linux_dsm_epyc7002/net/tipc
Tuong Lien 2320bcdae6 tipc: fix changeover issues due to large packet
In conjunction with changing the interfaces' MTU (e.g. especially in
the case of a bonding) where the TIPC links are brought up and down
in a short time, a couple of issues were detected with the current link
changeover mechanism:

1) When one link is up but immediately forced down again, the failover
procedure will be carried out in order to failover all the messages in
the link's transmq queue onto the other working link. The link and node
state is also set to FAILINGOVER as part of the process. The message
will be transmited in form of a FAILOVER_MSG, so its size is plus of 40
bytes (= the message header size). There is no problem if the original
message size is not larger than the link's MTU - 40, and indeed this is
the max size of a normal payload messages. However, in the situation
above, because the link has just been up, the messages in the link's
transmq are almost SYNCH_MSGs which had been generated by the link
synching procedure, then their size might reach the max value already!
When the FAILOVER_MSG is built on the top of such a SYNCH_MSG, its size
will exceed the link's MTU. As a result, the messages are dropped
silently and the failover procedure will never end up, the link will
not be able to exit the FAILINGOVER state, so cannot be re-established.

2) The same scenario above can happen more easily in case the MTU of
the links is set differently or when changing. In that case, as long as
a large message in the failure link's transmq queue was built and
fragmented with its link's MTU > the other link's one, the issue will
happen (there is no need of a link synching in advance).

3) The link synching procedure also faces with the same issue but since
the link synching is only started upon receipt of a SYNCH_MSG, dropping
the message will not result in a state deadlock, but it is not expected
as design.

The 1) & 3) issues are resolved by the last commit that only a dummy
SYNCH_MSG (i.e. without data) is generated at the link synching, so the
size of a FAILOVER_MSG if any then will never exceed the link's MTU.

For the 2) issue, the only solution is trying to fragment the messages
in the failure link's transmq queue according to the working link's MTU
so they can be failovered then. A new function is made to accomplish
this, it will still be a TUNNEL PROTOCOL/FAILOVER MSG but if the
original message size is too large, it will be fragmented & reassembled
at the receiving side.

Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-25 15:55:47 -07:00
..
addr.c tipc: handle collisions of 32-bit node address hash values 2018-03-23 13:12:18 -04:00
addr.h tipc: add 128-bit node identifier 2018-03-23 13:12:18 -04:00
bcast.c tipc: rename function msg_get_wrapped() to msg_inner_hdr() 2019-06-25 13:42:54 -07:00
bcast.h tipc: fix a null pointer deref 2019-03-21 09:56:55 -07:00
bearer.c tipc: use rcu dereference functions properly 2019-07-07 13:18:53 -07:00
bearer.h tipc: enable tracepoints in tipc 2018-12-19 11:49:24 -08:00
core.c tipc: change to use register_pernet_device 2019-06-22 16:51:47 -07:00
core.h tipc: introduce new capability flag for cluster 2019-03-19 13:56:17 -07:00
diag.c tipc: switch to rhashtable iterator 2018-08-29 18:04:54 -07:00
discover.c tipc: fix lockdep warning when reinitilaizing sockets 2018-11-17 22:01:31 -08:00
discover.h tipc: some cleanups in the file discover.c 2018-03-23 13:12:17 -04:00
eth_media.c tipc: make media address offset a common define 2015-02-27 18:18:48 -05:00
group.c tipc: purge deferredq list for each grp member in tipc_group_delete 2019-06-16 20:42:05 -07:00
group.h tipc: extend sock diag for group communication 2018-06-30 21:05:42 +09:00
ib_media.c tipc: rename media/msg related definitions 2015-02-27 18:18:48 -05:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
link.c tipc: fix changeover issues due to large packet 2019-07-25 15:55:47 -07:00
link.h tipc: fix missing Name entries due to half-failover 2019-05-04 00:59:51 -04:00
Makefile tipc: enable tracepoints in tipc 2018-12-19 11:49:24 -08:00
monitor.c netlink: make nla_nest_start() add NLA_F_NESTED flag 2019-04-27 17:03:44 -04:00
monitor.h tipc: dump monitor attributes 2016-07-26 14:26:42 -07:00
msg.c tipc: fix changeover issues due to large packet 2019-07-25 15:55:47 -07:00
msg.h tipc: fix changeover issues due to large packet 2019-07-25 15:55:47 -07:00
name_distr.c tipc: ensure head->lock is initialised 2019-07-12 15:34:26 -07:00
name_distr.h tipc: permit overlapping service ranges in name table 2018-03-31 22:19:52 -04:00
name_table.c netlink: make nla_nest_start() add NLA_F_NESTED flag 2019-04-27 17:03:44 -04:00
name_table.h tipc: eliminate message disordering during binding table update 2018-10-22 19:29:12 -07:00
net.c netlink: make validation more configurable for future strictness 2019-04-27 17:07:21 -04:00
net.h tipc: fix lockdep warning when reinitilaizing sockets 2018-11-17 22:01:31 -08:00
netlink_compat.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-27 21:06:39 -07:00
netlink.c tipc: fix missing indentation in source code 2019-06-24 07:29:45 -07:00
netlink.h tipc: make cluster size threshold for monitoring configurable 2016-07-26 14:26:42 -07:00
node.c tipc: optimize link synching mechanism 2019-07-25 15:55:47 -07:00
node.h tipc: optimize link synching mechanism 2019-07-25 15:55:47 -07:00
socket.c tipc: fix hanging clients using poll with EPOLLOUT flag 2019-05-09 09:26:09 -07:00
socket.h tipc: add trace_events for tipc socket 2018-12-19 11:49:24 -08:00
subscr.c tipc: fix unbalanced reference counter 2018-04-12 21:46:10 -04:00
subscr.h tipc: fix modprobe tipc failed after switch order of device registration 2019-05-20 10:45:43 -07:00
sysctl.c proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
topsrv.c tipc: Fix a typo 2019-07-21 11:41:01 -07:00
topsrv.h tipc: rename tipc_server to tipc_topsrv 2018-02-16 15:26:34 -05:00
trace.c tipc: remove unneeded semicolon in trace.c 2019-01-17 22:04:43 -08:00
trace.h tipc: add trace_events for tipc bearer 2018-12-19 11:49:25 -08:00
udp_media.c tipc: use rcu dereference functions properly 2019-07-07 13:18:53 -07:00
udp_media.h tipc: implement configuration of UDP media MTU 2018-04-20 11:04:05 -04:00