[PATCH 5.10 46/92] afs: Fix fileserver probe RTT handling

[Greg Kroah-Hartman]

From: David Howells <dhowells at redhat.com>

[ Upstream commit ca57f02295f188d6c65ec02202402979880fa6d8 ]

The fileserver probing code attempts to work out the best fileserver to
use for a volume by retrieving the RTT calculated by AF_RXRPC for the
probe call sent to each server and comparing them.  Sometimes, however,
no RTT estimate is available and rxrpc_kernel_get_srtt() returns false,
leading good fileservers to be given an RTT of UINT_MAX and thus causing
the rotation algorithm to ignore them.

Fix afs_select_fileserver() to ignore rxrpc_kernel_get_srtt()'s return
value and just take the estimated RTT it provides - which will be capped
at 1 second.

Fixes: 1d4adfaf6574 ("rxrpc: Make rxrpc_kernel_get_srtt() indicate validity")
Signed-off-by: David Howells <dhowells at redhat.com>
Reviewed-by: Marc Dionne <marc.dionne at auristor.com>
Tested-by: Marc Dionne <marc.dionne at auristor.com>
cc: linux-afs at lists.infradead.org
Link: https://lore.kernel.org/r/166965503999.3392585.13954054113218099395.stgit@warthog.procyon.org.uk/
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 fs/afs/fs_probe.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/afs/fs_probe.c b/fs/afs/fs_probe.c
index e7e98ad63a91..04d42e49fc59 100644
--- a/fs/afs/fs_probe.c
+++ b/fs/afs/fs_probe.c
@@ -161,8 +161,8 @@ void afs_fileserver_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;
 		server->rtt = rtt_us;
 		alist->preferred = index;
-- 
2.35.1