For the general process of submitting patches to Ceph, read the below

`Submitting Patches`_

For documentation patches the following guide will help you get started

`Documenting Ceph`_

Performance enhancements must come with test data and detailed
explanations.

Code cleanup is appreciated, as are patches that fix bugs or
implement features. Except on rare occasions, code cleanup that only
relates to coding style or modifies whitespace is discouraged,
primarily because it can cause problems when rebasing and backporting.

.. _Submitting Patches: SubmittingPatches.rst
.. _Documenting Ceph:  doc/start/documenting-ceph.rst
