[PATCH AUTOSEL 5.4 51/57] afs: Fix to actually set AFS_SERVER_FL_HAVE_EPOCH

[Sasha Levin]

From: David Howells <dhowells@xxxxxxxxxx>

[ Upstream commit 69cf3978f3ada4e54beae4ad44868b5627864884 ]

AFS keeps track of the epoch value from the rxrpc protocol to note (a) when
a fileserver appears to have restarted and (b) when different endpoints of
a fileserver do not appear to be associated with the same fileserver
(ie. all probes back from a fileserver from all of its interfaces should
carry the same epoch).

However, the AFS_SERVER_FL_HAVE_EPOCH flag that indicates that we've
received the server's epoch is never set, though it is used.

Fix this to set the flag when we first receive an epoch value from a probe
sent to the filesystem client from the fileserver.

Fixes: 3bf0fb6f33dd ("afs: Probe multiple fileservers simultaneously")
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/afs/cmservice.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c
index b378cd780ed54..fc5eb0f893049 100644
--- a/fs/afs/cmservice.c
+++ b/fs/afs/cmservice.c
@@ -169,7 +169,7 @@ static int afs_record_cm_probe(struct afs_call *call, struct afs_server *server)
 
 	spin_lock(&server->probe_lock);
 
-	if (!test_bit(AFS_SERVER_FL_HAVE_EPOCH, &server->flags)) {
+	if (!test_and_set_bit(AFS_SERVER_FL_HAVE_EPOCH, &server->flags)) {
 		server->cm_epoch = call->epoch;
 		server->probe.cm_epoch = call->epoch;
 		goto out;
-- 
2.20.1