linux.git/include/trace/events/rxrpc.h, branch v6.6

rxrpc: Fix overproduction of wakeups to recvmsg()

2023-02-20T07:33:25+00:00

Fix three cases of overproduction of wakeups:

 (1) rxrpc_input_split_jumbo() conditionally notifies the app that there's
     data for recvmsg() to collect if it queues some data - and then its
     only caller, rxrpc_input_data(), goes and wakes up recvmsg() anyway.

     Fix the rxrpc_input_data() to only do the wakeup in failure cases.

 (2) If a DATA packet is received for a call by the I/O thread whilst
     recvmsg() is busy draining the call's rx queue in the app thread, the
     call will left on the recvmsg() queue for recvmsg() to pick up, even
     though there isn't any data on it.

     This can cause an unexpected recvmsg() with a 0 return and no MSG_EOR
     set after the reply has been posted to a service call.

     Fix this by discarding pending calls from the recvmsg() queue that
     don't need servicing yet.

 (3) Not-yet-completed calls get requeued after having data read from them,
     even if they have no data to read.

     Fix this by only requeuing them if they have data waiting on them; if
     they don't, the I/O thread will requeue them when data arrives or they
     fail.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/3386149.1676497685@warthog.procyon.org.uk
Signed-off-by: Paolo Abeni

rxrpc: Trace ack.rwind

2023-02-07T23:11:21+00:00

Log ack.rwind in the rxrpc_tx_ack tracepoint.  This value is useful to see
as it represents flow-control information to the peer.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Change rx_packet tracepoint to display securityIndex not type twice

2023-01-31T16:38:35+00:00

Change the rx_packet tracepoint to display the securityIndex from the
packet header instead of displaying the type in numeric form.  There's no
need for the latter, as the display of the type in symbolic form will fall
back automatically to displaying the hex value if no symbol is available.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Simplify ACK handling

2023-01-31T16:38:35+00:00

Now that general ACK transmission is done from the same thread as incoming
DATA packet wrangling, there's no possibility that the SACK table will be
being updated by the latter whilst the former is trying to copy it to an
ACK.

This means that we can safely rotate the SACK table whilst updating it
without having to take a lock, rather than keeping all the bits inside it
in fixed place and copying and then rotating it in the transmitter.

Therefore, simplify SACK handing by keeping track of starting point in the
ring and rotate slots down as we consume them.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

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

2023-01-31T16:38:26+00:00

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 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

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

2023-01-31T16:38:10+00:00

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 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Shrink the tabulation in the rxrpc trace header a bit

2023-01-31T16:37:44+00:00

Shrink the tabulation in the rxrpc trace header a bit to allow for fields
with long type names that have been removed.

Signed-off-by: David Howells

rxrpc: Remove whitespace before ')' in trace header

2023-01-31T16:36:15+00:00

Work around checkpatch warnings in the rxrpc trace header by removing
whitespace before ')' on lines defining the trace record struct.

Signed-off-by: David Howells

rxrpc: Fix trace string

2023-01-30T14:13:29+00:00

Fix a trace string to indicate that it's discarding the local endpoint for
a preallocated peer, not a preallocated connection.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Move client call connection to the I/O thread

2023-01-06T09:43:33+00:00

Move the connection setup of client calls to the I/O thread so that a whole
load of locking and barrierage can be eliminated.  This necessitates the
app thread waiting for connection to complete before it can begin
encrypting data.

This also completes the 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 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org