[PATCH 5.4 59/64] afs: Fix vlserver probe RTT handling - Greg Kroah-Hartman

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev, Marc Dionne <marc.dionne@auristor.com>,
	David Howells <dhowells@redhat.com>,
	linux-afs@lists.infradead.org,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 59/64] afs: Fix vlserver probe RTT handling
Date: Mon, 19 Jun 2023 12:30:55 +0200	[thread overview]
Message-ID: <20230619102135.875423267@linuxfoundation.org> (raw)
In-Reply-To: <20230619102132.808972458@linuxfoundation.org>

From: David Howells <dhowells@redhat.com>

[ Upstream commit ba00b190670809c1a89326d80de96d714f6004f2 ]

In the same spirit as commit ca57f02295f1 ("afs: Fix fileserver probe
RTT handling"), don't rule out using a vlserver just because there
haven't been enough packets yet to calculate a real rtt.  Always set the
server's probe rtt from the estimate provided by rxrpc_kernel_get_srtt,
which is capped at 1 second.

This could lead to EDESTADDRREQ errors when accessing a cell for the
first time, even though the vl servers are known and have responded to a
probe.

Fixes: 1d4adfaf6574 ("rxrpc: Make rxrpc_kernel_get_srtt() indicate validity")
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-afs@lists.infradead.org
Link: http://lists.infradead.org/pipermail/linux-afs/2023-June/006746.html
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/afs/vl_probe.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/afs/vl_probe.c b/fs/afs/vl_probe.c
index 081b7e5b13f58..163069d9fc161 100644
--- a/fs/afs/vl_probe.c
+++ b/fs/afs/vl_probe.c
@@ -92,8 +92,8 @@ void afs_vlserver_probe_result(struct afs_call *call)
 		}
 	}
 
-	if (rxrpc_kernel_get_srtt(call->net->socket, call->rxcall, &rtt_us) &&
-	    rtt_us < server->probe.rtt) {
+	rxrpc_kernel_get_srtt(call->net->socket, call->rxcall, &rtt_us);
+	if (rtt_us < server->probe.rtt) {
 		server->probe.rtt = rtt_us;
 		alist->preferred = index;
 		have_result = true;
-- 
2.39.2



