[PATCH] expand-on-first-boot: search until no device mapper is used

[Quirin Gylstorff <Quirin.Gylstorff@siemens.com>]

From: Quirin Gylstorff <quirin.gylstorff@siemens.com>

Device mapper block devices can be stacked e.g.
in case a hard disk is encrypted and uses lvm:
sda
+-sda1                  259:3    0 2G  0 part
  +-sda1_crypt          253:0    0 2G  0 crypt
    +-debian--vg-root   253:1    0 1G  0 lvm

So we should traverse the `slaves` until we reach the endpoint.

Signed-off-by: Quirin Gylstorff <quirin.gylstorff@siemens.com>
---
 .../expand-on-first-boot/files/expand-last-partition.sh        | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh b/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
index 84f1219f..0cb2ee21 100755
--- a/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
+++ b/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
@@ -12,6 +12,9 @@ set -e
 ROOT_DEV="$(findmnt / -o source -n)"
 ROOT_DEV_NAME=${ROOT_DEV##*/}
 ROOT_DEV_SLAVE=$(find /sys/block/"${ROOT_DEV_NAME}"/slaves -mindepth 1 -print -quit 2>/dev/null || true)
+while [ -d "${ROOT_DEV_SLAVE}/slaves" ]; do
+	ROOT_DEV_SLAVE=$(find "${ROOT_DEV_SLAVE}"/slaves -mindepth 1 -print -quit 2>/dev/null || true)
+done
 if [ -n "${ROOT_DEV_SLAVE}" ]; then
 	ROOT_DEV=/dev/${ROOT_DEV_SLAVE##*/}
 fi
-- 
2.43.0