usr/src/test/zfs-tests/cmd/largest_file/largest_file.c

   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 2007 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*
  28  * Copyright (c) 2012 by Delphix. All rights reserved.
  29  */
  30
  31 #include "../file_common.h"
  32 #include <sys/param.h>
  33 #include <signal.h>
  34 #include <stdio.h>
  35
  36 /*
  37  * --------------------------------------------------------------
  38  *
  39  *      Assertion:
  40  *              The last byte of the largest file size can be
  41  *              accessed without any errors.  Also, the writing
  42  *              beyond the last byte of the largest file size
  43  *              will produce an errno of EFBIG.
  44  *
  45  * --------------------------------------------------------------
  46  *      If the write() system call below returns a "1",
  47  *      then the last byte can be accessed.
  48  * --------------------------------------------------------------
  49  */
  50 static void     sigxfsz(int);
  51 static void     usage(char *);
  52
  53 int
  54 main(int argc, char **argv)
  55 {
  56         int             fd = 0;
  57         offset_t        offset = (MAXOFFSET_T - 1);
  58         offset_t        llseek_ret = 0;
  59         int             write_ret = 0;
  60         int             err = 0;
  61         char            mybuf[5];
  62         char            *testfile;
  63         mode_t          mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
  64
  65         if (argc != 2) {
  66                 usage(argv[0]);
  67         }
  68
  69         (void) sigset(SIGXFSZ, sigxfsz);
  70
  71         testfile = strdup(argv[1]);
  72
  73         fd = open(testfile, O_CREAT | O_RDWR, mode);
  74         if (fd < 0) {
  75                 perror("Failed to create testfile");
  76                 err = errno;
  77                 goto out;
  78         }
  79
  80         llseek_ret = llseek(fd, offset, SEEK_SET);
  81         if (llseek_ret < 0) {
  82                 perror("Failed to seek to end of testfile");
  83                 err = errno;
  84                 goto out;
  85         }
  86
  87         write_ret = write(fd, mybuf, 1);
  88         if (write_ret < 0) {
  89                 perror("Failed to write to end of file");
  90                 err = errno;
  91                 goto out;
  92         }
  93
  94         offset = 0;
  95         llseek_ret = llseek(fd, offset, SEEK_CUR);
  96         if (llseek_ret < 0) {
  97                 perror("Failed to seek to end of file");
  98                 err = errno;
  99                 goto out;
 100         }
 101
 102         write_ret = write(fd, mybuf, 1);
 103         if (write_ret < 0) {
 104                 if (errno == EFBIG) {
 105                         (void) printf("write errno=EFBIG: success\n");
 106                         err = 0;
 107                 } else {
 108                         perror("Did not receive EFBIG");
 109                         err = errno;
 110                 }
 111         } else {
 112                 (void) printf("write completed successfully, test failed\n");
 113                 err = 1;
 114         }
 115
 116 out:
 117         (void) unlink(testfile);
 118         free(testfile);
 119         return (err);
 120 }
 121
 122 static void
 123 usage(char *name)
 124 {
 125         (void) printf("%s <testfile>\n", name);
 126         exit(1);
 127 }
 128
 129 /* ARGSUSED */
 130 static void
 131 sigxfsz(int signo)
 132 {
 133         (void) printf("\nlargest_file: sigxfsz() caught SIGXFSZ\n");
 134 }