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  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25
  26 /*      (c) 1997-1998,2001 Apple Computer, Inc.  All Rights Reserved */
  27 /*
  28  * Copyright (c) 1991, 1993
  29  *      The Regents of the University of California.  All rights reserved.
  30  *
  31  * This code is derived from software contributed to Berkeley by
  32  * Scooter Morris at Genentech Inc.
  33  *
  34  * Redistribution and use in source and binary forms, with or without
  35  * modification, are permitted provided that the following conditions
  36  * are met:
  37  * 1. Redistributions of source code must retain the above copyright
  38  *    notice, this list of conditions and the following disclaimer.
  39  * 2. Redistributions in binary form must reproduce the above copyright
  40  *    notice, this list of conditions and the following disclaimer in the
  41  *    documentation and/or other materials provided with the distribution.
  42  * 3. All advertising materials mentioning features or use of this software
  43  *    must display the following acknowledgement:
  44  *      This product includes software developed by the University of
  45  *      California, Berkeley and its contributors.
  46  * 4. Neither the name of the University nor the names of its contributors
  47  *    may be used to endorse or promote products derived from this software
  48  *    without specific prior written permission.
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  60  * SUCH DAMAGE.
  61  *
  62  *
  63  *      @(#)hfs_lockf.h 1.0 5/5/98
  64  *      derived from @(#)lockf.h        8.2 (Berkeley) 10/26/94
  65  */
  66
  67 #ifndef  __HFS_LOCKF__
  68 #define  __HFS_LOCKF__
  69
  70 #include <sys/appleapiopts.h>
  71
  72 #ifdef KERNEL
  73 #ifdef __APPLE_API_PRIVATE
  74 /*
  75  * The hfslockf structure is a kernel structure which contains the information
  76  * associated with a byte range lock.  The hfslockf structures are linked into
  77  * a cnode's file fork.  Locks are sorted by the starting byte of the lock for
  78  * efficiency.
  79  */
  80 TAILQ_HEAD(locklist, hfslockf);
  81
  82 struct hfslockf {
  83         short   lf_flags;           /* Semantics: F_POSIX, F_FLOCK, F_WAIT */
  84         short   lf_type;            /* Lock type: F_RDLCK, F_WRLCK */
  85         off_t   lf_start;           /* Byte # of the start of the lock */
  86         off_t   lf_end;             /* Byte # of the end of the lock (-1=EOF) */
  87         caddr_t lf_id;              /* Id of the resource holding the lock */
  88         struct  filefork *lf_fork;  /* Back pointer to the file fork */
  89         struct  hfslockf *lf_next;  /* Pointer to the next lock on this fork */
  90         struct  locklist lf_blkhd;  /* List of requests blocked on this lock */
  91         TAILQ_ENTRY(hfslockf) lf_block;/* A request waiting for a lock */
  92 };
  93
  94 /* Maximum length of sleep chains to traverse to try and detect deadlock. */
  95 #define MAXDEPTH 50
  96
  97 __BEGIN_DECLS
  98 void     hfs_addblock __P((struct hfslockf *, struct hfslockf *));
  99 int      hfs_clearlock __P((struct hfslockf *));
 100 int      hfs_findoverlap __P((struct hfslockf *,
 101             struct hfslockf *, int, struct hfslockf ***, struct hfslockf **));
 102 struct hfslockf *
 103          hfs_getblock __P((struct hfslockf *));
 104 int      hfs_getlock __P((struct hfslockf *, struct flock *));
 105 int      hfs_setlock __P((struct hfslockf *));
 106 void     hfs_split __P((struct hfslockf *, struct hfslockf *));
 107 void     hfs_wakelock __P((struct hfslockf *));
 108 __END_DECLS
 109
 110 #ifdef LOCKF_DEBUG
 111 extern int lockf_debug;
 112
 113 __BEGIN_DECLS
 114 void    hfs_lprint __P((char *, struct hfslockf *));
 115 void    hfs_lprintlist __P((char *, struct hfslockf *));
 116 __END_DECLS
 117 #endif  /* LOCKF_DEBUG */
 118 #endif /* __APPLE_API_PRIVATE */
 119 #endif /* KERNEL */
 120 #endif  /* __HFS_LOCKF__ */