mount_root: support extroot from block-mount on jffs2

	- retry extroot after mounting jffs2
	- look for /sbin/block in jffs2
	- load all kmods from jffs2
	- cleanup temporary directories after extroot

diff --git a/mount_root.c b/mount_root.c
index bc236fe8e95b5751c1b3058f386b3de8ad93a311..eec60d67afde10499db78f2850cd828f14e37eba 100644 (file)
--- a/mount_root.c
+++ b/mount_root.c
@@ -677,50 +677,63 @@ static int main_switch2jffs(int argc, char **argv)
        return ret;
 }
 
-static int extroot(void)
+static int extroot(const char *prefix)
 {
+       char block_path[32];
+       char kmod_loader[64];
        struct stat s;
        pid_t pid;
 
-       if (stat("/sbin/block", &s))
+       sprintf(block_path, "%s/sbin/block", prefix);
+
+       if (stat(block_path, &s))
                return -1;
 
+       sprintf(kmod_loader, "/sbin/kmodloader %s/etc/modules-boot.d/ %s", prefix, prefix);
+       system(kmod_loader);
+
        pid = fork();
        if (!pid) {
                mkdir("/tmp/extroot", 0755);
-               execl("/sbin/block", "/sbin/block", "extroot", NULL);
+               execl(block_path, block_path, "extroot", NULL);
                exit(-1);
        } else if (pid > 0) {
                int status;
 
                waitpid(pid, &status, 0);
                if (!WEXITSTATUS(status)) {
-                       if (find_mount("/tmp/mnt")) {
+                       if (find_mount("/tmp/extroot/mnt")) {
                                mount("/dev/root", "/", NULL, MS_NOATIME | MS_REMOUNT | MS_RDONLY, 0);
 
-                               mkdir("/tmp/mnt/proc", 0755);
-                               mkdir("/tmp/mnt/dev", 0755);
-                               mkdir("/tmp/mnt/sys", 0755);
-                               mkdir("/tmp/mnt/tmp", 0755);
-                               mkdir("/tmp/mnt/rom", 0755);
+                               mkdir("/tmp/extroot/mnt/proc", 0755);
+                               mkdir("/tmp/extroot/mnt/dev", 0755);
+                               mkdir("/tmp/extroot/mnt/sys", 0755);
+                               mkdir("/tmp/extroot/mnt/tmp", 0755);
+                               mkdir("/tmp/extroot/mnt/rom", 0755);
 
-                               if (mount_move("/tmp", "", "/mnt")) {
+                               if (mount_move("/tmp/extroot", "", "/mnt")) {
                                        ERROR("moving pivotroot failed - continue normal boot\n");
-                                       umount("/tmp/mnt");
+                                       umount("/tmp/extroot/mnt");
                                } else if (pivot("/mnt", "/rom")) {
                                        ERROR("switching to pivotroot failed - continue normal boot\n");
                                        umount("/mnt");
                                } else {
+                                       rmdir("/tmp/extroot/mnt");
+                                       rmdir("/tmp/extroot");
                                        return 0;
                                }
-                       } else if (find_mount("/tmp/overlay")) {
-                               if (mount_move("/tmp", "", "/overlay")) {
+                       } else if (find_mount("/tmp/extroot/overlay")) {
+                               if (mount_move("/tmp/extroot", "", "/overlay")) {
                                        ERROR("moving extroot failed - continue normal boot\n");
-                                       umount("/tmp/overlay");
+                                       umount("/tmp/extroot/overlay");
                                } else if (fopivot("/overlay", "/rom")) {
                                        ERROR("switching to extroot failed - continue normal boot\n");
                                        umount("/overlay");
                                } else {
+                                       umount("/tmp/overlay");
+                                       rmdir("/tmp/overlay");
+                                       rmdir("/tmp/extroot/overlay");
+                                       rmdir("/tmp/extroot");
                                        return 0;
                                }
                        }
@@ -754,7 +767,7 @@ int main(int argc, char **argv)
                LOG("mounting /dev/root\n");
                mount("/dev/root", "/", NULL, MS_NOATIME | MS_REMOUNT, 0);
        } else {
-               if (!extroot()) {
+               if (!extroot("")) {
                        fprintf(stderr, "mount_root: switched to extroot\n");
                        return 0;
                }
@@ -773,6 +786,12 @@ int main(int argc, char **argv)
                        }
 
                        mtd_mount_jffs2();
+
+                       if (!extroot("/tmp/overlay")) {
+                               fprintf(stderr, "mount_root: switched to extroot\n");
+                               return 0;
+                       }
+
                        DEBUG(1, "switching to jffs2\n");
                        if (mount_move("/tmp", "", "/overlay") || fopivot("/overlay", "/rom")) {
                                ERROR("switching to jffs2 failed - fallback to ramoverlay\n");