From: Jan Palus <atler@pld-linux.org>
Date: Wed, 28 Sep 2022 20:06:30 +0000 (+0200)
Subject: check if /newroot/dev/console creation can succeed
X-Git-Tag: 12818^0
X-Git-Url: http://git.pld-linux.org/gitweb.cgi?a=commitdiff_plain;h=9552a28d03e1b9bf8c5fdb933d5fa8464022a219;p=projects%2Fgeninitrd.git

check if /newroot/dev/console creation can succeed

/newroot is mounted read-only hence by default nothing can be created
below it unless /newroot/dev is mounted to something else.

unfortunately `test -w /newroot/dev` in initrd does not check whether
containing filesystem is mounted read-only
---

diff --git a/geninitrd b/geninitrd
index 0a422ee..46b2fc6 100755
--- a/geninitrd
+++ b/geninitrd
@@ -1066,9 +1066,9 @@ initrd_gen_initramfs_switchroot() {
 	kmsg "geninitrd/$VERSION switching root"
 
 	umount_all
-	busybox_applet switch_root usleep
+	busybox_applet switch_root usleep mountpoint
 	add_linuxrc <<-'EOF'
-		[ ! -e /newroot/dev/console ] && mknod -m 660 /newroot/dev/console c 5 1
+		[ ! -e /newroot/dev/console ] && mountpoint -q /newroot/dev && mknod -m 660 /newroot/dev/console c 5 1
 
 		# switch root to empty dir will make kernel panic, so sleep 10s before it
 		# switch_root needs to be pid 1, so there's no other way to recover from here