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 GPLv2, see file LICENSE in this source tree.
   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 #else
  17 # define resolve_mount_spec(fsname) ((void)0)
  18 #endif
  19
  20 #if ENABLE_FEATURE_SWAPON_PRI
  21 struct globals {
  22         int flags;
  23 } FIX_ALIASING;
  24 #define G (*(struct globals*)&bb_common_bufsiz1)
  25 #define g_flags (G.flags)
  26 #else
  27 #define g_flags 0
  28 #endif
  29
  30 static int swap_enable_disable(char *device)
  31 {
  32         int status;
  33         struct stat st;
  34
  35         resolve_mount_spec(&device);
  36         if (stat(device, &st)) {
  37                 bb_perror_msg("warning: can't stat '%s'", device);
  38                 return 1;
  39         }
  40
  41 #if ENABLE_DESKTOP
  42         /* test for holes */
  43         if (S_ISREG(st.st_mode))
  44                 if (st.st_blocks * (off_t)512 < st.st_size)
  45                         bb_error_msg("warning: swap file has holes");
  46 #endif
  47
  48         if (applet_name[5] == 'n')
  49                 status = swapon(device, g_flags);
  50         else
  51                 status = swapoff(device);
  52
  53         if (status != 0) {
  54                 bb_simple_perror_msg(device);
  55                 return 1;
  56         }
  57
  58         return 0;
  59 }
  60
  61 static int do_em_all(void)
  62 {
  63         struct mntent *m;
  64         FILE *f;
  65         int err;
  66
  67         f = setmntent("/etc/fstab", "r");
  68         if (f == NULL)
  69                 bb_perror_msg_and_die("/etc/fstab");
  70
  71         err = 0;
  72         while ((m = getmntent(f)) != NULL) {
  73                 if (strcmp(m->mnt_type, MNTTYPE_SWAP) == 0) {
  74                         /* swapon -a should ignore entries with noauto,
  75                          * but swapoff -a should process them */
  76                         if (applet_name[5] != 'n'
  77                          || hasmntopt(m, MNTOPT_NOAUTO) == NULL
  78                         ) {
  79                                 err += swap_enable_disable(m->mnt_fsname);
  80                         }
  81                 }
  82         }
  83
  84         if (ENABLE_FEATURE_CLEAN_UP)
  85                 endmntent(f);
  86
  87         return err;
  88 }
  89
  90 int swap_on_off_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  91 int swap_on_off_main(int argc UNUSED_PARAM, char **argv)
  92 {
  93         int ret;
  94
  95 #if !ENABLE_FEATURE_SWAPON_PRI
  96         ret = getopt32(argv, "a");
  97 #else
  98         opt_complementary = "p+";
  99         ret = getopt32(argv, (applet_name[5] == 'n') ? "ap:" : "a", &g_flags);
 100
 101         if (ret & 2) { // -p
 102                 g_flags = SWAP_FLAG_PREFER |
 103                         ((g_flags & SWAP_FLAG_PRIO_MASK) << SWAP_FLAG_PRIO_SHIFT);
 104                 ret &= 1;
 105         }
 106 #endif
 107
 108         if (ret /* & 1: not needed */) // -a
 109                 return do_em_all();
 110
 111         argv += optind;
 112         if (!*argv)
 113                 bb_show_usage();
 114
 115         /* ret = 0; redundant */
 116         do {
 117                 ret += swap_enable_disable(*argv);
 118         } while (*++argv);
 119
 120         return ret;
 121 }