linux/net/tipc/node.c, branch v4.5

tipc: fix premature addition of node to lookup table

2016-02-16T20:57:11Z

In commit 5266698661401a ("tipc: let broadcast packet reception use new link receive function") we introduced a new per-node broadcast reception link instance. This link is created at the moment the node itself is created. Unfortunately, the allocation is done after the node instance has already been added to the node lookup hash table. This creates a potential race condition, where arriving broadcast packets are able to find and access the node before it has been fully initialized, and before the above mentioned link has been created. The result is occasional crashes in the function tipc_bcast_rcv(), which is trying to access the not-yet existing link. We fix this by deferring the addition of the node instance until after it has been fully initialized in the function tipc_node_create(). Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: fix node reference count bug

2015-12-03T20:19:40Z

Commit 5405ff6e15f40f2f ("tipc: convert node lock to rwlock") introduced a bug to the node reference counter handling. When a message is successfully sent in the function tipc_node_xmit(), we return directly after releasing the node lock, instead of continuing and decrementing the node reference counter as we should do. This commit fixes this bug. Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: eliminate remnants of hungarian notation

2015-11-20T19:06:10Z

The number of variables with Hungarian notation (l_ptr, n_ptr etc.) has been significantly reduced over the last couple of years. We now root out the last traces of this practice. There are no functional changes in this commit. Reviewed-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: narrow down interface towards struct tipc_link

2015-11-20T19:06:10Z

We move the definition of struct tipc_link from link.h to link.c in order to minimize its exposure to the rest of the code. When needed, we define new functions to make it possible for external entities to access and set data in the link. Apart from the above, there are no functional changes. Reviewed-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: narrow down exposure of struct tipc_node

2015-11-20T19:06:10Z

In our effort to have less code and include dependencies between entities such as node, link and bearer, we try to narrow down the exposed interface towards the node as much as possible. In this commit, we move the definition of struct tipc_node, along with many of its associated function declarations, from node.h to node.c. We also move some function definitions from link.c and name_distr.c to node.c, since they access fields in struct tipc_node that should not be externally visible. The moved functions are renamed according to new location, and made static whenever possible. There are no functional changes in this commit. Reviewed-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: convert node lock to rwlock

2015-11-20T19:06:10Z

According to the node FSM a node in state SELF_UP_PEER_UP cannot change state inside a lock context, except when a TUNNEL_PROTOCOL (SYNCH or FAILOVER) packet arrives. However, the node's individual links may still change state. Since each link now is protected by its own spinlock, we finally have the conditions in place to convert the node spinlock to an rwlock_t. If the node state and arriving packet type are rigth, we can let the link directly receive the packet under protection of its own spinlock and the node lock in read mode. In all other cases we use the node lock in write mode. This enables full concurrent execution between parallel links during steady-state traffic situations, i.e., 99+ % of the time. This commit implements this change. Reviewed-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: introduce per-link spinlock

2015-11-20T19:06:10Z

As a preparation to allow parallel links to work more independently from each other we introduce a per-link spinlock, to be stored in the struct nodes's link entry area. Since the node lock still is a regular spinlock there is no increase in parallellism at this stage. Reviewed-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: reduce code dependency between binding table and node layer

2015-11-20T19:06:10Z

The file name_distr.c currently contains three functions, named_cluster_distribute(), tipc_publ_subcscribe() and tipc_publ_unsubscribe() that all directly access fields in struct tipc_node. We want to eliminate such dependencies, so we move those functions to the file node.c and rename them to tipc_node_broadcast(), tipc_node_subscribe() and tipc_node_unsubscribe() respectively. Reviewed-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: small cleanup of function tipc_node_check_state()

2015-11-20T19:06:10Z

The function tipc_node_check_state() contains the core logics for handling link synchronization and failover. For this reason, it is important to keep it as comprehensible as possible. In this commit, we make three small cleanups. 1) If the node is in state SELF_DOWN_PEER_LEAVING and the received packet confirms that the peer has lost contact, there will be no further action in this function. To make this clearer, we return from the function directly after the state change. 2) Since commit 0f8b8e28fb3241f9fd ("tipc: eliminate risk of stalled link synchronization") only the logically first TUNNEL_PROTO/SYNCH packet can alter the link state and set the synch point, independently of arrival order. Hence, there is not any longer any need to adjust the synch value in case such packets arrive in disorder. We remove this adjustment. 3) It is the intention that any message arriving on any of the links may trig a check for and possible termination of a node SYNCH state. A redundant and unnoticed check for tipc_link_is_synching() obviously beats this purpose, with the effect that only packets arriving on the synching link may currently end the synch state. We remove this check. This change will further shorten the synchronization period between parallel links. Reviewed-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: link_is_bc_sndlink() can be static

2015-10-25T13:31:52Z

TO: "David S. Miller" CC: netdev@vger.kernel.org CC: Jon Maloy CC: Ying Xue CC: tipc-discussion@lists.sourceforge.net CC: linux-kernel@vger.kernel.org Signed-off-by: Fengguang Wu Acked-by: Jon Maloy Signed-off-by: David S. Miller