libfstools/mount_root.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 <stdio.h>
  16 #include <stdlib.h>
  17
  18 #include "../fs-state.h"
  19
  20 #include "volume.h"
  21
  22 int
  23 backend_mount(char *name)
  24 {
  25         struct backend *b = find_backend(name);
  26
  27         if (!b || !b->mount)
  28                 return -1;
  29
  30         return b->mount();
  31 }
  32
  33 static int
  34 backend_info(char *name)
  35 {
  36         struct backend *b = find_backend(name);
  37
  38         if (!b || !b->info)
  39                 return -1;
  40
  41         return b->info();
  42 }
  43
  44 static int
  45 start(int argc, char **argv)
  46 {
  47         struct volume *v = volume_find("rootfs_data");
  48
  49         if (!getenv("PREINIT"))
  50                 return -1;
  51
  52         if (!v) {
  53                 v = volume_find("rootfs");
  54                 volume_init(v);
  55                 fprintf(stderr, "mounting /dev/root\n");
  56                 mount("/dev/root", "/", NULL, MS_NOATIME | MS_REMOUNT, 0);
  57                 return 0;
  58         }
  59
  60         extroot_prefix = "";
  61         if (!backend_mount("extroot")) {
  62                 fprintf(stderr, "fs-state: switched to extroot\n");
  63                 return 0;
  64         }
  65
  66         switch (volume_identify(v)) {
  67         case FS_NONE:
  68         case FS_DEADCODE:
  69                 return ramoverlay();
  70
  71         case FS_JFFS2:
  72                 backend_mount("overlay");
  73                 break;
  74
  75         case FS_SNAPSHOT:
  76                 backend_mount("snapshot");
  77                 break;
  78         }
  79
  80         return 0;
  81 }
  82
  83 static int
  84 stop(int argc, char **argv)
  85 {
  86         if (!getenv("SHUTDOWN"))
  87                 return -1;
  88
  89         return 0;
  90 }
  91
  92 static int
  93 done(int argc, char **argv)
  94 {
  95         struct volume *v = volume_find("rootfs_data");
  96
  97         if (!v)
  98                 return -1;
  99
 100         switch (volume_identify(v)) {
 101         case FS_NONE:
 102         case FS_DEADCODE:
 103                 return jffs2_switch(argc, argv);
 104         }
 105
 106         return 0;
 107 }
 108
 109 static int
 110 info(int argc, char **argv)
 111 {
 112         struct volume *v = volume_find("rootfs_data");
 113
 114         if (!v)
 115                 return -1;
 116
 117         switch (volume_identify(v)) {
 118         case FS_SNAPSHOT:
 119                 backend_info("snapshot");
 120                 return 0;
 121         }
 122
 123         return 0;
 124 }
 125
 126 static struct backend start_backend = {
 127         .name = "start",
 128         .cli = start,
 129 };
 130 BACKEND(start_backend);
 131
 132 static struct backend stop_backend = {
 133         .name = "stop",
 134         .cli = stop,
 135 };
 136 BACKEND(stop_backend);
 137
 138 static struct backend done_backend = {
 139         .name = "done",
 140         .cli = done,
 141 };
 142 BACKEND(done_backend);
 143
 144 static struct backend info_backend = {
 145         .name = "info",
 146         .cli = info,
 147 };
 148 BACKEND(info_backend);