[PATCH bpf-next v9 3/7] bpf: Generalize bpf_sk_storage

[Martin KaFai Lau]

On Sun, Aug 23, 2020 at 06:56:08PM +0200, KP Singh wrote:
> From: KP Singh <kpsingh at google.com>
> 
> Refactor the functionality in bpf_sk_storage.c so that concept of
> storage linked to kernel objects can be extended to other objects like
> inode, task_struct etc.
> 
> Each new local storage will still be a separate map and provide its own
> set of helpers. This allows for future object specific extensions and
> still share a lot of the underlying implementation.
> 
> This includes the changes suggested by Martin in:
> 
>   https://lore.kernel.org/bpf/20200725013047.4006241-1-kafai@fb.com/
> 
> adding new map operations to support bpf_local_storage maps:
> 
> * storages for different kernel objects to optionally have different
>   memory charging strategy (map_local_storage_charge,
>   map_local_storage_uncharge)
> * Functionality to extract the storage pointer from a pointer to the
>   owning object (map_owner_storage_ptr)
> 
> Co-developed-by: Martin KaFai Lau <kafai at fb.com>
> Signed-off-by: KP Singh <kpsingh at google.com>
Signed-off-by: Martin KaFai Lau <kafai at fb.com>