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

`Submitting Patches`_

For documentation patches the the following guide will help you get started

`Documenting Ceph`_

Performance enhancements must come with test data and detailed
explanations.

Code cleanup is appreciated along with a patch that fixes a bug or
implements a feature. Except on rare occasions, code cleanup that only
involve coding style or whitespace modifications are discouraged,
primarily because they cause problems when rebasing and backporting.

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