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    rxrpc: Rework peer object handling to use hash table and RCU · be6e6707
    David Howells 提交于
    Rework peer object handling to use a hash table instead of a flat list and
    to use RCU.  Peer objects are no longer destroyed by passing them to a
    workqueue to process, but rather are just passed to the RCU garbage
    collector as kfree'able objects.
    
    The hash function uses the local endpoint plus all the components of the
    remote address, except for the RxRPC service ID.  Peers thus represent a
    UDP port on the remote machine as contacted by a UDP port on this machine.
    
    The RCU read lock is used to handle non-creating lookups so that they can
    be called from bottom half context in the sk_error_report handler without
    having to lock the hash table against modification.
    rxrpc_lookup_peer_rcu() *does* take a reference on the peer object as in
    the future, this will be passed to a work item for error distribution in
    the error_report path and this function will cease being used in the
    data_ready path.
    
    Creating lookups are done under spinlock rather than mutex as they might be
    set up due to an external stimulus if the local endpoint is a server.
    
    Captured network error messages (ICMP) are handled with respect to this
    struct and MTU size and RTT are cached here.
    Signed-off-by: NDavid Howells <dhowells@redhat.com>
    be6e6707
input.c 19.8 KB