bsd/sys/lockf.h

   1 /*
   2  * Copyright (c) 2004-2005 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
   5  *
   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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*
  31  * Copyright (c) 1991, 1993
  32  *      The Regents of the University of California.  All rights reserved.
  33  *
  34  * This code is derived from software contributed to Berkeley by
  35  * Scooter Morris at Genentech Inc.
  36  *
  37  * Redistribution and use in source and binary forms, with or without
  38  * modification, are permitted provided that the following conditions
  39  * are met:
  40  * 1. Redistributions of source code must retain the above copyright
  41  *    notice, this list of conditions and the following disclaimer.
  42  * 2. Redistributions in binary form must reproduce the above copyright
  43  *    notice, this list of conditions and the following disclaimer in the
  44  *    documentation and/or other materials provided with the distribution.
  45  * 4. Neither the name of the University nor the names of its contributors
  46  *    may be used to endorse or promote products derived from this software
  47  *    without specific prior written permission.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  59  * SUCH DAMAGE.
  60  *
  61  *      @(#)lockf.h     8.1 (Berkeley) 6/11/93
  62  * $FreeBSD: src/sys/sys/lockf.h,v 1.16 2004/04/07 04:19:49 imp Exp $
  63  */
  64
  65 #ifndef _SYS_LOCKF_H_
  66 #define _SYS_LOCKF_H_
  67
  68 #include <sys/queue.h>
  69 #include <sys/cdefs.h>
  70
  71 struct vnop_advlock_args;
  72 struct vnode;
  73
  74 #ifdef MALLOC_DECLARE
  75 MALLOC_DECLARE(M_LOCKF);
  76 #endif
  77
  78 /*
  79  * The lockf structure is a kernel structure which contains the information
  80  * associated with a byte range lock.  The lockf structures are linked into
  81  * the inode structure. Locks are sorted by the starting byte of the lock for
  82  * efficiency.
  83  */
  84 TAILQ_HEAD(locklist, lockf);
  85
  86 #if __DARWIN_ALIGN_POWER
  87 #pragma options align=power
  88 #endif
  89
  90 struct lockf {
  91         short   lf_flags;           /* Semantics: F_POSIX, F_FLOCK, F_WAIT */
  92         short   lf_type;         /* Lock type: F_RDLCK, F_WRLCK */
  93         off_t   lf_start;           /* Byte # of the start of the lock */
  94         off_t   lf_end;             /* Byte # of the end of the lock (-1=EOF) */
  95         caddr_t lf_id;              /* Id of the resource holding the lock */
  96         struct  lockf **lf_head;    /* Back pointer to the head of the locf list */
  97         struct vnode *lf_vnode;     /* Back pointer to the inode */
  98         struct  lockf *lf_next;     /* Pointer to the next lock on this inode */
  99         struct  locklist lf_blkhd;  /* List of requests blocked on this lock */
 100         TAILQ_ENTRY(lockf) lf_block;/* A request waiting for a lock */
 101 };
 102
 103 #if __DARWIN_ALIGN_POWER
 104 #pragma options align=reset
 105 #endif
 106
 107 /* Maximum length of sleep chains to traverse to try and detect deadlock. */
 108 #define MAXDEPTH 50
 109
 110 __BEGIN_DECLS
 111
 112 int      lf_advlock(struct vnop_advlock_args *);
 113
 114 #ifdef LOCKF_DEBUG
 115 void    lf_print(char *, struct lockf *);
 116 void    lf_printlist(char *, struct lockf *);
 117 #endif
 118
 119 __END_DECLS
 120
 121 #endif /* !_SYS_LOCKF_H_ */