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2015-09-08net: tipc: fix stall during bclink wakeup procedureKolmakov Dmitriy
If an attempt to wake up users of broadcast link is made when there is no enough place in send queue than it may hang up inside the tipc_sk_rcv() function since the loop breaks only after the wake up queue becomes empty. This can lead to complete CPU stall with the following message generated by RCU: INFO: rcu_sched self-detected stall on CPU { 0} (t=2101 jiffies g=54225 c=54224 q=11465) Task dump for CPU 0: tpch R running task 0 39949 39948 0x0000000a ffffffff818536c0 ffff88181fa037a0 ffffffff8106a4be 0000000000000000 ffffffff818536c0 ffff88181fa037c0 ffffffff8106d8a8 ffff88181fa03800 0000000000000001 ffff88181fa037f0 ffffffff81094a50 ffff88181fa15680 Call Trace: <IRQ> [<ffffffff8106a4be>] sched_show_task+0xae/0x120 [<ffffffff8106d8a8>] dump_cpu_task+0x38/0x40 [<ffffffff81094a50>] rcu_dump_cpu_stacks+0x90/0xd0 [<ffffffff81097c3b>] rcu_check_callbacks+0x3eb/0x6e0 [<ffffffff8106e53f>] ? account_system_time+0x7f/0x170 [<ffffffff81099e64>] update_process_times+0x34/0x60 [<ffffffff810a84d1>] tick_sched_handle.isra.18+0x31/0x40 [<ffffffff810a851c>] tick_sched_timer+0x3c/0x70 [<ffffffff8109a43d>] __run_hrtimer.isra.34+0x3d/0xc0 [<ffffffff8109aa95>] hrtimer_interrupt+0xc5/0x1e0 [<ffffffff81030d52>] ? native_smp_send_reschedule+0x42/0x60 [<ffffffff81032f04>] local_apic_timer_interrupt+0x34/0x60 [<ffffffff810335bc>] smp_apic_timer_interrupt+0x3c/0x60 [<ffffffff8165a3fb>] apic_timer_interrupt+0x6b/0x70 [<ffffffff81659129>] ? _raw_spin_unlock_irqrestore+0x9/0x10 [<ffffffff8107eb9f>] __wake_up_sync_key+0x4f/0x60 [<ffffffffa313ddd1>] tipc_write_space+0x31/0x40 [tipc] [<ffffffffa313dadf>] filter_rcv+0x31f/0x520 [tipc] [<ffffffffa313d699>] ? tipc_sk_lookup+0xc9/0x110 [tipc] [<ffffffff81659259>] ? _raw_spin_lock_bh+0x19/0x30 [<ffffffffa314122c>] tipc_sk_rcv+0x2dc/0x3e0 [tipc] [<ffffffffa312e7ff>] tipc_bclink_wakeup_users+0x2f/0x40 [tipc] [<ffffffffa313ce26>] tipc_node_unlock+0x186/0x190 [tipc] [<ffffffff81597c1c>] ? kfree_skb+0x2c/0x40 [<ffffffffa313475c>] tipc_rcv+0x2ac/0x8c0 [tipc] [<ffffffffa312ff58>] tipc_l2_rcv_msg+0x38/0x50 [tipc] [<ffffffff815a76d3>] __netif_receive_skb_core+0x5a3/0x950 [<ffffffff815a98d3>] __netif_receive_skb+0x13/0x60 [<ffffffff815a993e>] netif_receive_skb_internal+0x1e/0x90 [<ffffffff815aa138>] napi_gro_receive+0x78/0xa0 [<ffffffffa07f93f4>] tg3_poll_work+0xc54/0xf40 [tg3] [<ffffffff81597c8c>] ? consume_skb+0x2c/0x40 [<ffffffffa07f9721>] tg3_poll_msix+0x41/0x160 [tg3] [<ffffffff815ab0f2>] net_rx_action+0xe2/0x290 [<ffffffff8104b92a>] __do_softirq+0xda/0x1f0 [<ffffffff8104bc26>] irq_exit+0x76/0xa0 [<ffffffff81004355>] do_IRQ+0x55/0xf0 [<ffffffff8165a12b>] common_interrupt+0x6b/0x6b <EOI> The issue occurs only when tipc_sk_rcv() is used to wake up postponed senders: tipc_bclink_wakeup_users() // wakeupq - is a queue which consists of special // messages with SOCK_WAKEUP type. tipc_sk_rcv(wakeupq) ... while (skb_queue_len(inputq)) { filter_rcv(skb) // Here the type of message is checked // and if it is SOCK_WAKEUP then // it tries to wake up a sender. tipc_write_space(sk) wake_up_interruptible_sync_poll() } After the sender thread is woke up it can gather control and perform an attempt to send a message. But if there is no enough place in send queue it will call link_schedule_user() function which puts a message of type SOCK_WAKEUP to the wakeup queue and put the sender to sleep. Thus the size of the queue actually is not changed and the while() loop never exits. The approach I proposed is to wake up only senders for which there is enough place in send queue so the described issue can't occur. Moreover the same approach is already used to wake up senders on unicast links. I have got into the issue on our product code but to reproduce the issue I changed a benchmark test application (from tipcutils/demos/benchmark) to perform the following scenario: 1. Run 64 instances of test application (nodes). It can be done on the one physical machine. 2. Each application connects to all other using TIPC sockets in RDM mode. 3. When setup is done all nodes start simultaneously send broadcast messages. 4. Everything hangs up. The issue is reproducible only when a congestion on broadcast link occurs. For example, when there are only 8 nodes it works fine since congestion doesn't occur. Send queue limit is 40 in my case (I use a critical importance level) and when 64 nodes send a message at the same moment a congestion occurs every time. Signed-off-by: Dmitry S Kolmakov <kolmakov.dmitriy@huawei.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>
2015-07-20tipc: reduce locking scope during packet receptionJon Paul Maloy
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>
2015-07-20tipc: clean up definitions and usage of link flagsJon Paul Maloy
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>
2015-07-20tipc: change sk_buffer handling in tipc_link_xmit()Jon Paul Maloy
When the function tipc_link_xmit() is given a buffer list for transmission, it currently consumes the list both when transmission is successful and when it fails, except for the special case when it encounters link congestion. This behavior is inconsistent, and needs to be corrected if we want to avoid problems in later commits in this series. In this commit, we change this to let the function consume the list only when transmission is successful, and leave the list with the sender in all other cases. We also modifiy the socket code so that it adapts to this change, i.e., purges the list when a non-congestion error code is returned. 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>
2015-07-20tipc: introduce link entry structure to struct tipc_nodeJon Paul Maloy
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>
2015-06-28tipc: purge backlog queue counters when broadcast link is resetJon Paul Maloy
In commit 1f66d161ab3d8b518903fa6c3f9c1f48d6919e74 ("tipc: introduce starvation free send algorithm") we introduced a counter per priority level for buffers in the link backlog queue. We also introduced a new function tipc_link_purge_backlog(), to reset these counters to zero when the link is reset. Unfortunately, we missed to call this function when the broadcast link is reset, with the result that the values of these counters might be permanently skewed when new nodes are attached. This may in the worst case lead to permananent, but spurious, broadcast link congestion, where no broadcast packets can be sent at all. We fix this bug with this commit. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-14tipc: add packet sequence number at instant of transmissionJon Paul Maloy
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>
2015-05-14tipc: rename fields in struct tipc_linkJon Paul Maloy
We rename some fields in struct tipc_link, in order to give them more descriptive names: next_in_no -> rcv_nxt next_out_no-> snd_nxt fsm_msg_cnt-> silent_intv_cnt cont_intv -> keepalive_intv last_retransmitted -> last_retransm 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>
2015-05-09tipc: add broadcast link window set/get to nl apiRichard Alpe
Add the ability to get or set the broadcast link window through the new netlink API. The functionality was unintentionally missing from the new netlink API. Adding this means that we also fix the breakage in the old API when coming through the compat layer. Fixes: 37e2d4843f9e (tipc: convert legacy nl link prop set to nl compat) Reported-by: Tomi Ollila <tomi.ollila@iki.fi> 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> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-02tipc: simplify link mtu negotiationJon Paul Maloy
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>
2015-03-29tipc: involve reference counter for node structureYing Xue
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>
2015-03-29tipc: fix potential deadlock when all links are resetYing Xue
[ 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>
2015-03-25tipc: introduce starvation free send algorithmJon Paul Maloy
Currently, we only use a single counter; the length of the backlog queue, to determine whether a message should be accepted to the queue or not. Each time a message is being sent, the queue length is compared to a threshold value for the message's importance priority. If the queue length is beyond this threshold, the message is rejected. This algorithm implies a risk of starvation of low importance senders during very high load, because it may take a long time before the backlog queue has decreased enough to accept a lower level message. We now eliminate this risk by introducing a counter for each importance priority. When a message is sent, we check only the queue level for that particular message's priority. If that is ok, the message can be added to the backlog, irrespective of the queue level for other priorities. This way, each level is guaranteed a certain portion of the total bandwidth, and any risk of starvation is eliminated. Reviewed-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-25tipc: fix a link reset issue due to retransmission failuresYing Xue
When a node joins a cluster while we are transmitting a fragment stream over the broadcast link, it's missing the preceding fragments needed to build a meaningful message. As a result, the node has to drop it. However, as the fragment message is not acknowledged to its sender before it's dropped, it accidentally causes link reset of retransmission failure on the node. Reported-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: Ying Xue <ying.xue@windriver.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>
2015-03-14tipc: clean up handling of message prioritiesJon Paul Maloy
Messages transferred by TIPC are assigned an "importance priority", -an integer value indicating how to treat the message when there is link or destination socket congestion. There is no separate header field for this value. Instead, the message user values have been chosen in ascending order according to perceived importance, so that the message user field can be used for this. This is not a good solution. First, we have many more users than the needed priority levels, so we end up with treating more priority levels than necessary. Second, the user field cannot always accurately reflect the priority of the message. E.g., a message fragment packet should really have the priority of the enveloped user data message, and not the priority of the MSG_FRAGMENTER user. Until now, we have been working around this problem in different ways, but it is now time to implement a consistent way of handling such priorities, although still within the constraint that we cannot allocate any more bits in the regular data message header for this. In this commit, we define a new priority level, TIPC_SYSTEM_IMPORTANCE, that will be the only one used apart from the four (lower) user data levels. All non-data messages map down to this priority. Furthermore, we take some free bits from the MSG_FRAGMENTER header and allocate them to store the priority of the enveloped message. We then adjust the functions msg_importance()/msg_set_importance() so that they read/set the correct header fields depending on user type. This small protocol change is fully compatible, because the code at the receiving end of a link currently reads the importance level only from user data messages, where there is no change. Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-14tipc: split link outqueueJon Paul Maloy
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>
2015-03-14tipc: eliminate unnecessary call to broadcast ack functionJon Paul Maloy
The unicast packet header contains a broadcast acknowledge sequence number, that may need to be conveyed to the broadcast link for proper treatment. Currently, the function tipc_rcv(), which is on the most critical data path, calls the function tipc_bclink_acknowledge() to have this done. This call is made for each received packet, and results in the unconditional grabbing of the broadcast link spinlock. This is unnecessary, since we can see directly from tipc_rcv() if the acknowledged number differs from what has been previously acked from the node in question. In the vast majority of cases the numbers won't differ, and there is nothing to update. We now make the call to tipc_bclink_acknowledge() conditional to that the two ack values differ. 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>
2015-02-09tipc: convert legacy nl link stat to nl compatRichard Alpe
Add functionality for safely appending string data to a TLV without keeping write count in the caller. Convert TIPC_CMD_SHOW_LINK_STATS to compat dumpit. 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>
2015-02-09tipc: move and rename the legacy nl api to "nl compat"Richard Alpe
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>
2015-02-05tipc: eliminate race condition at multicast receptionJon Paul Maloy
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>
2015-02-05tipc: simplify socket multicast receptionJon Paul Maloy
The structure 'tipc_port_list' is used to collect port numbers representing multicast destination socket on a receiving node. The list is not based on a standard linked list, and is in reality optimized for the uncommon case that there are more than one multicast destinations per node. This makes the list handling unecessarily complex, and as a consequence, even the socket multicast reception becomes more complex. In this commit, we replace 'tipc_port_list' with a new 'struct tipc_plist', which is based on a standard list. We give the new list stack (push/pop) semantics, someting that simplifies the implementation of the function tipc_sk_mcast_rcv(). 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>
2015-02-05tipc: resolve race problem at unicast message receptionJon Paul Maloy
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>
2015-02-05tipc: reduce usage of context info in socket and linkJon Paul Maloy
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>
2015-01-12tipc: make tipc node address support net namespaceYing Xue
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>
2015-01-12tipc: make tipc broadcast link support net namespaceYing Xue
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>
2015-01-12tipc: make bearer list support net namespaceYing Xue
Bearer list defined as a global variable is used to store bearer instances. When tipc supports net namespace, bearers created in one namespace must be isolated with others allocated in other namespaces, which requires us that the bearer list(bearer_list) must be moved to tipc_net structure. As a result, a net namespace pointer has to be passed to functions which access the bearer list. 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>
2015-01-12tipc: make tipc node table aware of net namespaceYing Xue
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>
2015-01-12tipc: involve namespace infrastructureYing Xue
Involve namespace infrastructure, make the "tipc_net_id" global variable aware of per namespace, and rename it to "net_id". In order that the conversion can be successfully done, an instance of networking namespace must be passed to relevant functions, allowing them to access the "net_id" variable of per 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>
2015-01-12tipc: fix bug in broadcast retransmit codeJon Maloy
In commit 58dc55f25631178ee74cd27185956a8f7dcb3e32 ("tipc: use generic SKB list APIs to manage link transmission queue") we replace all list traversal loops with the macros skb_queue_walk() or skb_queue_walk_safe(). While the previous loops were based on the assumption that the list was NULL-terminated, the standard macros stop when the iterator reaches the list head, which is non-NULL. In the function bclink_retransmit_pkt() this macro replacement has lead to a bug. When we receive a BCAST STATE_MSG we unconditionally call the function bclink_retransmit_pkt(), whether there really is anything to retransmit or not, assuming that the sequence number comparisons will lead to the correct behavior. However, if the transmission queue is empty, or if there are no eligible buffers in the transmission queue, we will by mistake pass the list head pointer to the function tipc_link_retransmit(). Since the list head is not a valid sk_buff, this leads to a crash. In this commit we fix this by only calling tipc_link_retransmit() if we actually found eligible buffers in the transmission 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>
2014-12-09tipc: fix missing spinlock init and nullptr oopsErik Hugne
commit 908344cdda80 ("tipc: fix bug in multicast congestion handling") introduced two bugs with the bclink wakeup function. This commit fixes the missing spinlock init for the waiting_sks list. We also eliminate the race condition between the waiting_sks length check/dequeue operations in tipc_bclink_wakeup_users by simply removing the redundant length check. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Acked-by: Tero Aho <Tero.Aho@coriant.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-26tipc: use generic SKB list APIs to manage TIPC outgoing packet chainsYing Xue
Use standard SKB list APIs associated with struct sk_buff_head to manage socket outgoing packet chain and name table outgoing packet chain, having relevant code simpler and more readable. 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>
2014-11-26tipc: use generic SKB list APIs to manage deferred queue of linkYing Xue
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>
2014-11-26tipc: use generic SKB list APIs to manage link transmission queueYing Xue
Use standard SKB list APIs associated with struct sk_buff_head to manage link transmission queue, having relevant code more clean. 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>
2014-11-26tipc: clean up the process of link pushing packetsYing Xue
In original tipc_link_push_packet(), it pushes messages from protocol message queue, retransmission queue and next_out queue. But as the two first queues are removed, we can simplify its relevant code through deleting tipc_link_push_queue(). 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>
2014-11-24tipc: fix sparse warnings in new nl apiRichard Alpe
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>
2014-11-21tipc: add link get/dump to new netlink apiRichard Alpe
Add TIPC_NL_LINK_GET command to the new tipc netlink API. This command supports dumping all information about all links (including the broadcast link) or getting all information about a specific link (not the broadcast link). The information about a link includes name, transmission info, properties and link statistics. As the tipc broadcast link is special we unfortunately have to treat it specially. It is a deliberate decision not to abstract the broadcast link on this (API) level. Netlink logical layout of link response message: -> port -> name -> MTU -> RX -> TX -> up flag -> active flag -> properties -> priority -> tolerance -> window -> statistics -> rx_info -> rx_fragments -> rx_fragmented -> rx_bundles -> rx_bundled -> tx_info -> tx_fragments -> tx_fragmented -> tx_bundles -> tx_bundled -> msg_prof_tot -> msg_len_cnt -> msg_len_tot -> msg_len_p0 -> msg_len_p1 -> msg_len_p2 -> msg_len_p3 -> msg_len_p4 -> msg_len_p5 -> msg_len_p6 -> rx_states -> rx_probes -> rx_nacks -> rx_deferred -> tx_states -> tx_probes -> tx_nacks -> tx_acks -> retransmitted -> duplicates -> link_congs -> max_queue -> avg_queue 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>
2014-10-07tipc: fix bug in multicast congestion handlingJon Maloy
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>
2014-08-23tipc: remove include file port.hJon Paul Maloy
We move the inline functions in the file port.h to socket.c, and modify their names accordingly. We move struct tipc_port and some macros to socket.h. Finally, we remove the file port.h. 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>
2014-08-23tipc: use pseudo message to wake up sockets after link congestionJon Paul Maloy
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>
2014-07-16tipc: ensure sequential message delivery across dual bearersJon Paul Maloy
When we run broadcast packets over dual bearers/interfaces, the current transmission code is flipping bearers between each sent packet, with the purpose of leveraging the double bandwidth available. The receiving bclink is resequencing the packets if needed, so all messages are delivered upwards from the broadcast link in the correct order, even if they may arrive in concurrent interrupts. However, at the moment of delivery upwards to the socket, we release all spinlocks (bclink_lock, node_lock), so it is still possible that arriving messages bypass each other before they reach the socket queue. We fix this by applying the same technique we are using for unicast traffic. We use a link selector (i.e., the last bit of sending port number) to ensure that messages from the same sender socket always are sent over the same bearer. This guarantees sequential delivery between socket pairs, which is sufficient to satisfy the protocol spec, as well as all known user requirements. 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>
2014-07-16tipc: rename temporarily named functionsJon Paul Maloy
After the previous commit, we can now give the functions with temporary names, such as tipc_link_xmit2(), tipc_msg_build2() etc., their proper names. There are no functional changes in this commit. 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>
2014-07-16tipc: remove unreferenced functionsJon Paul Maloy
We can now remove a number of functions which have become obsolete and unreferenced through this commit series. There are no functional changes in this commit. 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>
2014-07-16tipc: start using the new multicast functionsJon Paul Maloy
In this commit, we convert the socket multicast send function to directly call the new multicast/broadcast function (tipc_bclink_xmit2()) introduced in the previous commit. We do this instead of letting the call go via the now obsolete tipc_port_mcast_xmit(), hence saving a call level and some code complexity. We also remove the initial destination lookup at the message sending side, and replace that with an unconditional lookup at the receiving side, including on the sending node itself. This makes the destination lookup and message transfer more uniform than before. 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>
2014-07-16tipc: add new functions for multicast and broadcast distributionJon Paul Maloy
We add a new broadcast link transmit function in bclink.c and a new receive function in socket.c. The purpose is to move the branching between external and internal destination down to the link layer, just as we have done with unicast in earlier commits. We also make use of the new link-independent fragmentation support that was introduced in an earlier commit series. This gives a shorter and simpler code path, and makes it possible to obtain copy-free buffer delivery to all node local destination sockets. The new transmission code is added in parallel with the existing one, and will be used by the socket multicast send function in the next commit in this series. 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>
2014-07-11tipc: clear 'next'-pointer of message fragments before reassemblyJon Paul Maloy
If the 'next' pointer of the last fragment buffer in a message is not zeroed before reassembly, we risk ending up with a corrupt message, since the reassembly function itself isn't doing this. Currently, when a buffer is retrieved from the deferred queue of the broadcast link, the next pointer is not cleared, with the result as described above. This commit corrects this, and thereby fixes a bug that may occur when long broadcast messages are transmitted across dual interfaces. The bug has been present since 40ba3cdf542a469aaa9083fa041656e59b109b90 ("tipc: message reassembly using fragment chain") This commit should be applied to both net and net-next. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-11net: add __pskb_copy_fclone and pskb_copy_for_cloneOctavian Purdila
There are several instances where a pskb_copy or __pskb_copy is immediately followed by an skb_clone. Add a couple of new functions to allow the copy skb to be allocated from the fclone cache and thus speed up subsequent skb_clone calls. Cc: Alexander Smirnov <alex.bluesman.smirnov@gmail.com> Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Cc: Marek Lindner <mareklindner@neomailbox.ch> Cc: Simon Wunderlich <sw@simonwunderlich.de> Cc: Antonio Quartulli <antonio@meshcoding.com> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Gustavo Padovan <gustavo@padovan.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Arvid Brodin <arvid.brodin@alten.se> Cc: Patrick McHardy <kaber@trash.net> Cc: Pablo Neira Ayuso <pablo@netfilter.org> Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Cc: Lauro Ramos Venancio <lauro.venancio@openbossa.org> Cc: Aloisio Almeida Jr <aloisio.almeida@openbossa.org> Cc: Samuel Ortiz <sameo@linux.intel.com> Cc: Jon Maloy <jon.maloy@ericsson.com> Cc: Allan Stephens <allan.stephens@windriver.com> Cc: Andrew Hendry <andrew.hendry@gmail.com> Cc: Eric Dumazet <edumazet@google.com> Reviewed-by: Christoph Paasch <christoph.paasch@uclouvain.be> Signed-off-by: Octavian Purdila <octavian.purdila@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-14tipc: rename and move message reassembly functionJon Paul Maloy
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>
2014-05-05tipc: avoid to asynchronously reset all linksYing Xue
Postpone the actions of resetting all links until after bclink lock is released, avoiding to asynchronously reset all links. 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>
2014-05-05tipc: convert allocations of global variables associated with bclinkYing Xue
Convert allocations of global variables associated with bclink from static way to dynamical way for the convenience of bclink instance initialisation. Meanwhile, this also helps TIPC support name space in the future easily. 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>
2014-05-05tipc: define new functions to operate bc_lockYing Xue
As we are going to do more jobs when bc_lock is released, the two operations of holding/releasing the lock should be encapsulated with functions. In addition, we move bc_lock spin lock into tipc_bclink structure avoiding to define the global variable. 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>