How to mount ftp mounted .iso file to ubuntu

Question

In my windows, I have created a folder. I have mounted that folder using curlftps. It was successful. there's .iso file (centos.iso) in that folder.then I tried to mount that iso image to my linux again as a mount point. But it was unsuccessful.

root@UbuntuServer:/mnt/test# mount -o loop CentOS-7-x86_64-Everything-1804.iso /mnt/test2/
mount: /mnt/test/CentOS-7-x86_64-Everything-1804.iso: failed to setup loop device: Operation not supported  

Appreciated if anyone can help me with this

root@UbuntuServer:~# curlftpfs ftp://randeer:randeer@192.168.0.2 /mnt/test/
root@UbuntuServer:~# ls -l
total 0
root@UbuntuServer:~# cd /mnt/test/
root@UbuntuServer:/mnt/test# ls
CentOS-7-x86_64-Everything-1804.iso  new public             rootnewprivate.ppk
fromcentos.txt                       randeernewprivate.ppk  rootpub
root@UbuntuServer:/mnt/test# mount CentOS-7-x86_64-Everything-1804.iso /mnt/test                                                                                        2/ -t iso9600 -o loop
mount: /mnt/test/CentOS-7-x86_64-Everything-1804.iso: failed to setup loop devic                                                                                        e: Operation not supported

Answer 1

I got the answer for this quiz, (https://unix.stackexchange.com/questions/465764/how-to-mount-ftp-mounted-iso-file-to-ubuntu/465786#465786) curlftps is userspace, mount loopback is kernelspace. Kernel can't see the userspace mounted file. Use fuseiso for mounting which is a userspace based solution. Thanks mate, it works.

sudo apt install fuseiso  
modprobe fuse 
sudo mkdir /mnt/iso 
fuseiso -p /mnt/test/CentOS-7.iso /mnt/iso/