linux-stable.git/net/rxrpc/input_rack.c, branch linux-rolling-stable Linux kernel stable tree rxrpc: Fix rack timer warning to report unexpected mode 2026-04-18T08:46:47+00:00 Alok Tiwari alok.a.tiwari@oracle.com 2026-04-08T12:12:35+00:00 eefa0102bfcb0871ece9ac3e633c602698413139 commit 65b3ffe0972ed023acc3981a0f7e1ae5d0208bd3 upstream. rxrpc_rack_timer_expired() clears call->rack_timer_mode to OFF before the switch. The default case warning therefore always prints OFF and doesn't identify the unexpected timer mode. Log the saved mode value instead so the warning reports the actual unexpected rack timer mode. Fixes: 7c482665931b ("rxrpc: Implement RACK/TLP to deal with transmission stalls [RFC8985]") Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Jeffrey Altman <jaltman@auristor.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260408121252.2249051-8-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 65b3ffe0972ed023acc3981a0f7e1ae5d0208bd3 upstream.

rxrpc_rack_timer_expired() clears call->rack_timer_mode to OFF before
the switch. The default case warning therefore always prints OFF and
doesn't identify the unexpected timer mode.

Log the saved mode value instead so the warning reports the actual
unexpected rack timer mode.

Fixes: 7c482665931b ("rxrpc: Implement RACK/TLP to deal with transmission stalls [RFC8985]")
Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: stable@kernel.org
Link: https://patch.msgid.link/20260408121252.2249051-8-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rxrpc: Implement RACK/TLP to deal with transmission stalls [RFC8985] 2024-12-09T21:48:33+00:00 David Howells dhowells@redhat.com 2024-12-04T07:47:07+00:00 7c482665931b6ce7bc72fa5feae6c35567070296 When an rxrpc call is in its transmission phase and is sending a lot of packets, stalls occasionally occur that cause severe performance degradation (eg. increasing the transmission time for a 256MiB payload from 0.7s to 2.5s over a 10G link). rxrpc already implements TCP-style congestion control [RFC5681] and this helps mitigate the effects, but occasionally we're missing a time event that deals with a missing ACK, leading to a stall until the RTO expires. Fix this by implementing RACK/TLP in rxrpc. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
When an rxrpc call is in its transmission phase and is sending a lot of
packets, stalls occasionally occur that cause severe performance
degradation (eg. increasing the transmission time for a 256MiB payload from
0.7s to 2.5s over a 10G link).

rxrpc already implements TCP-style congestion control [RFC5681] and this
helps mitigate the effects, but occasionally we're missing a time event
that deals with a missing ACK, leading to a stall until the RTO expires.

Fix this by implementing RACK/TLP in rxrpc.

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