ocfs2: support IPv6 communication in o2cb cluster

o2cb cluster only support IPv4 node configuration nowadays. Along with IPv6 used more widely, ocfs2 should also keep up with the pace. This patch series add configfs attribute for IPv6 configure and build connnection between nodes with IPv6 socket. So the nodes in cluster could send dlm messages through IPv6 network protocol.

Jun Piao (5):
ocfs2/cluster: add configfs attributes for IPv6 address and port ocfs2/cluster: implement show & store method for IPv6 attribute ocfs2/cluster: support IPv6 socket connection between nodes ocfs2/dlm: modify message DLM_QUERY_NODEINFO to adapt IPv6 node ocfs2/cluster: modify socket container macro to adapt IPv6

 cluster/nodemanager.c |  157 +++++++++++++++++++-----
 cluster/nodemanager.h |   11 +
 cluster/tcp.c         |  323 ++++++++++++++++++++++++++++++++++++--------------
 cluster/tcp.h         |    2
 dlm/dlmcommon.h       |   12 +
 dlm/dlmdomain.c       |   93 ++++++++++----
 6 files changed, 450 insertions(+), 148 deletions(-)

Big patchset. I'll await some reviewer input before looking at merging this, I think.

Please update Documentation/filesystems/ocfs2.txt to document all the new userspace interfaces and the overall feature, etc.

Should the new code be hidden behind `#ifdef CONFIG_IPV6'? That would avoid some code bloat.

(That being said, if ocfs2 was concerned about code bloat, it would do something about the fact that mlog() and mlog_errno() more than double the file system's object code size).

Hi Andrew,

OK, there is some work in userspace, such as o2cb_ctl, and I will add another patch to update the document.

Good suggestion, and I will consider using CONFIG_IPV6 to make code thiner.

Thanks,
Jun