Currently, when ocfs2 nodes connect via TCP, they advertise their
compatibility level.  If the versions do not match, two nodes cannot speak
to each other and they disconnect. As a result, this provides no forward or
backwards compatibility.

This patch implements a simple protocol negotiation at the dlm level by
introducing a major/minor version number scheme for entities that
communicate.  Specifically, o2dlm has a major/minor version for interaction
with o2dlm on other nodes, and ocfs2 itself has a major/minor version for
interacting with the filesystem on other nodes.

This will allow rolling upgrades of ocfs2 clusters when changes to the
locking or network protocols can be done in a backwards compatible manner.
In those cases, only the minor number is changed and the negotatied protocol
minor is returned from dlm join. In the far less likely event that a
required protocol change makes backwards compatibility impossible, we simply
bump the major number.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

There is a small window where a joining node may not see the node(s) that
just died but are still part of the domain. To fix this, we must disallow
join requests if the joining node has a different node map.

A new field node_map is added to dlm_query_join_request to send the current
nodes nodemap along with join request. On the receiving end the nodes that
are part of the cluster verifies if this new node sees all the nodes that
are still part of the cluster. They disallow the join if the maps mismatch.
Signed-off-by: NSrinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Eventhough the set refmap bit message is sent before the clear refmap
message, currently there is no guarentee that the set message will be
handled before the clear. This patch prevents the clear refmap to be
processed while the node is sending assert master messages to other
nodes. (The set refmap message is sent as a response to the assert
master request).
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

This patch prevents the dlm from sending the clear refmap message
before the set refmap. We use the newly created post function handler
routine to accomplish the task.
Signed-off-by: NKurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Currently o2net allows one handler function per message type. This
patch adds the ability to call another function to be called after
the handler has returned the message to the other node.

Handlers are now given the option of returning a context (in the form of a
void **) which will be passed back into the post message handler function.
Signed-off-by: NKurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

dlmthread was removing lockres' from the dirty list
and resetting the dirty flag before shuffling the list.
This patch retains the dirty state flag until the lists
are shuffled.
Signed-off-by: NKurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: NSunil Mushran <Sunil.Mushran@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

This patch makes some needlessly global functions static.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

This was previously broken and migration of some locks had to be temporarily
disabled. We use a new (and backward-incompatible) set of network messages
to account for all references to a lock resources held across the cluster.
once these are all freed, the master node may then free the lock resource
memory once its local references are dropped.
Signed-off-by: NKurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Fix up for make allyesconfig.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>

The OCFS2 DLM uses strlen() to determine lock name length, which excludes
the possibility of putting binary values in the name string. Fix this by
requiring that string length be passed in as a parameter.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

dlm_lockres_master_requery() became global without any external usage.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

The work that is done can block for long periods of time and so is not
appropriate for keventd.
Signed-off-by: NKurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Signed-off-by: NKurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Signed-off-by: NKurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Makes it easier for the recovery process to deal with node death.
Signed-off-by: NKurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Take a reference on lockres structures while they are on the recovery list.
Signed-off-by: NKurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

The check for an empty lvb should check the entire buffer not just the first
byte.
Signed-off-by: NKurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

The OCFS2 DLM allocates a number of pages for a hash to lookup locks.
There was a bug where a PAGE_SIZE bigger than the hash size (eg, 64K
pages) would result in zero pages allocated.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

This allows us to have a hash table greater than a single page which greatly
improves dlm performance on some tests.
Signed-off-by: NDaniel Phillips <phillips@google.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

It's called on every lookup so this might help performance a bit.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Fixes a performance bug - pointed out by Andrew.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Gains us a bit of performance on loads which heavily hit the lockres hash.
Patch suggested by Daniel Phillips <phillips@google.com>.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Signed-off-by: NKurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

when starting lock mastery (excepting the recovery lock) wait on any nodes
needing recovery. fix one instance where lock resources were left attached
to the recovery list after recovery completed.  ensure that the node_down
code is run uniformly regardless of which node found the dead node first.
Signed-off-by: NKurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

Switch from list_head to hlist_head. Make the size of the hash dependent
upon the allocated area, rather than a constant.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

* add dlm_wait_for_node_death function to be used after receiving a network
  error.  this will wait for the given timeout to allow the heartbeat
  callbacks to update the domain map.  without this, some paths may spin
  and consume enough cpu that the heartbeat gets starved and never updates.
Signed-off-by: NKurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

* fix a hang which can occur during shutdown migration
* do not allow nodes to join during recovery
* when restarting lock mastery, do not ignore nodes which come up
* more than one node could become recovery master, fix this
* sleep to allow some time for heartbeat state to catch up to network
* extra debug info for bad recovery state problems
* make DLM_RECO_NODE_DATA_DONE a valid state for non-master recovery nodes
* prune all locks from dead nodes on $RECOVERY lock resources
* do NOT automatically add new nodes to mle nodemaps until they have properly
  joined the domain
* make sure dlm_pick_recovery_master only exits when all nodes have synced
* properly handle dlmunlock errors in dlm_pick_recovery_master
* do not propagate network errors in dlm_send_begin_reco_message
* dead nodes were not being put in the recovery map sometimes, fix this
* dlmunlock was failing to clear the unlock actions on DLM_DENIED
Signed-off-by: NKurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>

A distributed lock manager built with the cluster file system use case
in mind. The OCFS2 dlm exposes a VMS style API, though things have
been simplified internally. The only lock levels implemented currently
are NLMODE, PRMODE and EXMODE.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: NKurt Hackel <kurt.hackel@oracle.com>