NBD client and server on same machine

Question

Is there any way to run an NBD (Network Block Device) client and server on the same machine without deadlocking the system?

I am very exhausted looking to find an answer for this. I appreciate if anyone can help.

UPDATE:

I'm writing an NBD server that talks to Google Storage system. I want to mount a file system on the NBD and backup my files. I will be hugely disappointed if I have to end up running the server on another machine. Few ideas I already had seem to lead nowhere:

• telling the file system to open the block device using O_DIRECT flag to bypass the linux buffer cache
• using a raw device (unfortunately, raw devices are character devices and FSes refuse to use them as underlying device)

Answer 1

Just for the record, having the NBD client and server on the same machine has been possible since 2008.