diff --git a/tests/sys/cddl/zfs/bin/mkfile.c b/tests/sys/cddl/zfs/bin/mkfile.c
index b1034b9ca500..c1afdbd61196 100644
--- a/tests/sys/cddl/zfs/bin/mkfile.c
+++ b/tests/sys/cddl/zfs/bin/mkfile.c
@@ -1,212 +1,212 @@
 /*-
  * Copyright (c) 2001-2013
  *	HATANO Tomomi.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
 
 #ifndef	lint
 static char rcsid[] = "$Id: mkfile.c,v 1.5 2013-10-26 10:11:34+09 hatanou Exp $";
 #endif	/* !lint */
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <strings.h>
 #include <fcntl.h>
 #include <limits.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/uio.h>
 #include <unistd.h>
 #include <ctype.h>
 #include <errno.h>
 
 #define	MKFILE_WBUF	((size_t)(1048576))	/* Is 1M a reasonable value? */
 
 /* SunOS's mkfile(8) sets "sticky bit." */
 #define	MKFILE_FLAG	(O_WRONLY | O_CREAT | O_TRUNC)
 #define	MKFILE_MODE	(S_IRUSR | S_IWUSR | S_ISVTX)
 
 static char	buf[MKFILE_WBUF];
 static int	nofill = 0;
 static int	verbose = 0;
 
 static void
 usage()
 {
 	fprintf(stderr,
 	    "Usage: mkfile [-nv] <size>[e|p|t|g|m|k|b] <filename> ...\n");
 }
 
 static unsigned long long
 getsize(char *s)
 {
 	int sh;
 	unsigned long long length;
 	char *suffix;
 
 	/*
 	 * NOTE: We don't handle 'Z' (zetta) or 'Y' (yotta) suffixes yet.
 	 * These are too large to store in unsigned long long (64bits).
 	 * In the future, we'll have to use larger type,
 	 * something like uint128_t.
 	 */
 	length = strtoull(s, &suffix, 10);
 	sh = 0;
 	switch (tolower(*suffix)) {
 	case 'e':	/* Exabytes. */
 		sh = 60;
 		break;
 	case 'p':	/* Petabytes. */
 		sh = 50;
 		break;
 	case 't':	/* Terabytes. */
 		sh = 40;
 		break;
 	case 'g':	/* Gigabytes. */
 		sh = 30;
 		break;
 	case 'm':	/* Megabytes. */
 		sh = 20;
 		break;
 	case 'k':	/* Kilobytes. */
 		sh = 10;
 		break;
 	case 'b':	/* Blocks. */
 		sh = 9;
 		break;
 	case '\0':	/* Bytes. */
 		break;
 	default:	/* Unknown... */
 		errno = EINVAL;
 		return 0;
 	}
 	if (sh) {
 		unsigned long long l;
 
 		l = length;
 		length <<= sh;
 		/* Check overflow. */
 		if ((length >> sh) != l) {
 			errno = ERANGE;
 			return 0;
 		}
 	}
 
 	return length;
 }
 
 static int
 create_file(char *f, unsigned long long s)
 {
 	int fd;
 	size_t w;
 	ssize_t ws;
 
 	if (verbose) {
 		fprintf(stdout, "%s %llu bytes\n", f, s);
 		fflush(stdout);
 	}
 
 	/* Open file to create. */
 	if ((fd = open(f, MKFILE_FLAG, MKFILE_MODE)) < 0) {
 		return -1;
 	}
 
 	/* Seek to the end and write 1 byte. */
 	if ((lseek(fd, (off_t)(s - 1LL), SEEK_SET) == (off_t)-1) ||
 	    (write(fd, buf, (size_t)1) == (ssize_t)-1)) {
 		/*
 		 * We don't close(fd) here to avoid overwriting errno.
 		 * This is fd-leak, but is not harmful
 		 * because returning error causes mkfile(8) to exit.
 		 */
 		return -1;
 	}
 
 	/* Fill. */
 	if (!nofill) {
 		if (lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) {
 			/* Same as above. */
 			return -1;
 		}
 		while (s) {
 			w = (s > MKFILE_WBUF) ? MKFILE_WBUF : s;
 			if ((ws = write(fd, buf, w)) == (ssize_t)-1) {
 				/* Same as above. */
 				return -1;
 			}
 			s -= ws;
 		}
 	}
 	close(fd);
 
 	return 0;
 }
 
 int
 main(int argc, char *argv[])
 {
 	unsigned long long fsize;
-	char ch;
+	int ch;
 
 	/* We have at least 2 arguments. */
 	if (argc < 3) {
 		usage();
 		return EXIT_FAILURE;
 	}
 
 	/* Options. */
 	while ((ch = getopt(argc, argv, "nv")) != -1) {
 		switch (ch) {
 		case 'n':
 			nofill = 1;
 			break;
 		case 'v':
 			verbose = 1;
 			break;
 		default:
 			usage();
 			return EXIT_FAILURE;
 		}
 	}
 	argc -= optind;
 	argv += optind;
 
 	/* File size to create. */
 	if ((fsize = getsize(*argv)) == 0) {
 		perror(*argv);
 		return EXIT_FAILURE;
 	}
 
 	/* Filenames to create. */
 	bzero(buf, MKFILE_WBUF);
 	while (++argv, --argc) {
 		if (create_file(*argv, fsize) == -1) {
 			perror(*argv);
 			return EXIT_FAILURE;
 		}
 	}
 
 	return EXIT_SUCCESS;
 }