Bug#906664: initramfs-tools: Add partition table support to get_fstype

[Nazar Mokrynskyi <nazar@mokrynskyi.com>]

Package: initramfs-tools
Version: 0.131ubuntu8
Severity: wishlist


Hi,
I'd like to have fully encrypted system with partition table inside of LUKS container. It is easier to manage for me than multi-layer LVM.

However, there are 2 issues with this described here: https://bugs.launchpad.net/ubuntu/+source/cryptsetup/+bug/1786688

The first issue is that after decryption of LUKS container there is a filesystem check and `get_fstype` function returns `undefined` for any partition table.

I'd like it to return `pttable` or something similar instead, so that after decryption it will not lock container back with "unknown fstype, bad password or options?".

Patch would look something like this:

get_fstype ()
{
	local FS FSTYPE FSSIZE RET
	FS="${1}"

	# blkid has a more complete list of file systems,
	# but fstype is more robust
	FSTYPE="unknown"
	eval $(fstype "${FS}" 2> /dev/null)
	if [ "$FSTYPE" = "unknown" ]; then
		FSTYPE=$(blkid -o value -s TYPE "${FS}")
	fi
-	RET=$?
+
+	if [ -z "${FSTYPE}" ]; then
+		if [ ! -z $(blkid -o value -s PTTABLE "${FS}") ]; then
+			FSTYPE="pttable"
+		fi
+		RET=$?
+	fi
+
+	RET=$?

	if [ -z "${FSTYPE}" ]; then
		FSTYPE="unknown"
	fi

	echo "${FSTYPE}"
	return ${RET}
}


This would be the first step, after that it would be possible to adjust cryptsetup integration to scan decrypted partition table for partitions with partprobe or kpartx.

I don't know how to send patch properly, so redirect me to proper place if this is not the right one.