Re: [PATCH bpf-next v6 1/7] bpf: Renames to prepare for generalizing sk_storage.

From: Martin KaFai Lau
Date: Fri Jul 24 2020 - 01:32:06 EST

On Thu, Jul 23, 2020 at 01:50:26PM +0200, KP Singh wrote:
> From: KP Singh <kpsingh@xxxxxxxxxx>
> A purely mechanical change to split the renaming from the actual
> generalization.
> Flags/consts:
> Structs:
> bucket bpf_local_storage_map_bucket
> bpf_sk_storage_map bpf_local_storage_map
> bpf_sk_storage_data bpf_local_storage_data
> bpf_sk_storage_elem bpf_local_storage_elem
> bpf_sk_storage bpf_local_storage
> selem_linked_to_sk selem_linked_to_storage
> selem_alloc bpf_selem_alloc
> The "sk" member in bpf_local_storage is also updated to "owner"
> in preparation for changing the type to void * in a subsequent patch.
> Functions:
> __selem_unlink_sk bpf_selem_unlink_storage
> __selem_link_sk bpf_selem_link_storage
> selem_unlink_sk __bpf_selem_unlink_storage
> sk_storage_update bpf_local_storage_update
> __sk_storage_lookup bpf_local_storage_lookup
> bpf_sk_storage_map_free bpf_local_storage_map_free
> bpf_sk_storage_map_alloc bpf_local_storage_map_alloc
> bpf_sk_storage_map_alloc_check bpf_local_storage_map_alloc_check
> bpf_sk_storage_map_check_btf bpf_local_storage_map_check_btf
Thanks for separating this mechanical name change in a separate patch.
It is much easier to follow. This patch looks good.

A minor thought is, when I look at unlink_map() and unlink_storage(),
it keeps me looking back for the lock situation. I think
the main reason is the bpf_selem_unlink_map() is locked but
bpf_selem_unlink_storage() is unlocked now. May be:

bpf_selem_unlink_map() => bpf_selem_unlink_map_locked()
bpf_selem_link_map() => bpf_selem_link_map_locked()
__bpf_selem_unlink_storage() => bpf_selem_unlink_storage_locked()
bpf_link_storage() means unlocked
bpf_unlink_storage() means unlocked.

I think it could be one follow-up patch later instead of interrupting
multiple patches in this set for this minor thing. For now, lets
continue with this and remember default is nolock for storage.

I will continue tomorrow.