Re: [PATCH v7 07/22] liveupdate: luo_session: Add ioctls for file preservation

[Mike Rapoport]

On Sat, Nov 22, 2025 at 05:23:34PM -0500, Pasha Tatashin wrote:
> Introducing the userspace interface and internal logic required to
> manage the lifecycle of file descriptors within a session. Previously, a
> session was merely a container; this change makes it a functional
> management unit.
> 
> The following capabilities are added:
> 
> A new set of ioctl commands are added, which operate on the file
> descriptor returned by CREATE_SESSION. This allows userspace to:
> - LIVEUPDATE_SESSION_PRESERVE_FD: Add a file descriptor to a session
>   to be preserved across the live update.
> - LIVEUPDATE_SESSION_RETRIEVE_FD: Retrieve a preserved file in the
>   new kernel using its unique token.
> - LIVEUPDATE_SESSION_FINISH: finish session
> 
> The session's .release handler is enhanced to be state-aware. When a
> session's file descriptor is closed, it correctly unpreserves
> the session based on its current state before freeing all
> associated file resources.
> 
> Signed-off-by: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
> Reviewed-by: Pratyush Yadav <pratyush@xxxxxxxxxx>

Reviewed-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>

> ---
>  include/uapi/linux/liveupdate.h | 103 ++++++++++++++++++
>  kernel/liveupdate/luo_session.c | 187 +++++++++++++++++++++++++++++++-
>  2 files changed, 288 insertions(+), 2 deletions(-)

-- 
Sincerely yours,
Mike.