util-linux/swaponoff.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini swapon/swapoff implementation for busybox
   4  *
   5  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
   6  *
   7  * Licensed under the GPL version 2, see the file LICENSE in this tarball.
   8  */
   9
  10 #include "libbb.h"
  11 #include <mntent.h>
  12 #include <sys/swap.h>
  13
  14 static int swap_enable_disable(char *device)
  15 {
  16         int status;
  17         struct stat st;
  18
  19         xstat(device, &st);
  20
  21 #if ENABLE_DESKTOP
  22         /* test for holes */
  23         if (S_ISREG(st.st_mode))
  24                 if (st.st_blocks * 512 < st.st_size)
  25                         bb_error_msg("warning: swap file has holes");
  26 #endif
  27
  28         if (applet_name[5] == 'n')
  29                 status = swapon(device, 0);
  30         else
  31                 status = swapoff(device);
  32
  33         if (status != 0) {
  34                 bb_simple_perror_msg(device);
  35                 return 1;
  36         }
  37
  38         return 0;
  39 }
  40
  41 static int do_em_all(void)
  42 {
  43         struct mntent *m;
  44         FILE *f;
  45         int err;
  46
  47         f = setmntent("/etc/fstab", "r");
  48         if (f == NULL)
  49                 bb_perror_msg_and_die("/etc/fstab");
  50
  51         err = 0;
  52         while ((m = getmntent(f)) != NULL)
  53                 if (strcmp(m->mnt_type, MNTTYPE_SWAP) == 0)
  54                         err += swap_enable_disable(m->mnt_fsname);
  55
  56         endmntent(f);
  57
  58         return err;
  59 }
  60
  61 int swap_on_off_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  62 int swap_on_off_main(int argc, char **argv)
  63 {
  64         int ret;
  65
  66         if (argc == 1)
  67                 bb_show_usage();
  68
  69         ret = getopt32(argv, "a");
  70         if (ret)
  71                 return do_em_all();
  72
  73         /* ret = 0; redundant */
  74         while (*++argv)
  75                 ret += swap_enable_disable(*argv);
  76         return ret;
  77 }