SUNRPC: Fix rpcauth_prune_expired

We need to make sure that we don't remove creds from the cred_unused list
if they are still under the moratorium, or else they will never get
garbage collected.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

net/sunrpc/auth.c

@@ -228,19 +228,21 @@ static int
 rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
 {
 	spinlock_t *cache_lock;
-	struct rpc_cred *cred;
+	struct rpc_cred *cred, *next;
 	unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
 
-	while (!list_empty(&cred_unused)) {
-		cred = list_entry(cred_unused.next, struct rpc_cred, cr_lru);
+	list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
+
+		/* Enforce a 60 second garbage collection moratorium */
+		if (time_in_range(cred->cr_expire, expired, jiffies) &&
+		    test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
+			continue;
+
 		list_del_init(&cred->cr_lru);
 		number_cred_unused--;
 		if (atomic_read(&cred->cr_count) != 0)
 			continue;
-		/* Enforce a 5 second garbage collection moratorium */
-		if (time_in_range(cred->cr_expire, expired, jiffies) &&
-		    test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0)
-			continue;
+
 		cache_lock = &cred->cr_auth->au_credcache->lock;
 		spin_lock(cache_lock);
 		if (atomic_read(&cred->cr_count) == 0) {