bsd/hfs/hfs_lockf.h

   1 /*
   2  * Copyright (c) 1999,2001-2002 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 /*      (c) 1997-1998,2001 Apple Computer, Inc.  All Rights Reserved */
  24 /*
  25  * Copyright (c) 1991, 1993
  26  *      The Regents of the University of California.  All rights reserved.
  27  *
  28  * This code is derived from software contributed to Berkeley by
  29  * Scooter Morris at Genentech Inc.
  30  *
  31  * Redistribution and use in source and binary forms, with or without
  32  * modification, are permitted provided that the following conditions
  33  * are met:
  34  * 1. Redistributions of source code must retain the above copyright
  35  *    notice, this list of conditions and the following disclaimer.
  36  * 2. Redistributions in binary form must reproduce the above copyright
  37  *    notice, this list of conditions and the following disclaimer in the
  38  *    documentation and/or other materials provided with the distribution.
  39  * 3. All advertising materials mentioning features or use of this software
  40  *    must display the following acknowledgement:
  41  *      This product includes software developed by the University of
  42  *      California, Berkeley and its contributors.
  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  *
  60  *      @(#)hfs_lockf.h 1.0 5/5/98
  61  *      derived from @(#)lockf.h        8.2 (Berkeley) 10/26/94
  62  */
  63
  64 #ifndef  __HFS_LOCKF__
  65 #define  __HFS_LOCKF__
  66
  67 #include <sys/appleapiopts.h>
  68
  69 #ifdef KERNEL
  70 #ifdef __APPLE_API_PRIVATE
  71 /*
  72  * The hfslockf structure is a kernel structure which contains the information
  73  * associated with a byte range lock.  The hfslockf structures are linked into
  74  * a cnode's file fork.  Locks are sorted by the starting byte of the lock for
  75  * efficiency.
  76  */
  77 TAILQ_HEAD(locklist, hfslockf);
  78
  79 struct hfslockf {
  80         short   lf_flags;           /* Semantics: F_POSIX, F_FLOCK, F_WAIT */
  81         short   lf_type;            /* Lock type: F_RDLCK, F_WRLCK */
  82         off_t   lf_start;           /* Byte # of the start of the lock */
  83         off_t   lf_end;             /* Byte # of the end of the lock (-1=EOF) */
  84         caddr_t lf_id;              /* Id of the resource holding the lock */
  85         struct  filefork *lf_fork;  /* Back pointer to the file fork */
  86         struct  hfslockf *lf_next;  /* Pointer to the next lock on this fork */
  87         struct  locklist lf_blkhd;  /* List of requests blocked on this lock */
  88         TAILQ_ENTRY(hfslockf) lf_block;/* A request waiting for a lock */
  89 };
  90
  91 /* Maximum length of sleep chains to traverse to try and detect deadlock. */
  92 #define MAXDEPTH 50
  93
  94 __BEGIN_DECLS
  95 void     hfs_addblock __P((struct hfslockf *, struct hfslockf *));
  96 int      hfs_clearlock __P((struct hfslockf *));
  97 int      hfs_findoverlap __P((struct hfslockf *,
  98             struct hfslockf *, int, struct hfslockf ***, struct hfslockf **));
  99 struct hfslockf *
 100          hfs_getblock __P((struct hfslockf *));
 101 int      hfs_getlock __P((struct hfslockf *, struct flock *));
 102 int      hfs_setlock __P((struct hfslockf *));
 103 void     hfs_split __P((struct hfslockf *, struct hfslockf *));
 104 void     hfs_wakelock __P((struct hfslockf *));
 105 __END_DECLS
 106
 107 #ifdef LOCKF_DEBUG
 108 extern int lockf_debug;
 109
 110 __BEGIN_DECLS
 111 void    hfs_lprint __P((char *, struct hfslockf *));
 112 void    hfs_lprintlist __P((char *, struct hfslockf *));
 113 __END_DECLS
 114 #endif  /* LOCKF_DEBUG */
 115 #endif /* __APPLE_API_PRIVATE */
 116 #endif /* KERNEL */
 117 #endif  /* __HFS_LOCKF__ */