linux/net/tipc
Jon Paul Maloy 662921cd0a tipc: merge link->exec_mode and link->state into one FSM
Until now, we have been handling link failover and synchronization
by using an additional link state variable, "exec_mode". This variable
is not independent of the link FSM state, something causing a risk of
inconsistencies, apart from the fact that it clutters the code.

The conditions are now in place to define a new link FSM that covers
all existing use cases, including failover and synchronization, and
eliminate the "exec_mode" field altogether. The FSM must also support
non-atomic resetting of links, which will be introduced later.

The new link FSM is shown below, with 7 states and 8 events.
Only events leading to state change are shown as edges.

+------------------------------------+
|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            |
|           |    |                   |                         |
|           |    |                   |                         |
|           V    V                   |                         |
|    +-------------+          +--------------+        RESET_EVT|
+--->|    RESET    |--------->| ESTABLISHING |<----------------+
     +-------------+ PEER_    +--------------+
      |           A  RESET_EVT       |
      |           |                  |
      |           |                  |
      |FAILOVER_  |FAILOVER_         |FAILOVER_
      |BEGIN_EVT  |END_EVT           |BEGIN_EVT
      |           |                  |
      V           |                  |
     +-------------+                 |
     | FAILINGOVER |<----------------+
     +-------------+

These changes are fully backwards compatible.

Tested-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>
2015-07-30 17:25:14 -07:00
..
addr.c tipc: simplify include dependencies 2015-05-14 12:24:45 -04:00
addr.h tipc: simplify include dependencies 2015-05-14 12:24:45 -04:00
bcast.c tipc: reduce locking scope during packet reception 2015-07-20 20:41:16 -07:00
bcast.h tipc: reduce locking scope during packet reception 2015-07-20 20:41:16 -07:00
bearer.c tipc: move all link_reset() calls to link aggregation level 2015-07-30 17:25:13 -07:00
bearer.h tipc: make media xmit call outside node spinlock context 2015-07-20 20:41:15 -07:00
core.c tipc: rename functions defined in subscr.c 2015-05-04 15:04:00 -04:00
core.h tipc: reduce locking scope during packet reception 2015-07-20 20:41:16 -07:00
discover.c tipc: move link creation from neighbor discoverer to node 2015-07-20 20:41:14 -07:00
discover.h tipc: involve namespace infrastructure 2015-01-12 16:24:32 -05:00
eth_media.c tipc: make media address offset a common define 2015-02-27 18:18:48 -05:00
ib_media.c tipc: rename media/msg related definitions 2015-02-27 18:18:48 -05:00
Kconfig tipc: add ip/udp media type 2015-03-05 22:08:42 -05:00
link.c tipc: merge link->exec_mode and link->state into one FSM 2015-07-30 17:25:14 -07:00
link.h tipc: merge link->exec_mode and link->state into one FSM 2015-07-30 17:25:14 -07:00
Makefile tipc: add ip/udp media type 2015-03-05 22:08:42 -05:00
msg.c tipc: clean up socket layer message reception 2015-07-26 16:31:50 -07:00
msg.h tipc: move link synch and failover to link aggregation level 2015-07-30 17:25:14 -07:00
name_distr.c tipc: make media xmit call outside node spinlock context 2015-07-20 20:41:15 -07:00
name_distr.h tipc: resolve race problem at unicast message reception 2015-02-05 16:00:02 -08:00
name_table.c tipc: rename functions defined in subscr.c 2015-05-04 15:04:00 -04:00
name_table.h tipc: convert legacy nl name table dump to nl compat 2015-02-09 13:20:48 -08:00
net.c tipc: simplify include dependencies 2015-05-14 12:24:45 -04:00
net.h tipc: make tipc node table aware of net namespace 2015-01-12 16:24:32 -05:00
netlink_compat.c tipc: send explicit not supported error in nl compat 2015-05-09 16:40:03 -04:00
netlink.c tipc: move and rename the legacy nl api to "nl compat" 2015-02-09 13:20:47 -08:00
netlink.h tipc: move and rename the legacy nl api to "nl compat" 2015-02-09 13:20:47 -08:00
node.c tipc: merge link->exec_mode and link->state into one FSM 2015-07-30 17:25:14 -07:00
node.h tipc: move link synch and failover to link aggregation level 2015-07-30 17:25:14 -07:00
server.c tipc: use sock_create_kern interface to create kernel socket 2015-05-14 13:39:33 -04:00
server.h tipc: make subscriber server support net namespace 2015-01-12 16:24:33 -05:00
socket.c tipc: clean up socket layer message reception 2015-07-26 16:31:50 -07:00
socket.h tipc: clean up socket layer message reception 2015-07-26 16:31:50 -07:00
subscr.c tipc: adjust locking policy of subscription 2015-05-04 15:04:01 -04:00
subscr.h tipc: rename functions defined in subscr.c 2015-05-04 15:04:00 -04:00
sysctl.c tipc: add name distributor resiliency queue 2014-09-01 17:51:48 -07:00
udp_media.c udp_tunnel: Pass UDP socket down through udp_tunnel{, 6}_xmit_skb(). 2015-04-07 15:29:08 -04:00