d343909a9e0ccb6e898f57e1dd20500d7a400051
[project/fstools.git] / 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 <sys/types.h>
16 #include <sys/stat.h>
17 #include <unistd.h>
18 #include <stdio.h>
19 #include <stdlib.h>
20
21 #include <libubox/ulog.h>
22
23 #include "libfstools/libfstools.h"
24 #include "libfstools/volume.h"
25
26 /*
27 * Called in the early (PREINIT) stage, when we immediately need some writable
28 * filesystem.
29 */
30 static int
31 start(int argc, char *argv[1])
32 {
33 struct volume *root;
34 struct volume *data = volume_find("rootfs_data");
35 struct stat s;
36
37 if (!getenv("PREINIT") && stat("/tmp/.preinit", &s))
38 return -1;
39
40 if (!data) {
41 root = volume_find("rootfs");
42 volume_init(root);
43 ULOG_NOTE("mounting /dev/root\n");
44 mount("/dev/root", "/", NULL, MS_NOATIME | MS_REMOUNT, 0);
45 }
46
47 /* Check for extroot config in rootfs before even trying rootfs_data */
48 if (!mount_extroot("")) {
49 ULOG_NOTE("switched to extroot\n");
50 return 0;
51 }
52
53 /* There isn't extroot, so just try to mount "rootfs_data" */
54 volume_init(data);
55 switch (volume_identify(data)) {
56 case FS_NONE:
57 ULOG_WARN("no usable overlay filesystem found, using tmpfs overlay\n");
58 return ramoverlay();
59
60 case FS_DEADCODE:
61 /*
62 * Filesystem isn't ready yet and we are in the preinit, so we
63 * can't afford waiting for it. Use tmpfs for now and handle it
64 * properly in the "done" call.
65 */
66 ULOG_NOTE("jffs2 not ready yet, using temporary tmpfs overlay\n");
67 return ramoverlay();
68
69 case FS_EXT4:
70 case FS_F2FS:
71 case FS_JFFS2:
72 case FS_UBIFS:
73 mount_overlay(data);
74 break;
75
76 case FS_SNAPSHOT:
77 mount_snapshot(data);
78 break;
79 }
80
81 return 0;
82 }
83
84 static int
85 stop(int argc, char *argv[1])
86 {
87 if (!getenv("SHUTDOWN"))
88 return -1;
89
90 return 0;
91 }
92
93 /*
94 * Called at the end of init, it can wait for filesystem if needed.
95 */
96 static int
97 done(int argc, char *argv[1])
98 {
99 struct volume *v = volume_find("rootfs_data");
100
101 if (!v)
102 return -1;
103
104 switch (volume_identify(v)) {
105 case FS_NONE:
106 case FS_DEADCODE:
107 return jffs2_switch(v);
108
109 case FS_EXT4:
110 case FS_F2FS:
111 case FS_JFFS2:
112 case FS_UBIFS:
113 fs_state_set("/overlay", FS_STATE_READY);
114 break;
115 }
116
117 return 0;
118 }
119
120 int main(int argc, char **argv)
121 {
122 if (argc < 2)
123 return start(argc, argv);
124 if (!strcmp(argv[1], "ram"))
125 return ramoverlay();
126 if (!strcmp(argv[1], "stop"))
127 return stop(argc, argv);
128 if (!strcmp(argv[1], "done"))
129 return done(argc, argv);
130 return -1;
131 }