Jon Paul Maloy c637c10355 tipc: resolve race problem at unicast message reception ... TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2015-02-05 16:00:02 -08:00
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addr.c	tipc: make tipc node address support net namespace	2015-01-12 16:24:33 -05:00
addr.h	tipc: make tipc node address support net namespace	2015-01-12 16:24:33 -05:00
bcast.c	tipc: resolve race problem at unicast message reception	2015-02-05 16:00:02 -08:00
bcast.h	tipc: reduce usage of context info in socket and link	2015-02-05 16:00:01 -08:00
bearer.c	tipc: make tipc node address support net namespace	2015-01-12 16:24:33 -05:00
bearer.h	tipc: make tipc broadcast link support net namespace	2015-01-12 16:24:33 -05:00
config.c	tipc: make tipc node address support net namespace	2015-01-12 16:24:33 -05:00
config.h	tipc: involve namespace infrastructure	2015-01-12 16:24:32 -05:00
core.c	tipc: make tipc random value aware of net namespace	2015-01-12 16:24:33 -05:00
core.h	tipc: make tipc random value aware of net namespace	2015-01-12 16:24:33 -05:00
discover.c	tipc: reduce usage of context info in socket and link	2015-02-05 16:00:01 -08:00
discover.h	tipc: involve namespace infrastructure	2015-01-12 16:24:32 -05:00
eth_media.c	tipc: improve and extend media address conversion functions	2014-05-14 15:19:48 -04:00
ib_media.c	tipc: improve and extend media address conversion functions	2014-05-14 15:19:48 -04:00
Kconfig	tipc: convert tipc reference table to use generic rhashtable	2015-01-08 19:47:14 -08:00
link.c	tipc: resolve race problem at unicast message reception	2015-02-05 16:00:02 -08:00
link.h	tipc: resolve race problem at unicast message reception	2015-02-05 16:00:02 -08:00
log.c	tipc: remove print_buf and deprecated log buffer code	2012-07-13 19:34:43 -04:00
Makefile	tipc: remove node subscription infrastructure	2014-11-26 12:30:16 -05:00
msg.c	tipc: resolve race problem at unicast message reception	2015-02-05 16:00:02 -08:00
msg.h	tipc: resolve race problem at unicast message reception	2015-02-05 16:00:02 -08:00
name_distr.c	tipc: resolve race problem at unicast message reception	2015-02-05 16:00:02 -08:00
name_distr.h	tipc: resolve race problem at unicast message reception	2015-02-05 16:00:02 -08:00
name_table.c	tipc: make tipc node address support net namespace	2015-01-12 16:24:33 -05:00
name_table.h	tipc: name tipc name table support net namespace	2015-01-12 16:24:33 -05:00
net.c	tipc: make tipc node address support net namespace	2015-01-12 16:24:33 -05:00
net.h	tipc: make tipc node table aware of net namespace	2015-01-12 16:24:32 -05:00
netlink.c	tipc: make netlink support net namespace	2015-01-12 16:24:34 -05:00
netlink.h	tipc: cleanup core.c and core.h files	2015-01-12 16:24:31 -05:00
node.c	tipc: resolve race problem at unicast message reception	2015-02-05 16:00:02 -08:00
node.h	tipc: resolve race problem at unicast message reception	2015-02-05 16:00:02 -08:00
server.c	tipc: make subscriber server support net namespace	2015-01-12 16:24:33 -05:00
server.h	tipc: make subscriber server support net namespace	2015-01-12 16:24:33 -05:00
socket.c	tipc: resolve race problem at unicast message reception	2015-02-05 16:00:02 -08:00
socket.h	tipc: resolve race problem at unicast message reception	2015-02-05 16:00:02 -08:00
subscr.c	tipc: make subscriber server support net namespace	2015-01-12 16:24:33 -05:00
subscr.h	tipc: make subscriber server support net namespace	2015-01-12 16:24:33 -05:00
sysctl.c	tipc: add name distributor resiliency queue	2014-09-01 17:51:48 -07:00