bsd/sys/lockf.h

   1 /*
   2  * Copyright (c) 2004-2005 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1991, 1993
  24  *      The Regents of the University of California.  All rights reserved.
  25  *
  26  * This code is derived from software contributed to Berkeley by
  27  * Scooter Morris at Genentech Inc.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. Redistributions in binary form must reproduce the above copyright
  35  *    notice, this list of conditions and the following disclaimer in the
  36  *    documentation and/or other materials provided with the distribution.
  37  * 4. Neither the name of the University nor the names of its contributors
  38  *    may be used to endorse or promote products derived from this software
  39  *    without specific prior written permission.
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  *      @(#)lockf.h     8.1 (Berkeley) 6/11/93
  54  * $FreeBSD: src/sys/sys/lockf.h,v 1.16 2004/04/07 04:19:49 imp Exp $
  55  */
  56
  57 #ifndef _SYS_LOCKF_H_
  58 #define _SYS_LOCKF_H_
  59
  60 #include <sys/queue.h>
  61 #include <sys/cdefs.h>
  62
  63 struct vnop_advlock_args;
  64 struct vnode;
  65
  66 #ifdef MALLOC_DECLARE
  67 MALLOC_DECLARE(M_LOCKF);
  68 #endif
  69
  70 /*
  71  * The lockf structure is a kernel structure which contains the information
  72  * associated with a byte range lock.  The lockf structures are linked into
  73  * the inode structure. Locks are sorted by the starting byte of the lock for
  74  * efficiency.
  75  */
  76 TAILQ_HEAD(locklist, lockf);
  77
  78 #pragma pack(4)
  79
  80 struct lockf {
  81         short   lf_flags;           /* Semantics: F_POSIX, F_FLOCK, F_WAIT */
  82         short   lf_type;         /* Lock type: F_RDLCK, F_WRLCK */
  83         off_t   lf_start;           /* Byte # of the start of the lock */
  84         off_t   lf_end;             /* Byte # of the end of the lock (-1=EOF) */
  85         caddr_t lf_id;              /* Id of the resource holding the lock */
  86         struct  lockf **lf_head;    /* Back pointer to the head of the locf list */
  87         struct vnode *lf_vnode;     /* Back pointer to the inode */
  88         struct  lockf *lf_next;     /* Pointer to the next lock on this inode */
  89         struct  locklist lf_blkhd;  /* List of requests blocked on this lock */
  90         TAILQ_ENTRY(lockf) lf_block;/* A request waiting for a lock */
  91 };
  92
  93 #pragma pack()
  94
  95 /* Maximum length of sleep chains to traverse to try and detect deadlock. */
  96 #define MAXDEPTH 50
  97
  98 __BEGIN_DECLS
  99
 100 int      lf_advlock(struct vnop_advlock_args *);
 101
 102 #ifdef LOCKF_DEBUG
 103 void    lf_print(char *, struct lockf *);
 104 void    lf_printlist(char *, struct lockf *);
 105 #endif
 106
 107 __END_DECLS
 108
 109 #endif /* !_SYS_LOCKF_H_ */