linux-stable.git/net/tipc/link.c, branch v3.18

tipc: fix bug in bundled buffer reception

2014-10-18T03:50:53+00:00

In commit ec8a2e5621db2da24badb3969eda7fd359e1869f ("tipc: same receive
code path for connection protocol and data messages") we omitted the
the possiblilty that an arriving message extracted from a bundle buffer
may be a multicast message. Such messages need to be to be delivered to
the socket via a separate function, tipc_sk_mcast_rcv(). As a result,
small multicast messages arriving as members of a bundle buffer will be
silently dropped.

This commit corrects the error by considering this case in the function
tipc_link_bundle_rcv().

Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: remove include file port.h

2014-08-23T18:18:35+00:00

We move the inline functions in the file port.h to socket.c, and modify
their names accordingly.

We move struct tipc_port and some macros to socket.h.

Finally, we remove the file port.h.

Signed-off-by: Jon Maloy 
Reviewed-by: Erik Hugne 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: use pseudo message to wake up sockets after link congestion

2014-08-23T18:18:33+00:00

The current link implementation keeps a linked list of blocked ports/
sockets that is populated when there is link congestion. The purpose
of this is to let the link know which users to wake up when the
congestion abates.

This adds unnecessary complexity to the data structure and the code,
since it forces us to involve the link each time we want to delete
a socket. It also forces us to grab the spinlock port_lock within
the scope of node_lock. We want to get rid of this direct dependence,
as well as the deadlock hazard resulting from the usage of port_lock.

In this commit, we instead let the link keep list of a "wakeup" pseudo
messages for use in such situations. Those messages are sent to the
pending sockets via the ordinary message reception path, and wake up
the socket's owner when they are received.

This enables us to get rid of the 'waiting_ports' linked lists in struct
tipc_port that manifest this direct reference. As a consequence, we can
eliminate another BH entry into the socket, and hence the need to grab
port_lock. This is a further step in our effort to remove port_lock
altogether.

Signed-off-by: Jon Maloy 
Reviewed-by: Erik Hugne 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: rename temporarily named functions

2014-07-17T04:38:19+00:00

After the previous commit, we can now give the functions with temporary
names, such as tipc_link_xmit2(), tipc_msg_build2() etc., their proper
names.

There are no functional changes in this commit.

Signed-off-by: Jon Maloy 
Reviewed-by: Erik Hugne 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: remove unreferenced functions

2014-07-17T04:38:19+00:00

We can now remove a number of functions which have become obsolete
and unreferenced through this commit series. There are no functional
changes in this commit.

Signed-off-by: Jon Maloy 
Reviewed-by: Erik Hugne 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: let internal link users call the new link send function

2014-07-17T04:38:18+00:00

We convert the link internal users (changeover protocol, broadcast
synchronization) to use the new packet send function.

Signed-off-by: Jon Maloy 
Reviewed-by: Erik Hugne 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: make name table distributor use new send function

2014-07-17T04:38:18+00:00

In a previous commit series ("tipc: new unicast transmission code")
we introduced a new message sending function, tipc_link_xmit2(),
and moved the unicast data users over to use that function. We now
let the internal name table distributor do the same.

The interaction between the name distributor and the node/link
layer also becomes significantly simpler, so we can eliminate
the function tipc_link_names_xmit().

Signed-off-by: Jon Maloy 
Reviewed-by: Erik Hugne 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: fix link acknowledge logic in receive path

2014-07-08T02:55:07+00:00

Link state acks triggered from the receive path is done before
the last received packet have been processed by the link layer.
The effect of this is that the last received packet will not be
included in the ack. This causes problems if the link window is
set to TIPC_MIN_LINK_WIN, where the ack interval will be equal to
the link tolerance, and the link enters a stop-and-go behavior.
We move the ack logic to after link state processing, just before
the packet is delivered to higher layers.

Signed-off-by: Erik Hugne 
Signed-off-by: Carl Sigurjonsson 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: refactor message delivery out of tipc_rcv

2014-07-08T02:55:07+00:00

This is a cosmetic change, separating message delivery from the
link state processing.

Signed-off-by: Erik Hugne 
Reviewed-by: Ying Xue 
Reviewed-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: simplify connection congestion handling

2014-06-27T19:50:56+00:00

As a consequence of the recently introduced serialized access
to the socket in commit 8d94168a761819d10252bab1f8de6d7b202c3baa
("tipc: same receive code path for connection protocol and data
messages") we can make a number of simplifications in the
detection and handling of connection congestion situations.

- We don't need to keep two counters, one for sent messages and one
  for acked messages. There is no longer any risk for races between
  acknowledge messages arriving in BH and data message sending
  running in user context. So we merge this into one counter,
  'sent_unacked', which is incremented at sending and subtracted
  from at acknowledge reception.

- We don't need to set the 'congested' field in tipc_port to
  true before we sent the message, and clear it when sending
  is successful. (As a matter of fact, it was never necessary;
  the field was set in link_schedule_port() before any wakeup
  could arrive anyway.)

- We keep the conditions for link congestion and connection connection
  congestion separated. There would otherwise be a risk that an arriving
  acknowledge message may wake up a user sleeping because of link
  congestion.

- We can simplify reception of acknowledge messages.

We also make some cosmetic/structural changes:

- We rename the 'congested' field to the more correct 'link_cong´.

- We rename 'conn_unacked' to 'rcv_unacked'

- We move the above mentioned fields from struct tipc_port to
  struct tipc_sock.

Signed-off-by: Jon Maloy 
Reviewed-by: Erik Hugne 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller