cef0223191
Make the ops->init_rreq() callback optional. This isn't required for the erofs changes I'm implementing to do on-demand read through fscache[1]. Further, ceph has an empty init_rreq method that can then be removed and it's marked optional in the documentation. Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/20211227125444.21187-1-jefflexu@linux.alibaba.com/ [1] Link: https://lore.kernel.org/r/20211228124419.103020-1-jefflexu@linux.alibaba.com Link: https://lore.kernel.org/r/164251410387.3435901.2504600788262093313.stgit@warthog.procyon.org.uk/ # v1
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.