docs: add ext4 kernel-ci

Document ext4 kernel-ci.

Signed-off-by: Luis Chamberlain <[email protected]>

Author: mcgrof

docs/kernel-ci/README.md

@@ -80,6 +80,7 @@ are:
   * [kdevops CI](kdevops-ci.md)
   * [Linux kernel filesystem kdevops CI](linux-filesystems-kdevops-CI-testing.md)
       * [Linux kernel XFS kdevops CI](linux-xfs-kdevops-ci.md)
+      * [Linux kernel ext4 kdevops CI](linux-ext4-kdevops-ci.md)
   * Linux kernel simple subsystems:
       * [Linux kernel modules kdevops CI](linux-modules-kdevops-ci.md)
       * [Linux kernel firmware loader kdevops CI](linux-firmware-kdevops-ci.md)

docs/kernel-ci/linux-ext4-kdevops-ci.md

@@ -0,0 +1,23 @@
+# The Linux kernel ext4 kdevops CI
+
+The ext4 kdevops CI is used to help proactively allow ext4 Linux kernel
+developers test branches automatically through kdevops. Although
+[kpd](https://github.com/facebookincubator/kernel-patches-daemon)
+is not used we use the kpd prefix for the ext4 kdevops CI tree in case a
+patchwork instance and
+[kpd](https://github.com/facebookincubator/kernel-patches-daemon)
+may be leveraged at later future time. The ext4 kdevops CI tree is:
+
+  * [linux-xfs-kpd](https://github.com/linux-kdevops/linux-ext4-kpd)
+
+## linux-ext4-kpd tests
+
+Read [kdevops filesystem CI testing](linux-filesystems-kdevops-CI-testing.md)
+first.
+
+## linux-ext4-kpd CI testing results
+
+You can see linux-ext4-kpd test results here:
+
+  * [Ephemeral  interactive linux-ext4-kpd CI results](https://github.com/linux-kdevops/linux-ext4-kpd/actions)
+  * [Persistent kdevops-results-archive linux-ext4-kpd test results](https://github.com/search?q=repo%3Alinux-kdevops%2Fkdevops-results-archive+is%3Acommit+%22linux-ext4-kpd%3A%22&type=commits)