release/src/router/busybox/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 #if ENABLE_FEATURE_MOUNT_LABEL
  15 #include "volume_id.h"
  16 #endif
  17
  18 #if ENABLE_FEATURE_SWAPON_PRI
  19 struct globals {
  20         int flags;
  21 };
  22 #define G (*(struct globals*)&bb_common_bufsiz1)
  23 #define g_flags (G.flags)
  24 #else
  25 #define g_flags 0
  26 #endif
  27
  28 static int swap_enable_disable(char *device)
  29 {
  30         int status;
  31         struct stat st;
  32
  33 #if ENABLE_FEATURE_MOUNT_LABEL
  34         char *tmp = NULL;
  35
  36         if (!strncmp(device, "UUID=", 5))
  37                 tmp = get_devname_from_uuid(device + 5);
  38         else if (!strncmp(device, "LABEL=", 6))
  39                 tmp = get_devname_from_label(device + 6);
  40         if (tmp)
  41                 device = tmp;
  42 #endif
  43
  44         if (stat(device, &st)) {
  45                 bb_perror_msg("can't stat '%s'", device);
  46                 return 1;
  47         }
  48
  49 #if ENABLE_DESKTOP
  50         /* test for holes */
  51         if (S_ISREG(st.st_mode))
  52                 if (st.st_blocks * (off_t)512 < st.st_size)
  53                         bb_error_msg("warning: swap file has holes");
  54 #endif
  55
  56         if (applet_name[5] == 'n')
  57                 status = swapon(device, g_flags);
  58         else
  59                 status = swapoff(device);
  60
  61         if (status != 0) {
  62                 bb_simple_perror_msg(device);
  63                 return 1;
  64         }
  65
  66         return 0;
  67 }
  68
  69 static int do_em_all(void)
  70 {
  71         struct mntent *m;
  72         FILE *f;
  73         int err;
  74
  75         f = setmntent("/etc/fstab", "r");
  76         if (f == NULL)
  77                 bb_perror_msg_and_die("/etc/fstab");
  78
  79         err = 0;
  80         while ((m = getmntent(f)) != NULL)
  81                 if (strcmp(m->mnt_type, MNTTYPE_SWAP) == 0)
  82                         err += swap_enable_disable(m->mnt_fsname);
  83
  84         endmntent(f);
  85
  86         return err;
  87 }
  88
  89 int swap_on_off_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  90 int swap_on_off_main(int argc UNUSED_PARAM, char **argv)
  91 {
  92         int ret;
  93
  94 #if !ENABLE_FEATURE_SWAPON_PRI
  95         ret = getopt32(argv, "a");
  96 #else
  97         opt_complementary = "p+";
  98         ret = getopt32(argv, (applet_name[5] == 'n') ? "ap:" : "a", &g_flags);
  99
 100         if (ret & 2) { // -p
 101                 g_flags = SWAP_FLAG_PREFER |
 102                         ((g_flags & SWAP_FLAG_PRIO_MASK) << SWAP_FLAG_PRIO_SHIFT);
 103                 ret &= 1;
 104         }
 105 #endif
 106
 107         if (ret /* & 1: not needed */) // -a
 108                 return do_em_all();
 109
 110         argv += optind;
 111         if (!*argv)
 112                 bb_show_usage();
 113
 114         /* ret = 0; redundant */
 115         do {
 116                 ret += swap_enable_disable(*argv);
 117         } while (*++argv);
 118
 119         return ret;
 120 }