fs: dlm: add more midcomms hooks

This patch prepares hooks to redirect to the midcomms layer which will
be used by the midcomms re-transmit handling.

There exists the new concept of stateless buffers allocation and
commits. This can be used to bypass the midcomms re-transmit handling. It
is used by RCOM_STATUS and RCOM_NAMES messages, because they have their
own ping-like re-transmit handling. As well these two messages will be
used to determine the DLM version per node, because these two messages
are per observation the first messages which are exchanged.

Cluster manager events for node membership are added to add support for
half-closed connections in cases that the peer connection get to
an end of file but DLM still holds membership of the node. In
this time DLM can still trigger new message which we should allow. After
the cluster manager node removal event occurs it safe to close the
connection.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

1 files changed, 30 insertions, 1 deletions

diff --git a/fs/dlm/midcomms.c b/fs/dlm/midcomms.c
index 1c6654a21ec43..1a280dda99d3a 100644
--- a/fs/dlm/midcomms.c
+++ b/fs/dlm/midcomms.c
@@ -28,6 +28,36 @@
 #include "lock.h"
 #include "midcomms.h"
 
+struct dlm_mhandle *dlm_midcomms_get_mhandle(int nodeid, int len,
+					     gfp_t allocation, char **ppc)
+{
+	return dlm_lowcomms_get_buffer(nodeid, len, allocation, ppc);
+}
+
+void dlm_midcomms_commit_mhandle(struct dlm_mhandle *mh)
+{
+	dlm_lowcomms_commit_buffer(mh);
+}
+
+void dlm_midcomms_add_member(int nodeid) { }
+
+void dlm_midcomms_remove_member(int nodeid) { }
+
+int dlm_midcomms_start(void)
+{
+	return dlm_lowcomms_start();
+}
+
+void dlm_midcomms_shutdown(void)
+{
+	dlm_lowcomms_shutdown();
+}
+
+int dlm_midcomms_close(int nodeid)
+{
+	return dlm_lowcomms_close(nodeid);
+}
+
 /*
  * Called from the low-level comms layer to process a buffer of
  * commands.
@@ -101,4 +131,3 @@ skip:
 
 	return ret;
 }
-