e2fsck/flushb.c

   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
  31 const char *progname;
  32
  33 static void usage(void)
  34 {
  35         fprintf(stderr, _("Usage: %s disk\n"), progname);
  36         exit(1);
  37 }
  38
  39 int 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 }