2 * Copyright (C) 2014 John Crispin <blogic@openwrt.org>
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
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.
18 #include <sys/mount.h>
19 #include <sys/types.h>
24 #include "libfstools.h"
26 char const *extroot_prefix
= NULL
;
29 * This will execute "block extroot" and make use of mounted extroot or return
32 int mount_extroot(void)
43 /* try finding the library directory */
44 snprintf(ldlib_path
, sizeof(ldlib_path
), "%s/upper/lib", extroot_prefix
);
46 if (stat(ldlib_path
, &s
) || !S_ISDIR(s
.st_mode
))
47 snprintf(ldlib_path
, sizeof(ldlib_path
), "%s/lib", extroot_prefix
);
49 /* try finding the block executable */
50 snprintf(block_path
, sizeof(block_path
), "%s/upper/sbin/block", extroot_prefix
);
52 if (stat(block_path
, &s
) || !S_ISREG(s
.st_mode
))
53 snprintf(block_path
, sizeof(block_path
), "%s/sbin/block", extroot_prefix
);
55 if (stat(block_path
, &s
) || !S_ISREG(s
.st_mode
))
56 snprintf(block_path
, sizeof(block_path
), "/sbin/block");
58 if (stat(block_path
, &s
) || !S_ISREG(s
.st_mode
))
61 /* set LD_LIBRARY_PATH env var and load kmods from overlay if we found a lib directory there */
62 if (!stat(ldlib_path
, &s
) && S_ISDIR(s
.st_mode
)) {
63 ULOG_INFO("loading kmods from internal overlay\n");
64 setenv("LD_LIBRARY_PATH", ldlib_path
, 1);
65 snprintf(kmod_loader
, sizeof(kmod_loader
),
66 "/sbin/kmodloader %s/etc/modules-boot.d/", dirname(ldlib_path
));
72 mkdir("/tmp/extroot", 0755);
73 execl(block_path
, block_path
, "extroot", NULL
);
78 waitpid(pid
, &status
, 0);
79 if (!WEXITSTATUS(status
)) {
80 if (find_mount("/tmp/extroot/mnt")) {
81 mount("/dev/root", "/", NULL
, MS_NOATIME
| MS_REMOUNT
| MS_RDONLY
, 0);
83 mkdir("/tmp/extroot/mnt/proc", 0755);
84 mkdir("/tmp/extroot/mnt/dev", 0755);
85 mkdir("/tmp/extroot/mnt/sys", 0755);
86 mkdir("/tmp/extroot/mnt/tmp", 0755);
87 mkdir("/tmp/extroot/mnt/rom", 0755);
89 if (mount_move("/tmp/extroot", "", "/mnt")) {
90 ULOG_ERR("moving pivotroot failed - continue normal boot\n");
91 umount("/tmp/extroot/mnt");
92 } else if (pivot("/mnt", "/rom")) {
93 ULOG_ERR("switching to pivotroot failed - continue normal boot\n");
96 umount("/tmp/overlay");
97 rmdir("/tmp/overlay");
98 rmdir("/tmp/extroot/mnt");
99 rmdir("/tmp/extroot");
102 } else if (find_mount("/tmp/extroot/overlay")) {
103 if (mount_move("/tmp/extroot", "", "/overlay")) {
104 ULOG_ERR("moving extroot failed - continue normal boot\n");
105 umount("/tmp/extroot/overlay");
106 } else if (fopivot("/overlay", "/rom")) {
107 ULOG_ERR("switching to extroot failed - continue normal boot\n");
110 umount("/tmp/overlay");
111 rmdir("/tmp/overlay");
112 rmdir("/tmp/extroot/overlay");
113 rmdir("/tmp/extroot");