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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>
2014-04-22tipc: use bc_lock to protect node map in bearer structureYing Xue
The node map variable - 'nodes' in bearer structure is only used by bclink. When bclink accesses it, bc_lock is held. But when change it, for instance, in tipc_bearer_add_dest() or tipc_bearer_remove_dest() the bc_lock is not taken at all. To avoid any inconsistent data, we should always grab bc_lock while accessing node map variable. 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>
2014-04-22tipc: purge tipc_net_lock lockYing Xue
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>
2014-04-22tipc: decouple the relationship between bearer and linkYing Xue
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>
2014-04-22tipc: convert bearer_list to RCU listYing Xue
Convert bearer_list to RCU list. It's protected by RTNL lock on update side, and RCU read lock is applied to read side. 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>
2014-03-27tipc: make broadcast bearer store in bearer_list arrayYing Xue
Now unicast bearer is dynamically allocated and placed into its identity specified slot of bearer_list array. When we search bearer_list array with a bearer identity, the corresponding bearer instance can be found. But broadcast bearer is statically allocated and it is not located in the bearer_list array yet. So we decide to enlarge bearer_list array into MAX_BEARERS + 1 slots, and its last slot stores the broadcast bearer so that the broadcast bearer can be found from bearer_list array with MAX_BEARERS as index. The change will help us reduce the complex relationship between bearer and link in the future. 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>
2014-03-27tipc: remove active flag from tipc_bearer structureYing Xue
After the allocation of tipc_bearer structure instance is converted from statical way to dynamical way, we identify whether a certain tipc_bearer structure pointer is valid by checking whether the pointer is NULL or not. So the active flag in tipc_bearer structure becomes redundant. 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>
2014-03-27tipc: convert tipc_bearers array to pointer listYing Xue
As part of the effort to introduce RCU protection for the bearer list, we first need to change it to a list of pointers. 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>
2014-02-18tipc: align tipc function names with common naming practice in the networkYing Xue
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>
2014-02-13tipc: remove bearer_lock from tipc_bearer structYing Xue
After the earlier commits ("tipc: remove 'links' list from tipc_bearer struct") and ("tipc: introduce new spinlock to protect struct link_req"), there is no longer any need to protect struct link_req or or any link list by use of bearer_lock. Furthermore, we have eliminated the need for using bearer_lock during downcalls (send) from the link to the bearer, since we have ensured that bearers always have a longer life cycle that their associated links, and always contain valid data. So, the only need now for a lock protecting bearers is for guaranteeing consistency of the bearer list itself. For this, it is sufficient, at least for the time being, to continue applying 'net_lockĀ“ in write mode. By removing bearer_lock we also pre-empt introduction of issue b) descibed in the previous commit "tipc: remove 'links' list from tipc_bearer struct": "b) When the outer protection from net_lock is gone, taking bearer_lock and node_lock in opposite order of method 1) and 2) will become an obvious deadlock hazard". Therefore, we now eliminate the bearer_lock spinlock. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-13tipc: stricter behavior of message reassembly functionJon Paul Maloy
The function tipc_link_recv_fragment(struct sk_buff **buf) currently leaves the value of the input buffer pointer undefined when it returns, except when the return code indicates that the reassembly is complete. This despite the fact that it always consumes the input buffer. Here, we enforce a stricter behavior by this function, ensuring that the returned buffer pointer is non-NULL if and only if the reassembly is complete. This makes it possible to test for the buffer pointer as criteria for successful reassembly. We also rename the function to tipc_link_frag_rcv(), which is both shorter and more in line with common naming practice in the network subsystem. Apart from the new name, these changes have no impact on current users of the function, but makes it more practical for use in some planned future commits. 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>
2014-01-07tipc: make link start event synchronousJon Paul Maloy
When a link is created we delay the start event by launching it to be executed later in a tasklet. As we hold all the necessary locks at the moment of creation, and there is no risk of deadlock or contention, this delay serves no purpose in the current code. We remove this obsolete indirection step, and the associated function link_start(). At the same time, we rename the function tipc_link_stop() to the more appropriate tipc_link_purge_queues(). Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-09tipc: remove interface state mirroring in bearerErik Hugne
struct 'tipc_bearer' is a generic representation of the underlying media type, and exists in a one-to-one relationship to each interface TIPC is using. The struct contains a 'blocked' flag that mirrors the operational and execution state of the represented interface, and is updated through notification calls from the latter. The users of tipc_bearer are checking this flag before each attempt to send a packet via the interface. This state mirroring serves no purpose in the current code base. TIPC links will not discover a media failure any faster through this mechanism, and in reality the flag only adds overhead at packet sending and reception. Furthermore, the fact that the flag needs to be protected by a spinlock aggregated into tipc_bearer has turned out to cause a serious and completely unnecessary deadlock problem. CPU0 CPU1 ---- ---- Time 0: bearer_disable() link_timeout() Time 1: spin_lock_bh(&b_ptr->lock) tipc_link_push_queue() Time 2: tipc_link_delete() tipc_bearer_blocked(b_ptr) Time 3: k_cancel_timer(&req->timer) spin_lock_bh(&b_ptr->lock) Time 4: del_timer_sync(&req->timer) I.e., del_timer_sync() on CPU0 never returns, because the timer handler on CPU1 is waiting for the bearer lock. We eliminate the 'blocked' flag from struct tipc_bearer, along with all tests on this flag. This not only resolves the deadlock, but also simplifies and speeds up the data path execution of TIPC. It also fits well into our ongoing effort to make the locking policy simpler and more manageable. An effect of this change is that we can get rid of functions such as tipc_bearer_blocked(), tipc_continue() and tipc_block_bearer(). We replace the latter with a new function, tipc_reset_bearer(), which resets all links associated to the bearer immediately after an interface goes down. A user might notice one slight change in link behaviour after this change. When an interface goes down, (e.g. through a NETDEV_DOWN event) all attached links will be reset immediately, instead of leaving it to each link to detect the failure through a timer-driven mechanism. We consider this an improvement, and see no obvious risks with the new behavior. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Paul Gortmaker <Paul.Gortmaker@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-07tipc: message reassembly using fragment chainErik Hugne
When the first fragment of a long data data message is received on a link, a reassembly buffer large enough to hold the data from this and all subsequent fragments of the message is allocated. The payload of each new fragment is copied into this buffer upon arrival. When the last fragment is received, the reassembled message is delivered upwards to the port/socket layer. Not only is this an inefficient approach, but it may also cause bursts of reassembly failures in low memory situations. since we may fail to allocate the necessary large buffer in the first place. Furthermore, after 100 subsequent such failures the link will be reset, something that in reality aggravates the situation. To remedy this problem, this patch introduces a different approach. Instead of allocating a big reassembly buffer, we now append the arriving fragments to a reassembly chain on the link, and deliver the whole chain up to the socket layer once the last fragment has been received. This is safe because the retransmission layer of a TIPC link always delivers packets in strict uninterrupted order, to the reassembly layer as to all other upper layers. Hence there can never be more than one fragment chain pending reassembly at any given time in a link, and we can trust (but still verify) that the fragments will be chained up in the correct order. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-07tipc: don't reroute message fragmentsErik Hugne
When a message fragment is received in a broadcast or unicast link, the reception code will append the fragment payload to a big reassembly buffer through a call to the function tipc_recv_fragm(). However, after the return of that call, the logics goes on and passes the fragment buffer to the function tipc_net_route_msg(), which will simply drop it. This behavior is a remnant from the now obsolete multi-cluster functionality, and has no relevance in the current code base. Although currently harmless, this unnecessary call would be fatal after applying the next patch in this series, which introduces a completely new reassembly algorithm. So we change the code to eliminate the redundant call. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-17tipc: cosmetic realignment of function argumentsPaul Gortmaker
No runtime code changes here. Just a realign of the function arguments to start where the 1st one was, and fit as many args as can be put in an 80 char line. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-03tipc: pskb_copy() buffers when sending on more than one bearerGerlando Falauto
When sending packets, TIPC bearers use skb_clone() before writing their hardware header. This will however NOT copy the data buffer. So when the same packet is sent over multiple bearers (to reach multiple nodes), the same socket buffer data will be treated by multiple tipc_media drivers which will write their own hardware header through dev_hard_header(). Most of the time this is not a problem, because by the time the packet is processed by the second media, it has already been sent over the first one. However, when the first transmission is delayed (e.g. because of insufficient bandwidth or through a shaper), the next bearer will overwrite the hardware header, resulting in the packet being sent: a) with the wrong source address, when bearers of the same type, e.g. ethernet, are involved b) with a completely corrupt header, or even dropped, when bearers of different types are involved. So when the same socket buffer is to be sent multiple times, send a pskb_copy() instead (from the second instance on), and release it afterwards (the bearer will skb_clone() it anyway). Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-03tipc: tipc_bcbearer_send(): simplify bearer selectionGerlando Falauto
Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-03tipc: cosmetic: clean up comments and break a long lineGerlando Falauto
Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-17tipc: move bcast_addr from struct tipc_media to struct tipc_bearerPatrick McHardy
Some network protocols, like InfiniBand, don't have a fixed broadcast address but one that depends on the configuration. Move the bcast_addr to struct tipc_bearer and initialize it with the broadcast address of the network device when the bearer is enabled. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-15tipc: fix missing spinlock init in broadcast codeErik Hugne
After commit 3c294cb3 "tipc: remove the bearer congestion mechanism", we try to grab the broadcast bearer lock when sending multicast messages over the broadcast link. This will cause an oops because the lock is never initialized. This is an old bug, but the lock was never actually used before commit 3c294cb3, so that why it was not visible until now. The oops will look something like: BUG: spinlock bad magic on CPU#2, daemon/147 lock: bcast_bearer+0x48/0xffffffffffffd19a [tipc], .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 Pid: 147, comm: daemon Not tainted 3.8.0-rc3+ #206 Call Trace: spin_dump+0x8a/0x8f spin_bug+0x21/0x26 do_raw_spin_lock+0x114/0x150 _raw_spin_lock_bh+0x19/0x20 tipc_bearer_blocked+0x1f/0x40 [tipc] tipc_link_send_buf+0x82/0x280 [tipc] ? __alloc_skb+0x9f/0x2b0 tipc_bclink_send_msg+0x77/0xa0 [tipc] tipc_multicast+0x11b/0x1b0 [tipc] send_msg+0x225/0x530 [tipc] sock_sendmsg+0xca/0xe0 The above can be triggered by running the multicast demo program. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-22tipc: rename supported flag to recv_permittedYing Xue
Rename the "supported" flag in bclink structure to "recv_permitted" to better reflect what it is used for. When this flag is set for a given node, we are permitted to receive and acknowledge broadcast messages from that node. Convert it to a bool at the same time, since it is not used to store any numerical values. Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-11-21tipc: remove the bearer congestion mechanismYing Xue
Currently at the TIPC bearer layer there is the following congestion mechanism: Once sending packets has failed via that bearer, the bearer will be flagged as being in congested state at once. During bearer congestion, all packets arriving at link will be queued on the link's outgoing buffer. When we detect that the state of bearer congestion has relaxed (e.g. some packets are received from the bearer) we will try our best to push all packets in the link's outgoing buffer until the buffer is empty, or until the bearer is congested again. However, in fact the TIPC bearer never receives any feedback from the device layer whether a send was successful or not, so it must always assume it was successful. Therefore, the bearer congestion mechanism as it exists currently is of no value. But the bearer blocking state is still useful for us. For example, when the physical media goes down/up, we need to change the state of the links bound to the bearer. So the code maintaing the state information is not removed. Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-07-13tipc: phase out most of the struct print_buf usageErik Hugne
The tipc_printf is renamed to tipc_snprintf, as the new name describes more what the function actually does. It is also changed to take a buffer and length parameter and return number of characters written to the buffer. All callers of this function that used to pass a print_buf are updated. Final removal of the struct print_buf itself will be done synchronously with the pending removal of the deprecated logging code that also was using it. Functions that build up a response message with a list of ports, nametable contents etc. are changed to return the number of characters written to the output buffer. This information was previously hidden in a field of the print_buf struct, and the number of chars written was fetched with a call to tipc_printbuf_validate. This function is removed since it is no longer referenced nor needed. A generic max size ULTRA_STRING_MAX_LEN is defined, named in keeping with the existing TIPC_TLV_ULTRA_STRING, and the various definitions in port, link and nametable code that largely duplicated this information are removed. This means that amount of link statistics that can be returned is now increased from 2k to 32k. The buffer overflow check is now done just before the reply message is passed over netlink or TIPC to a remote node and the message indicating a truncated buffer is changed to a less dramatic one (less CAPS), placed at the end of the message. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-07-13tipc: use standard printk shortcut macros (pr_err etc.)Erik Hugne
All messages should go directly to the kernel log. The TIPC specific error, warning, info and debug trace macro's are removed and all references replaced with pr_err, pr_warn, pr_info and pr_debug. Commonly used sub-strings are explicitly declared as a const char to reduce .text size. Note that this means the debug messages (changed to pr_debug), are now enabled through dynamic debugging, instead of a TIPC specific Kconfig option (TIPC_DEBUG). The latter will be phased out completely Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> [PG: use pr_fmt as suggested by Joe Perches <joe@perches.com>] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-07-10net: Fix (nearly-)kernel-doc comments for various functionsBen Hutchings
Fix incorrect start markers, wrapped summary lines, missing section breaks, incorrect separators, and some name mismatches. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-30tipc: compress out gratuitous extra carriage returnsPaul Gortmaker
Some of the comment blocks are floating in limbo between two functions, or between blocks of code. Delete the extra line feeds between any comment and its associated following block of code, to be consistent with the majority of the rest of the kernel. Also delete trailing newlines at EOF and fix a couple trivial typos in existing comments. This is a 100% cosmetic change with no runtime impact. We get rid of over 500 lines of non-code, and being blank line deletes, they won't even show up as noise in git blame. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-24tipc: Eliminate trivial buffer manipulation helper routinesAllan Stephens
Gets rid of two inlined routines that simply call existing sk_buff manipulation routines, since there is no longer any extra processing done by the helper routines. Note that these changes are essentially cosmetic in nature, and have no impact on the actual operation of TIPC. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06tipc: Prevent loss of fragmented messages over broadcast linkAllan Stephens
Modifies broadcast link so that an incoming fragmented message is not lost if reassembly cannot begin because there currently is no buffer big enough to hold the entire reassembled message. The broadcast link now ignores the first fragment completely, which causes the sending node to retransmit the first fragment so that reassembly can be re-attempted. Previously, the sender would have had no reason to retransmit the 1st fragment, so we would never have a chance to re-try the allocation. To do this cleanly without duplicaton, a new bclink_accept_pkt() function is introduced. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06tipc: Remove obsolete broadcast tag capabilityAllan Stephens
Eliminates support for the broadcast tag field, which is no longer used by broadcast link NACK messages. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06tipc: Major redesign of broadcast link ACK/NACK algorithmsAllan Stephens
Completely redesigns broadcast link ACK and NACK mechanisms to prevent spurious retransmit requests in dual LAN networks, and to prevent the broadcast link from stalling due to the failure of a receiving node to acknowledge receiving a broadcast message or request its retransmission. Note: These changes only impact the timing of when ACK and NACK messages are sent, and not the basic broadcast link protocol itself, so inter- operability with nodes using the "classic" algorithms is maintained. The revised algorithms are as follows: 1) An explicit ACK message is still sent after receiving 16 in-sequence messages, and implicit ACK information continues to be carried in other unicast link message headers (including link state messages). However, the timing of explicit ACKs is now based on the receiving node's absolute network address rather than its relative network address to ensure that the failure of another node does not delay the ACK beyond its 16 message target. 2) A NACK message is now typically sent only when a message gap persists for two consecutive incoming link state messages; this ensures that a suspected gap is not confirmed until both LANs in a dual LAN network have had an opportunity to deliver the message, thereby preventing spurious NACKs. A NACK message can also be generated by the arrival of a single link state message, if the deferred queue is so big that the current message gap cannot be the result of "normal" mis-ordering due to the use of dual LANs (or one LAN using a bonded interface). Since link state messages typically arrive at different nodes at different times the problem of multiple nodes issuing identical NACKs simultaneously is inherently avoided. 3) Nodes continue to "peek" at NACK messages sent by other nodes. If another node requests retransmission of a message gap suspected (but not yet confirmed) by the peeking node, the peeking node forgets about the gap and does not generate a duplicate retransmit request. (If the peeking node subsequently fails to receive the lost message, later link state messages will cause it to rediscover and confirm the gap and send another NACK.) 4) Message gap "equality" is now determined by the start of the gap only. This is sufficient to deal with the most common cases of message loss, and eliminates the need for complex end of gap computations. 5) A peeking node no longer tries to determine whether it should send a complementary NACK, since the most common cases of message loss don't require it to be sent. Consequently, the node no longer examines the "broadcast tag" field of a NACK message when peeking. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06tipc: Add missing locks in broadcast link statistics accumulationAllan Stephens
Ensures that all attempts to update broadcast link statistics are done only while holding the lock that protects the link's main data structures, to prevent interference by simultaneous updates caused by messages arriving on other interfaces. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06tipc: Fix bug in broadcast link duplicate message statisticsAllan Stephens
Modifies broadcast link so that it increments the "received duplicate message" count if an incoming message cannot be added to the deferred message queue because it is already present in the queue. (The aligns broadcast link behavior with that of TIPC's unicast links.) Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06tipc: Fix node lock reclamation issues in broadcast link receptionAllan Stephens
Fixes a pair of problems in broadcast link message reception code relating to the reclamation of the node lock after consuming an in-sequence message. 1) Now retests to see if the sending node is still up after reclaiming the node lock, and bails out if it is non-operational. 2) Now manipulates the node's deferred message queue only after reclaiming the node lock, rather than using queue head pointer information that was cached previously. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06tipc: Add missing broadcast link lock when sending NACKAllan Stephens
Ensures that any attempt to send a NACK message over TIPC's broadcast link has exclusive access to the link's main data structures, to prevent interference with a simultaneous attempt to send other broadcast link traffic (such as application-generated multicast messages). Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-12-29tipc: rename struct link* to struct tipc_link*Paul Gortmaker
This converts the following: struct link -> struct tipc_link struct link_req -> struct tipc_link_req struct link_name -> struct tipc_link_name Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-12-29tipc: rename struct bcbearer* to tipc_bcbearer*Paul Gortmaker
This changes both the struct bcbearer and struct bcbearer_pair to have the "tipc_" prefix. Runtime behaviour is unchanged. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>