jffs2reset.c

   1 /*
   2  * Copyright (C) 2014 John Crispin <blogic@openwrt.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU Lesser General Public License version 2.1
   6  * as published by the Free Software Foundation
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <sys/mount.h>
  15 #include <sys/types.h>
  16 #include <sys/stat.h>
  17
  18 #include <libubox/ulog.h>
  19
  20 #include <fcntl.h>
  21 #include <dirent.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <unistd.h>
  26
  27 #include "libfstools/libfstools.h"
  28 #include "libfstools/volume.h"
  29
  30 static int jffs2_mark(struct volume *v);
  31
  32 static int
  33 ask_user(int argc, char **argv)
  34 {
  35         if ((argc < 2) || strcmp(argv[1], "-y")) {
  36                 ULOG_WARN("This will erase all settings and remove any installed packages. Are you sure? [N/y]\n");
  37                 if (getchar() != 'y')
  38                         return -1;
  39         }
  40         return 0;
  41
  42 }
  43
  44 static int jffs2_reset(struct volume *v)
  45 {
  46         char *mp;
  47
  48         mp = find_mount_point(v->blk, 1);
  49         if (mp) {
  50                 ULOG_INFO("%s is mounted as %s, only erasing files\n", v->blk, mp);
  51                 fs_state_set("/overlay", FS_STATE_PENDING);
  52                 overlay_delete(mp, false);
  53                 mount(mp, "/", NULL, MS_REMOUNT, 0);
  54         } else {
  55                 ULOG_INFO("%s is not mounted\n", v->blk);
  56                 return jffs2_mark(v);
  57         }
  58
  59         return 0;
  60 }
  61
  62 static int jffs2_mark(struct volume *v)
  63 {
  64         __u32 deadc0de = __cpu_to_be32(0xdeadc0de);
  65         size_t sz;
  66         int fd;
  67
  68         fd = open(v->blk, O_WRONLY);
  69         ULOG_INFO("%s will be erased on next mount\n", v->blk);
  70         if (!fd) {
  71                 ULOG_ERR("opening %s failed\n", v->blk);
  72                 return -1;
  73         }
  74
  75         sz = write(fd, &deadc0de, sizeof(deadc0de));
  76         close(fd);
  77
  78         if (sz != 4) {
  79                 ULOG_ERR("writing %s failed: %s\n", v->blk, strerror(errno));
  80                 return -1;
  81         }
  82
  83         return 0;
  84 }
  85
  86 int main(int argc, char **argv)
  87 {
  88         struct volume *v;
  89
  90         if (ask_user(argc, argv))
  91                 return -1;
  92
  93         /*
  94          * TODO: Currently this only checks if kernel supports OverlayFS. We
  95          * should check if there is a mount point using it with rootfs_data
  96          * as upperdir.
  97          */
  98         if (find_filesystem("overlay")) {
  99                 ULOG_ERR("overlayfs not supported by kernel\n");
 100                 return -1;
 101         }
 102
 103         v = volume_find("rootfs_data");
 104         if (!v) {
 105                 ULOG_ERR("MTD partition 'rootfs_data' not found\n");
 106                 return -1;
 107         }
 108
 109         if (!strcmp(*argv, "jffs2mark"))
 110                 return jffs2_mark(v);
 111         return jffs2_reset(v);
 112 }