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  1. 08 Sep, 2016 20 commits
  3. 07 Sep, 2016 10 commits
    • David Howells's avatar
      rxrpc: Add tracepoint for working out where aborts happen · 5a42976d
      David Howells authored 
      Add a tracepoint for working out where local aborts happen.  Each
tracepoint call is labelled with a 3-letter code so that they can be
distinguished - and the DATA sequence number is added too where available.

rxrpc_kernel_abort_call() also takes a 3-letter code so that AFS can
indicate the circumstances when it aborts a call.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      5a42976d
    • David Howells's avatar
      rxrpc: Fix returns of call completion helpers · e8d6bbb0
      David Howells authored 
      rxrpc_set_call_completion() returns bool, not int, so the ret variable
should match this.

rxrpc_call_completed() and __rxrpc_call_completed() should return the value
of rxrpc_set_call_completion().
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      e8d6bbb0
    • David Howells's avatar
      rxrpc: Calls shouldn't hold socket refs · 8d94aa38
      David Howells authored 
      rxrpc calls shouldn't hold refs on the sock struct.  This was done so that
the socket wouldn't go away whilst the call was in progress, such that the
call could reach the socket's queues.

However, we can mark the socket as requiring an RCU release and rely on the
RCU read lock.

To make this work, we do:

 (1) rxrpc_release_call() removes the call's call user ID.  This is now
     only called from socket operations and not from the call processor:

	rxrpc_accept_call() / rxrpc_kernel_accept_call()
	rxrpc_reject_call() / rxrpc_kernel_reject_call()
	rxrpc_kernel_end_call()
	rxrpc_release_calls_on_socket()
	rxrpc_recvmsg()

     Though it is also called in the cleanup path of
     rxrpc_accept_incoming_call() before we assign a user ID.

 (2) Pass the socket pointer into rxrpc_release_call() rather than getting
     it from the call so that we can get rid of uninitialised calls.

 (3) Fix call processor queueing to pass a ref to the work queue and to
     release that ref at the end of the processor function (or to pass it
     back to the work queue if we have to requeue).

 (4) Skip out of the call processor function asap if the call is complete
     and don't requeue it if the call is complete.

 (5) Clean up the call immediately that the refcount reaches 0 rather than
     trying to defer it.  Actual deallocation is deferred to RCU, however.

 (6) Don't hold socket refs for allocated calls.

 (7) Use the RCU read lock when queueing a message on a socket and treat
     the call's socket pointer according to RCU rules and check it for
     NULL.

     We also need to use the RCU read lock when viewing a call through
     procfs.

 (8) Transmit the final ACK/ABORT to a client call in rxrpc_release_call()
     if this hasn't been done yet so that we can then disconnect the call.
     Once the call is disconnected, it won't have any access to the
     connection struct and the UDP socket for the call work processor to be
     able to send the ACK.  Terminal retransmission will be handled by the
     connection processor.

 (9) Release all calls immediately on the closing of a socket rather than
     trying to defer this.  Incomplete calls will be aborted.

The call refcount model is much simplified.  Refs are held on the call by:

 (1) A socket's user ID tree.

 (2) A socket's incoming call secureq and acceptq.

 (3) A kernel service that has a call in progress.

 (4) A queued call work processor.  We have to take care to put any call
     that we failed to queue.

 (5) sk_buffs on a socket's receive queue.  A future patch will get rid of
     this.

Whilst we're at it, we can do:

 (1) Get rid of the RXRPC_CALL_EV_RELEASE event.  Release is now done
     entirely from the socket routines and never from the call's processor.

 (2) Get rid of the RXRPC_CALL_DEAD state.  Calls now end in the
     RXRPC_CALL_COMPLETE state.

 (3) Get rid of the rxrpc_call::destroyer work item.  Calls are now torn
     down when their refcount reaches 0 and then handed over to RCU for
     final cleanup.

 (4) Get rid of the rxrpc_call::deadspan timer.  Calls are cleaned up
     immediately they're finished with and don't hang around.
     Post-completion retransmission is handled by the connection processor
     once the call is disconnected.

 (5) Get rid of the dead call expiry setting as there's no longer a timer
     to set.

 (6) rxrpc_destroy_all_calls() can just check that the call list is empty.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      8d94aa38
    • David Howells's avatar
      rxrpc: Use rxrpc_is_service_call() rather than rxrpc_conn_is_service() · 6543ac52
      David Howells authored 
      Use rxrpc_is_service_call() rather than rxrpc_conn_is_service() if the call
is available just in case call->conn is NULL.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      6543ac52
    • David Howells's avatar
      rxrpc: Pass the connection pointer to rxrpc_post_packet_to_call() · 8b7fac50
      David Howells authored 
      Pass the connection pointer to rxrpc_post_packet_to_call() as the call
might get disconnected whilst we're looking at it, but the connection
pointer determined by rxrpc_data_read() is guaranteed by RCU for the
duration of the call.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      8b7fac50
    • David Howells's avatar
      rxrpc: Cache the security index in the rxrpc_call struct · 278ac0cd
      David Howells authored 
      Cache the security index in the rxrpc_call struct so that we can get at it
even when the call has been disconnected and the connection pointer
cleared.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      278ac0cd
    • David Howells's avatar
      rxrpc: Use call->peer rather than call->conn->params.peer · f4fdb352
      David Howells authored 
      Use call->peer rather than call->conn->params.peer to avoid the possibility
of call->conn being NULL and, whilst we're at it, check it for NULL before we
access it.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      f4fdb352
    • David Howells's avatar
      rxrpc: Improve the call tracking tracepoint · fff72429
      David Howells authored 
      Improve the call tracking tracepoint by showing more differentiation
between some of the put and get events, including:

  (1) Getting and putting refs for the socket call user ID tree.

  (2) Getting and putting refs for queueing and failing to queue the call
      processor work item.

Note that these aren't necessarily used in this patch, but will be taken
advantage of in future patches.

An enum is added for the event subtype numbers rather than coding them
directly as decimal numbers and a table of 3-letter strings is provided
rather than a sequence of ?: operators.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      fff72429
    • David Howells's avatar
      rxrpc: Delete unused rxrpc_kernel_free_skb() · e796cb41
      David Howells authored 
      Delete rxrpc_kernel_free_skb() as it's unused.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      e796cb41
    • David Howells's avatar
      rxrpc: Whitespace cleanup · 71a17de3
      David Howells authored 
      Remove some whitespace.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      71a17de3
  5. 06 Sep, 2016 10 commits
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