[Cluster-devel] [PATCH dlm/next 1/5] fs: dlm: add comment about lkb IFL flags

[Alexander Aring]

Hi,

On Fri, Jun 17, 2022 at 4:00 PM Alexander Aring <aahringo at redhat.com> wrote:
>
> This patch adds comments about the difference between the lower 2 bytes
> of lkb flags and the 2 upper bytes of the lkb IFL flags. In short the
> upper 2 bytes will be handled as internal flags whereas the lower 2
> bytes are part of the DLM protocol and are used to exchange messages.
>
> Signed-off-by: Alexander Aring <aahringo at redhat.com>
> ---
>  fs/dlm/dlm_internal.h | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
> index c03388a3875c..151f98fc3f22 100644
> --- a/fs/dlm/dlm_internal.h
> +++ b/fs/dlm/dlm_internal.h
> @@ -207,6 +207,13 @@ struct dlm_args {
>  #define DLM_IFL_TIMEOUT_CANCEL 0x00800000
>  #define DLM_IFL_DEADLOCK_CANCEL        0x01000000
>  #define DLM_IFL_STUB_MS                0x02000000 /* magic number for m_flags */
> +/* least significant 2 bytes are message changed, they are full transmitted
> + * but at receive side only the 2 bytes LSB will be set.
> + *
> + * Even wireshark dlm dissector does only evaluate the lower bytes and note
> + * that they may not be used on transceiver side, we assume the higher bytes
> + * are for internal use or reserved so long they are parsed on receiver side.

not parsed*

- Alex