Cleanup of created loop device fails though .qcow2 created suuccessfully from CentOS-7.4

[hardikkumar hirpara]

On successful completion of .qcow2 generation, disk image builder should cleanup all created loop devices for that specific process.
After completion of .qcow2 image generation from base image CentOS-7.4, I am getting stale loop devices which are causing issue for new process of ceating .qcow2 using disk-image-builder. Dut to erros like, "umount: /tmp/dib_image.XCmCAY5Z: target is busy" and "mount: could not find any device /dev/loop#Bad address".

Please find below output of commands "lsblk" and "losetup -a" where we can see stale loop devices though we have successful completion of .qcow2 image creation using disk-image-builder:

IS THERE ANY CONFIGURATION/FLAG I AM MISSING AS PART OF DIB SETUP?

lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 500G 0 disk
├─sda1 8:1 0 286M 0 part /boot
└─sda2 8:2 0 499.7G 0 part
  ├─centos_docker--pipeline1-root 253:0 0 481.1G 0 lvm /
  └─centos_docker--pipeline1-swap 253:1 0 18.6G 0 lvm [SWAP]
sr0 11:0 1 1024M 0 rom
sr1 11:1 1 1024M 0 rom
loop0 7:0 0 20G 0 loop
├─loop0p1 253:2 0 512M 0 part
├─loop0p2 253:3 0 2G 0 part
└─loop0p3 253:4 0 17.6G 0 part
loop1 7:1 0 20G 0 loop
├─loop1p1 253:7 0 512M 0 part
├─loop1p2 253:8 0 2G 0 part
└─loop1p3 253:9 0 17.6G 0 part
loop2 7:2 0 20G 0 loop
├─loop2p1 253:5 0 512M 0 part
├─loop2p2 253:6 0 2G 0 part
└─loop2p3 253:10 0 17.6G 0 part

losetup -a
/dev/loop0: [0152]:57696572 (/image0.raw (deleted))
/dev/loop1: [0154]:57450728 (/image0.raw (deleted))
/dev/loop2: [0094]:57896699 (/image0.raw (deleted))