New features: lock timeouts and time warnings.  If the DLM_LKF_TIMEOUT
flag is set, then the request/conversion will be canceled after waiting
the specified number of centiseconds (specified per lock).  This feature
is only available for locks requested through libdlm (can be enabled for
kernel dlm users if there's a use for it.)

If the new DLM_LSFL_TIMEWARN flag is set when creating the lockspace, then
a warning message will be sent to userspace (using genetlink) after a
request/conversion has been waiting for a given number of centiseconds
(configurable per node).  The time warnings will be used in the future
to do deadlock detection in userspace.
Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Red Hat BZ 211914

With the new cluster infrastructure, dlm recovery for a node removal can
be aborted and restarted for a node addition.  When this happens, the
restarted recovery isn't aware that it's doing recovery for the earlier
removal as well as the addition.  So, it then skips the recovery steps
only required when nodes are removed.  This can result in locks not being
purged for failed/removed nodes.  The fix is to check for removed nodes
for which recovery has not been completed at the start of a new recovery
sequence.
Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

To aid debugging, it's useful to be able to see what nodeid the dlm is
waiting on for a message reply.
Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

When we abort one recovery to do another, break out of the ping_members()
routine more quickly, and wake up the dlm_recoverd thread more quickly
instead of waiting for it to time out.
Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

When a node is removed from a lockspace configuration, close our
connection to it, clearing any remaining messages for it.
Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NPatrick Caulfield <pcaulfie@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteve Whitehouse <swhiteho@redhat.com>

This is the core of the distributed lock manager which is required
to use GFS2 as a cluster filesystem. It is also used by CLVM and
can be used as a standalone lock manager independantly of either
of these two projects.

It implements VAX-style locking modes.
Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteve Whitehouse <swhiteho@redhat.com>