[PATCH] fadump-init: clean up mount points properly

[Kairui Song]

When running with squash module enabled for both initramfs, /dev and
/run are also mounted by squash-init, so move them to newroot as well,
else they might leak.

Also don't mount /sys since squash-init/systemd will mount it and
it's not required here.

Also pass `-d` to umount so loop devices (if used) will be force freed.

Signed-off-by: Kairui Song <kasong(a)redhat.com&gt;
---
 dracut-fadump-init-fadump.sh | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/dracut-fadump-init-fadump.sh b/dracut-fadump-init-fadump.sh
index 5468d99..cc67d1c 100755
--- a/dracut-fadump-init-fadump.sh
+++ b/dracut-fadump-init-fadump.sh
@@ -5,9 +5,6 @@ export SYSTEMD_IN_INITRD=lenient
 [ -e /proc/mounts ] ||
 	(mkdir -p /proc && mount -t proc -o nosuid,noexec,nodev proc /proc)
 
-grep -q '^sysfs /sys sysfs' /proc/mounts ||
-	(mkdir -p /sys && mount -t sysfs -o nosuid,noexec,nodev sysfs /sys)
-
 grep -q '^none / ' /proc/mounts || grep -q '^rootfs / ' /proc/mounts
&& ROOTFS_IS_RAMFS=1
 
 if [ -f /proc/device-tree/rtas/ibm,kernel-dump ] || [ -f
/proc/device-tree/ibm,opal/dump/mpipl-boot ]; then
@@ -20,9 +17,13 @@ if [ -f /proc/device-tree/rtas/ibm,kernel-dump ] || [ -f
/proc/device-tree/ibm,o
 		done
 		exec switch_root /newroot /init
 	else
-		mkdir /newroot/sys /newroot/proc /newroot/oldroot
+		mkdir /newroot/sys /newroot/proc /newroot/dev /newroot/run /newroot/oldroot
+
+		grep -q '^devtmpfs /dev devtmpfs' /proc/mounts && mount --move /dev
/newroot/dev
+		grep -q '^tmpfs /run tmpfs' /proc/mounts && mount --move /run
/newroot/run
+		grep -q '^sysfs /sys sysfs' /proc/mounts && mount --move /sys
/newroot/sys
 		mount --move /proc /newroot/proc
-		mount --move /sys /newroot/sys
+
 		cp --reflink=auto --sparse=auto --preserve=mode,timestamps,links -dfr /fadumproot/.
/newroot/
 		cd /newroot && pivot_root . oldroot
 
@@ -31,11 +32,11 @@ if [ -f /proc/device-tree/rtas/ibm,kernel-dump ] || [ -f
/proc/device-tree/ibm,o
 			unset loop
 			while read -r _ mp _; do
 				case $mp in
-				/oldroot/*) umount "$mp" && loop=1 ;;
+				/oldroot/*) umount -d "$mp" && loop=1 ;;
 				esac
 			done </proc/mounts
 		done
-		umount -l oldroot
+		umount -d -l oldroot
 
 		exec /init
 	fi
-- 
2.31.1