udev-extraconf: skip mounting partitions already mounted by systemd

For some devices, udev may sometimes trigger twice the 'add' rule during
boot. Calling the mount.sh script twice will eventually fail for
already mounted partitions, but in that case, the script tries to remove
the created mountpoint, when it shouldn't.
This has been observed on USB sticks connected to a USB hub and may
result in devices not being mounted if plugged-in before booting.

This patch checks for already mounted partitions earlier (before creating
the mount point) and returns with no actions.

(From OE-Core rev: 4cf076879ac038ebf76679a19249ea6363e63e0f)

Signed-off-by: Hector Palacios <hector.palacios@digi.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-core/udev/udev-extraconf/mount.sh

@@ -38,6 +38,12 @@ done
 automount_systemd() {
     name="`basename "$DEVNAME"`"
 
+    # Skip already mounted partitions
+    if [ -f /run/systemd/transient/run-media-$name.mount ]; then
+        logger "mount.sh/automount" "/run/media/$name already mounted"
+        return
+    fi
+
     # Skip the partition which are already in /etc/fstab
     grep "^[[:space:]]*$DEVNAME" /etc/fstab && return
     for n in LABEL PARTLABEL UUID PARTUUID; do