rxrpc: Extract useful fields from a received ACK to skb priv data

Extract useful fields from a received ACK packet into the skb private data
early on in the process of parsing incoming packets. Thi

rxrpc: Extract useful fields from a received ACK to skb priv data

Extract useful fields from a received ACK packet into the skb private data
early on in the process of parsing incoming packets. This makes the ACK
fields available even before we've matched the ACK up to a call and will
allow us to deal with path MTU discovery probe responses even after the
relevant call has been completed.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

show more ...

rxrpc: Clean up the resend algorithm

Clean up the DATA packet resending algorithm to retransmit packets as we
come across them whilst walking the transmission buffer rather than queuing
them for ret

rxrpc: Clean up the resend algorithm

Clean up the DATA packet resending algorithm to retransmit packets as we
come across them whilst walking the transmission buffer rather than queuing
them for retransmission at the end. This can be done as ACK parsing - and
thus the discarding of successful packets - is now done in the same thread
rather than separately in softirq context and a locked section is no longer
required.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

show more ...

rxrpc: Use ktimes for call timeout tracking and set the timer lazily

Track the call timeouts as ktimes rather than jiffies as the latter's
granularity is too high and only set the timer at the end o

rxrpc: Use ktimes for call timeout tracking and set the timer lazily

Track the call timeouts as ktimes rather than jiffies as the latter's
granularity is too high and only set the timer at the end of the event
handling function.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

show more ...

rxrpc: Differentiate PING ACK transmission traces.

There are three points that transmit PING ACKs and all of them use the same
trace string. Change two of them to use different strings.

Signed-off

rxrpc: Differentiate PING ACK transmission traces.

There are three points that transmit PING ACKs and all of them use the same
trace string. Change two of them to use different strings.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

show more ...

rxrpc: Don't permit resending after all Tx packets acked

Once all the packets transmitted as part of a call have been acked, don't
permit any resending.

Signed-off-by: David Howells <dhowells@redha

rxrpc: Don't permit resending after all Tx packets acked

Once all the packets transmitted as part of a call have been acked, don't
permit any resending.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

show more ...

rxrpc: Parse received packets before dealing with timeouts

Parse the received packets before going and processing timeouts as the
timeouts may be reset by the reception of a packet.

Signed-off-by:

rxrpc: Parse received packets before dealing with timeouts

Parse the received packets before going and processing timeouts as the
timeouts may be reset by the reception of a packet.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

show more ...

rxrpc: Move rxrpc_send_ACK() to output.c with rxrpc_send_ack_packet()

Move rxrpc_send_ACK() to output.c to so that it is with
rxrpc_send_ack_packet() prior to merging the two.

Signed-off-by: David

rxrpc: Move rxrpc_send_ACK() to output.c with rxrpc_send_ack_packet()

Move rxrpc_send_ACK() to output.c to so that it is with
rxrpc_send_ack_packet() prior to merging the two.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

show more ...

rxrpc: Remove atomic handling on some fields only used in I/O thread

call->tx_transmitted and call->acks_prev_seq don't need to be managed with
cmpxchg() and barriers as it's only used within the si

rxrpc: Remove atomic handling on some fields only used in I/O thread

call->tx_transmitted and call->acks_prev_seq don't need to be managed with
cmpxchg() and barriers as it's only used within the singular I/O thread.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

show more ...

rxrpc: Strip barriers and atomics off of timer tracking

Strip the atomic ops and barriering off of the call timer tracking as this
is handled solely within the I/O thread, except for expect_term_by

rxrpc: Strip barriers and atomics off of timer tracking

Strip the atomic ops and barriering off of the call timer tracking as this
is handled solely within the I/O thread, except for expect_term_by which is
set by sendmsg().

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

show more ...

rxrpc: Convert rxrpc_txbuf::flags into a mask and don't use atomics

Convert the transmission buffer flags into a mask and use | and & rather
than bitops functions (atomic ops are not required as onl

rxrpc: Convert rxrpc_txbuf::flags into a mask and don't use atomics

Convert the transmission buffer flags into a mask and use | and & rather
than bitops functions (atomic ops are not required as only the I/O thread
can manipulate them once submitted for transmission).

The bottom byte can then correspond directly to the Rx protocol header
flags.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

show more ...

rxrpc: Record the Tx serial in the rxrpc_txbuf and retransmit trace

Each Rx protocol packet contains a per-connection monotonically increasing
serial number used to correlate outgoing messages with

rxrpc: Record the Tx serial in the rxrpc_txbuf and retransmit trace

Each Rx protocol packet contains a per-connection monotonically increasing
serial number used to correlate outgoing messages with their replies -
something that can be used for RTT calculation.

Note this value in the rxrpc_txbuf struct in addition to the wire header
and then log it in the rxrpc_retransmit trace for reference.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

show more ...

rxrpc: Fix counting of new acks and nacks

Fix the counting of new acks and nacks when parsing a packet - something
that is used in congestion control.

As the code stands, it merely notes if there a

rxrpc: Fix counting of new acks and nacks

Fix the counting of new acks and nacks when parsing a packet - something
that is used in congestion control.

As the code stands, it merely notes if there are any nacks whereas what we
really should do is compare the previous SACK table to the new one,
assuming we get two successive ACK packets with nacks in them. However, we
really don't want to do that if we can avoid it as the tables might not
correspond directly as one may be shifted from the other - something that
will only get harder to deal with once extended ACK tables come into full
use (with a capacity of up to 8192).

Instead, count the number of nacks shifted out of the old SACK, the number
of nacks retained in the portion still active and the number of new acks
and nacks in the new table then calculate what we need.

Note this ends up a bit of an estimate as the Rx protocol allows acks to be
withdrawn by the receiver and packets requested to be retransmitted.

Fixes: d57a3a151660 ("rxrpc: Save last ACK's SACK table rather than marking txbufs")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

rxrpc: Fix delayed ACKs to not set the reference serial number

Fix the construction of delayed ACKs to not set the reference serial number
as they can't be used as an RTT reference.

Fixes: 17926a79

rxrpc: Fix delayed ACKs to not set the reference serial number

Fix the construction of delayed ACKs to not set the reference serial number
as they can't be used as an RTT reference.

Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

rxrpc: De-atomic call->ackr_window and call->ackr_nr_unacked

call->ackr_window doesn't need to be atomic as ACK generation and ACK
transmission are now done in the same thread, so drop the atomic64

rxrpc: De-atomic call->ackr_window and call->ackr_nr_unacked

call->ackr_window doesn't need to be atomic as ACK generation and ACK
transmission are now done in the same thread, so drop the atomic64 handling
and split it into two separate members.

Similarly, call->ackr_nr_unacked doesn't need to be atomic now either.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

show more ...

rxrpc: Generate extra pings for RTT during heavy-receive call

When doing a call that has a single transmitted data packet and a massive
amount of received data packets, we only ping for one RTT samp

rxrpc: Generate extra pings for RTT during heavy-receive call

When doing a call that has a single transmitted data packet and a massive
amount of received data packets, we only ping for one RTT sample, which
means we don't get a good reading on it.

Fix this by converting occasional IDLE ACKs into PING ACKs to elicit a
response.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

show more ...

rxrpc: Remove call->state_lock

All the setters of call->state are now in the I/O thread and thus the state
lock is now unnecessary.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionn

rxrpc: Remove call->state_lock

All the setters of call->state are now in the I/O thread and thus the state
lock is now unnecessary.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

show more ...

rxrpc: Move call state changes from sendmsg to I/O thread

Move all the call state changes that are made in rxrpc_sendmsg() to the I/O
thread. This is a step towards removing the call state lock.

T

rxrpc: Move call state changes from sendmsg to I/O thread

Move all the call state changes that are made in rxrpc_sendmsg() to the I/O
thread. This is a step towards removing the call state lock.

This requires the switch to the RXRPC_CALL_CLIENT_AWAIT_REPLY and
RXRPC_CALL_SERVER_SEND_REPLY states to be done when the last packet is
decanted from ->tx_sendmsg to ->tx_buffer in the I/O thread, not when it is
added to ->tx_sendmsg by sendmsg().

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

show more ...

rxrpc: Tidy up abort generation infrastructure

Tidy up the abort generation infrastructure in the following ways:

(1) Create an enum and string mapping table to list the reasons an abort
migh

rxrpc: Tidy up abort generation infrastructure

Tidy up the abort generation infrastructure in the following ways:

(1) Create an enum and string mapping table to list the reasons an abort
might be generated in tracing.

(2) Replace the 3-char string with the values from (1) in the places that
use that to log the abort source. This gets rid of a memcpy() in the
tracepoint.

(3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint
and use values from (1) to indicate the trace reason.

(4) Always make a call to an abort function at the point of the abort
rather than stashing the values into variables and using goto to get
to a place where it reported. The C optimiser will collapse the calls
together as appropriate. The abort functions return a value that can
be returned directly if appropriate.

Note that this extends into afs also at the points where that generates an
abort. To aid with this, the afs sources need to #define
RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header
because they don't have access to the rxrpc internal structures that some
of the tracepoints make use of.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

show more ...

rxrpc: Only disconnect calls in the I/O thread

Only perform call disconnection in the I/O thread to reduce the locking
requirement.

This is the first part of a fix for a race that exists between ca

rxrpc: Only disconnect calls in the I/O thread

Only perform call disconnection in the I/O thread to reduce the locking
requirement.

This is the first part of a fix for a race that exists between call
connection and call disconnection whereby the data transmission code adds
the call to the peer error distribution list after the call has been
disconnected (say by the rxrpc socket getting closed).

The fix is to complete the process of moving call connection, data
transmission and call disconnection into the I/O thread and thus forcibly
serialising them.

Note that the issue may predate the overhaul to an I/O thread model that
were included in the merge window for v6.2, but the timing is very much
changed by the change given below.

Fixes: cf37b5987508 ("rxrpc: Move DATA transmission into call processor work item")
Reported-by: syzbot+c22650d2844392afdcfd@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

show more ...

rxrpc: Only set/transmit aborts in the I/O thread

Only set the abort call completion state in the I/O thread and only
transmit ABORT packets from there. rxrpc_abort_call() can then be made to
actua

rxrpc: Only set/transmit aborts in the I/O thread

Only set the abort call completion state in the I/O thread and only
transmit ABORT packets from there. rxrpc_abort_call() can then be made to
actually send the packet.

Further, ABORT packets should only be sent if the call has been exposed to
the network (ie. at least one attempted DATA transmission has occurred for
it).

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

show more ...

rxrpc: Transmit ACKs at the point of generation

For ACKs generated inside the I/O thread, transmit the ACK at the point of
generation. Where the ACK is generated outside of the I/O thread, it's
off

rxrpc: Transmit ACKs at the point of generation

For ACKs generated inside the I/O thread, transmit the ACK at the point of
generation. Where the ACK is generated outside of the I/O thread, it's
offloaded to the I/O thread to transmit it.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

show more ...

rxrpc: Move the cwnd degradation after transmitting packets

When we've gone for >1RTT without transmitting a packet, we should reduce
the ssthresh and cut the cwnd by half (as suggested in RFC2861 s

rxrpc: Move the cwnd degradation after transmitting packets

When we've gone for >1RTT without transmitting a packet, we should reduce
the ssthresh and cut the cwnd by half (as suggested in RFC2861 sec 3.1).

However, we may receive ACK packets in a batch and the first of these may
cut the cwnd, preventing further transmission, and each subsequent one cuts
the cwnd yet further, reducing it to the floor and killing performance.

Fix this by moving the cwnd reset to after doing the transmission and
resetting the base time such that we don't cut the cwnd by half again for
at least another RTT.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

show more ...

rxrpc: Trace/count transmission underflows and cwnd resets

Add a tracepoint to log when a cwnd reset occurs due to lack of
transmission on a call.

Add stat counters to count transmission underflows

rxrpc: Trace/count transmission underflows and cwnd resets

Add a tracepoint to log when a cwnd reset occurs due to lack of
transmission on a call.

Add stat counters to count transmission underflows (ie. when we have tx
window space, but sendmsg doesn't manage to keep up), cwnd resets and
transmission failures.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

show more ...

rxrpc: Remove the _bh annotation from all the spinlocks

None of the spinlocks in rxrpc need a _bh annotation now as the RCU
callback routines no longer take spinlocks and the bulk of the packet
wran

rxrpc: Remove the _bh annotation from all the spinlocks

None of the spinlocks in rxrpc need a _bh annotation now as the RCU
callback routines no longer take spinlocks and the bulk of the packet
wrangling code is now run in the I/O thread, not softirq context.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

show more ...

rxrpc: Make the I/O thread take over the call and local processor work

Move the functions from the call->processor and local->processor work items
into the domain of the I/O thread.

The call event

rxrpc: Make the I/O thread take over the call and local processor work

Move the functions from the call->processor and local->processor work items
into the domain of the I/O thread.

The call event processor, now called from the I/O thread, then takes over
the job of cranking the call state machine, processing incoming packets and
transmitting DATA, ACK and ABORT packets. In a future patch,
rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it
for later transmission.

The call event processor becomes purely received-skb driven. It only
transmits things in response to events. We use "pokes" to queue a dummy
skb to make it do things like start/resume transmitting data. Timer expiry
also results in pokes.

The connection event processor, becomes similar, though crypto events, such
as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item
to avoid doing crypto in the I/O thread.

The local event processor is removed and VERSION response packets are
generated directly from the packet parser. Similarly, ABORTs generated in
response to protocol errors will be transmitted immediately rather than
being pushed onto a queue for later transmission.

Changes:
========
ver #2)
- Fix a couple of introduced lock context imbalances.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

show more ...