1. 27 Oct, 2015 7 commits
  2. 26 Oct, 2015 13 commits
  3. 25 Oct, 2015 7 commits
  4. 24 Oct, 2015 13 commits
    • David S. Miller's avatar
      Merge branch 'tipc-next' · 687f079a
      David S. Miller authored
      Jon Maloy says:
      
      ====================
      tipc: improve broadcast implementation
      
      The TIPC broadcast link implementation is currently complex and hard to
      follow. It also incurs some amount of code and structure duplication,
      something that can be reduced significantly with a little effort.
      
      This commit series introduces a number of improvements which address
      both the locking structure, the code/structure duplication issue, and
      the overall readbility of the code.
      
      The series consists of three main parts:
      
      1-7: Adaptation to the new link structure, and preparation for the next
           step. In particular, we want the broadcast transmission link to
           have a life cycle that is longer than any of its potential (unicast
           and broadcast receive links) users. This eliminates the need to
           always test for the presence of this link before accessing it.
      
      8-10: This is what is really new in this series. Commit #9 is by far
            the largest and most important one, because it moves most of
            the broadcast functionality into link.c, partially reusing the
            fields and functionality of the unicast link. The removal of
            the "node_map" infrastructure in commit #10 is also an important
            achievement.
      
      11-16: Some improvements leveraging the changes made in the previous
             commits.
      
      The series needs commit 53387c4e ("tipc: extend broadcast link window size")
      and commit e5356794 ("tipc: conditionally expand buffer headroom over udp tunnel")
      which are both present in 'net' but not yet in 'net-next', to apply cleanly.
      ====================
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      687f079a
    • Jon Paul Maloy's avatar
      tipc: clean up unused code and structures · 2af5ae37
      Jon Paul Maloy authored
      After the previous changes in this series, we can now remove some
      unused code and structures, both in the broadcast, link aggregation
      and link code.
      
      There are no functional changes in this commit.
      Signed-off-by: default avatarJon Maloy <jon.maloy@ericsson.com>
      Reviewed-by: default avatarYing Xue <ying.xue@windriver.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      2af5ae37
    • Jon Paul Maloy's avatar
      tipc: ensure binding table initial distribution is sent via first link · c49a0a84
      Jon Paul Maloy authored
      Correct synchronization of the broadcast link at first contact between
      two nodes is dependent on the assumption that the binding table "bulk"
      update passes via the same link as the initial broadcast syncronization
      message, i.e., via the first link that is established.
      
      This is not guaranteed in the current implementation. If two link
      come up very close to each other in time, the "bulk" may quite well
      pass via the second link, and hence void the guarantee of a correct
      initial synchronization before the broadcast link is opened.
      
      This commit makes two small changes to strengthen this guarantee.
      
      1) We let the second established link occupy slot 1 of the
         "active_links" array, while the first link will retain slot 0.
         (This is in reality a cosmetic change, we could just as well keep
          the current, opposite order)
      
      2) We let the name distributor always use link selector/slot 0 when
         it sends it binding table updates.
      
      The extra traffic bias on the first link caused by this change should
      be negligible, since binding table updates constitutes a very small
      fraction of the total traffic.
      Signed-off-by: default avatarJon Maloy <jon.maloy@ericsson.com>
      Reviewed-by: default avatarYing Xue <ying.xue@windriver.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c49a0a84
    • Jon Paul Maloy's avatar
      tipc: eliminate link's reference to owner node · c72fa872
      Jon Paul Maloy authored
      With the recent commit series, we have established a one-way dependency
      between the link aggregation (struct tipc_node) instances and their
      pertaining tipc_link instances. This has enabled quite significant code
      and structure simplifications.
      
      In this commit, we eliminate the field 'owner', which points to an
      instance of struct tipc_node, from struct tipc_link, and replace it with
      a pointer to struct net, which is the only external reference now needed
      by a link instance.
      Signed-off-by: default avatarJon Maloy <jon.maloy@ericsson.com>
      Reviewed-by: default avatarYing Xue <ying.xue@windriver.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c72fa872
    • Jon Paul Maloy's avatar
      tipc: eliminate redundant buffer cloning at transmission · 7214bcf8
      Jon Paul Maloy authored
      Since all packet transmitters (link, bcast, discovery) are now sending
      consumable buffer clones to the bearer layer, we can remove the
      redundant buffer cloning that is perfomed in the lower level functions
      tipc_l2_send_msg() and tipc_udp_send_msg().
      Signed-off-by: default avatarJon Maloy <jon.maloy@ericsson.com>
      Reviewed-by: default avatarYing Xue <ying.xue@windriver.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      7214bcf8
    • Jon Paul Maloy's avatar
      tipc: let neighbor discoverer tranmsit consumable buffers · 60852d67
      Jon Paul Maloy authored
      The neighbor discovery function currently uses the function
      tipc_bearer_send() for transmitting packets, assuming that the
      sent buffers are not consumed by the called function.
      
      We want to change this, in order to avoid unnecessary buffer cloning
      elswhere in the code.
      
      This commit introduces a new function tipc_bearer_skb() which consumes
      the sent buffers, and let the discoverer functions use this new call
      instead. The discoverer does now itself perform the cloning when
      that is necessary.
      Signed-off-by: default avatarJon Maloy <jon.maloy@ericsson.com>
      Reviewed-by: default avatarYing Xue <ying.xue@windriver.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      60852d67
    • Jon Paul Maloy's avatar
      tipc: introduce jumbo frame support for broadcast · 959e1781
      Jon Paul Maloy authored
      Until now, we have only been supporting a fix MTU size of 1500 bytes
      for all broadcast media, irrespective of their actual capability.
      
      We now make the broadcast MTU adaptable to the carrying media, i.e.,
      we use the smallest MTU supported by any of the interfaces attached
      to TIPC.
      Signed-off-by: default avatarJon Maloy <jon.maloy@ericsson.com>
      Reviewed-by: default avatarYing Xue <ying.xue@windriver.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      959e1781
    • Jon Paul Maloy's avatar
      tipc: simplify bearer level broadcast · b06b281e
      Jon Paul Maloy authored
      Until now, we have been keeping track of the exact set of broadcast
      destinations though the help structure tipc_node_map. This leads us to
      have to maintain a whole infrastructure for supporting this, including
      a pseudo-bearer and a number of functions to manipulate both the bearers
      and the node map correctly. Apart from the complexity, this approach is
      also limiting, as struct tipc_node_map only can support cluster local
      broadcast if we want to avoid it becoming excessively large. We want to
      eliminate this limitation, in order to enable introduction of scoped
      multicast in the future.
      
      A closer analysis reveals that it is unnecessary maintaining this "full
      set" overview; it is sufficient to keep a counter per bearer, indicating
      how many nodes can be reached via this bearer at the moment. The protocol
      is now robust enough to handle transitional discrepancies between the
      nominal number of reachable destinations, as expected by the broadcast
      protocol itself, and the number which is actually reachable at the
      moment. The initial broadcast synchronization, in conjunction with the
      retransmission mechanism, ensures that all packets will eventually be
      acknowledged by the correct set of destinations.
      
      This commit introduces these changes.
      Signed-off-by: default avatarJon Maloy <jon.maloy@ericsson.com>
      Reviewed-by: default avatarYing Xue <ying.xue@windriver.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      b06b281e
    • Jon Paul Maloy's avatar
      tipc: let broadcast packet reception use new link receive function · 52666986
      Jon Paul Maloy authored
      The code path for receiving broadcast packets is currently distinct
      from the unicast path. This leads to unnecessary code and data
      duplication, something that can be avoided with some effort.
      
      We now introduce separate per-peer tipc_link instances for handling
      broadcast packet reception. Each receive link keeps a pointer to the
      common, single, broadcast link instance, and can hence handle release
      and retransmission of send buffers as if they belonged to the own
      instance.
      
      Furthermore, we let each unicast link instance keep a reference to both
      the pertaining broadcast receive link, and to the common send link.
      This makes it possible for the unicast links to easily access data for
      broadcast link synchronization, as well as for carrying acknowledges for
      received broadcast packets.
      Signed-off-by: default avatarJon Maloy <jon.maloy@ericsson.com>
      Reviewed-by: default avatarYing Xue <ying.xue@windriver.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      52666986
    • Jon Paul Maloy's avatar
      tipc: introduce capability bit for broadcast synchronization · fd556f20
      Jon Paul Maloy authored
      Until now, we have tried to support both the newer, dedicated broadcast
      synchronization mechanism along with the older, less safe, RESET_MSG/
      ACTIVATE_MSG based one. The latter method has turned out to be a hazard
      in a highly dynamic cluster, so we find it safer to disable it completely
      when we find that the former mechanism is supported by the peer node.
      
      For this purpose, we now introduce a new capabability bit,
      TIPC_BCAST_SYNCH, to inform any peer nodes that dedicated broadcast
      syncronization is supported by the present node. The new bit is conveyed
      between peers in the 'capabilities' field of neighbor discovery messages.
      Signed-off-by: default avatarJon Maloy <jon.maloy@ericsson.com>
      Reviewed-by: default avatarYing Xue <ying.xue@windriver.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      fd556f20
    • Jon Paul Maloy's avatar
      tipc: let broadcast transmission use new link transmit function · 2f566124
      Jon Paul Maloy authored
      This commit simplifies the broadcast link transmission function, by
      leveraging previous changes to the link transmission function and the
      broadcast transmission link life cycle.
      Signed-off-by: default avatarJon Maloy <jon.maloy@ericsson.com>
      Reviewed-by: default avatarYing Xue <ying.xue@windriver.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      2f566124
    • Jon Paul Maloy's avatar
      tipc: make struct tipc_link generic to support broadcast · c1ab3f1d
      Jon Paul Maloy authored
      Realizing that unicast is just a special case of broadcast, we also see
      that we can go in the other direction, i.e., that modest changes to the
      current unicast link can make it generic enough to support broadcast.
      
      The following changes are introduced here:
      
      - A new counter ("ackers") in struct tipc_link, to indicate how many
        peers need to ack a packet before it can be released.
      - A corresponding counter in the skb user area, to keep track of how
        many peers a are left to ack before a buffer can be released.
      - A new counter ("acked"), to keep persistent track of how far a peer
        has acked at the moment, i.e., where in the transmission queue to
        start updating buffers when the next ack arrives. This is to avoid
        double acknowledgements from a peer, with inadvertent relase of
        packets as a result.
      - A more generic tipc_link_retrans() function, where retransmit starts
        from a given sequence number, instead of the first packet in the
        transmision queue. This is to minimize the number of retransmitted
        packets on the broadcast media.
      
      When the new functionality is taken into use in the next commits,
      we expect it to have minimal effect on unicast mode performance.
      Signed-off-by: default avatarJon Maloy <jon.maloy@ericsson.com>
      Reviewed-by: default avatarYing Xue <ying.xue@windriver.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c1ab3f1d
    • Jon Paul Maloy's avatar
      tipc: use explicit allocation of broadcast send link · 32301906
      Jon Paul Maloy authored
      The broadcast link instance (struct tipc_link) used for sending is
      currently aggregated into struct tipc_bclink. This means that we cannot
      use the regular tipc_link_create() function for initiating the link, but
      do instead have to initiate numerous fields directly from the
      bcast_init() function.
      
      We want to reduce dependencies between the broadcast functionality
      and the inner workings of tipc_link. In this commit, we introduce
      a new function tipc_bclink_create() to link.c, and allocate the
      instance of the link separately using this function.
      Signed-off-by: default avatarJon Maloy <jon.maloy@ericsson.com>
      Reviewed-by: default avatarYing Xue <ying.xue@windriver.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      32301906