Small regression test tool to generate two forms of ENOSPC on a file

system: out of blocks, and out of inodes.  Useful for exercising the
uprintf(9) calls in UFS/ext2fs in order to detect races.

2 files changed, 195 insertions, 0 deletions

diff --git a/tools/regression/ufs/uprintf/Makefile b/tools/regression/ufs/uprintf/Makefile
new file mode 100644
index 0000000..cb07e55
--- /dev/null
+++ b/tools/regression/ufs/uprintf/Makefile
@@ -0,0 +1,7 @@
+# $FreeBSD$
+
+PROG=	ufs_uprintf
+WARNS=	3
+NO_MAN=
+
+.include <bsd.prog.mk>
diff --git a/tools/regression/ufs/uprintf/ufs_uprintf.c b/tools/regression/ufs/uprintf/ufs_uprintf.c
new file mode 100644
index 0000000..d9f7125
--- /dev/null
+++ b/tools/regression/ufs/uprintf/ufs_uprintf.c
@@ -0,0 +1,188 @@
+/*-
+ * Copyright (c) 2005 Robert N. M. Watson
+ * 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.
+ *
+ * $FreeBSD$
+ */
+
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+/*
+ * This regression test attempts to exercise two instances of uprintf(9) in
+ * UFS: (1) when blocks are exhausted, and (2) when inodes are exhausted, in
+ * order to attempt to trigger races in the uprintf(9) code.  The test
+ * accepts a pointer to a path -- ideally, a very small UFS partition -- and
+ * then proceeds to fill it in various ways.
+ *
+ * This tool assumes that it is alright to create, and delete, entries in the
+ * directory with names of integer values.  Don't run this tool against a
+ * directory that has files with names along those lines if you want to keep
+ * the files.
+ *
+ * Suggested usage is:
+ *
+ * mdconfig -a -t malloc -s 512
+ * newfs /dev/mdX
+ * mount /dev/mdX /mnt
+ * ufs_uprintf /mnt
+ * umount /mnt
+ * mdconfig -d -u X
+ */
+
+#define	NUMTRIES	200
+
+/*
+ * Fill up the disk, then generate NUMTRIES additional ENOSPC errors.
+ */
+#define	BLOCKSIZE	1024
+#define	BLOCKS_FILENAME	"0"
+static void
+fill_blocks(void)
+{
+	char block[BLOCKSIZE];
+	ssize_t len;
+	int fd, i;
+
+	fd = open(BLOCKS_FILENAME, O_CREAT | O_TRUNC | O_RDWR, 0600);
+	if (fd < 0)
+		err(-1, "fill_blocks: open(%s)", BLOCKS_FILENAME);
+
+	/*
+	 * First step: fill the disk device.  Keep extending the file until
+	 * we hit our first error, and hope it is ENOSPC.
+	 */
+	bzero(block, BLOCKSIZE);
+	errno = 0;
+	while (1) {
+		len = write(fd, block, BLOCKSIZE);
+		if (len < 0)
+			break;
+		if (len != BLOCKSIZE) {
+			warnx("fill_blocks: write(%d) returned %d",
+			    BLOCKSIZE, len);
+			close(fd);
+			(void)unlink(BLOCKS_FILENAME);
+			exit(-1);
+		}
+
+	}
+	if (errno != ENOSPC) {
+		warn("fill_blocks: write");
+		close(fd);
+		(void)unlink(BLOCKS_FILENAME);
+		exit(-1);
+	}
+
+	/*
+	 * Second step: generate NUMTRIES instances of the error by retrying
+	 * the write.
+	 */
+	for (i = 0; i < NUMTRIES; i++) {
+		len = write(fd, block, BLOCKSIZE);
+		if (len < 0 && errno != ENOSPC) {
+			warn("fill_blocks: write after ENOSPC");
+			close(fd);
+			(void)unlink(BLOCKS_FILENAME);
+			exit(-1);
+		}
+	}
+
+	close(fd);
+	(void)unlink(BLOCKS_FILENAME);
+}
+
+/*
+ * Create as many entries in the directory as we can, then once we start
+ * hitting ENOSPC, try NUMTRIES additional times.  Note that we don't be able
+ * to tell the difference between running out of inodes and running out of
+ * room to extend the directory, so this is just a best effort.
+ */
+static void
+fill_inodes(void)
+{
+	char path[PATH_MAX];
+	int fd, i, max;
+
+	/*
+	 * First step, fill the directory.
+	 */
+	i = 0;
+	while (1) {
+		snprintf(path, PATH_MAX, "%d", i);
+		fd = open(path, O_CREAT | O_TRUNC | O_RDWR, 0600);
+		if (fd < 0)
+			break;
+		close(fd);
+		i++;
+	}
+	max = i;
+	if (errno != ENOSPC) {
+		warn("fill_inodes: open(%s)", path);
+		goto teardown;
+	}
+
+	for (i = 0; i < NUMTRIES; i++) {
+		fd = open(path, O_CREAT | O_TRUNC | O_RDWR, 0600);
+		if (fd < 0 && errno != ENOSPC) {
+			warn("fill_inodes: open(%s) after ENOSPC", path);
+			goto teardown;
+		}
+		if (fd >= 0) {
+			warnx("fill_inodes: open(%s) after ENOSPC returned "
+			    " %d", path, fd);
+			close(fd);
+			goto teardown;
+		}
+	}
+
+teardown:
+	for (i = 0; i < max; i++) {
+		snprintf(path, PATH_MAX, "%d", i);
+		(void)unlink(path);
+	}
+}
+
+int
+main(int argc, char *argv[])
+{
+
+	if (argc != 2)
+		err(-1, "usage: ufs_uprintf /non_optional_path");
+
+	if (chdir(argv[1]) < 0)
+		err(-1, "chdir(%s)", argv[1]);
+
+	fill_blocks();
+
+	fill_inodes();
+
+	return (0);
+}