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* tipc: simplify link mtu negotiationJon Paul Maloy2015-04-02
| | | | | | | | | | | | | | | | | | | | | | | | 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 Maloy2015-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | 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 Xue2015-03-29
| | | | | | | | | | | | | | | | | | | | | 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 Xue2015-03-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ 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 Maloy2015-03-14
| | | | | | | | | | | | | | | | | | | | 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 Alpe2015-02-09
| | | | | | | | | | | | | 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 Alpe2015-02-09
| | | | | | | | | | | 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 Alpe2015-02-09
| | | | | | | | | | | 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 Alpe2015-02-09
| | | | | | | | | | | | | 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 Maloy2015-02-05
| | | | | | | | | | | | | | | | | | | | 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 Maloy2015-02-05
| | | | | | | | | | | | | | | | 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 Maloy2015-02-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Maloy2015-02-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Maloy2015-02-04
| | | | | | | | | | | | | | | | | | | | | | 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 Maloy2015-02-04
| | | | | | | | | | | | | | | | | | | | | | | | | | 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 Hugne2015-01-26
| | | | | | | | | | | | 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 Xue2015-01-12
| | | | | | | | | | | | | | 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 Xue2015-01-12
| | | | | | | | | | | | | | 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 Xue2015-01-12
| | | | | | | | | | | | | | | | | | | | | | | 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 Alpe2014-12-10
| | | | | | | | | | | | | | 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 Xue2014-11-26
| | | | | | | | | 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 Xue2014-11-26
| | | | | | | | | | | | | | | 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 Alpe2014-11-24
| | | | | | | | 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 Alpe2014-11-21
| | | | | | | | | | | | | | | | | | 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 Xue2014-10-21
| | | | | | | | | | | | | | | | | | | | | 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>
* tipc: fix bug in multicast congestion handlingJon Maloy2014-10-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One aim of commit 50100a5e39461b2a61d6040e73c384766c29975d ("tipc: use pseudo message to wake up sockets after link congestion") was to handle link congestion abatement in a uniform way for both unicast and multicast transmit. However, the latter doesn't work correctly, and has been broken since the referenced commit was applied. If a user now sends a burst of multicast messages that is big enough to cause broadcast link congestion, it will be put to sleep, and not be waked up when the congestion abates as it should be. This has two reasons. First, the flag that is used, TIPC_WAKEUP_USERS, is set correctly, but in the wrong field. Instead of setting it in the 'action_flags' field of the arrival node struct, it is by mistake set in the dummy node struct that is owned by the broadcast link, where it will never tested for. Second, we cannot use the same flag for waking up unicast and multicast users, since the function tipc_node_unlock() needs to pick the wakeup pseudo messages to deliver from different queues. It must hence be able to distinguish between the two cases. This commit solves this problem by adding a new flag TIPC_WAKEUP_BCAST_USERS, and a new function tipc_bclink_wakeup_user(). The latter is to be called by tipc_node_unlock() when the named flag, now set in the correct field, is encountered. v2: using explicit 'unsigned int' declaration instead of 'uint', as per comment from David Miller. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: use message to abort connections when losing contact to nodeJon Paul Maloy2014-08-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the current implementation, each 'struct tipc_node' instance keeps a linked list of those ports/sockets that are connected to the node represented by that struct. The purpose of this is to let the node object know which sockets to alert when it loses contact with its peer node, i.e., which sockets need to have their connections aborted. This entails an unwanted direct reference from the node structure back to the port/socket structure, and a need to grab port_lock when we have to make an upcall to the port. We want to get rid of this unecessary BH entry point into the socket, and also eliminate its use of port_lock. In this commit, we instead let the node struct keep list of "connected socket" structs, which each represents a connected socket, but is allocated independently by the node at the moment of connection. If the node loses contact with its peer node, the list is traversed, and a "connection abort" message is created for each entry in the list. The message is sent to it respective connected socket using the ordinary data path, and the receiving socket aborts its connections upon reception of the message. This enables us to get rid of the direct reference from 'struct node' to ´struct port', and another unwanted BH access point to the latter. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: use pseudo message to wake up sockets after link congestionJon Paul Maloy2014-08-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current link implementation keeps a linked list of blocked ports/ sockets that is populated when there is link congestion. The purpose of this is to let the link know which users to wake up when the congestion abates. This adds unnecessary complexity to the data structure and the code, since it forces us to involve the link each time we want to delete a socket. It also forces us to grab the spinlock port_lock within the scope of node_lock. We want to get rid of this direct dependence, as well as the deadlock hazard resulting from the usage of port_lock. In this commit, we instead let the link keep list of a "wakeup" pseudo messages for use in such situations. Those messages are sent to the pending sockets via the ordinary message reception path, and wake up the socket's owner when they are received. This enables us to get rid of the 'waiting_ports' linked lists in struct tipc_port that manifest this direct reference. As a consequence, we can eliminate another BH entry into the socket, and hence the need to grab port_lock. This is a further step in our effort to remove port_lock altogether. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: make name table distributor use new send functionJon Paul Maloy2014-07-17
| | | | | | | | | | | | | | | | In a previous commit series ("tipc: new unicast transmission code") we introduced a new message sending function, tipc_link_xmit2(), and moved the unicast data users over to use that function. We now let the internal name table distributor do the same. The interaction between the name distributor and the node/link layer also becomes significantly simpler, so we can eliminate the function tipc_link_names_xmit(). Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: make link mtu easily accessible from socketJon Paul Maloy2014-06-27
| | | | | | | | | | | | | | | | | | Message fragmentation is currently performed at link level, inside the protection of node_lock. This potentially binds up the sending link structure for a long time, instead of letting it do other tasks, such as handle reception of new packets. In this commit, we make the MTUs of each active link become easily accessible from the socket level, i.e., without taking any spinlock or dereferencing the target link pointer. This way, we make it possible to perform fragmentation in the sending socket, before sending the whole fragment chain to the link for transport. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: rename and move message reassembly functionJon Paul Maloy2014-05-14
| | | | | | | | | | | | | | | | The function tipc_link_frag_rcv() is in reality a re-entrant generic message reassemby function that has nothing in particular to do with the link, where it is defined now. This becomes obvious when we see the need to call the function from other places in the code. In this commit rename it to tipc_buf_append() and move it to the file msg.c. We also simplify its signature by moving the tail pointer to the control block of the head buffer, hence making the head buffer self-contained. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: don't directly overwrite node action_flagsYing Xue2014-05-09
| | | | | | | | | | | | Each node action flag should be set or cleared separately, instead we now set the whole flags variable in one shot, and it's turned out to be hard to see which other flags are affected. Therefore, for instance, we explicitly clear TIPC_WAIT_OWN_LINKS_DOWN bit in node_lost_contact(). 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: rename enum names of node flagsYing Xue2014-05-09
| | | | | | | | | Rename node flags to action_flags as well as its enum names so that they can reflect its real meanings. 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: avoid to asynchronously deliver name tables to peer nodeYing Xue2014-05-05
| | | | | | | | | | Postpone the actions of delivering name tables until after node lock is released, avoiding to do it under asynchronous context. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: remove TIPC_NAMES_GONE node flagYing Xue2014-05-05
| | | | | | | | | | | | | | Since previously what all publications pertaining to the lost node were removed from name table was finished in tasklet context asynchronously, we need to TIPC_NAMES_GONE flag indicating whether the node cleanup work is finished or not. But now as the cleanup work has been finished when node lock is released, the flag becomes meaningless for us. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: avoid to asynchronously notify subscriptionsYing Xue2014-05-05
| | | | | | | | | | | Postpone the actions of notifying subscriptions until after node lock is released, avoiding to asynchronously execute registered handlers when node is lost. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: rename setup_blocked variable of node struct to flagsYing Xue2014-05-05
| | | | | | | | | | | Rename setup_blocked variable of node struct to a more common name called "flags", which will be used to represent kinds of node states. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: fix out of bounds indexingErik Hugne2014-04-28
| | | | | | | | | | | | | Commit 78acb1f9b898e85fa2c1e28e700b54b66b288e8d ("tipc: add ioctl to fetch link names") introduced a buffer overflow bug where specially crafted ioctl requests could cause out-of-bounds indexing of the node->links array. This was caused by an incorrect check vs MAX_BEARERS, and the static code checker complaint is: net/tipc/node.c:459 tipc_node_get_linkname() error: buffer overflow 'node->links' 2 <= 2 Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: add ioctl to fetch link namesErik Hugne2014-04-26
| | | | | | | | | | | | | We add a new ioctl for AF_TIPC that can be used to fetch the logical name for a link to a remote node on a given bearer. This should be used in combination with link state subscriptions. The logical name size limit definitions are moved to tipc.h, as they are now also needed by the new ioctl. Signed-off-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: add support for link state subscriptionsErik Hugne2014-04-26
| | | | | | | | | | | | | When links are established over a bearer plane, we create a node local publication containing information about the peer node and bearer plane. This allows TIPC applications to use the standard TIPC topology server subscription mechanism to get notifications when a link goes up or down. Signed-off-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: purge tipc_net_lock lockYing Xue2014-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now tipc routing hierarchy comprises the structures 'node', 'link'and 'bearer'. The whole hierarchy is protected by a big read/write lock, tipc_net_lock, to ensure that nothing is added or removed while code is accessing any of these structures. Obviously the locking policy makes node, link and bearer components closely bound together so that their relationship becomes unnecessarily complex. In the worst case, such locking policy not only has a negative influence on performance, but also it's prone to lead to deadlock occasionally. In order o decouple the complex relationship between bearer and node as well as link, the locking policy is adjusted as follows: - Bearer level RTNL lock is used on update side, and RCU is used on read side. Meanwhile, all bearer instances including broadcast bearer are saved into bearer_list array. - Node and link level All node instances are saved into two tipc_node_list and node_htable lists. The two lists are protected by node_list_lock on write side, and they are guarded with RCU lock on read side. All members in node structure including link instances are protected by node spin lock. - The relationship between bearer and node When link accesses bearer, it first needs to find the bearer with its bearer identity from the bearer_list array. When bearer accesses node, it can iterate the node_htable hash list with the node address to find the corresponding node. In the new locking policy, every component has its private locking solution and the relationship between bearer and node is very simple, that is, they can find each other with node address or bearer identity from node_htable hash list or bearer_list array. Until now above all changes have been done, so tipc_net_lock can be removed safely. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Tested-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: decouple the relationship between bearer and linkYing Xue2014-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently on both paths of message transmission and reception, the read lock of tipc_net_lock must be held before bearer is accessed, while the write lock of tipc_net_lock has to be taken before bearer is configured. Although it can ensure that bearer is always valid on the two data paths, link and bearer is closely bound together. So as the part of effort of removing tipc_net_lock, the locking policy of bearer protection will be adjusted as below: on the two data paths, RCU is used, and on the configuration path of bearer, RTNL lock is applied. Now RCU just covers the path of message reception. To make it possible to protect the path of message transmission with RCU, link should not use its stored bearer pointer to access bearer, but it should use the bearer identity of its attached bearer as index to get bearer instance from bearer_list array, which can help us decouple the relationship between bearer and link. As a result, bearer on the path of message transmission can be safely protected by RCU when we access bearer_list array within RCU lock protection. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Tested-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: use node list lock to protect tipc_num_links variableYing Xue2014-03-27
| | | | | | | | | | | | | | | | Without properly implicit or explicit read memory barrier, it's unsafe to read an atomic variable with atomic_read() from another thread which is different with the thread of changing the atomic variable with atomic_inc() or atomic_dec(). So a stale tipc_num_links may be got with atomic_read() in tipc_node_get_links(). If the tipc_num_links variable type is converted from atomic to unsigned integer and node list lock is used to protect it, the issue would be avoided. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: use node_list_lock to protect tipc_num_nodes variableYing Xue2014-03-27
| | | | | | | | | | | | As tipc_node_list is protected by rcu read lock on read side, it's unnecessary to hold node_list_lock to protect tipc_node_list in tipc_node_get_links(). Instead, node_list_lock should just protects tipc_num_nodes in the function. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: tipc: convert node list and node hlist to RCU listsYing Xue2014-03-27
| | | | | | | | | | | Convert tipc_node_list list and node_htable hash list to RCU lists. On read side, the two lists are protected with RCU read lock, and on update side, node_list_lock is applied to them. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: rename node create lock to protect node list and hlistYing Xue2014-03-27
| | | | | | | | | | | | | | | | | | | | | | When a node is created, tipc_net_lock read lock is first held and then node_create_lock is grabbed in order to prevent the same node from being created and inserted into both node list and hlist twice. But when we query node from the two node lists, we only hold tipc_net_lock read lock without grabbing node_create_lock. Obviously this locking policy is unable to guarantee that the two node lists are always synchronized especially when the operation of changing and accessing them occurs in different contexts like currently doing. Therefore, rename node_create_lock to node_list_lock to protect the two node lists, that is, whenever node is inserted into them or node is queried from them, the node_list_lock should be always held. As a result, tipc_net_lock read lock becomes redundant and then can be removed from the node query functions. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: remove unnecessary checking for node objectYing Xue2014-03-27
| | | | | | | | | | | | tipc_node_create routine doesn't need to check whether a node object specified with a node address exists or not because its caller(ie, tipc_disc_recv_msg routine) has checked this before calling it. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: align tipc function names with common naming practice in the networkYing Xue2014-02-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename the following functions, which are shorter and more in line with common naming practice in the network subsystem. tipc_bclink_send_msg->tipc_bclink_xmit tipc_bclink_recv_pkt->tipc_bclink_rcv tipc_disc_recv_msg->tipc_disc_rcv tipc_link_send_proto_msg->tipc_link_proto_xmit link_recv_proto_msg->tipc_link_proto_rcv link_send_sections_long->tipc_link_iovec_long_xmit tipc_link_send_sections_fast->tipc_link_iovec_xmit_fast tipc_link_send_sync->tipc_link_sync_xmit tipc_link_recv_sync->tipc_link_sync_rcv tipc_link_send_buf->__tipc_link_xmit tipc_link_send->tipc_link_xmit tipc_link_send_names->tipc_link_names_xmit tipc_named_recv->tipc_named_rcv tipc_link_recv_bundle->tipc_link_bundle_rcv tipc_link_dup_send_queue->tipc_link_dup_queue_xmit link_send_long_buf->tipc_link_frag_xmit tipc_multicast->tipc_port_mcast_xmit tipc_port_recv_mcast->tipc_port_mcast_rcv tipc_port_reject_sections->tipc_port_iovec_reject tipc_port_recv_proto_msg->tipc_port_proto_rcv tipc_connect->tipc_port_connect __tipc_connect->__tipc_port_connect __tipc_disconnect->__tipc_port_disconnect tipc_disconnect->tipc_port_disconnect tipc_shutdown->tipc_port_shutdown tipc_port_recv_msg->tipc_port_rcv tipc_port_recv_sections->tipc_port_iovec_rcv release->tipc_release accept->tipc_accept bind->tipc_bind get_name->tipc_getname poll->tipc_poll send_msg->tipc_sendmsg send_packet->tipc_send_packet send_stream->tipc_send_stream recv_msg->tipc_recvmsg recv_stream->tipc_recv_stream connect->tipc_connect listen->tipc_listen shutdown->tipc_shutdown setsockopt->tipc_setsockopt getsockopt->tipc_getsockopt Above changes have no impact on current users of the functions. 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 a loop style problemJon Paul Maloy2014-02-17
| | | | | | | | | | | | | | | | | | In commit 7d33939f475d403e79124e3143d7951dcfe8629f ("tipc: delay delete of link when failover is needed") we introduced a loop for finding and removing a link pointer in an array. The removal is done after we have left the loop, giving the impression that one may remove the wrong pointer if no matching element is found. This is not really a bug, since we know that there will always be a matching element, but it looks wrong, and causes a smatch warning. We fix this loop with this commit. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: delay delete of link when failover is neededJon Paul Maloy2014-02-13
| | | | | | | | | | | | | | | | | | | | | When a bearer is disabled, all its attached links are deleted. Ideally, we should do link failover to redundant links on other bearers, if there are any, in such cases. This would be consistent with current behavior when a link is reset, but not deleted. However, due to the complexity involved, and the (wrongly) perceived low demand for this feature, it was never implemented until now. We mark the doomed link for deletion with a new flag, but wait until the failover process is finished before we actually delete it. With the improved link tunnelling/failover code introduced earlier in this commit series, it is now easy to identify a spot in the code where the failover is finished and it is safe to delete the marked link. Moreover, the test for the flag and the deletion can be done synchronously, and outside the most time critical data path. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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