kernel_optimize_test/net
Jon Paul Maloy 73f646cec3 tipc: delay ESTABLISH state event when link is established
Link establishing, just like link teardown, is a non-atomic action, in
the sense that discovering that conditions are right to establish a link,
and the actual adding of the link to one of the node's send slots is done
in two different lock contexts. The link FSM is designed to help bridging
the gap between the two contexts in a safe manner.

We have now discovered a weakness in the implementaton of this FSM.
Because we directly let the link go from state LINK_ESTABLISHING to
state LINK_ESTABLISHED already in the first lock context, we are unable
to distinguish between a fully established link, i.e., a link that has
been added to its slot, and a link that has not yet reached the second
lock context. It may hence happen that a manual intervention, e.g., when
disabling an interface, causes the function tipc_node_link_down() to try
removing the link from the node slots, decrementing its active link
counter etc, although the link was never added there in the first place.

We solve this by delaying the actual state change until we reach the
second lock context, inside the function tipc_node_link_up(). This
makes it possible for potentail callers of __tipc_node_link_down() to
know if they should proceed or not, and the problem is solved.

Unforunately, the situation described above also has a second problem.
Since there by necessity is a tipc_node_link_up() call pending once
the node lock has been released, we must defuse that call by setting
the link back from LINK_ESTABLISHING to LINK_RESET state. This forces
us to make a slight modification to the link FSM, which will now look
as follows.

 +------------------------------------+
 |RESET_EVT                           |
 |                                    |
 |                             +--------------+
 |           +-----------------|   SYNCHING   |-----------------+
 |           |FAILURE_EVT      +--------------+   PEER_RESET_EVT|
 |           |                  A            |                  |
 |           |                  |            |                  |
 |           |                  |            |                  |
 |           |                  |SYNCH_      |SYNCH_            |
 |           |                  |BEGIN_EVT   |END_EVT           |
 |           |                  |            |                  |
 |           V                  |            V                  V
 |    +-------------+          +--------------+          +------------+
 |    |  RESETTING  |<---------|  ESTABLISHED |--------->| PEER_RESET |
 |    +-------------+ FAILURE_ +--------------+ PEER_    +------------+
 |           |        EVT        |    A         RESET_EVT       |
 |           |                   |    |                         |
 |           |  +----------------+    |                         |
 |  RESET_EVT|  |RESET_EVT            |                         |
 |           |  |                     |                         |
 |           |  |                     |ESTABLISH_EVT            |
 |           |  |  +-------------+    |                         |
 |           |  |  | RESET_EVT   |    |                         |
 |           |  |  |             |    |                         |
 |           V  V  V             |    |                         |
 |    +-------------+          +--------------+        RESET_EVT|
 +--->|    RESET    |--------->| ESTABLISHING |<----------------+
      +-------------+ PEER_    +--------------+
       |           A  RESET_EVT       |
       |           |                  |
       |           |                  |
       |FAILOVER_  |FAILOVER_         |FAILOVER_
       |BEGIN_EVT  |END_EVT           |BEGIN_EVT
       |           |                  |
       V           |                  |
      +-------------+                 |
      | FAILINGOVER |<----------------+
      +-------------+

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>
2015-10-15 23:55:21 -07:00
..
6lowpan 6lowpan: move shared settings to lowpan_netdev_setup 2015-10-08 14:25:34 +02:00
9p net/9p: Remove ib_get_dma_mr calls 2015-08-30 18:12:36 -04:00
802
8021q net: 8021q: convert to using IFF_NO_QUEUE 2015-08-18 11:55:06 -07:00
appletalk
atm atm: deal with setting entry before mkip was called 2015-09-17 22:13:32 -07:00
ax25 NET: AX.25: Stop heartbeat timer on disconnect. 2015-07-15 15:59:58 -07:00
batman-adv batman-adv: turn batadv_neigh_node_get() into local function 2015-08-27 20:15:34 +02:00
bluetooth Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next 2015-10-11 05:15:30 -07:00
bridge bridge: defer switchdev fdb del call in fdb_del_external_learn 2015-10-15 06:09:50 -07:00
caif net: caif: convert to using IFF_NO_QUEUE 2015-08-18 11:55:07 -07:00
can can: avoid using timeval for uapi 2015-10-13 17:42:34 +02:00
ceph libceph: don't access invalid memory in keepalive2 path 2015-09-17 20:14:15 +03:00
core net: SO_INCOMING_CPU setsockopt() support 2015-10-12 19:28:20 -07:00
dcb net/dcb: make dcbnl.c explicitly non-modular 2015-10-09 07:52:27 -07:00
dccp tcp/dccp: fix behavior of stale SYN_RECV request sockets 2015-10-13 18:26:34 -07:00
decnet dst: Pass net into dst->output 2015-10-08 04:27:03 -07:00
dns_resolver
dsa switchdev: remove pointers from switchdev objects 2015-10-15 06:09:49 -07:00
ethernet net: help compiler generate better code in eth_get_headlen 2015-09-28 22:51:15 -07:00
hsr net: hsr: convert to using IFF_NO_QUEUE 2015-08-18 11:55:07 -07:00
ieee802154 6lowpan: move shared settings to lowpan_netdev_setup 2015-10-08 14:25:34 +02:00
ipv4 tcp: avoid spurious SYN flood detection at listen() time 2015-10-14 19:06:32 -07:00
ipv6 tcp/dccp: fix behavior of stale SYN_RECV request sockets 2015-10-13 18:26:34 -07:00
ipx
irda
iucv s390/iucv: do not use arrays as argument 2015-09-21 16:03:04 -07:00
key net: Fix RCU splat in af_key 2015-08-24 14:48:10 -07:00
l2tp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-10-02 07:21:25 -07:00
l3mdev net: Add netif_is_l3_slave 2015-10-07 04:27:43 -07:00
lapb
llc tcp: fix recv with flags MSG_WAITALL | MSG_PEEK 2015-07-27 01:06:53 -07:00
mac80211 For the current cycle, we have the following right now: 2015-10-07 04:29:18 -07:00
mac802154 ieee802154: change mtu size behaviour 2015-09-30 13:21:32 +02:00
mpls dst: Pass net into dst->output 2015-10-08 04:27:03 -07:00
netfilter ipv4: Pass struct net into ip_defrag and ip_check_defrag 2015-10-12 19:44:16 -07:00
netlabel
netlink net/netlink: lockdep_genl_is_held can be boolean 2015-10-09 07:48:59 -07:00
netrom netfilter: Remove spurios included of netfilter.h 2015-06-18 21:14:32 +02:00
nfc nfc: netlink: Add capability to reply to vendor_cmd with data 2015-08-20 22:00:11 +02:00
openvswitch ipv6: Pass struct net into nf_ct_frag6_gather 2015-10-12 19:44:17 -07:00
packet ipv4: Pass struct net into ip_defrag and ip_check_defrag 2015-10-12 19:44:16 -07:00
phonet
rds RDS-TCP: Reset tcp callbacks if re-using an outgoing socket in rds_tcp_accept_one() 2015-10-13 04:22:41 -07:00
rfkill rfkill: Copy "all" global state to other types 2015-09-04 14:26:56 +02:00
rose Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-06-24 02:58:51 -07:00
rxrpc rxrpc: Replace get_seconds with ktime_get_seconds 2015-09-20 21:53:56 -07:00
sched net: synack packets can be attached to request sockets 2015-10-11 05:05:06 -07:00
sctp net: sctp: avoid incorrect time_t use 2015-10-05 03:16:48 -07:00
sunrpc Changes for 4.3-rc4 2015-10-01 16:38:52 -04:00
switchdev switchdev: assert rtnl mutex when going over lower netdevs 2015-10-15 06:09:53 -07:00
tipc tipc: delay ESTABLISH state event when link is established 2015-10-15 23:55:21 -07:00
unix af_unix: return data from multiple SKBs on recv() with MSG_PEEK flag 2015-09-29 13:47:08 -07:00
vmw_vsock
wimax net:wimax: Fix doucble word "the the" in networking.xml 2015-08-09 22:43:52 -07:00
wireless For the current cycle, we have the following right now: 2015-10-07 04:29:18 -07:00
x25
xfrm dst: Pass net into dst->output 2015-10-08 04:27:03 -07:00
compat.c
Kconfig net: Introduce L3 Master device abstraction 2015-09-29 20:40:32 -07:00
Makefile net: Introduce L3 Master device abstraction 2015-09-29 20:40:32 -07:00
socket.c
sysctl_net.c