SUNRPC: Simplify lookup code

We no longer need to worry about whether or not the entry is hashed in
order to figure out if the contents are valid. We only care whether or
not the refcount is non-zero.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

include/linux/sunrpc/auth.h

@@ -206,11 +206,11 @@ bool			rpcauth_cred_key_to_expire(struct rpc_auth *, struct rpc_cred *);
 char *			rpcauth_stringify_acceptor(struct rpc_cred *);
 
 static inline
-struct rpc_cred *	get_rpccred(struct rpc_cred *cred)
+struct rpc_cred *get_rpccred(struct rpc_cred *cred)
 {
-	if (cred != NULL)
-		atomic_inc(&cred->cr_count);
-	return cred;
+	if (cred != NULL && atomic_inc_not_zero(&cred->cr_count))
+		return cred;
+	return NULL;
 }
 
 /**
@@ -226,9 +226,7 @@ struct rpc_cred *	get_rpccred(struct rpc_cred *cred)
 static inline struct rpc_cred *
 get_rpccred_rcu(struct rpc_cred *cred)
 {
-	if (atomic_inc_not_zero(&cred->cr_count))
-		return cred;
-	return NULL;
+	return get_rpccred(cred);
 }
 
 #endif /* __KERNEL__ */

net/sunrpc/auth.c

@@ -588,19 +588,15 @@ rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
 		if (!entry->cr_ops->crmatch(acred, entry, flags))
 			continue;
 		if (flags & RPCAUTH_LOOKUP_RCU) {
-			if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) &&
-			    !test_bit(RPCAUTH_CRED_NEW, &entry->cr_flags))
-				cred = entry;
+			if (test_bit(RPCAUTH_CRED_NEW, &entry->cr_flags) ||
+			    atomic_read(&entry->cr_count) == 0)
+				continue;
+			cred = entry;
 			break;
 		}
-		spin_lock(&cache->lock);
-		if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
-			spin_unlock(&cache->lock);
-			continue;
-		}
 		cred = get_rpccred(entry);
-		spin_unlock(&cache->lock);
-		break;
+		if (cred)
+			break;
 	}
 	rcu_read_unlock();
 
@@ -621,7 +617,8 @@ rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
 		if (!entry->cr_ops->crmatch(acred, entry, flags))
 			continue;
 		cred = get_rpccred(entry);
-		break;
+		if (cred)
+			break;
 	}
 	if (cred == NULL) {
 		cred = new;