Compiling and Installing the Bcache

CentOS 7.6

Obtain the bcache source code and save it to /home.
Download address: https://github.com/kunpengcompute/bcache/releases/tag/swc-v0.2.0

Decompress the source package.

cd /home
unzip bcache-swc-v0.2.0.zip

Compile and obtain the bcache driver module.
1 2
cd /home/bcache-swc-v0.2.0/drivers/md/bcache make -C /lib/modules/$(uname -r)/build M=$(pwd)
When running the make command, select the build directory of the kernel where bcache.ko needs to be run for compilation based on the site environment.
View the reference count of the bcache module.
```
lsmod | grep -w bcache
```
Check that the reference count is 0.
```
bcache                458752  0
```
Check that bcache.ko is not loaded in the current environment.
```
modprobe -r bcache
```
(Optional) Delete the installation directory.
```
rm -rf /lib/modules/$(uname -r)/kernel/drivers/md/bcache
```
If the bcache is not installed, skip this step.

Create an installation directory.

mkdir -p /lib/modules/$(uname -r)/kernel/drivers/md/bcache

Copy bcache.ko to the installation directory.

cp bcache.ko /lib/modules/$(uname -r)/kernel/drivers/md/bcache

Compress bcache.ko.

xz -z /lib/modules/$(uname -r)/kernel/drivers/md/bcache/bcache.ko

Update the dependency of bcache.ko.
```
depmod -a
```

Update initramfs.

dracut --add-drivers bcache -f /boot/initramfs-$(uname -r).img

Check whether bcache.ko is successfully installed.

lsinitrd /boot/initramfs-$(uname -r).img | grep bcache.ko.xz
-rw-r--r-- 1 root root 997136 Nov 30 11:45usr/lib/modules/4.14.0-115.el7a.0.1.aarch64/kernel/drivers/md/bcache/bcache.ko.xz
ls -l /lib/modules/$(uname -r)/kernel/drivers/md/bcache/bcache.ko.xz
-rw-r--r-- 1 root root 997136 Nov 30 11:45/lib/modules/4.14.0-115.el7a.0.1.aarch64/kernel/drivers/md/bcache/bcache.ko.xz

Load bcache.ko.
```
modprobe bcache
```

openEuler 20.03

Download the bcache source code and to /home.
https://gitee.com/openeuler/kernel/tree/openEuler-1.0-LTS/kernel

Decompress the source package.

unzip openeuler-kernel-openEuler-1.0-LTS.zip

Replace the system header file temporarily.

mv /usr/src/kernels/$(uname -r)/include/trace/events/bcache.h /usr/src/kernels/$(uname -r)/include/trace/events/bcache.h.bak
cp /home/kernel/include/trace/events/bcache.h /usr/src/kernels/$(uname -r)/include/trace/events/bcache.h

Compile and obtain the bcache driver module.
1 2
cd /home/kernel/drivers/md/bcache make -C /lib/modules/$(uname -r)/build M=$(pwd)
When running the make command, select the build directory of the kernel where bcache.ko needs to be run for compilation based on the site environment.

Replace it with the original file.

mv /usr/src/kernels/$(uname -r)/include/trace/events/bcache.h.bak /usr/src/kernels/$(uname -r)/include/trace/events/bcache.h

View the reference count of the bcache module.
```
lsmod | grep -w bcache
```
Check that the reference count is 0.
```
bcache                458752  0
```
Check that bcache.ko is not loaded in the current environment.
```
modprobe -r bcache
```

Delete the installation directory.

rm -rf /lib/modules/$(uname -r)/kernel/drivers/md/bcache

Create an installation directory.

mkdir -p /lib/modules/$(uname -r)/kernel/drivers/md/bcache

Copy bcache.ko to the installation directory.

cp bcache.ko /lib/modules/$(uname -r)/kernel/drivers/md/bcache

Compress bcache.ko.

xz -z /lib/modules/$(uname -r)/kernel/drivers/md/bcache/bcache.ko

Update the dependency of bcache.ko.
```
depmod -a
```

Update initramfs.

dracut --add-drivers bcache -f /boot/initramfs-$(uname -r).img

Check whether bcache.ko is successfully installed.

lsinitrd /boot/initramfs-$(uname -r).img | grep bcache.ko.xz
-rw-r--r-- 1 root root 997136 Nov 30 11:45usr/lib/modules/4.19.90-2012.4.0.0053.oe1.aarch64/kernel/drivers/md/bcache/bcache.ko.xz
ls -l /lib/modules/$(uname -r)/kernel/drivers/md/bcache/bcache.ko.xz
-rw-r--r-- 1 root root 997136 Nov 30 11:45/lib/modules/4.19.90-2012.4.0.0053.oe1.aarch64/kernel/drivers/md/bcache/bcache.ko.xz

Load bcache.ko.
```
modprobe bcache
```

Parent topic: Installing the Bcache