[PATCH] initramfs-framework: unmount automounts before switch_root

[PATCH] initramfs-framework: unmount automounts before switch_root

[Justin Bronder]

If mounts are left lingering, then after we switch_root, attempts to
modify the block devices will result in an EBUSY with no way to unmount
them.  As we're about to switch_root anyways, there isn't much use to
keep anything mounted unless it has the new rootfs.

Signed-off-by: Justin Bronder <jsbronder@cold-front.org>
---
 .../initrdscripts/initramfs-framework/finish         | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/meta/recipes-core/initrdscripts/initramfs-framework/finish b/meta/recipes-core/initrdscripts/initramfs-framework/finish
index 717383ebac8..f08a9208675 100755
--- a/meta/recipes-core/initrdscripts/initramfs-framework/finish
+++ b/meta/recipes-core/initrdscripts/initramfs-framework/finish
@@ -12,6 +12,18 @@ finish_run() {
 			fatal "ERROR: There's no '/dev' on rootfs."
 		fi
 
+		# Unmount anything that was automounted by busybox via mdev-mount.sh.
+		# We're about to switch_root, and leaving anything mounted will prevent
+		# the next rootfs from modifying the block device.  Ignore ROOT_DISK,
+		# if it was set by setup-live, because it'll be mounted over loopback
+		# to ROOTFS_DIR.
+		local dev
+		for dev in /run/media/*; do
+			if mountpoint -q "${dev}" && [ "${dev##*/}" != "${ROOT_DISK}" ]; then
+				umount -f "${dev}" || debug "Failed to unmount ${dev}"
+			fi
+		done
+
 		info "Switching root to '$ROOTFS_DIR'..."
 
 		debug "Moving /dev, /proc and /sys onto rootfs..."
-- 
2.35.0