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* tipc: fix stale link problem during synchronizationJon Paul Maloy2015-08-231-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recent changes to the link synchronization means that we can now just drop packets arriving on the synchronizing link before the synch point is reached. This has lead to significant simplifications to the implementation, but also turns out to have a flip side that we need to consider. Under unlucky circumstances, the two endpoints may end up repeatedly dropping each other's packets, while immediately asking for retransmission of the same packets, just to drop them once more. This pattern will eventually be broken when the synch point is reached on the other link, but before that, the endpoints may have arrived at the retransmission limit (stale counter) that indicates that the link should be broken. We see this happen at rare occasions. The fix for this is to not ask for retransmissions when a link is in state LINK_SYNCHING. The fact that the link has reached this state means that it has already received the first SYNCH packet, and that it knows the synch point. Hence, it doesn't need any more packets until the other link has reached the synch point, whereafter it can go ahead and ask for the missing packets. However, because of the reduced traffic on the synching link that follows this change, it may now take longer to discover that the synch point has been reached. We compensate for this by letting all packets, on any of the links, trig a check for synchronization termination. This is possible because the packets themselves don't contain any information that is needed for discovering this condition. Reviewed-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>
* tipc: interrupt link synchronization when a link goes downJon Paul Maloy2015-08-231-3/+8
| | | | | | | | | | | | | | | | | | | | When we introduced the new link failover/synch mechanism in commit 6e498158a827fd515b514842e9a06bdf0f75ab86 ("tipc: move link synch and failover to link aggregation level"), we missed the case when the non-tunnel link goes down during the link synchronization period. In this case the tunnel link will remain in state LINK_SYNCHING, something leading to unpredictable behavior when the failover procedure is initiated. In this commit, we ensure that the node and remaining link goes back to regular communication state (SELF_UP_PEER_UP/LINK_ESTABLISHED) when one of the parallel links goes down. We also ensure that we don't re-enter synch mode if subsequent SYNCH packets arrive on the remaining link. Reviewed-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>
* tipc: eliminate risk of premature link setup during failoverJon Paul Maloy2015-08-231-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a link goes down, and there is still a working link towards its destination node, a failover is initiated, and the failed link is not allowed to re-establish until that procedure is finished. To ensure this, the concerned link endpoints are set to state LINK_FAILINGOVER, and the node endpoints to NODE_FAILINGOVER during the failover period. However, if the link reset is due to a disabled bearer, the corres- ponding link endpoint is deleted, and only the node endpoint knows about the ongoing failover. Now, if the disabled bearer is re-enabled during the failover period, the discovery mechanism may create a new link endpoint that is ready to be established, despite that this is not permitted. This situation may cause both the ongoing failover and any subsequent link synchronization to fail. In this commit, we ensure that a newly created link goes directly to state LINK_FAILINGOVER if the corresponding node state is NODE_FAILINGOVER. This eliminates the problem described above. Furthermore, we tighten the criteria for which packets are allowed to end a failover state in the function tipc_node_check_state(). By checking that the receiving link is up and running, instead of just checking that it is not in failover mode, we eliminate the risk that protocol packets from the re-created link may cause the failover to be prematurely terminated. Reviewed-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>
* tipc: clean up link creationJon Paul Maloy2015-07-301-32/+16
| | | | | | | | | | | We simplify the link creation function tipc_link_create() and the way the link struct it is connected to the node struct. In particular, we remove the duplicate initialization of some fields which are anyway set in tipc_link_reset(). 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>
* tipc: remove implicit message delivery in node_unlock()Jon Paul Maloy2015-07-301-19/+7
| | | | | | | | | | | | | | | | | | After the most recent changes, all access calls to a link which may entail addition of messages to the link's input queue are postpended by an explicit call to tipc_sk_rcv(), using a reference to the correct queue. This means that the potentially hazardous implicit delivery, using tipc_node_unlock() in combination with a binary flag and a cached queue pointer, now has become redundant. This commit removes this implicit delivery mechanism both for regular data messages and for binding table update messages. 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>
* tipc: make resetting of links non-atomicJon Paul Maloy2015-07-301-69/+97
| | | | | | | | | | | | | | | | | | In order to facilitate future improvements to the locking structure, we want to make resetting and establishing of links non-atomic. I.e., the functions tipc_node_link_up() and tipc_node_link_down() should be called from outside the node lock context, and grab/release the node lock themselves. This requires that we can freeze the link state from the moment it is set to RESETTING or PEER_RESET in one lock context until it is set to RESET or ESTABLISHING in a later context. The recently introduced link FSM makes this possible, so we are now ready to introduce the above change. This commit implements this. 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>
* tipc: move received discovery data evaluation inside node.cJon Paul Maloy2015-07-301-21/+102
| | | | | | | | | | | | | The node lock is currently grabbed and and released in the function tipc_disc_rcv() in the file discover.c. As a preparation for the next commits, we need to move this node lock handling, along with the code area it is covering, to node.c. This commit introduces this change. 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>
* tipc: merge link->exec_mode and link->state into one FSMJon Paul Maloy2015-07-301-13/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* tipc: move protocol message sending away from link FSMJon Paul Maloy2015-07-301-0/+1
| | | | | | | | | | | | | | | | | | The implementation of the link FSM currently takes decisions about and sends out link protocol messages. This is unnecessary, since such actions are not the result of any link state change, and are even decided based on non-FSM state information ("silent_intv_cnt"). We now move the sending of unicast link protocol messages to the function tipc_link_timeout(), and the initial broadcast synchronization message to tipc_node_link_up(). The latter is done because a link instance should not need to know whether it is the first or second link to a destination. Such information is now restricted to and handled by the link aggregation layer in node.c 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>
* tipc: move link synch and failover to link aggregation levelJon Paul Maloy2015-07-301-101/+190
| | | | | | | | | | | | | | | Link failover and synchronization have until now been handled by the links themselves, forcing them to have knowledge about and to access parallel links in order to make the two algorithms work correctly. In this commit, we move the control part of this functionality to the link aggregation level in node.c, which is the right location for this. As a result, the two algorithms become easier to follow, and the link implementation becomes simpler. 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>
* tipc: extend node FSMJon Paul Maloy2015-07-301-7/+82
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the next commit, we will move link synch/failover orchestration to the link aggregation level. In order to do this, we first need to extend the node FSM with two more states, NODE_SYNCHING and NODE_FAILINGOVER, plus four new events to enter and leave those states. This commit introduces this change, without yet making use of it. The node FSM now looks as follows: +-----------------------------------------+ | PEER_DOWN_EVT| | | +------------------------+----------------+ | |SELF_DOWN_EVT | | | | | | | | +-----------+ +-----------+ | | |NODE_ | |NODE_ | | | +----------|FAILINGOVER|<---------|SYNCHING |------------+ | | |SELF_ +-----------+ FAILOVER_+-----------+ PEER_ | | | |DOWN_EVT | A BEGIN_EVT A | DOWN_EVT| | | | | | | | | | | | | | | | | | | | |FAILOVER_|FAILOVER_ |SYNCH_ |SYNCH_ | | | | |END_EVT |BEGIN_EVT |BEGIN_EVT|END_EVT | | | | | | | | | | | | | | | | | | | | | +--------------+ | | | | | +------->| SELF_UP_ |<-------+ | | | | +----------------| PEER_UP |------------------+ | | | | |SELF_DOWN_EVT +--------------+ PEER_DOWN_EVT| | | | | | A A | | | | | | | | | | | | | | PEER_UP_EVT| |SELF_UP_EVT | | | | | | | | | | | V V V | | V V V +------------+ +-----------+ +-----------+ +------------+ |SELF_DOWN_ | |SELF_UP_ | |PEER_UP_ | |PEER_DOWN | |PEER_LEAVING|<------|PEER_COMING| |SELF_COMING|------>|SELF_LEAVING| +------------+ SELF_ +-----------+ +-----------+ PEER_ +------------+ | DOWN_EVT A A DOWN_EVT | | | | | | | | | | SELF_UP_EVT| |PEER_UP_EVT | | | | | | | | | |PEER_DOWN_EVT +--------------+ SELF_DOWN_EVT| +------------------->| SELF_DOWN_ |<--------------------+ | PEER_DOWN | +--------------+ 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>
* tipc: reverse call order for link_reset()->node_link_down()Jon Paul Maloy2015-07-301-9/+21
| | | | | | | | | | | | | | | | | In many cases the call order when a link is reset goes as follows: tipc_node_xx()->tipc_link_reset()->tipc_node_link_down() This is not the right order if we want the node to be in control, so in this commit we change the order to: tipc_node_xx()->tipc_node_link_down()->tipc_link_reset() The fact that tipc_link_reset() now is called from only one location with a well-defined state will also facilitate later simplifications of tipc_link_reset() and the link FSM. 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>
* tipc: move all link_reset() calls to link aggregation levelJon Paul Maloy2015-07-301-3/+81
| | | | | | | | | | | | | | | | In line with our effort to let the node level have full control over its links, we want to move all link reset calls from link.c to node.c. Some of the calls can be moved by simply moving the calling function, when this is the right thing to do. For the remaining calls we use the now established technique of returning a TIPC_LINK_DOWN_EVT flag from tipc_link_rcv(), whereafter we perform the reset call when the call returns. This change serves as a preparation for the coming commits. 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>
* tipc: eliminate function tipc_link_activate()Jon Paul Maloy2015-07-301-2/+4
| | | | | | | | | | | | | | | | | | | | | | The function tipc_link_activate() is redundant, since it mostly performs settings that have already been done in a preceding tipc_link_reset(). There are three exceptions to this: - The actual state change to TIPC_LINK_WORKING. This should anyway be done in the FSM, and not in a separate function. - Registration of the link with the bearer. This should be done by the node, since we don't want the link to have any knowledge about its specific bearer. - Call to tipc_node_link_up() for user access registration. With the new role distribution between link aggregation and link level this becomes the wrong call order; tipc_node_link_up() should instead be called directly as a result of a TIPC_LINK_UP event, hence by the node itself. This commit implements those changes. 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>
* tipc: reduce locking scope during packet receptionJon Paul Maloy2015-07-201-7/+98
| | | | | | | | | | | | | | | | | | | | | | | | | | We convert packet/message reception according to the same principle we have been using for message sending and timeout handling: We move the function tipc_rcv() to node.c, hence handling the initial packet reception at the link aggregation level. The function grabs the node lock, selects the receiving link, and accesses it via a new call tipc_link_rcv(). This function appends buffers to the input queue for delivery upwards, but it may also append outgoing packets to the xmit queue, just as we do during regular message sending. The latter will happen when buffers are forwarded from the link backlog, or when retransmission is requested. Upon return of this function, and after having released the node lock, tipc_rcv() delivers/tranmsits the contents of those queues, but it may also perform actions such as link activation or reset, as indicated by the return flags from the link. This reduces the number of cpu cycles spent inside the node spinlock, and reduces contention on that lock. Reviewed-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>
* tipc: introduce node contact FSMJon Paul Maloy2015-07-201-5/+125
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The logics for determining when a node is permitted to establish and maintain contact with its peer node becomes non-trivial in the presence of multiple parallel links that may come and go independently. A known failure scenario is that one endpoint registers both its links to the peer lost, cleans up it binding table, and prepares for a table update once contact is re-establihed, while the other endpoint may see its links reset and re-established one by one, hence seeing no need to re-synchronize the binding table. To avoid this, a node must not allow re-establishing contact until it has confirmation that even the peer has lost both links. Currently, the mechanism for handling this consists of setting and resetting two state flags from different locations in the code. This solution is hard to understand and maintain. A closer analysis even reveals that it is not completely safe. In this commit we do instead introduce an FSM that keeps track of the conditions for when the node can establish and maintain links. It has six states and four events, and is strictly based on explicit knowledge about the own node's and the peer node's contact states. Only events leading to state change are shown as edges in the figure below. +--------------+ | SELF_UP/ | +---------------->| PEER_COMING |-----------------+ SELF_ | +--------------+ |PEER_ ESTBL_ | | |ESTBL_ CONTACT| SELF_LOST_CONTACT | |CONTACT | v | | +--------------+ | | PEER_ | SELF_DOWN/ | SELF_ | | LOST_ +--| PEER_LEAVING |<--+ LOST_ v +-------------+ CONTACT | +--------------+ | CONTACT +-----------+ | SELF_DOWN/ |<----------+ +----------| SELF_UP/ | | PEER_DOWN |<----------+ +----------| PEER_UP | +-------------+ SELF_ | +--------------+ | PEER_ +-----------+ | LOST_ +--| SELF_LEAVING/|<--+ LOST_ A | CONTACT | PEER_DOWN | CONTACT | | +--------------+ | | A | PEER_ | PEER_LOST_CONTACT | |SELF_ ESTBL_ | | |ESTBL_ CONTACT| +--------------+ |CONTACT +---------------->| PEER_UP/ |-----------------+ | SELF_COMING | +--------------+ Reviewed-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>
* tipc: move link supervision timer to node levelJon Paul Maloy2015-07-201-4/+62
| | | | | | | | | | | | | | In our effort to move control of the links to the link aggregation layer, we move the perodic link supervision timer to struct tipc_node. The new timer is shared between all links belonging to the node, thus saving resources, while still kicking the FSM on both its pertaining links at each expiration. The current link timer and corresponding functions are removed. Reviewed-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>
* tipc: clean up definitions and usage of link flagsJon Paul Maloy2015-07-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | The status flag LINK_STOPPED is not needed any more, since the mechanism for delayed deletion of links has been removed. Likewise, LINK_STARTED and LINK_START_EVT are unnecessary, because we can just as well start the link timer directly from inside tipc_link_create(). We eliminate these flags in this commit. Instead of the above flags, we now introduce three new link modes, TIPC_LINK_OPEN, TIPC_LINK_BLOCKED and TIPC_LINK_TUNNEL. The values indicate whether, and in the case of TIPC_LINK_TUNNEL, which, messages the link is allowed to receive in this state. TIPC_LINK_BLOCKED also blocks timer-driven protocol messages to be sent out, and any change to the link FSM. Since the modes are mutually exclusive, we convert them to state values, and rename the 'flags' field in struct tipc_link to 'exec_mode'. Finally, we move the #defines for link FSM states and events from link.h into enums inside the file link.c, which is the real usage scope of these definitions. Reviewed-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>
* tipc: make media xmit call outside node spinlock contextJon Paul Maloy2015-07-201-0/+78
| | | | | | | | | | | | | | | | | | | | | Currently, message sending is performed through a deep call chain, where the node spinlock is grabbed and held during a significant part of the transmission time. This is clearly detrimental to overall throughput performance; it would be better if we could send the message after the spinlock has been released. In this commit, we do instead let the call revert on the stack after the buffer chain has been added to the transmission queue, whereafter clones of the buffers are transmitted to the device layer outside the spinlock scope. As a further step in our effort to separate the roles of the node and link entities we also move the function tipc_link_xmit() to node.c, and rename it to tipc_node_xmit(). Reviewed-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>
* tipc: use bearer index when looking up active linksJon Paul Maloy2015-07-201-62/+44
| | | | | | | | | | | | | | | | | | | struct tipc_node currently holds two arrays of link pointers; one, indexed by bearer identity, which contains all links irrespective of current state, and one two-slot array for the currently active link or links. The latter array contains direct pointers into the elements of the former. This has the effect that we cannot know the bearer id of a link when accessing it via the "active_links[]" array without actually dereferencing the pointer, something we want to avoid in some cases. In this commit, we do instead store the bearer identity in the "active_links" array, and use this as an index to find the right element in the overall link entry array. This change should be seen as a preparation for the later commits in this series. Reviewed-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>
* tipc: move link input queue to tipc_nodeJon Paul Maloy2015-07-201-1/+3
| | | | | | | | | | | | | | | | | At present, the link input queue and the name distributor receive queues are fields aggregated in struct tipc_link. This is a hazard, because a link might be deleted while a receiving socket still keeps reference to one of the queues. This commit fixes this bug. However, rather than adding yet another reference counter to the critical data path, we move the two queues to safe ground inside struct tipc_node, which is already protected, and let the link code only handle references to the queues. This is also in line with planned later changes in this area. Reviewed-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>
* tipc: move link creation from neighbor discoverer to nodeJon Paul Maloy2015-07-201-0/+27
| | | | | | | | | | | | | | | As a step towards turning links into node internal entities, we move the creation of links from the neighbor discovery logics to the node's link control logics. We also create an additional entry for the link's media address in the newly introduced struct tipc_link_entry, since this is where it is needed in the upcoming commits. The current copy in struct tipc_link is kept for now, but will be removed later. Reviewed-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>
* tipc: introduce link entry structure to struct tipc_nodeJon Paul Maloy2015-07-201-85/+78
| | | | | | | | | | | | | | | struct 'tipc_node' currently contains two arrays for link attributes, one for the link pointers, and one for the usable link MTUs. We now group those into a new struct 'tipc_link_entry', and intoduce one single array consisting of such enties. Apart from being a cosmetic improvement, this is a starting point for the strict master-slave relation between node and link that we will introduce in the following commits. Reviewed-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>
* tipc: add packet sequence number at instant of transmissionJon Paul Maloy2015-05-141-1/+1
| | | | | | | | | | | | | | | | | | | | Currently, the packet sequence number is updated and added to each packet at the moment a packet is added to the link backlog queue. This is wasteful, since it forces the code to traverse the send packet list packet by packet when adding them to the backlog queue. It would be better to just splice the whole packet list into the backlog queue when that is the right action to do. In this commit, we do this change. Also, since the sequence numbers cannot now be assigned to the packets at the moment they are added the backlog queue, we do instead calculate and add them at the moment of transmission, when the backlog queue has to be traversed anyway. We do this in the function tipc_link_push_packet(). Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-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>
* tipc: simplify include dependenciesJon Paul Maloy2015-05-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | When we try to add new inline functions in the code, we sometimes run into circular include dependencies. The main problem is that the file core.h, which really should be at the root of the dependency chain, instead is a leaf. I.e., core.h includes a number of header files that themselves should be allowed to include core.h. In reality this is unnecessary, because core.h does not need to know the full signature of any of the structs it refers to, only their type declaration. In this commit, we remove all dependencies from core.h towards any other tipc header file. As a consequence of this change, we can now move the function tipc_own_addr(net) from addr.c to addr.h, and make it inline. There are no functional changes in this commit. Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-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>
* tipc: simplify link mtu negotiationJon Paul Maloy2015-04-021-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | When a link is being established, the two endpoints advertise their respective interface MTU in the transmitted RESET and ACTIVATE messages. If there is any difference, the lower of the two MTUs will be selected for use by both endpoints. However, as a remnant of earlier attempts to introduce TIPC level routing. there also exists an MTU discovery mechanism. If an intermediate node has a lower MTU than the two endpoints, they will discover this through a bisectional approach, and finally adopt this MTU for common use. Since there is no TIPC level routing, and probably never will be, this mechanism doesn't make any sense, and only serves to make the link level protocol unecessarily complex. In this commit, we eliminate the MTU discovery algorithm,and fall back to the simple MTU advertising approach. This change is fully backwards compatible. Reviewed-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>
* tipc: eliminate delayed link deletion at link failoverJon Paul Maloy2015-04-021-7/+6
| | | | | | | | | | | | | | | | | | | | | | | | | When a bearer is disabled manually, all its links have to be reset and deleted. However, if there is a remaining, parallel link ready to take over a deleted link's traffic, we currently delay the delete of the removed link until the failover procedure is finished. This is because the remaining link needs to access state from the reset link, such as the last received packet number, and any partially reassembled buffer, in order to perform a successful failover. In this commit, we do instead move the state data over to the new link, so that it can fulfill the procedure autonomously, without accessing any data on the old link. This means that we can now proceed and delete all pertaining links immediately when a bearer is disabled. This saves us from some unnecessary complexity in such situations. We also choose to change the confusing definitions CHANGEOVER_PROTOCOL, ORIGINAL_MSG and DUPLICATE_MSG to the more descriptive TUNNEL_PROTOCOL, FAILOVER_MSG and SYNCH_MSG respectively. Reviewed-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>
* tipc: involve reference counter for node structureYing Xue2015-03-291-24/+61
| | | | | | | | | | | | | | | | | | | | | TIPC node hash node table is protected with rcu lock on read side. tipc_node_find() is used to look for a node object with node address through iterating the hash node table. As the entire process of what tipc_node_find() traverses the table is guarded with rcu read lock, it's safe for us. However, when callers use the node object returned by tipc_node_find(), there is no rcu read lock applied. Therefore, this is absolutely unsafe for callers of tipc_node_find(). Now we introduce a reference counter for node structure. Before tipc_node_find() returns node object to its caller, it first increases the reference counter. Accordingly, after its caller used it up, it decreases the counter again. This can prevent a node being used by one thread from being freed by another thread. Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericson.com> Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: fix potential deadlock when all links are resetYing Xue2015-03-291-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ 60.988363] ====================================================== [ 60.988754] [ INFO: possible circular locking dependency detected ] [ 60.989152] 3.19.0+ #194 Not tainted [ 60.989377] ------------------------------------------------------- [ 60.989781] swapper/3/0 is trying to acquire lock: [ 60.990079] (&(&n_ptr->lock)->rlock){+.-...}, at: [<ffffffffa0006dca>] tipc_link_retransmit+0x1aa/0x240 [tipc] [ 60.990743] [ 60.990743] but task is already holding lock: [ 60.991106] (&(&bclink->lock)->rlock){+.-...}, at: [<ffffffffa00004be>] tipc_bclink_lock+0x8e/0xa0 [tipc] [ 60.991738] [ 60.991738] which lock already depends on the new lock. [ 60.991738] [ 60.992174] [ 60.992174] the existing dependency chain (in reverse order) is: [ 60.992174] -> #1 (&(&bclink->lock)->rlock){+.-...}: [ 60.992174] [<ffffffff810a9c0c>] lock_acquire+0x9c/0x140 [ 60.992174] [<ffffffff8179c41f>] _raw_spin_lock_bh+0x3f/0x50 [ 60.992174] [<ffffffffa00004be>] tipc_bclink_lock+0x8e/0xa0 [tipc] [ 60.992174] [<ffffffffa0000f57>] tipc_bclink_add_node+0x97/0xf0 [tipc] [ 60.992174] [<ffffffffa0011815>] tipc_node_link_up+0xf5/0x110 [tipc] [ 60.992174] [<ffffffffa0007783>] link_state_event+0x2b3/0x4f0 [tipc] [ 60.992174] [<ffffffffa00193c0>] tipc_link_proto_rcv+0x24c/0x418 [tipc] [ 60.992174] [<ffffffffa0008857>] tipc_rcv+0x827/0xac0 [tipc] [ 60.992174] [<ffffffffa0002ca3>] tipc_l2_rcv_msg+0x73/0xd0 [tipc] [ 60.992174] [<ffffffff81646e66>] __netif_receive_skb_core+0x746/0x980 [ 60.992174] [<ffffffff816470c1>] __netif_receive_skb+0x21/0x70 [ 60.992174] [<ffffffff81647295>] netif_receive_skb_internal+0x35/0x130 [ 60.992174] [<ffffffff81648218>] napi_gro_receive+0x158/0x1d0 [ 60.992174] [<ffffffff81559e05>] e1000_clean_rx_irq+0x155/0x490 [ 60.992174] [<ffffffff8155c1b7>] e1000_clean+0x267/0x990 [ 60.992174] [<ffffffff81647b60>] net_rx_action+0x150/0x360 [ 60.992174] [<ffffffff8105ec43>] __do_softirq+0x123/0x360 [ 60.992174] [<ffffffff8105f12e>] irq_exit+0x8e/0xb0 [ 60.992174] [<ffffffff8179f9f5>] do_IRQ+0x65/0x110 [ 60.992174] [<ffffffff8179da6f>] ret_from_intr+0x0/0x13 [ 60.992174] [<ffffffff8100de9f>] arch_cpu_idle+0xf/0x20 [ 60.992174] [<ffffffff8109dfa6>] cpu_startup_entry+0x2f6/0x3f0 [ 60.992174] [<ffffffff81033cda>] start_secondary+0x13a/0x150 [ 60.992174] -> #0 (&(&n_ptr->lock)->rlock){+.-...}: [ 60.992174] [<ffffffff810a8f7d>] __lock_acquire+0x163d/0x1ca0 [ 60.992174] [<ffffffff810a9c0c>] lock_acquire+0x9c/0x140 [ 60.992174] [<ffffffff8179c41f>] _raw_spin_lock_bh+0x3f/0x50 [ 60.992174] [<ffffffffa0006dca>] tipc_link_retransmit+0x1aa/0x240 [tipc] [ 60.992174] [<ffffffffa0001e11>] tipc_bclink_rcv+0x611/0x640 [tipc] [ 60.992174] [<ffffffffa0008646>] tipc_rcv+0x616/0xac0 [tipc] [ 60.992174] [<ffffffffa0002ca3>] tipc_l2_rcv_msg+0x73/0xd0 [tipc] [ 60.992174] [<ffffffff81646e66>] __netif_receive_skb_core+0x746/0x980 [ 60.992174] [<ffffffff816470c1>] __netif_receive_skb+0x21/0x70 [ 60.992174] [<ffffffff81647295>] netif_receive_skb_internal+0x35/0x130 [ 60.992174] [<ffffffff81648218>] napi_gro_receive+0x158/0x1d0 [ 60.992174] [<ffffffff81559e05>] e1000_clean_rx_irq+0x155/0x490 [ 60.992174] [<ffffffff8155c1b7>] e1000_clean+0x267/0x990 [ 60.992174] [<ffffffff81647b60>] net_rx_action+0x150/0x360 [ 60.992174] [<ffffffff8105ec43>] __do_softirq+0x123/0x360 [ 60.992174] [<ffffffff8105f12e>] irq_exit+0x8e/0xb0 [ 60.992174] [<ffffffff8179f9f5>] do_IRQ+0x65/0x110 [ 60.992174] [<ffffffff8179da6f>] ret_from_intr+0x0/0x13 [ 60.992174] [<ffffffff8100de9f>] arch_cpu_idle+0xf/0x20 [ 60.992174] [<ffffffff8109dfa6>] cpu_startup_entry+0x2f6/0x3f0 [ 60.992174] [<ffffffff81033cda>] start_secondary+0x13a/0x150 [ 60.992174] [ 60.992174] other info that might help us debug this: [ 60.992174] [ 60.992174] Possible unsafe locking scenario: [ 60.992174] [ 60.992174] CPU0 CPU1 [ 60.992174] ---- ---- [ 60.992174] lock(&(&bclink->lock)->rlock); [ 60.992174] lock(&(&n_ptr->lock)->rlock); [ 60.992174] lock(&(&bclink->lock)->rlock); [ 60.992174] lock(&(&n_ptr->lock)->rlock); [ 60.992174] [ 60.992174] *** DEADLOCK *** [ 60.992174] [ 60.992174] 3 locks held by swapper/3/0: [ 60.992174] #0: (rcu_read_lock){......}, at: [<ffffffff81646791>] __netif_receive_skb_core+0x71/0x980 [ 60.992174] #1: (rcu_read_lock){......}, at: [<ffffffffa0002c35>] tipc_l2_rcv_msg+0x5/0xd0 [tipc] [ 60.992174] #2: (&(&bclink->lock)->rlock){+.-...}, at: [<ffffffffa00004be>] tipc_bclink_lock+0x8e/0xa0 [tipc] [ 60.992174] The correct the sequence of grabbing n_ptr->lock and bclink->lock should be that the former is first held and the latter is then taken, which exactly happened on CPU1. But especially when the retransmission of broadcast link is failed, bclink->lock is first held in tipc_bclink_rcv(), and n_ptr->lock is taken in link_retransmit_failure() called by tipc_link_retransmit() subsequently, which is demonstrated on CPU0. As a result, deadlock occurs. If the order of holding the two locks happening on CPU0 is reversed, the deadlock risk will be relieved. Therefore, the node lock taken in link_retransmit_failure() originally is moved to tipc_bclink_rcv() so that it's obtained before bclink lock. But the precondition of the adjustment of node lock is that responding to bclink reset event must be moved from tipc_bclink_unlock() to tipc_node_unlock(). Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: split link outqueueJon Paul Maloy2015-03-141-2/+2
| | | | | | | | | | | | | | | | | | | | struct tipc_link contains one single queue for outgoing packets, where both transmitted and waiting packets are queued. This infrastructure is hard to maintain, because we need to keep a number of fields to keep track of which packets are sent or unsent, and the number of packets in each category. A lot of code becomes simpler if we split this queue into a transmission queue, where sent/unacknowledged packets are kept, and a backlog queue, where we keep the not yet sent packets. In this commit we do this separation. Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-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>
* tipc: nl compat add noop and remove legacy nl frameworkRichard Alpe2015-02-091-1/+1
| | | | | | | | | | | | | Add TIPC_CMD_NOOP to compat layer and remove the old framework. All legacy nl commands are now converted to the compat layer in netlink_compat.c. Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: convert legacy nl node dump to nl compatRichard Alpe2015-02-091-54/+0
| | | | | | | | | | | Convert TIPC_CMD_GET_NODES to compat dumpit and remove global node counter solely used by the legacy API. Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: convert legacy nl link dump to nl compatRichard Alpe2015-02-091-73/+0
| | | | | | | | | | | Convert TIPC_CMD_GET_LINKS to compat dumpit and remove global link counter solely used by the legacy API. Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: move and rename the legacy nl api to "nl compat"Richard Alpe2015-02-091-1/+1
| | | | | | | | | | | | | The new netlink API is no longer "v2" but rather the standard API and the legacy API is now "nl compat". We split them into separate start/stop and put them in different files in order to further distinguish them. Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: eliminate race condition at multicast receptionJon Paul Maloy2015-02-051-4/+7
| | | | | | | | | | | | | | | | | | | | In a previous commit in this series we resolved a race problem during unicast message reception. Here, we resolve the same problem at multicast reception. We apply the same technique: an input queue serializing the delivery of arriving buffers. The main difference is that here we do it in two steps. First, the broadcast link feeds arriving buffers into the tail of an arrival queue, which head is consumed at the socket level, and where destination lookup is performed. Second, if the lookup is successful, the resulting buffer clones are fed into a second queue, the input queue. This queue is consumed at reception in the socket just like in the unicast case. Both queues are protected by the same lock, -the one of the input queue. Reviewed-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>
* tipc: simplify connection abort notifications when links breakJon Paul Maloy2015-02-051-40/+29
| | | | | | | | | | | | | | | | The new input message queue in struct tipc_link can be used for delivering connection abort messages to subscribing sockets. This makes it possible to simplify the code for such cases. This commit removes the temporary list in tipc_node_unlock() used for transforming abort subscriptions to messages. Instead, the abort messages are now created at the moment of lost contact, and then added to the last failed link's generic input queue for delivery to the sockets concerned. Reviewed-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>
* tipc: resolve race problem at unicast message receptionJon Paul Maloy2015-02-051-19/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. Reviewed-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>
* tipc: reduce usage of context info in socket and linkJon Paul Maloy2015-02-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The most common usage of namespace information is when we fetch the own node addess from the net structure. This leads to a lot of passing around of a parameter of type 'struct net *' between functions just to make them able to obtain this address. However, in many cases this is unnecessary. The own node address is readily available as a member of both struct tipc_sock and tipc_link, and can be fetched from there instead. The fact that the vast majority of functions in socket.c and link.c anyway are maintaining a pointer to their respective base structures makes this option even more compelling. In this commit, we introduce the inline functions tsk_own_node() and link_own_node() to make it easy for functions to fetch the node address from those structs instead of having to pass along and dereference the namespace struct. In particular, we make calls to the msg_xx() functions in msg.{h,c} context independent by directly passing them the own node address as parameter when needed. Those functions should be regarded as leaves in the code dependency tree, and it is hence desirable to keep them namspace unaware. Apart from a potential positive effect on cache behavior, these changes make it easier to introduce the changes that will follow later in this series. Reviewed-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>
* tipc: eliminate race during node creationJon Paul Maloy2015-02-041-6/+5
| | | | | | | | | | | | | | | | | | | | | | Instances of struct node are created in the function tipc_disc_rcv() under the assumption that there is no race between received discovery messages arriving from the same node. This assumption is wrong. When we use more than one bearer, it is possible that discovery messages from the same node arrive at the same moment, resulting in creation of two instances of struct tipc_node. This may later cause confusion during link establishment, and may result in one of the links never becoming activated. We fix this by making lookup and potential creation of nodes atomic. Instead of first looking up the node, and in case of failure, create it, we now start with looking up the node inside node_link_create(), and return a reference to that one if found. Otherwise, we go ahead and create the node as we did before. Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-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>
* tipc: avoid stale link after aborted failoverJon Paul Maloy2015-02-041-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | During link failover it may happen that the remaining link goes down while it is still in the process of taking over traffic from a previously failed link. When this happens, we currently abort the failover procedure and reset the first failed link to non-failover mode, so that it will be ready to re-establish contact with its peer when it comes available. However, if the first link goes down because its bearer was manually disabled, it is not enough to reset it; it must also be deleted; which is supposed to happen when the failover procedure is finished. Otherwise it will remain a zombie link: attached to the owner node structure, in mode LINK_STOPPED, and permanently blocking any re- establishing of the link to the peer via the interface in question. We fix this by amending the failover abort procedure. Apart from resetting the link to non-failover state, we test if the link is also in LINK_STOPPED mode. If so, we delete it, using the conditional tipc_link_delete() function introduced in the previous commit. Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-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>
* tipc: fix excessive network event loggingErik Hugne2015-01-261-11/+11
| | | | | | | | | | | | If a large number of namespaces is spawned on a node and TIPC is enabled in each of these, the excessive printk tracing of network events will cause the system to grind down to a near halt. The traces are still of debug value, so instead of removing them completely we fix it by changing the link state and node availability logging debug traces. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: make tipc node address support net namespaceYing Xue2015-01-121-10/+13
| | | | | | | | | | | | | | If net namespace is supported in tipc, each namespace will be treated as a separate tipc node. Therefore, every namespace must own its private tipc node address. This means the "tipc_own_addr" global variable of node address must be moved to tipc_net structure to satisfy the requirement. It's turned out that users also can assign node address for every namespace. Signed-off-by: Ying Xue <ying.xue@windriver.com> Tested-by: Tero Aho <Tero.Aho@coriant.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: make tipc broadcast link support net namespaceYing Xue2015-01-121-3/+3
| | | | | | | | | | | | | | TIPC broadcast link is statically established and its relevant states are maintained with the global variables: "bcbearer", "bclink" and "bcl". Allowing different namespace to own different broadcast link instances, these variables must be moved to tipc_net structure and broadcast link instances would be allocated and initialized when namespace is created. Signed-off-by: Ying Xue <ying.xue@windriver.com> Tested-by: Tero Aho <Tero.Aho@coriant.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: make tipc node table aware of net namespaceYing Xue2015-01-121-61/+69
| | | | | | | | | | | | | | | | | | | | | | | Global variables associated with node table are below: - node table list (node_htable) - node hash table list (tipc_node_list) - node table lock (node_list_lock) - node number counter (tipc_num_nodes) - node link number counter (tipc_num_links) To make node table support namespace, above global variables must be moved to tipc_net structure in order to keep secret for different namespaces. As a consequence, these variables are allocated and initialized when namespace is created, and deallocated when namespace is destroyed. After the change, functions associated with these variables have to utilize a namespace pointer to access them. So adding namespace pointer as a parameter of these functions is the major change made in the commit. Signed-off-by: Ying Xue <ying.xue@windriver.com> Tested-by: Tero Aho <Tero.Aho@coriant.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: fix broadcast wakeup contention after congestionRichard Alpe2014-12-101-1/+1
| | | | | | | | | | | | | | commit 908344cdda80 ("tipc: fix bug in multicast congestion handling") introduced a race in the broadcast link wakeup functionality. This patch eliminates this broadcast link wakeup race caused by operation on the wakeup list without proper locking. If this race hit and corrupted the list all subsequent wakeup messages would be lost, resulting in a considerable memory leak. Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: use generic SKB list APIs to manage deferred queue of linkYing Xue2014-11-261-2/+2
| | | | | | | | | Use standard SKB list APIs associated with struct sk_buff_head to manage link's deferred queue, simplifying relevant code. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: remove node subscription infrastructureYing Xue2014-11-261-3/+3
| | | | | | | | | | | | | | | The node subscribe infrastructure represents a virtual base class, so its users, such as struct tipc_port and struct publication, can derive its implemented functionalities. However, after the removal of struct tipc_port, struct publication is left as its only single user now. So defining an abstract infrastructure for one user becomes no longer reasonable. If corresponding new functions associated with the infrastructure are moved to name_table.c file, the node subscription infrastructure can be removed as well. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: fix sparse warnings in new nl apiRichard Alpe2014-11-241-1/+1
| | | | | | | | Fix sparse warnings about non-static declaration of static functions in the new tipc netlink API. Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: add node get/dump to new netlink apiRichard Alpe2014-11-211-0/+96
| | | | | | | | | | | | | | | | | | Add TIPC_NL_NODE_GET to the new tipc netlink API. This command can dump the address and node status of all nodes in the tipc cluster. Netlink logical layout of returned node/address data: -> node -> address -> up flag Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: fix a potential deadlockYing Xue2014-10-211-18/+28
| | | | | | | | | | | | | | | | | | | | | Locking dependency detected below possible unsafe locking scenario: CPU0 CPU1 T0: tipc_named_rcv() tipc_rcv() T1: [grab nametble write lock]* [grab node lock]* T2: tipc_update_nametbl() tipc_node_link_up() T3: tipc_nodesub_subscribe() tipc_nametbl_publish() T4: [grab node lock]* [grab nametble write lock]* The opposite order of holding nametbl write lock and node lock on above two different paths may result in a deadlock. If we move the the updating of the name table after link state named out of node lock, the reverse order of holding locks will be eliminated, and as a result, the deadlock risk. Signed-off-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>
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