From 662921cd0a53db4504838dfbb7d996f9e6e94001 Mon Sep 17 00:00:00 2001 From: Jon Paul Maloy Date: Thu, 30 Jul 2015 18:24:21 -0400 Subject: 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 Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/link.h | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) (limited to 'net/tipc/link.h') diff --git a/net/tipc/link.h b/net/tipc/link.h index b317c4df9079..39b8c4c5121e 100644 --- a/net/tipc/link.h +++ b/net/tipc/link.h @@ -49,13 +49,17 @@ */ #define INVALID_LINK_SEQ 0x10000 - -/* Link endpoint receive states +/* Link FSM events: */ enum { - TIPC_LINK_OPEN, - TIPC_LINK_BLOCKED, - TIPC_LINK_TUNNEL + LINK_ESTABLISH_EVT = 0xec1ab1e, + LINK_PEER_RESET_EVT = 0x9eed0e, + LINK_FAILURE_EVT = 0xfa110e, + LINK_RESET_EVT = 0x10ca1d0e, + LINK_FAILOVER_BEGIN_EVT = 0xfa110bee, + LINK_FAILOVER_END_EVT = 0xfa110ede, + LINK_SYNCH_BEGIN_EVT = 0xc1ccbee, + LINK_SYNCH_END_EVT = 0xc1ccede }; /* Events returned from link at packet reception or at timeout @@ -120,7 +124,6 @@ struct tipc_stats { * @pmsg: convenience pointer to "proto_msg" field * @priority: current link priority * @net_plane: current link network plane ('A' through 'H') - * @exec_mode: transmit/receive mode for link endpoint instance * @backlog_limit: backlog queue congestion thresholds (indexed by importance) * @exp_msg_count: # of tunnelled messages expected during link changeover * @reset_rcv_checkpt: seq # of last acknowledged message at time of link reset @@ -155,7 +158,7 @@ struct tipc_link { u32 tolerance; unsigned long keepalive_intv; u32 abort_limit; - int state; + u32 state; u32 silent_intv_cnt; struct { unchar hdr[INT_H_SIZE]; @@ -166,7 +169,6 @@ struct tipc_link { char net_plane; /* Failover/synch */ - u8 exec_mode; u16 drop_point; struct sk_buff *failover_reasm_skb; @@ -214,8 +216,13 @@ void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl, int mtyp, struct sk_buff_head *xmitq); void tipc_link_build_bcast_sync_msg(struct tipc_link *l, struct sk_buff_head *xmitq); +int tipc_link_fsm_evt(struct tipc_link *l, int evt); void tipc_link_reset_fragments(struct tipc_link *l_ptr); -int tipc_link_is_up(struct tipc_link *l_ptr); +bool tipc_link_is_up(struct tipc_link *l); +bool tipc_link_is_reset(struct tipc_link *l); +bool tipc_link_is_synching(struct tipc_link *l); +bool tipc_link_is_failingover(struct tipc_link *l); +bool tipc_link_is_blocked(struct tipc_link *l); int tipc_link_is_active(struct tipc_link *l_ptr); void tipc_link_purge_queues(struct tipc_link *l_ptr); void tipc_link_purge_backlog(struct tipc_link *l); -- cgit v1.2.1