flushb.c revision 18a1444b4f1e6a0948fd38fa0de382d86cfe04de 
1/*
2 * flushb.c --- This routine flushes the disk buffers for a disk
3 *
4 * Copyright 1997, 2000, by Theodore Ts'o.
5 *
6 * WARNING: use of flushb on some older 2.2 kernels on a heavily loaded
7 * system will corrupt filesystems.  This program is not really useful
8 * beyond for benchmarking scripts.
9 *
10 * %Begin-Header%
11 * This file may be redistributed under the terms of the GNU Public
12 * License.
13 * %End-Header%
14 */
15
16#include <stdio.h>
17#include <string.h>
18#include <unistd.h>
19#include <stdlib.h>
20#include <fcntl.h>
21#include <sys/ioctl.h>
22#include <sys/mount.h>
23#include "../misc/nls-enable.h"
24
25/* For Linux, define BLKFLSBUF if necessary */
26#if (!defined(BLKFLSBUF) && defined(__linux__))
27#define BLKFLSBUF	_IO(0x12,97)	/* flush buffer cache */
28#endif
29
30const char *progname;
31
32static void usage(void)
33{
34	fprintf(stderr, _("Usage: %s disk\n"), progname);
35	exit(1);
36}
37
38int main(int argc, char **argv)
39{
40	int	fd;
41
42	progname = argv[0];
43	if (argc != 2)
44		usage();
45
46	fd = open(argv[1], O_RDONLY, 0);
47	if (fd < 0) {
48		perror("open");
49		exit(1);
50	}
51	/*
52	 * Note: to reread the partition table, use the ioctl
53	 * BLKRRPART instead of BLKFSLBUF.
54	 */
55#ifdef BLKFLSBUF
56	if (ioctl(fd, BLKFLSBUF, 0) < 0) {
57		perror("ioctl BLKFLSBUF");
58		exit(1);
59	}
60	return 0;
61#else
62	fprintf(stderr,
63		_("BLKFLSBUF ioctl not supported!  Can't flush buffers.\n"));
64	return 1;
65#endif
66}
67