifdef KERNEL_PRIVATE
2d21ac55 A	108	int lf_advlock(struct vnop_advlock_args *);
	109	int lf_assert(struct vnop_advlock_args , void *);
	110	void lf_commit(void *, int);
1c79356b	111
91447636 A	112	#ifdef LOCKF_DEBUG
	113	void lf_print(char , struct lockf );
	114	void lf_printlist(char , struct lockf );
	115	#endif
b0d623f7	116	#endif /* KERNEL_PRIVATE */
9bccf70c	117
91447636	118	__END_DECLS
9bccf70c	119
1c79356b	120	#endif /* !_SYS_LOCKF_H_ */