From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Aring Date: Fri, 17 Jun 2022 16:00:32 -0400 Subject: [Cluster-devel] [PATCH dlm/next 1/5] fs: dlm: add comment about lkb IFL flags In-Reply-To: <20220617200036.251778-1-aahringo@redhat.com> References: <20220617200036.251778-1-aahringo@redhat.com> Message-ID: <20220617200036.251778-2-aahringo@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit 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 --- 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. + */ #define DLM_IFL_USER 0x00000001 #define DLM_IFL_ORPHAN 0x00000002 -- 2.31.1