Stopping array does not skip already unmounted filesystems

This instance on 7.2.0-beta3 but I believe stable has the same problem.

Can be reproduced by doing the array shrink procedure using the "clear drive first" method i.e. manually unmount a drive before dd'ing 0's to it. Problem is that on next array stop it'll stay stuck forever on

Sep 22 19:27:22 Unraid2 emhttpd: Retry unmounting disk share(s)...
Sep 22 19:27:27 Unraid2 emhttpd: Unmounting disks...
Sep 22 19:27:27 Unraid2 emhttpd: shcmd (450): umount /mnt/disk2
Sep 22 19:27:27 Unraid2 root: umount: /mnt/disk2: not mounted.
Sep 22 19:27:27 Unraid2 emhttpd: shcmd (450): exit status: 32
Sep 22 19:27:27 Unraid2 emhttpd: Retry unmounting disk share(s)...
Sep 22 19:27:32 Unraid2 emhttpd: Unmounting disks...
Sep 22 19:27:32 Unraid2 emhttpd: shcmd (451): umount /mnt/disk2
Sep 22 19:27:32 Unraid2 root: umount: /mnt/disk2: not mounted.

I've had a similar issue on my main system where sometimes a container gets stuck with a zombie process on /mnt/cache, array stop gets stuck on umount: /mnt/cache: target is busy.. I can manually force unmount it but then all it does is the above, changes to umount: /mnt/cache: not mounted. forever until I trigger a shutdown and the shutdown timeout expires.

I.e. shcmd should continue if a filesystem it wants to unmount is already not mounted, not stay stuck in an endless loop.