From 3655959143ebf1fd32e28a448d204be2f7f13e99 Mon Sep 17 00:00:00 2001 From: Allan Stephens Date: Mon, 24 Oct 2011 15:26:24 -0400 Subject: tipc: Ignore broadcast acknowledgements that are out-of-range Adds checks to TIPC's broadcast link so that it ignores any acknowledgement message containing a sequence number that does not correspond to an unacknowledged message currently in the broadcast link's transmit queue. This change prevents the broadcast link from becoming stalled if a newly booted node receives stale broadcast link acknowledgement information from another node that has not yet fully synchronized its end of the broadcast link to reflect the current state of the new node's end. Signed-off-by: Allan Stephens Signed-off-by: Paul Gortmaker --- net/tipc/bcast.c | 35 ++++++++++++++++++++++++++++------- net/tipc/link.c | 6 ++---- net/tipc/link.h | 6 ++++++ net/tipc/node.c | 3 +-- 4 files changed, 37 insertions(+), 13 deletions(-) diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c index 4609819ea807..15eb74458748 100644 --- a/net/tipc/bcast.c +++ b/net/tipc/bcast.c @@ -237,14 +237,36 @@ void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked) struct sk_buff *next; unsigned int released = 0; - if (less_eq(acked, n_ptr->bclink.acked)) - return; - spin_lock_bh(&bc_lock); - /* Skip over packets that node has previously acknowledged */ - + /* Bail out if tx queue is empty (no clean up is required) */ crs = bcl->first_out; + if (!crs) + goto exit; + + /* Determine which messages need to be acknowledged */ + if (acked == INVALID_LINK_SEQ) { + /* + * Contact with specified node has been lost, so need to + * acknowledge sent messages only (if other nodes still exist) + * or both sent and unsent messages (otherwise) + */ + if (bclink->bcast_nodes.count) + acked = bcl->fsm_msg_cnt; + else + acked = bcl->next_out_no; + } else { + /* + * Bail out if specified sequence number does not correspond + * to a message that has been sent and not yet acknowledged + */ + if (less(acked, buf_seqno(crs)) || + less(bcl->fsm_msg_cnt, acked) || + less_eq(acked, n_ptr->bclink.acked)) + goto exit; + } + + /* Skip over packets that node has previously acknowledged */ while (crs && less_eq(buf_seqno(crs), n_ptr->bclink.acked)) crs = crs->next; @@ -255,8 +277,6 @@ void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked) if (crs != bcl->next_out) bcbuf_decr_acks(crs); - else if (bclink->bcast_nodes.count) - break; else { bcbuf_set_acks(crs, 0); bcl->next_out = next; @@ -281,6 +301,7 @@ void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked) } if (unlikely(released && !list_empty(&bcl->waiting_ports))) tipc_link_wakeup_ports(bcl, 0); +exit: spin_unlock_bh(&bc_lock); } diff --git a/net/tipc/link.c b/net/tipc/link.c index 332915e43043..4eff342326e2 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -1733,10 +1733,8 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr) /* Release acked messages */ - if (less(n_ptr->bclink.acked, msg_bcast_ack(msg))) { - if (tipc_node_is_up(n_ptr) && n_ptr->bclink.supported) - tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg)); - } + if (tipc_node_is_up(n_ptr) && n_ptr->bclink.supported) + tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg)); crs = l_ptr->first_out; while ((crs != l_ptr->next_out) && diff --git a/net/tipc/link.h b/net/tipc/link.h index e56cb532913e..78792399d667 100644 --- a/net/tipc/link.h +++ b/net/tipc/link.h @@ -44,6 +44,12 @@ #define PUSH_FAILED 1 #define PUSH_FINISHED 2 +/* + * Out-of-range value for link sequence numbers + */ + +#define INVALID_LINK_SEQ 0x10000 + /* * Link states */ diff --git a/net/tipc/node.c b/net/tipc/node.c index 1861ae915f17..e530de279be9 100644 --- a/net/tipc/node.c +++ b/net/tipc/node.c @@ -351,8 +351,7 @@ static void node_lost_contact(struct tipc_node *n_ptr) } tipc_bclink_remove_node(n_ptr->addr); - tipc_bclink_acknowledge(n_ptr, - mod(n_ptr->bclink.acked + 10000)); + tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ); if (n_ptr->addr < tipc_own_addr) tipc_own_tag--; -- cgit v1.2.2