Build Network Block Device Kernel Module On CentOS7

nbd.sh

uname -r
sudo su
# useradd builder
# groupadd builder
cd /home/centos
# Get Source Code
wget http://vault.centos.org/7.2.1511/updates/Source/SPackages/kernel-3.10.0-327.28.3.el7.src.rpm
rpm -ivh kernel-3.10.0-327.28.3.el7.src.rpm

# Build Preparation
mkdir -p ~/rpmbuild/{BUILD,BUILDROOT,RPMS,SOURCES,SPECS,SRPMS}
echo '%_topdir %(echo $HOME)/rpmbuild' > ~/.rpmmacros
cd ~/rpmbuild/SPECS
rpmbuild -bp --target=$(uname -m) kernel.spec
cd ~/rpmbuild/BUILD/kernel-3.10.0-327.28.3.el7/linux-3.10.0-327.28.3.el7.centos.x86_64/

# Build
make menuconfig
# Device Driver -> Block devices -> Set “M” On “Network block device support”

make prepare && make modules_prepare && make
make M=drivers/block -j8
modinfo drivers/block/nbd.ko
cp drivers/block/nbd.ko /lib/modules/3.10.0-327.28.3.el7.x86_64/extra/
depmod -a && sudo modprobe nbd

I had to add:

sed -i 's/REQ_TYPE_SPECIAL/REQ_TYPE_DRV_PRIV/' drivers/block/nbd.c

Before "make" to compile successfully, according to this it was renamed:
https://centosfaq.org/centos/nbd-does-not-compile-for-3100-514262el7x86_64/

All the rest was very useful, nice work!