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. 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