[PATCH 0/2] liveupdate: Small FLB fixes

[David Matlack]

On Thu, May 28, 2026 at 10:41 AM David Matlack <dmatlack at google.com> wrote:
>
> This series has 2 small fixes to how FLBs are managed. First is to
> increase the outgoing FLB refcount during liveupdate_flb_get_outgoing()
> so it cannot be freed while the caller is using it, and to align with
> the semantics of liveupdate_flb_get_incoming(). The second is to prevent
> FLB retrieve() from being called multiple times if the first attempt
> fails.
>
> Both of these changes are needed for the correctness of the PCI core
> support for Live Update:
>
>   https://lore.kernel.org/linux-pci/20260522202410.3104264-1-dmatlack@google.com/

I'm wondering if we still want this series. After discussions with
Pratyush and Sami (some on-list, some off-list) the v7 of the PCI
series (which I haven't sent yet) does not depend on these changes for
correctness.

Patch 1: PCI core no longer calls get_outgoing() outside the scope of
file handler callbacks. So there is no need to increment the reference
count. We could still keep this to make get_outgoing behave the same
way as get_incoming for consisteny at the cost of some extra
complexity to manage outgoing FLB refcoutn.

Patch 2: PCI core panics if retrieve fails (proceeding without the PCI
FLB can lead to memory corruption due to ongoing DMA). So the behavior
of LUO on retrieve() errors does not matter.

Should we drop this series?