linux-toradex.git/net/rxrpc/call_object.c, branch v4.10

rxrpc: Fix checker warning by not passing always-zero value to ERR_PTR()

2016-10-13T07:39:52+00:00

Fix the following checker warning:

	net/rxrpc/call_object.c:279 rxrpc_new_client_call()
	warn: passing zero to 'ERR_PTR'

where a value that's always zero is passed to ERR_PTR() so that it can be
passed to a tracepoint in an auxiliary pointer field.

Just pass NULL instead to the tracepoint.

Fixes: a84a46d73050 ("rxrpc: Add some additional call tracing")
Reported-by: Dan Carpenter 
Signed-off-by: David Howells

rxrpc: Fix loss of PING RESPONSE ACK production due to PING ACKs

2016-10-06T07:11:49+00:00

Separate the output of PING ACKs from the output of other sorts of ACK so
that if we receive a PING ACK and schedule transmission of a PING RESPONSE
ACK, the response doesn't get cancelled by a PING ACK we happen to be
scheduling transmission of at the same time.

If a PING RESPONSE gets lost, the other side might just sit there waiting
for it and refuse to proceed otherwise.

Signed-off-by: David Howells

rxrpc: Fix warning by splitting rxrpc_send_call_packet()

2016-10-06T07:11:49+00:00

Split rxrpc_send_data_packet() to separate ACK generation (which is more
complicated) from ABORT generation.  This simplifies the code a bit and
fixes the following warning:

In file included from ../net/rxrpc/output.c:20:0:
net/rxrpc/output.c: In function 'rxrpc_send_call_packet':
net/rxrpc/ar-internal.h:1187:27: error: 'top' may be used uninitialized in this function [-Werror=maybe-uninitialized]
net/rxrpc/output.c:103:24: note: 'top' was declared here
net/rxrpc/output.c:225:25: error: 'hard_ack' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Reported-by: Arnd Bergmann 
Signed-off-by: David Howells

rxrpc: Fix the call timer handling

2016-09-30T13:40:11+00:00

The call timer's concept of a call timeout (of which there are three) that
is inactive is that it is the timeout has the same expiration time as the
call expiration timeout (the expiration timer is never inactive).  However,
I'm not resetting the timeouts when they expire, leading to repeated
processing of expired timeouts when other timeout events occur.

Fix this by:

 (1) Move the timer expiry detection into rxrpc_set_timer() inside the
     locked section.  This means that if a timeout is set that will expire
     immediately, we deal with it immediately.

 (2) If a timeout is at or before now then it has expired.  When an expiry
     is detected, an event is raised, the timeout is automatically
     inactivated and the event processor is queued.

 (3) If a timeout is at or after the expiry timeout then it is inactive.
     Inactive timeouts do not contribute to the timer setting.

 (4) The call timer callback can now just call rxrpc_set_timer() to handle
     things.

 (5) The call processor work function now checks the event flags rather
     than checking the timeouts directly.

Signed-off-by: David Howells

rxrpc: Keep the call timeouts as ktimes rather than jiffies

2016-09-30T13:40:11+00:00

Keep that call timeouts as ktimes rather than jiffies so that they can be
expressed as functions of RTT.

Signed-off-by: David Howells

rxrpc: Implement slow-start

2016-09-24T22:49:46+00:00

Implement RxRPC slow-start, which is similar to RFC 5681 for TCP.  A
tracepoint is added to log the state of the congestion management algorithm
and the decisions it makes.

Notes:

 (1) Since we send fixed-size DATA packets (apart from the final packet in
     each phase), counters and calculations are in terms of packets rather
     than bytes.

 (2) The ACK packet carries the equivalent of TCP SACK.

 (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly
     suited to SACK of a small number of packets.  It seems that, almost
     inevitably, by the time three 'duplicate' ACKs have been seen, we have
     narrowed the loss down to one or two missing packets, and the
     FLIGHT_SIZE calculation ends up as 2.

 (4) In rxrpc_resend(), if there was no data that apparently needed
     retransmission, we transmit a PING ACK to ask the peer to tell us what
     its Rx window state is.

Signed-off-by: David Howells

rxrpc: Add a tracepoint for the call timer

2016-09-23T14:49:19+00:00

Add a tracepoint to log call timer initiation, setting and expiry.

Signed-off-by: David Howells

rxrpc: Fix call timer

2016-09-23T14:49:19+00:00

Fix the call timer in the following ways:

 (1) If call->resend_at or call->ack_at are before or equal to the current
     time, then ignore that timeout.

 (2) If call->expire_at is before or equal to the current time, then don't
     set the timer at all (possibly we should queue the call).

 (3) Don't skip modifying the timer if timer_pending() is true.  This
     indicates that the timer is working, not that it has expired and is
     running/waiting to run its expiry handler.

Also call rxrpc_set_timer() to start the call timer going rather than
calling add_timer().

Signed-off-by: David Howells

rxrpc: Improve skb tracing

2016-09-17T10:24:04+00:00

Improve sk_buff tracing within AF_RXRPC by the following means:

 (1) Use an enum to note the event type rather than plain integers and use
     an array of event names rather than a big multi ?: list.

 (2) Distinguish Rx from Tx packets and account them separately.  This
     requires the call phase to be tracked so that we know what we might
     find in rxtx_buffer[].

 (3) Add a parameter to rxrpc_{new,see,get,free}_skb() to indicate the
     event type.

 (4) A pair of 'rotate' events are added to indicate packets that are about
     to be rotated out of the Rx and Tx windows.

 (5) A pair of 'lost' events are added, along with rxrpc_lose_skb() for
     packet loss injection recording.

Signed-off-by: David Howells

rxrpc: Add connection tracepoint and client conn state tracepoint

2016-09-17T10:24:03+00:00

Add a pair of tracepoints, one to track rxrpc_connection struct ref
counting and the other to track the client connection cache state.

Signed-off-by: David Howells