1/* $NetBSD: lockf.c,v 1.3 2008/04/28 20:22:59 martin Exp $ */ 2/*- 3 * Copyright (c) 1997 The NetBSD Foundation, Inc. 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to The NetBSD Foundation 7 * by Klaus Klein. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 20 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 21 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 22 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31#include <sys/cdefs.h> 32__FBSDID("$FreeBSD: src/lib/libc/gen/lockf.c,v 1.10 2009/03/04 01:01:26 delphij Exp $"); 33 34#ifdef VARIANT_CANCELABLE 35int __fcntl(int, int, void *); 36#else /* !VARIANT_CANCELABLE */ 37int __fcntl_nocancel(int, int, void *); 38#endif /* VARIANT_CANCELABLE */ 39 40 41#include "namespace.h" 42#include <errno.h> 43#include <fcntl.h> 44#include <unistd.h> 45#include "un-namespace.h" 46 47int 48lockf(int filedes, int function, off_t size) 49{ 50 struct flock fl; 51 int cmd; 52 53 fl.l_start = 0; 54 fl.l_len = size; 55 fl.l_whence = SEEK_CUR; 56 57 switch (function) { 58 case F_ULOCK: 59 cmd = F_SETLK; 60 fl.l_type = F_UNLCK; 61 break; 62 case F_LOCK: 63 cmd = F_SETLKW; 64 fl.l_type = F_WRLCK; 65 break; 66 case F_TLOCK: 67 cmd = F_SETLK; 68 fl.l_type = F_WRLCK; 69 break; 70 case F_TEST: 71 fl.l_type = F_WRLCK; 72#ifdef VARIANT_CANCELABLE 73 if (__fcntl(filedes, F_GETLK, &fl) == -1) 74 return (-1); 75#else /* !VARIANT_CANCELABLE */ 76 if (__fcntl_nocancel(filedes, F_GETLK, &fl) == -1) 77 return (-1); 78#endif /* VARIANT_CANCELABLE */ 79 if (fl.l_type == F_UNLCK || fl.l_pid == getpid()) 80 return (0); 81 errno = EAGAIN; 82 return (-1); 83 /* NOTREACHED */ 84 default: 85 errno = EINVAL; 86 return (-1); 87 /* NOTREACHED */ 88 } 89 90#ifdef VARIANT_CANCELABLE 91 return (__fcntl(filedes, cmd, &fl)); 92#else /* !VARIANT_CANCELABLE */ 93 return (__fcntl_nocancel(filedes, cmd, &fl)); 94#endif /* VARIANT_CANCELABLE */ 95} 96 97