Currently SCTP shutdown() call gets stuck because there is no incoming
EOF indicator on its socket. On the peer side the EOF indicator as
recvmsg() returns 0 will be triggered as mechanism to flush the socket
queue on the receive side. In SCTP recvmsg() function sctp_recvmsg() we
can see that only if sk_shutdown has the bit RCV_SHUTDOWN set SCTP will
recvmsg() will return EOF. The RCV_SHUTDOWN bit will only be set when
shutdown with SHUT_RD is called. We use now SHUT_RDWR to also get a EOF
indicator from recvmsg() call on the shutdown() initiator.

SCTP does not support half closed sockets and the semantic of SHUT_WR is
different here, it seems that calling SHUT_WR on sctp sockets keeps the
socket open to have the possibility to do some specific SCTP operations on
it that we don't do here.

There exists still a difference in the limitations of TCP vs SCTP in
case if we are required to have a half closed socket functionality. This
was tried to archieve with DLM protocol changes in the past and
hopefully we really don't require half closed socket functionality.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Tested-by: Heming zhao <heming.zhao@suse.com>
Reviewed-by: Heming zhao <heming.zhao@suse.com>
Signed-off-by: David Teigland <teigland@redhat.com>

The sk->sk_shutdown value is flag value so use masking to check if
RCV_SHUTDOWN is set as other possible values like SEND_SHUTDOWN can set
as well.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Tested-by: Heming zhao <heming.zhao@suse.com>
Reviewed-by: Heming zhao <heming.zhao@suse.com>
Signed-off-by: David Teigland <teigland@redhat.com>

This patch bypasses multi-link errors in TCP mode, allowing dlm
to operate on the first tcp link.

Signed-off-by: Heming Zhao <heming.zhao@suse.com>
Signed-off-by: David Teigland <teigland@redhat.com>

The return type of srcu_read_lock() is int and not bool. Whereas we
using the ret variable only to evaluate a bool type of
dlm_lowcomms_con_has_addr() to check if an address is already being set.

Fixes: 6f0b0b5d7ae7 ("fs: dlm: remove dlm_node_addrs lookup list")
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

This patch handles the DLM listen port setting internally as byte order
as it is a value that is used as network byte on the wire. The user
space still sets this value as host byte order for configfs as we don't
break UAPI here.

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

To avoid -EINPROGRESS cases on connect that just ends in a retry we just
call connect in a synchronized way to wait until its done. Since commit
dbb751ffab0b ("fs: dlm: parallelize lowcomms socket handling") we have a
non ordered workqueue running for serving the DLM sockets that allows us
to call send/recv for each DLM socket connection in parallel. Before
each worker needed to wait until the previous worker was done and
probably the reason why connect() was called in an asynchronous way to
not block other workers. This is however not necessary anymore as other
socket handling workers don't need to wait.

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

The last use of 'dlm_processed_nodes' was removed in
commit 1696c75f1864 ("fs: dlm: add send ack threshold and append acks to
msgs").

Remove it.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: David Teigland <teigland@redhat.com>

This patch removes an parameter which is currently not used by
dlm_midcomms_addr().

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

Move dlm message processing from an ordered workqueue context to an
ordered softirq context.  Handling dlm messages in softirq will allow
requests to be cleared more quickly and efficiently, and should avoid
longer queues of incomplete requests.  Later patches are expected to
run completion/blocking callbacks directly from this message processing
context, further reducing context switches required to complete a request.
In the longer term, concurrent message processing could be implemented.

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

Use spin_lock_bh for all spinlocks involved in message processing,
in preparation for softirq message processing.  DLM lock requests
from user space involve dlm processing in user context, in addition
to the standard kernel context, necessitating bh variants.

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