1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1988 AT&T */ 28 /* All Rights Reserved */ 29 30 #pragma ident "%Z%%M% %I% %E% SMI" 31 32 /* 33 * ftruncate() and truncate() set a file to a specified 34 * length using fcntl(F_FREESP) system call. If the file 35 * was previously longer than length, the bytes past the 36 * length will no longer be accessible. If it was shorter, 37 * bytes not written will be zero filled. 38 */ 39 40 #include <sys/feature_tests.h> 41 42 #if !defined(_LP64) && _FILE_OFFSET_BITS == 64 43 #pragma weak _ftruncate64 = ftruncate64 44 #pragma weak _truncate64 = truncate64 45 #define ftruncate ftruncate64 46 #define truncate truncate64 47 #endif /* !_LP64 && _FILE_OFFSET_BITS == 64 */ 48 49 #include "lint.h" 50 #include <unistd.h> 51 #include <stdio.h> 52 #include <fcntl.h> 53 #include <pthread.h> 54 #include <sys/types.h> 55 56 int 57 ftruncate(int fildes, off_t len) 58 { 59 struct flock lck; 60 61 lck.l_whence = 0; /* offset l_start from beginning of file */ 62 lck.l_start = len; 63 lck.l_type = F_WRLCK; /* setting a write lock */ 64 lck.l_len = (off_t)0; /* until the end of the file address space */ 65 66 if (fcntl(fildes, F_FREESP, &lck) == -1) { 67 return (-1); 68 } 69 return (0); 70 } 71 72 int 73 truncate(const char *path, off_t len) 74 { 75 76 int rval = 0; 77 int cancel_state; 78 int fd; 79 80 /* 81 * truncate() is not a cancellation point, 82 * even though it calls open() and close(). 83 */ 84 (void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cancel_state); 85 if ((fd = open(path, O_WRONLY)) == -1 || ftruncate(fd, len) == -1) 86 rval = -1; 87 if (fd >= 0) 88 (void) close(fd); 89 (void) pthread_setcancelstate(cancel_state, NULL); 90 return (rval); 91 } 92