diskctl(8) tool

commands/diskctl/Makefile

@@ -0,0 +1,4 @@
+PROG=	diskctl
+MAN=
+
+.include <bsd.prog.mk>

commands/diskctl/diskctl.c

@@ -0,0 +1,100 @@
+/* diskctl - control disk device driver parameters - by D.C. van Moolenbroek */
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+static char *name, *dev;
+
+static void usage(void)
+{
+	fprintf(stderr, "usage: %s <device> <command> [args]\n"
+			"\n"
+			"supported commands:\n"
+			"  getwcache           return write cache status\n"
+			"  setwcache [on|off]  set write cache status\n"
+			"  flush               flush write cache\n",
+			name);
+
+	exit(EXIT_FAILURE);
+}
+
+static int open_dev(int flags)
+{
+	int fd;
+
+	fd = open(dev, flags);
+
+	if (fd < 0) {
+		perror("open");
+
+		exit(EXIT_FAILURE);
+	}
+
+	return fd;
+}
+
+int main(int argc, char **argv)
+{
+	int fd, val;
+
+	name = argv[0];
+
+	if (argc < 3) usage();
+
+	dev = argv[1];
+
+	if (!strcasecmp(argv[2], "getwcache")) {
+		if (argc != 3) usage();
+
+		fd = open_dev(O_RDONLY);
+
+		if (ioctl(fd, DIOCGETWC, &val) != 0) {
+			perror("ioctl");
+
+			return EXIT_FAILURE;
+		}
+
+		close(fd);
+
+		printf("write cache is %s\n", val ? "on" : "off");
+	}
+	else if (!strcasecmp(argv[2], "setwcache")) {
+		if (argc != 4) usage();
+
+		fd = open_dev(O_WRONLY);
+
+		if (!strcasecmp(argv[3], "on")) val = 1;
+		else if (!strcasecmp(argv[3], "off")) val = 0;
+		else usage();
+
+		if (ioctl(fd, DIOCSETWC, &val) != 0) {
+			perror("ioctl");
+
+			return EXIT_FAILURE;
+		}
+
+		close(fd);
+
+		printf("write cache %sabled\n", val ? "en" : "dis");
+	}
+	else if (!strcasecmp(argv[2], "flush")) {
+		if (argc != 3) usage();
+
+		fd = open_dev(O_WRONLY);
+
+		if (ioctl(fd, DIOCFLUSH, NULL) != 0) {
+			perror("ioctl");
+
+			return EXIT_FAILURE;
+		}
+
+		close(fd);
+
+		printf("write cache flushed\n");
+	}
+	else usage();
+
+	return EXIT_SUCCESS;
+}

man/man8/Makefile

@@ -1,6 +1,6 @@
 MAN=	add_route.8 adduser.8 backup.8 badblocks.8 boot.8 \
 	cdprobe.8 checkhier.8 chown.8 cleantmp.8 config.8 cron.8 \
-	dhcpd.8 dosminix.8 elvprsv.8 fdisk.8 fingerd.8 ftpd.8 \
+	dhcpd.8 diskctl.8 dosminix.8 elvprsv.8 fdisk.8 fingerd.8 ftpd.8 \
 	getty.8 halt.8 hgfs.8 httpd.8 ifconfig.8 inet.8 init.8 \
 	installboot.8 intr.8 irdpd.8 loadramdisk.8 MAKEDEV.8 \
 	mkdist.8 mknod.8 monitor.8 netconf.8 newroot.8 nonamed.8 \

man/man8/diskctl.8

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+.TH DISKCTL 8
+.SH NAME
+diskctl \- control disk drive
+.SH SYNOPSIS
+\fBdiskctl\fR \fIdevice\fR \fIcommand\fR [\fIarguments\fR]
+.SH DESCRIPTION
+The \fBdiskctl\fR tool allows one to view and manage settings of,
+and perform actions on, disk drives. The following paragraph lists the
+commands that are currently supported by this tool.
+Please note that not all disks and drivers support all commands.
+.SH COMMANDS
+.TP 10
+\fBgetwcache\fR
+Retrieve the status (on or off) of the write cache on the device.
+.TP 10
+\fBsetwcache\fR [\fBon\fR|\fBoff\fR]
+Enable or disable the write cache on the device.
+Disabling the write cache typically also triggers a cache flush.
+.TP 10
+\fBflush\fR
+Tell the device to flush its write cache.
+The call will not return until the cache flush has completed.
+.SH EXAMPLES
+.TP 20
+.B diskctl /dev/c0d0 setwcache on
+# Turn on the write cache on c0d0.
+.TP 20
+.B diskctl /dev/c1d2 flush
+# Trigger a cache flush on c1d2.
+.SH "SEE ALSO"
+.BR controller (4).
+.SH AUTHOR
+David van Moolenbroek <dcvmoole@cs.vu.nl>