linux-stable.git/net/tipc/link.c, branch v3.2

tipc: Remove unused link event tracking code

2011-09-18T02:55:15+00:00

Elimintes prototype link event tracking functionality that has never
been fleshed out and doesn't do anything useful at the current time.

Signed-off-by: Ying Xue 
Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Enhance sending of bulk name table messages

2011-09-18T02:55:10+00:00

Modifies the initial transfer of name table entries to a new neighboring
node so that the messages are enqueued as a unit, rather than individually.

The revised algorithm now locates the link carrying the message only once,
and eliminates unnecessary checks for link congestion, message fragmentation,
and message bundling that are not required when sending these messages.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Ensure both nodes recognize loss of contact between them

2011-09-18T02:55:03+00:00

Enhances TIPC to ensure that a node that loses contact with a
neighboring node does not allow contact to be re-established until
it sees that its peer has also recognized the loss of contact.

Previously, nodes that were connected by two or more links could
encounter a situation in which node A would lose contact with node B
on all of its links, purge its name table of names published by B,
and then fail to repopulate those names once contact with B was restored.
This would happen because B was able to re-establish one or more links
so quickly that it never reached a point where it had no links to A --
meaning that B never saw a loss of contact with A, and consequently
didn't re-publish its names to A.

This problem is now prevented by enhancing the cleanup done by TIPC
following a loss of contact with a neighboring node to ensure that
node A ignores all messages sent by B until it receives a LINK_PROTOCOL
message that indicates B has lost contact with A, thereby preventing
the (re)establishment of links between the nodes. The loss of contact
is recognized when a RESET or ACTIVATE message is received that has
a "redundant link exists" field of 0, indicating that B's sending link
endpoint is in a reset state and that B has no other working links.

Additionally, TIPC now suppresses the sending of (most) link protocol
messages to a neighboring node while it is cleaning up after an earlier
loss of contact with that node. This stops the peer node from prematurely
activating its link endpoint, which would prevent TIPC from later
activating its own end. TIPC still allows outgoing RESET messages to
occur during cleanup, to avoid problems if its own node recognizes
the loss of contact first and tries to notify the peer of the situation.

Finally, TIPC now recognizes an impending loss of contact with a peer node
as soon as it receives a RESET message on a working link that is the
peer's only link to the node, and ensures that the link protocol
suppression mentioned above goes into effect right away -- that is,
even before its own link endpoints have failed. This is necessary to
ensure correct operation when there are redundant links between the nodes,
since otherwise TIPC would send an ACTIVATE message upon receiving a RESET
on its first link and only begin suppressing when a RESET on its second
link was received, instead of initiating suppression with the first RESET
message as it needs to.

Note: The reworked cleanup code also eliminates a check that prevented
a link endpoint's discovery object from responding to incoming messages
while stale name table entries are being purged. This check is now
unnecessary and would have slowed down re-establishment of communication
between the nodes in some situations.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Eliminate redundant check when sending messages

2011-09-01T15:16:37+00:00

Eliminates code in tipc_send_buf_fast() that handles messages
sent to a destination on the current node, since the only caller
of the routine only passes in messages destined for other nodes.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Enhance filtering of out-dated link reset messages

2011-09-01T15:16:35+00:00

Ensure TIPC ignores an out-dated link reset message whose session
number predates the current session number. (Previously, TIPC only
ignored an out-date reset message whose session number was equal
to the current link session number.)

Out-dated link reset messages should not occur under normal circumstances;
however, they can be generated if a link endpoint is unable to send a
link reset message right away and queues it for later delivery, but the
queued message is not sent until after the link is established.

Thanks to Laser [gotolaser@gmail.com] for diagnosing the problem and
contributing a prototype patch.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Initialize peer session field of newly created link endpoint

2011-09-01T15:16:35+00:00

Initializes the peer session number field of a newly created link
endpoint to an invalid value. This eliminates the remote possibility
that it will accidentally match the session number used by the peer
the first time the link is activated, and cause the link to ignore
a valid RESET message.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Display meaningful peer interface name during link creation

2011-09-01T15:16:35+00:00

Sets the peer interface portion of the name of a newly created link
endpoint to "unknown". This ensures that state and statistics information
can be properly displayed during the time between the link endpoint's
creation and the time handshaking with its peer is completed.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Eliminate obsolete filter for unexpected unicast messages

2011-09-01T15:16:35+00:00

Removes a test that ensures unicast link endpoints discard an incoming
message if it will not be consumed by the node itself and cannot be
forwarded to another node, since the preceding test already ensures that
the message is destined for this node and single-cluster TIPC no longer
performs message forwarding.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Cleanup of message header size terminology

2011-06-24T20:18:17+00:00

Performs cosmetic cleanup of the symbolic names used to specify TIPC
payload message header sizes. The revised names now more accurately
reflect the payload messages in which they can appear. In addition,
several places where these payload message symbol names were being used
to create non-payload messages have been updated to use the proper
internal message symbolic name.

No functional changes are introduced by this rework.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Correct typo in link statistics output

2011-06-24T20:18:16+00:00

Fixes a minor error in the title of one of the message size profiling
values printed as part of TIPC's link statistics.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker