From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6EBBE471CE4 for ; Wed, 26 Aug 2026 20:27:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787776031; cv=none; b=tRaA0j92Q3aEDER9n8P5tKa8prWUnSBdsVr+MqiaufdcYBsa7t58E6rd68VzDt/sqkLDnULmHt/w6aZAKuzCaNpny1yTWCG4Nc0gaLonxhz62KdU/ZjoXcoMG6UXD2HIH0iGLJjz3v9tk/ym63IZ4yyxA2SJUVvcXKuVpdROrdc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787776031; c=relaxed/simple; bh=aq0RIZOA0Rm1iSojL4qVeXiKqTxXw6cRpM+5iAuLm5U=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=tKYZt/Np2++rV14Fu6zXzXG3CXDhjGcy/llZnuPEys735SUhBuOoEkk6RyPmiovAYVu5QRznqD899z7MhA5j0PADZ6JHbXTvnxMp3xYAAOOQpF6n6zKGZ2uhawp8C9zwH43FVSQ1i3Ozgf3P412ybQUu7vFUXcIrBC+OfHyUxgY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=N4X0Kujk; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="N4X0Kujk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 793DD1F000E9; Wed, 26 Aug 2026 20:27:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787776026; bh=S6pI0ycjmUUXDD+U51XyrdkpwGc8BLyYx7TpfN8ajHo=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=N4X0KujkUG/JWQYafKeuajtJlzFr/cOAFnpGOUqsH69Ozr9FTlXeDlaiiwikduaKS O7xpZ7KkH/HO46wkkOkoPuwZ7MKfDnhKxR5ysxG6ElYc5OEC/LT8tO30N8LGXL3g3S X1R8nupZN+mu3AroyO44l9r/gffQRUv+F/ADHhqRybUCicesNGq/26FBilcb+PvOAC LwcvY+haYtP9Gn5fHQ756kfc4r55Wlmam+Z8jI2oBm/1Msb2g6b1GJAq2xyvktAFBO ShAd65bKWCWBNmOETZuR7xAL/LKBbziboAtRFOrZ+9pFNC3Csv/eLtCcoctJOYBeNj Km5FkP4aC/kfw== From: Chuck Lever Date: Wed, 26 Aug 2026 16:26:54 -0400 Subject: [PATCH 4/7] SUNRPC: Mark connection-oriented transports on svc_xprt Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260826-duplicate-reply-cache-v1-4-b1d51e1af5c7@kernel.org> References: <20260826-duplicate-reply-cache-v1-0-b1d51e1af5c7@kernel.org> In-Reply-To: <20260826-duplicate-reply-cache-v1-0-b1d51e1af5c7@kernel.org> To: Jeff Layton , NeilBrown , Olga Kornievskaia , Dai Ngo , Tom Talpey Cc: Rick Macklem , linux-nfs@vger.kernel.org, Chuck Lever X-Mailer: b4 0.16-dev-da966 X-Developer-Signature: v=1; a=openpgp-sha256; l=3279; i=cel@kernel.org; h=from:subject:message-id; bh=aq0RIZOA0Rm1iSojL4qVeXiKqTxXw6cRpM+5iAuLm5U=; b=owEBbQKS/ZANAwAKATNqszNvZn+XAcsmYgBqj0wVDXRYrOqSv6zg/PSEoZqhjqeRNJHKF5u3W SqTchLjumuJAjMEAAEKAB0WIQQosuWwEobfJDzyPv4zarMzb2Z/lwUCao9MFQAKCRAzarMzb2Z/ l+xEEACas/4eUMdLeLYXvDAFEHqG73nU0LR+MqwanyFizqgj5danqEoXID0h1N4J/Tu5y/URcYl gOoZL6zqXXFjjMaFDEWC9upYCWarY5cTgJ6z41LvuZMa1jv/Go4eczPg4yuzCbRPDnBT7VV9eCv ZaTOZLAEDweqpqXs5wkCDw+GmIO/LAkNPAdnHQe7weIVop4ye1oZyo751fQ0Oeh7/U5BFHKG7ch fmE39gPH5xEhXGcgvbn7m78+9cSJkAGAcv3QEL0WRx1JpxiR3rGa6vIPfmYOpRIIMbiYIh53Vhm UR5MdN+XPO1uCgwVnHoWMCILY6VPKl9EffcJWD7K3LD1LOkj6CHA0SmKUiA5MqJYyeiHJzrOkQD SXzzogkfMOOnKUbpCxseA1VJhnCqDfGIJdD23RfkAv/m8uWq+gKt3DBkXV56iqgIgG65XLZ0ul3 Gf/5my0Zp25YqUuJG9AXeAxkPIzJl0svJK1P0uomE4QUX3+JbmpXDBy+Uec6W3VjGUge+UlxwZG Qt+dDuWE9wct8DYZlTGvTHBfYjXPtxyNxmRFzXBexMkllgAjEhKyZP7/VQjzFvdy0RTzZ7/1UH8 QqKem39qMyvo79TByf+9nXSLXm34DBiemZ9Ytp/wcvRpJSLnBMXvqekiRIgC/XN00tYYpj6iSsR nQxIBVTKbTCMQwA== X-Developer-Key: i=cel@kernel.org; a=openpgp; fpr=28B2E5B01286DF243CF23EFE336AB3336F667F97 A TCP or RDMA svc_xprt carries one client's request stream, delivered reliably and in order, so a later request on it indicates that earlier replies reached the client. A UDP svc_xprt is shared by every peer and offers no such signal. Add an XPT_ORDERED flag, set by the TCP and RDMA init paths and clear for UDP, so the NFSD duplicate reply cache can confine implied-ACK eviction to transports where the signal holds. The flag has a cost on svcrdma. handle_connect_req() zeroes the remote port in the DRC key so a cached reply survives a reconnect, and implied-ACK eviction can retire such an entry while the original connection is still up. TCP gives up the same thing whenever a client re-binds its reserved port, so this follows from the eviction policy rather than from RDMA. Signed-off-by: Chuck Lever --- include/linux/sunrpc/svc_xprt.h | 1 + include/trace/events/sunrpc.h | 1 + net/sunrpc/svcsock.c | 1 + net/sunrpc/xprtrdma/svc_rdma_transport.c | 1 + 4 files changed, 4 insertions(+) diff --git a/include/linux/sunrpc/svc_xprt.h b/include/linux/sunrpc/svc_xprt.h index 53ed073640a6..ebab18e403b2 100644 --- a/include/linux/sunrpc/svc_xprt.h +++ b/include/linux/sunrpc/svc_xprt.h @@ -99,6 +99,7 @@ enum { XPT_LOCAL, /* connection from loopback interface */ XPT_KILL_TEMP, /* call xpo_kill_temp_xprt before closing */ XPT_CONG_CTRL, /* has congestion control */ + XPT_ORDERED, /* connection-oriented, in-order delivery */ XPT_HANDSHAKE, /* xprt requests a handshake */ XPT_TLS_SESSION, /* transport-layer security established */ XPT_PEER_AUTH, /* peer has been authenticated */ diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h index 180346e520ff..2154fbe69945 100644 --- a/include/trace/events/sunrpc.h +++ b/include/trace/events/sunrpc.h @@ -1931,6 +1931,7 @@ TRACE_EVENT(svc_stats_latency, svc_xprt_flag(LOCAL) \ svc_xprt_flag(KILL_TEMP) \ svc_xprt_flag(CONG_CTRL) \ + svc_xprt_flag(ORDERED) \ svc_xprt_flag(HANDSHAKE) \ svc_xprt_flag(TLS_SESSION) \ svc_xprt_flag(PEER_AUTH) \ diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 840bec53e1ee..97a592ddeb48 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -1486,6 +1486,7 @@ static bool svc_tcp_init(struct svc_sock *svsk, struct svc_serv *serv) return false; set_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags); set_bit(XPT_CONG_CTRL, &svsk->sk_xprt.xpt_flags); + set_bit(XPT_ORDERED, &svsk->sk_xprt.xpt_flags); if (sk->sk_state == TCP_LISTEN) { strcpy(svsk->sk_xprt.xpt_remotebuf, "listener"); set_bit(XPT_LISTENER, &svsk->sk_xprt.xpt_flags); diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c index fabdfd891a41..5d39fce231a3 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -218,6 +218,7 @@ static struct svcxprt_rdma *svc_rdma_create_xprt(struct svc_serv *serv, * transports are suitable here. */ set_bit(XPT_CONG_CTRL, &cma_xprt->sc_xprt.xpt_flags); + set_bit(XPT_ORDERED, &cma_xprt->sc_xprt.xpt_flags); return cma_xprt; } -- 2.55.0