1. 07 12月, 2016 20 次提交
  2. 06 12月, 2016 19 次提交
  3. 04 12月, 2016 1 次提交
    • I
      ipv4: fib: Replay events when registering FIB notifier · c3852ef7
      Ido Schimmel 提交于
      Commit b90eb754 ("fib: introduce FIB notification infrastructure")
      introduced a new notification chain to notify listeners (f.e., switchdev
      drivers) about addition and deletion of routes.
      
      However, upon registration to the chain the FIB tables can already be
      populated, which means potential listeners will have an incomplete view
      of the tables.
      
      Solve that by dumping the FIB tables and replaying the events to the
      passed notification block. The dump itself is done using RCU in order
      not to starve consumers that need RTNL to make progress.
      
      The integrity of the dump is ensured by reading the FIB change sequence
      counter before and after the dump under RTNL. This allows us to avoid
      the problematic situation in which the dumping process sends a ENTRY_ADD
      notification following ENTRY_DEL generated by another process holding
      RTNL.
      
      Callers of the registration function may pass a callback that is
      executed in case the dump was inconsistent with current FIB tables.
      
      The number of retries until a consistent dump is achieved is set to a
      fixed number to prevent callers from looping for long periods of time.
      In case current limit proves to be problematic in the future, it can be
      easily converted to be configurable using a sysctl.
      Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
      Signed-off-by: NJiri Pirko <jiri@mellanox.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      c3852ef7