An NBD block device written using Linux ublk (user block device)

Commits [1] and [2] and more here.

ublk is a Linux-only io_uring-based user block device. It lets you write block devices in userspace. nbdublk is an NBD client written using ublk.

# modprobe ublk_drv
# nbdublk /dev/ublkb0 nbd://remote
# ublk list

# blockdev --getsize64 /dev/ublkb0
# mke2fs /dev/ublkb0
# (etc)

# ublk del -n 0