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 "config.h" 17#include <stdio.h> 18#include <string.h> 19#include <unistd.h> 20#include <stdlib.h> 21#include <fcntl.h> 22#include <sys/ioctl.h> 23#include <sys/mount.h> 24#include "../misc/nls-enable.h" 25 26/* For Linux, define BLKFLSBUF if necessary */ 27#if (!defined(BLKFLSBUF) && defined(__linux__)) 28#define BLKFLSBUF _IO(0x12,97) /* flush buffer cache */ 29#endif 30 31const char *progname; 32 33static void usage(void) 34{ 35 fprintf(stderr, _("Usage: %s disk\n"), progname); 36 exit(1); 37} 38 39int main(int argc, char **argv) 40{ 41 int fd; 42 43 progname = argv[0]; 44 if (argc != 2) 45 usage(); 46 47 fd = open(argv[1], O_RDONLY, 0); 48 if (fd < 0) { 49 perror("open"); 50 exit(1); 51 } 52 /* 53 * Note: to reread the partition table, use the ioctl 54 * BLKRRPART instead of BLKFSLBUF. 55 */ 56#ifdef BLKFLSBUF 57 if (ioctl(fd, BLKFLSBUF, 0) < 0) { 58 perror("ioctl BLKFLSBUF"); 59 exit(1); 60 } 61 return 0; 62#else 63 fprintf(stderr, 64 _("BLKFLSBUF ioctl not supported! Can't flush buffers.\n")); 65 return 1; 66#endif 67} 68