TIPC name table updates are distributed asynchronously in a cluster,
entailing a risk of certain race conditions. E.g., if two nodes
simultaneously issue conflicting (overlapping) publications, this may
not be detected until both publications have reached a third node, in
which case one of the publications will be silently dropped on that
node. Hence, we end up with an inconsistent name table.
In most cases this conflict is just a temporary race, e.g., one
node is issuing a publication under the assumption that a previous,
conflicting, publication has already been withdrawn by the other node.
However, because of the (rtt related) distributed update delay, this
may not yet hold true on all nodes. The symptom of this failure is a
syslog message: "tipc: Cannot publish {%u,%u,%u}, overlap error".
In this commit we add a resiliency queue at the receiving end of
the name table distributor. When insertion of an arriving publication
fails, we retain it in this queue for a short amount of time, assuming
that another update will arrive very soon and clear the conflict. If so
happens, we insert the publication, otherwise we drop it.
The (configurable) retention value defaults to 2000 ms. Knowing from
experience that the situation described above is extremely rare, there
is no risk that the queue will accumulate any large number of items.
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Postpone the actions of delivering name tables until after node
lock is released, avoiding to do it under asynchronous context.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit a89778d8ba ("tipc: add support
for link state subscriptions") introduced below possible deadlock
scenario:
CPU0 CPU1
T0: tipc_publish() link_timeout()
T1: tipc_nametbl_publish() [grab node lock]*
T2: [grab nametbl write lock]* link_state_event()
T3: named_cluster_distribute() link_activate()
T4: [grab node lock]* tipc_node_link_up()
T5: tipc_nametbl_publish()
T6: [grab nametble write lock]*
The opposite order of holding nametbl write lock and node lock on
above two different paths may result in a deadlock. If we move the
the delivery of named messages via link out of name nametbl lock,
the reverse order of holding locks will be eliminated, as a result,
the deadlock will be killed as well.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rename the following functions, which are shorter and more in line
with common naming practice in the network subsystem.
tipc_bclink_send_msg->tipc_bclink_xmit
tipc_bclink_recv_pkt->tipc_bclink_rcv
tipc_disc_recv_msg->tipc_disc_rcv
tipc_link_send_proto_msg->tipc_link_proto_xmit
link_recv_proto_msg->tipc_link_proto_rcv
link_send_sections_long->tipc_link_iovec_long_xmit
tipc_link_send_sections_fast->tipc_link_iovec_xmit_fast
tipc_link_send_sync->tipc_link_sync_xmit
tipc_link_recv_sync->tipc_link_sync_rcv
tipc_link_send_buf->__tipc_link_xmit
tipc_link_send->tipc_link_xmit
tipc_link_send_names->tipc_link_names_xmit
tipc_named_recv->tipc_named_rcv
tipc_link_recv_bundle->tipc_link_bundle_rcv
tipc_link_dup_send_queue->tipc_link_dup_queue_xmit
link_send_long_buf->tipc_link_frag_xmit
tipc_multicast->tipc_port_mcast_xmit
tipc_port_recv_mcast->tipc_port_mcast_rcv
tipc_port_reject_sections->tipc_port_iovec_reject
tipc_port_recv_proto_msg->tipc_port_proto_rcv
tipc_connect->tipc_port_connect
__tipc_connect->__tipc_port_connect
__tipc_disconnect->__tipc_port_disconnect
tipc_disconnect->tipc_port_disconnect
tipc_shutdown->tipc_port_shutdown
tipc_port_recv_msg->tipc_port_rcv
tipc_port_recv_sections->tipc_port_iovec_rcv
release->tipc_release
accept->tipc_accept
bind->tipc_bind
get_name->tipc_getname
poll->tipc_poll
send_msg->tipc_sendmsg
send_packet->tipc_send_packet
send_stream->tipc_send_stream
recv_msg->tipc_recvmsg
recv_stream->tipc_recv_stream
connect->tipc_connect
listen->tipc_listen
shutdown->tipc_shutdown
setsockopt->tipc_setsockopt
getsockopt->tipc_getsockopt
Above changes have no impact on current users of the functions.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Updated copyright notice to include the year the file was
actually created. Information about file creation dates
was extracted from the files in the old CVS repository
at tipc.sourceforge.net.
Signed-off-by: Per Liden <per.liden@nospam.ericsson.com>
The license header in each file now more clearly state that this
code is licensed under a dual BSD/GPL. Before this was only
evident if you looked at the MODULE_LICENSE line in core.c.
Signed-off-by: Per Liden <per.liden@nospam.ericsson.com>
TIPC (Transparent Inter Process Communication) is a protocol designed for
intra cluster communication. For more information see
http://tipc.sourceforge.net
Signed-off-by: Per Liden <per.liden@nospam.ericsson.com>
