$ lvremove /dev/vg0/snap-tmp-$vm -f
Logical volume vg0/snap-tmp-vm06.docker-disk contains a filesystem in use.

$ fuser -mv /dev/vg0/snap-tmp-vm06.docker-disk
                     USER        PID ACCESS COMMAND
/dev/dm-36:          root     kernel mount /media/snapshots/tmp-vm06.docker-disk

$ lvs|grep docker
  snap-tmp-vm06.docker-disk       vg0  swi-aos---   4.00g      vm06.docker-disk       20.44
  vm06.docker-disk                vg0  owi-aos---  80.00g
  vm06.docker-swap                vg0  -wi-ao----   8.00g
$ lvdisplay vg0/snap-tmp-vm06.docker-disk
  --- Logical volume ---
  LV Path                /dev/vg0/snap-tmp-vm06.docker-disk
  LV Name                snap-tmp-vm06.docker-disk
  VG Name                vg0
  LV UUID                xdoeHC-7PZ6-LUiZ-QKzS-QEf8-NJcU-bEpKHG
  LV Write Access        read/write
  LV Creation host, time xen-eclabs, 2018-08-15 02:21:02 +0200
  LV snapshot status     active destination for vm06.docker-disk
  LV Status              available
  # open                 1
  LV Size                80.00 GiB
  Current LE             20480
  COW-table size         4.00 GiB
  COW-table LE           1024
  Allocated to snapshot  20.44%
  Snapshot chunk size    4.00 KiB
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:36