Re: [PATCH v5 06/22] liveupdate: luo_session: add sessions support

Pasha Tatashin
2025-11-12T20:47:44Z

On Wed, Nov 12, 2025 at 3:39 PM Mike Rapoport <rppt@kernel.org> wrote:
>
> On Fri, Nov 07, 2025 at 04:03:04PM -0500, Pasha Tatashin wrote:
> > Introduce concept of "Live Update Sessions" within the LUO framework.
> > LUO sessions provide a mechanism to group and manage `struct file *`
> > instances (representing file descriptors) that need to be preserved
> > across a kexec-based live update.
> >
> > Each session is identified by a unique name and acts as a container
> > for file objects whose state is critical to a userspace workload, such
> > as a virtual machine or a high-performance database, aiming to maintain
> > their functionality across a kernel transition.
> >
> > This groundwork establishes the framework for preserving file-backed
> > state across kernel updates, with the actual file data preservation
> > mechanisms to be implemented in subsequent patches.
> >
> > Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
> > ---
> > include/linux/liveupdate/abi/luo.h | 81 ++++++
> > include/uapi/linux/liveupdate.h | 3 +
> > kernel/liveupdate/Makefile | 3 +-
> > kernel/liveupdate/luo_core.c | 9 +
> > kernel/liveupdate/luo_internal.h | 39 +++
> > kernel/liveupdate/luo_session.c | 405 +++++++++++++++++++++++++++++
> > 6 files changed, 539 insertions(+), 1 deletion(-)
> > create mode 100644 kernel/liveupdate/luo_session.c
> >
> > diff --git a/include/linux/liveupdate/abi/luo.h b/include/linux/liveupdate/abi/luo.h
> > index 9483a294287f..37b9fecef3f7 100644
> > --- a/include/linux/liveupdate/abi/luo.h
> > +++ b/include/linux/liveupdate/abi/luo.h
> > @@ -28,6 +28,11 @@
> > * / {
> > * compatible = "luo-v1";
> > * liveupdate-number = <...>;
> > + *
> > + * luo-session {
> > + * compatible = "luo-session-v1";
> > + * luo-session-head = <phys_addr_of_session_head_ser>;
>
> 'head' reads to me as list head rather than a header. I'd use 'hdr' for the
> latter.

Or just use the full name: "header" ? It is not too long as well.

Pasha

>
> --
> Sincerely yours,
> Mike.