10Sstevel@tonic-gate /*
20Sstevel@tonic-gate * CDDL HEADER START
30Sstevel@tonic-gate *
40Sstevel@tonic-gate * The contents of this file are subject to the terms of the
55891Sraf * Common Development and Distribution License (the "License").
65891Sraf * You may not use this file except in compliance with the License.
70Sstevel@tonic-gate *
80Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
90Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing.
100Sstevel@tonic-gate * See the License for the specific language governing permissions
110Sstevel@tonic-gate * and limitations under the License.
120Sstevel@tonic-gate *
130Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each
140Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
150Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the
160Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying
170Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner]
180Sstevel@tonic-gate *
190Sstevel@tonic-gate * CDDL HEADER END
200Sstevel@tonic-gate */
215891Sraf
220Sstevel@tonic-gate /*
235891Sraf * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
240Sstevel@tonic-gate * Use is subject to license terms.
250Sstevel@tonic-gate */
260Sstevel@tonic-gate
270Sstevel@tonic-gate /* Copyright (c) 1988 AT&T */
280Sstevel@tonic-gate /* All Rights Reserved */
290Sstevel@tonic-gate
30*6812Sraf #pragma ident "%Z%%M% %I% %E% SMI"
310Sstevel@tonic-gate
320Sstevel@tonic-gate /*
330Sstevel@tonic-gate * ftruncate() and truncate() set a file to a specified
340Sstevel@tonic-gate * length using fcntl(F_FREESP) system call. If the file
350Sstevel@tonic-gate * was previously longer than length, the bytes past the
360Sstevel@tonic-gate * length will no longer be accessible. If it was shorter,
370Sstevel@tonic-gate * bytes not written will be zero filled.
380Sstevel@tonic-gate */
390Sstevel@tonic-gate
400Sstevel@tonic-gate #include <sys/feature_tests.h>
410Sstevel@tonic-gate
420Sstevel@tonic-gate #if !defined(_LP64) && _FILE_OFFSET_BITS == 64
43*6812Sraf #pragma weak _ftruncate64 = ftruncate64
44*6812Sraf #pragma weak _truncate64 = truncate64
45*6812Sraf #define ftruncate ftruncate64
46*6812Sraf #define truncate truncate64
470Sstevel@tonic-gate #endif /* !_LP64 && _FILE_OFFSET_BITS == 64 */
480Sstevel@tonic-gate
49*6812Sraf #include "lint.h"
500Sstevel@tonic-gate #include <unistd.h>
510Sstevel@tonic-gate #include <stdio.h>
520Sstevel@tonic-gate #include <fcntl.h>
535891Sraf #include <pthread.h>
540Sstevel@tonic-gate #include <sys/types.h>
550Sstevel@tonic-gate
560Sstevel@tonic-gate int
ftruncate(int fildes,off_t len)57*6812Sraf ftruncate(int fildes, off_t len)
580Sstevel@tonic-gate {
590Sstevel@tonic-gate struct flock lck;
600Sstevel@tonic-gate
610Sstevel@tonic-gate lck.l_whence = 0; /* offset l_start from beginning of file */
620Sstevel@tonic-gate lck.l_start = len;
630Sstevel@tonic-gate lck.l_type = F_WRLCK; /* setting a write lock */
640Sstevel@tonic-gate lck.l_len = (off_t)0; /* until the end of the file address space */
650Sstevel@tonic-gate
660Sstevel@tonic-gate if (fcntl(fildes, F_FREESP, &lck) == -1) {
670Sstevel@tonic-gate return (-1);
680Sstevel@tonic-gate }
690Sstevel@tonic-gate return (0);
700Sstevel@tonic-gate }
710Sstevel@tonic-gate
720Sstevel@tonic-gate int
truncate(const char * path,off_t len)73*6812Sraf truncate(const char *path, off_t len)
740Sstevel@tonic-gate {
750Sstevel@tonic-gate
765891Sraf int rval = 0;
775891Sraf int cancel_state;
780Sstevel@tonic-gate int fd;
790Sstevel@tonic-gate
805891Sraf /*
815891Sraf * truncate() is not a cancellation point,
825891Sraf * even though it calls open() and close().
835891Sraf */
845891Sraf (void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cancel_state);
855891Sraf if ((fd = open(path, O_WRONLY)) == -1 || ftruncate(fd, len) == -1)
865891Sraf rval = -1;
875891Sraf if (fd >= 0)
880Sstevel@tonic-gate (void) close(fd);
895891Sraf (void) pthread_setcancelstate(cancel_state, NULL);
905891Sraf return (rval);
910Sstevel@tonic-gate }
92