To check that a directory is mounted in a bash script:
echo "Mounting /mnt/share..."
sudo mount /mnt/share
if ! mount | grep '/mnt/share ' > /dev/null; then
echo "/mnt/share not mounted. Exiting."
exit
fi
# Do stuff with /mnt/share
echo "Unmounting /mnt/share..."
sudo umount /mnt/share
if mount | grep '/mnt/share ' > /dev/null; then
echo "/mnt/share not unmounted"
fi
Reference: Check if directory mounted with bash