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"
27 * This will execute "block extroot" and make use of mounted extroot or return
30 int mount_extroot(char const *extroot_prefix
)
38 /* try finding the library directory */
39 snprintf(ldlib_path
, sizeof(ldlib_path
), "%s/upper/lib", extroot_prefix
);
41 if (stat(ldlib_path
, &s
) || !S_ISDIR(s
.st_mode
))
42 snprintf(ldlib_path
, sizeof(ldlib_path
), "%s/lib", extroot_prefix
);
44 /* try finding the block executable */
45 snprintf(block_path
, sizeof(block_path
), "%s/upper/sbin/block", extroot_prefix
);
47 if (stat(block_path
, &s
) || !S_ISREG(s
.st_mode
))
48 snprintf(block_path
, sizeof(block_path
), "%s/sbin/block", extroot_prefix
);
50 if (stat(block_path
, &s
) || !S_ISREG(s
.st_mode
))
51 snprintf(block_path
, sizeof(block_path
), "/sbin/block");
53 if (stat(block_path
, &s
) || !S_ISREG(s
.st_mode
))
56 /* set LD_LIBRARY_PATH env var and load kmods from overlay if we found a lib directory there */
57 if (!stat(ldlib_path
, &s
) && S_ISDIR(s
.st_mode
)) {
58 ULOG_INFO("loading kmods from internal overlay\n");
59 setenv("LD_LIBRARY_PATH", ldlib_path
, 1);
60 snprintf(kmod_loader
, sizeof(kmod_loader
),
61 "/sbin/kmodloader %s/etc/modules-boot.d/", dirname(ldlib_path
));
62 if (system(kmod_loader
))
63 ULOG_ERR("failed to launch kmodloader from internal overlay\n");
68 mkdir("/tmp/extroot", 0755);
69 execl(block_path
, block_path
, "extroot", NULL
);
74 waitpid(pid
, &status
, 0);
75 if (!WEXITSTATUS(status
)) {
76 if (find_mount("/tmp/extroot/mnt")) {
77 mount("/dev/root", "/", NULL
, MS_NOATIME
| MS_REMOUNT
| MS_RDONLY
, 0);
79 mkdir("/tmp/extroot/mnt/proc", 0755);
80 mkdir("/tmp/extroot/mnt/dev", 0755);
81 mkdir("/tmp/extroot/mnt/sys", 0755);
82 mkdir("/tmp/extroot/mnt/tmp", 0755);
83 mkdir("/tmp/extroot/mnt/rom", 0755);
85 if (mount_move("/tmp/extroot", "", "/mnt")) {
86 ULOG_ERR("moving pivotroot failed - continue normal boot\n");
87 umount("/tmp/extroot/mnt");
88 } else if (pivot("/mnt", "/rom")) {
89 ULOG_ERR("switching to pivotroot failed - continue normal boot\n");
92 umount("/tmp/overlay");
93 rmdir("/tmp/overlay");
94 rmdir("/tmp/extroot/mnt");
95 rmdir("/tmp/extroot");
98 } else if (find_mount("/tmp/extroot/overlay")) {
99 if (mount_move("/tmp/extroot", "", "/overlay")) {
100 ULOG_ERR("moving extroot failed - continue normal boot\n");
101 umount("/tmp/extroot/overlay");
102 } else if (fopivot("/overlay", "/rom")) {
103 ULOG_ERR("switching to extroot failed - continue normal boot\n");
106 umount("/tmp/overlay");
107 rmdir("/tmp/overlay");
108 rmdir("/tmp/extroot/overlay");
109 rmdir("/tmp/extroot");