17c478bd9Sstevel@tonic-gate /*
27c478bd9Sstevel@tonic-gate * CDDL HEADER START
37c478bd9Sstevel@tonic-gate *
47c478bd9Sstevel@tonic-gate * The contents of this file are subject to the terms of the
5a574db85Sraf * Common Development and Distribution License (the "License").
6a574db85Sraf * You may not use this file except in compliance with the License.
77c478bd9Sstevel@tonic-gate *
87c478bd9Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
97c478bd9Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing.
107c478bd9Sstevel@tonic-gate * See the License for the specific language governing permissions
117c478bd9Sstevel@tonic-gate * and limitations under the License.
127c478bd9Sstevel@tonic-gate *
137c478bd9Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each
147c478bd9Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
157c478bd9Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the
167c478bd9Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying
177c478bd9Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner]
187c478bd9Sstevel@tonic-gate *
197c478bd9Sstevel@tonic-gate * CDDL HEADER END
207c478bd9Sstevel@tonic-gate */
21a574db85Sraf
227c478bd9Sstevel@tonic-gate /*
23a574db85Sraf * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
247c478bd9Sstevel@tonic-gate * Use is subject to license terms.
257c478bd9Sstevel@tonic-gate */
267c478bd9Sstevel@tonic-gate
277c478bd9Sstevel@tonic-gate /* Copyright (c) 1988 AT&T */
287c478bd9Sstevel@tonic-gate /* All Rights Reserved */
297c478bd9Sstevel@tonic-gate
307c478bd9Sstevel@tonic-gate /*
317c478bd9Sstevel@tonic-gate * ftruncate() and truncate() set a file to a specified
327c478bd9Sstevel@tonic-gate * length using fcntl(F_FREESP) system call. If the file
337c478bd9Sstevel@tonic-gate * was previously longer than length, the bytes past the
347c478bd9Sstevel@tonic-gate * length will no longer be accessible. If it was shorter,
357c478bd9Sstevel@tonic-gate * bytes not written will be zero filled.
367c478bd9Sstevel@tonic-gate */
377c478bd9Sstevel@tonic-gate
387c478bd9Sstevel@tonic-gate #include <sys/feature_tests.h>
397c478bd9Sstevel@tonic-gate
407c478bd9Sstevel@tonic-gate #if !defined(_LP64) && _FILE_OFFSET_BITS == 64
41*7257d1b4Sraf #pragma weak _ftruncate64 = ftruncate64
42*7257d1b4Sraf #pragma weak _truncate64 = truncate64
43*7257d1b4Sraf #define ftruncate ftruncate64
44*7257d1b4Sraf #define truncate truncate64
457c478bd9Sstevel@tonic-gate #endif /* !_LP64 && _FILE_OFFSET_BITS == 64 */
467c478bd9Sstevel@tonic-gate
47*7257d1b4Sraf #include "lint.h"
487c478bd9Sstevel@tonic-gate #include <unistd.h>
497c478bd9Sstevel@tonic-gate #include <stdio.h>
507c478bd9Sstevel@tonic-gate #include <fcntl.h>
51a574db85Sraf #include <pthread.h>
527c478bd9Sstevel@tonic-gate #include <sys/types.h>
537c478bd9Sstevel@tonic-gate
547c478bd9Sstevel@tonic-gate int
ftruncate(int fildes,off_t len)55*7257d1b4Sraf ftruncate(int fildes, off_t len)
567c478bd9Sstevel@tonic-gate {
577c478bd9Sstevel@tonic-gate struct flock lck;
587c478bd9Sstevel@tonic-gate
597c478bd9Sstevel@tonic-gate lck.l_whence = 0; /* offset l_start from beginning of file */
607c478bd9Sstevel@tonic-gate lck.l_start = len;
617c478bd9Sstevel@tonic-gate lck.l_type = F_WRLCK; /* setting a write lock */
627c478bd9Sstevel@tonic-gate lck.l_len = (off_t)0; /* until the end of the file address space */
637c478bd9Sstevel@tonic-gate
647c478bd9Sstevel@tonic-gate if (fcntl(fildes, F_FREESP, &lck) == -1) {
657c478bd9Sstevel@tonic-gate return (-1);
667c478bd9Sstevel@tonic-gate }
677c478bd9Sstevel@tonic-gate return (0);
687c478bd9Sstevel@tonic-gate }
697c478bd9Sstevel@tonic-gate
707c478bd9Sstevel@tonic-gate int
truncate(const char * path,off_t len)71*7257d1b4Sraf truncate(const char *path, off_t len)
727c478bd9Sstevel@tonic-gate {
737c478bd9Sstevel@tonic-gate
74a574db85Sraf int rval = 0;
75a574db85Sraf int cancel_state;
767c478bd9Sstevel@tonic-gate int fd;
777c478bd9Sstevel@tonic-gate
78a574db85Sraf /*
79a574db85Sraf * truncate() is not a cancellation point,
80a574db85Sraf * even though it calls open() and close().
81a574db85Sraf */
82a574db85Sraf (void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cancel_state);
83a574db85Sraf if ((fd = open(path, O_WRONLY)) == -1 || ftruncate(fd, len) == -1)
84a574db85Sraf rval = -1;
85a574db85Sraf if (fd >= 0)
867c478bd9Sstevel@tonic-gate (void) close(fd);
87a574db85Sraf (void) pthread_setcancelstate(cancel_state, NULL);
88a574db85Sraf return (rval);
897c478bd9Sstevel@tonic-gate }
90