[PATCH net 0/3] rxrpc: Fix retransmission timeout and ACK discard [ver #2]

[David Howells]

Here are a couple of fixes and an extra tracepoint for AF_RXRPC:

 (1) Calculate the RTO pretty much as TCP does, rather than making
     something up, including an initial 4s timeout (which causes return
     probes from the fileserver to fail if a packet goes missing), and add
     backoff.

 (2) Fix the discarding of out-of-order received ACKs.  We mustn't let the
     hard-ACK point regress, nor do we want to do unnecessary
     retransmission because the soft-ACK list regresses.  This is not
     trivial, however, due to some loose wording in various old protocol
     specs, the ACK field that should be used for this sometimes has the
     wrong information in it.

 (3) Add a tracepoint to log a discarded ACK.

[V2] Fixed a "Fixes" line in a commit message.

The patches are tagged here:

	git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git
	rxrpc-fixes-20200520

and can also be found on the following branch:

	http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=rxrpc-fixes

David
---
David Howells (1):
      rxrpc: Fix ack discard


 fs/afs/fs_probe.c            |  18 ++--
 fs/afs/vl_probe.c            |  18 ++--
 include/net/af_rxrpc.h       |   2 +-
 include/trace/events/rxrpc.h |  52 +++++++++---
 net/rxrpc/Makefile           |   1 +
 net/rxrpc/ar-internal.h      |  25 ++++--
 net/rxrpc/call_accept.c      |   2 +-
 net/rxrpc/call_event.c       |  22 ++---
 net/rxrpc/input.c            |  44 ++++++++--
 net/rxrpc/misc.c             |   5 --
 net/rxrpc/output.c           |   9 +-
 net/rxrpc/peer_event.c       |  46 ----------
 net/rxrpc/peer_object.c      |  12 +--
 net/rxrpc/proc.c             |   8 +-
 net/rxrpc/rtt.c              | 195 +++++++++++++++++++++++++++++++++++++++++++
 net/rxrpc/sendmsg.c          |  26 ++----
 net/rxrpc/sysctl.c           |   9 --
 17 files changed, 335 insertions(+), 159 deletions(-)
 create mode 100644 net/rxrpc/rtt.c