svn commit: r367363 - user/pho/stress2/tools
Peter Holm
pho at FreeBSD.org
Thu Nov 5 07:59:06 UTC 2020
Author: pho
Date: Thu Nov 5 07:59:05 2020
New Revision: 367363
URL: https://svnweb.freebsd.org/changeset/base/367363
Log:
Add a helper tool for file system tests.
Added:
user/pho/stress2/tools/flip.c
Added: user/pho/stress2/tools/flip.c
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ user/pho/stress2/tools/flip.c Thu Nov 5 07:59:05 2020 (r367363)
@@ -0,0 +1,121 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2020 Peter Holm <pho at FreeBSD.org>
+ * 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.
+ */
+
+/*
+ * Flip one or more bits in a file.
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <err.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+extern char *optarg;
+extern int optind;
+
+static long
+random_long(long mi, long ma)
+{
+ return (arc4random() % (ma - mi + 1) + mi);
+}
+
+static void
+flip(void *ap, size_t len)
+{
+ unsigned char *cp;
+ int byte;
+ unsigned char bit, buf, mask, old;
+
+ cp = (unsigned char *)ap;
+ byte = random_long(0, len);
+ bit = random_long(0,7);
+ mask = ~(1 << bit);
+ buf = cp[byte];
+ old = cp[byte];
+ buf = (buf & mask) | (~buf & ~mask);
+ cp[byte] = buf;
+#if defined(DEBUG)
+ printf("Change %2x to %2x at %d by flipping bit %d\n",
+ old, buf, byte, bit);
+#endif
+}
+
+int
+main(int argc, char *argv[])
+{
+ struct stat st;
+ off_t pos;
+ int fd, i, times;
+ char c;
+
+ times = 1;
+ while ((c = getopt(argc, argv, "n:")) != -1) {
+ switch (c) {
+ case 'n':
+ times = atoi(optarg);
+ break;
+ case '?':
+ default:
+ fprintf(stderr,
+ "Usage: %s [ -n <num> <file>]\n",
+ argv[0]);
+ exit(1);
+ }
+ }
+ argc -= optind;
+ argv += optind;
+
+ if (argc != 1) {
+ fprintf(stderr, "Missing file name\n");
+ exit(1);
+ }
+
+ if ((fd = open(argv[0], O_RDWR)) == -1)
+ err(1, "open(%s)", argv[0]);
+
+ if (fstat(fd, &st) == -1)
+ err(1, "stat %s", argv[0]);
+
+ for (i = 0; i < times; i++) {
+ pos = arc4random() % st.st_size;
+ if (lseek(fd, pos, SEEK_SET) == -1)
+ err(1, "lseek()");
+ read(fd, &c, 1);
+ flip(&c, 1);
+ if (lseek(fd, pos, SEEK_SET) == -1)
+ err(1, "lseek()");
+ write(fd, &c, 1);
+ }
+
+ return (0);
+}
More information about the svn-src-user
mailing list