[RFC PATCH 3/5] sunrpc: wait for gssproxy to start on initial upcall attempt before falling back to legacy upcall

[Jeff Layton <jlayton@redhat.com>]

Currently, the only thing that waits for gssproxy to start is reads
from the use-gss-proxy procfile. That's a little odd, since nothing
but gssproxy itself will likely ever open that file, and all it does
it write to it.

It seems like what we really want instead is for svcrpc code to give
gssproxy a little time to start up in the event that some RPCs come
in before it's ready.

Change it so that the upcall instead waits a little while for gssproxy
to start before giving up. If the wait times out, we go ahead and
disable gssproxy so that later upcalls don't delay.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
 net/sunrpc/auth_gss/svcauth_gss.c | 28 ++++++++++------------------
 1 file changed, 10 insertions(+), 18 deletions(-)

diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index 64c025e..921f388 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -1265,24 +1265,6 @@ out:
 
 DEFINE_SPINLOCK(use_gssp_lock);
 
-static bool use_gss_proxy(struct net *net)
-{
-	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
-
-	if (sn->use_gss_proxy != -1)
-		return sn->use_gss_proxy;
-	spin_lock(&use_gssp_lock);
-	/*
-	 * If you wanted gss-proxy, you should have said so before
-	 * starting to accept requests:
-	 */
-	sn->use_gss_proxy = 0;
-	spin_unlock(&use_gssp_lock);
-	return 0;
-}
-
-#ifdef CONFIG_PROC_FS
-
 static int set_gss_proxy(struct net *net, int type)
 {
 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
@@ -1332,6 +1314,16 @@ static int wait_for_gss_proxy(struct net *net)
 	return ret < 0 ? ret : 0;
 }
 
+static bool use_gss_proxy(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+	if (wait_for_gss_proxy(net))
+		return false;
+	return gssp_ready(sn);
+}
+
+#ifdef CONFIG_PROC_FS
 
 static ssize_t write_gssp(struct file *file, const char __user *buf,
 			 size_t count, loff_t *ppos)
-- 
1.8.4.2