RPC: Shrink struct rpc_auth for those flavours that don't use the cache

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

include/linux/sunrpc/auth.h

@@ -58,10 +58,13 @@ struct rpc_cred {
  */
 #define RPC_CREDCACHE_NR	8
 #define RPC_CREDCACHE_MASK	(RPC_CREDCACHE_NR - 1)
+struct rpc_cred_cache {
+	struct hlist_head	hashtable[RPC_CREDCACHE_NR];
+	unsigned long		nextgc;		/* next garbage collection */
+	unsigned long		expire;		/* cache expiry interval */
+};
+
 struct rpc_auth {
-	struct hlist_head	au_credcache[RPC_CREDCACHE_NR];
-	unsigned long		au_expire;	/* cache expiry interval */
-	unsigned long		au_nextgc;	/* next garbage collection */
 	unsigned int		au_cslack;	/* call cred size estimate */
 	unsigned int		au_rslack;	/* reply verf size guess */
 	unsigned int		au_flags;	/* various flags */
@@ -72,6 +75,7 @@ struct rpc_auth {
 						 * case) */
 	atomic_t		au_count;	/* Reference counter */
 
+	struct rpc_cred_cache *	au_credcache;
 	/* per-flavor data */
 };
 #define RPC_AUTH_PROC_CREDS	0x0010		/* process creds (including
@@ -131,7 +135,7 @@ int			rpcauth_unwrap_resp(struct rpc_task *task, kxdrproc_t decode, void *rqstp,
 int			rpcauth_refreshcred(struct rpc_task *);
 void			rpcauth_invalcred(struct rpc_task *);
 int			rpcauth_uptodatecred(struct rpc_task *);
-void			rpcauth_init_credcache(struct rpc_auth *);
+int			rpcauth_init_credcache(struct rpc_auth *, unsigned long);
 void			rpcauth_free_credcache(struct rpc_auth *);
 
 static inline

net/sunrpc/auth.c

@@ -89,13 +89,21 @@ static DEFINE_SPINLOCK(rpc_credcache_lock);
 /*
  * Initialize RPC credential cache
  */
-void
-rpcauth_init_credcache(struct rpc_auth *auth)
+int
+rpcauth_init_credcache(struct rpc_auth *auth, unsigned long expire)
 {
+	struct rpc_cred_cache *new;
 	int i;
+
+	new = (struct rpc_cred_cache *)kmalloc(sizeof(*new), GFP_KERNEL);
+	if (!new)
+		return -ENOMEM;
 	for (i = 0; i < RPC_CREDCACHE_NR; i++)
-		INIT_HLIST_HEAD(&auth->au_credcache[i]);
-	auth->au_nextgc = jiffies + (auth->au_expire >> 1);
+		INIT_HLIST_HEAD(&new->hashtable[i]);
+	new->expire = expire;
+	new->nextgc = jiffies + (expire >> 1);
+	auth->au_credcache = new;
+	return 0;
 }
 
 /*
@@ -120,6 +128,7 @@ void rpcauth_destroy_credlist(struct hlist_head *head)
 void
 rpcauth_free_credcache(struct rpc_auth *auth)
 {
+	struct rpc_cred_cache *cache = auth->au_credcache;
 	HLIST_HEAD(free);
 	struct hlist_node *pos, *next;
 	struct rpc_cred	*cred;
@@ -127,7 +136,7 @@ rpcauth_free_credcache(struct rpc_auth *auth)
 
 	spin_lock(&rpc_credcache_lock);
 	for (i = 0; i < RPC_CREDCACHE_NR; i++) {
-		hlist_for_each_safe(pos, next, &auth->au_credcache[i]) {
+		hlist_for_each_safe(pos, next, &cache->hashtable[i]) {
 			cred = hlist_entry(pos, struct rpc_cred, cr_hash);
 			__hlist_del(&cred->cr_hash);
 			hlist_add_head(&cred->cr_hash, &free);
@@ -142,7 +151,7 @@ rpcauth_prune_expired(struct rpc_auth *auth, struct rpc_cred *cred, struct hlist
 {
 	if (atomic_read(&cred->cr_count) != 1)
 	       return;
-	if (time_after(jiffies, cred->cr_expire + auth->au_expire))
+	if (time_after(jiffies, cred->cr_expire + auth->au_credcache->expire))
 		cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
 	if (!(cred->cr_flags & RPCAUTH_CRED_UPTODATE)) {
 		__hlist_del(&cred->cr_hash);
@@ -156,18 +165,19 @@ rpcauth_prune_expired(struct rpc_auth *auth, struct rpc_cred *cred, struct hlist
 static void
 rpcauth_gc_credcache(struct rpc_auth *auth, struct hlist_head *free)
 {
+	struct rpc_cred_cache *cache = auth->au_credcache;
 	struct hlist_node *pos, *next;
 	struct rpc_cred	*cred;
 	int		i;
 
 	dprintk("RPC: gc'ing RPC credentials for auth %p\n", auth);
 	for (i = 0; i < RPC_CREDCACHE_NR; i++) {
-		hlist_for_each_safe(pos, next, &auth->au_credcache[i]) {
+		hlist_for_each_safe(pos, next, &cache->hashtable[i]) {
 			cred = hlist_entry(pos, struct rpc_cred, cr_hash);
 			rpcauth_prune_expired(auth, cred, free);
 		}
 	}
-	auth->au_nextgc = jiffies + auth->au_expire;
+	cache->nextgc = jiffies + cache->expire;
 }
 
 /*
@@ -177,6 +187,7 @@ struct rpc_cred *
 rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
 		int taskflags)
 {
+	struct rpc_cred_cache *cache = auth->au_credcache;
 	HLIST_HEAD(free);
 	struct hlist_node *pos, *next;
 	struct rpc_cred	*new = NULL,
@@ -187,9 +198,9 @@ rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
 		nr = acred->uid & RPC_CREDCACHE_MASK;
 retry:
 	spin_lock(&rpc_credcache_lock);
-	if (time_before(auth->au_nextgc, jiffies))
+	if (time_before(cache->nextgc, jiffies))
 		rpcauth_gc_credcache(auth, &free);
-	hlist_for_each_safe(pos, next, &auth->au_credcache[nr]) {
+	hlist_for_each_safe(pos, next, &cache->hashtable[nr]) {
 		struct rpc_cred *entry;
 	       	entry = hlist_entry(pos, struct rpc_cred, cr_hash);
 		if (entry->cr_ops->crmatch(acred, entry, taskflags)) {
@@ -206,7 +217,7 @@ rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
 			cred = new;
 	}
 	if (cred) {
-		hlist_add_head(&cred->cr_hash, &auth->au_credcache[nr]);
+		hlist_add_head(&cred->cr_hash, &cache->hashtable[nr]);
 		get_rpccred(cred);
 	}
 	spin_unlock(&rpc_credcache_lock);

net/sunrpc/auth_gss/auth_gss.c

@@ -581,12 +581,12 @@ gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 	auth = &gss_auth->rpc_auth;
 	auth->au_cslack = GSS_CRED_SLACK >> 2;
 	auth->au_rslack = GSS_VERF_SLACK >> 2;
-	auth->au_expire = GSS_CRED_EXPIRE;
 	auth->au_ops = &authgss_ops;
 	auth->au_flavor = flavor;
 	atomic_set(&auth->au_count, 1);
 
-	rpcauth_init_credcache(auth);
+	if (rpcauth_init_credcache(auth, GSS_CRED_EXPIRE) < 0)
+		goto err_put_mech;
 
 	snprintf(gss_auth->path, sizeof(gss_auth->path), "%s/%s",
 			clnt->cl_pathname,

net/sunrpc/auth_unix.c

@@ -37,6 +37,7 @@ struct unx_cred {
 #endif
 
 static struct rpc_auth		unix_auth;
+static struct rpc_cred_cache	unix_cred_cache;
 static struct rpc_credops	unix_credops;
 
 static struct rpc_auth *
@@ -44,7 +45,7 @@ unx_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 {
 	dprintk("RPC: creating UNIX authenticator for client %p\n", clnt);
 	if (atomic_inc_return(&unix_auth.au_count) == 0)
-		unix_auth.au_nextgc = jiffies + (unix_auth.au_expire >> 1);
+		unix_cred_cache.nextgc = jiffies + (unix_cred_cache.expire >> 1);
 	return &unix_auth;
 }
 
@@ -228,13 +229,18 @@ struct rpc_authops	authunix_ops = {
 	.crcreate	= unx_create_cred,
 };
 
+static
+struct rpc_cred_cache	unix_cred_cache = {
+	.expire		= UNX_CRED_EXPIRE,
+};
+
 static
 struct rpc_auth		unix_auth = {
 	.au_cslack	= UNX_WRITESLACK,
 	.au_rslack	= 2,			/* assume AUTH_NULL verf */
-	.au_expire	= UNX_CRED_EXPIRE,
 	.au_ops		= &authunix_ops,
 	.au_count	= ATOMIC_INIT(0),
+	.au_credcache	= &unix_cred_cache,
 };
 
 static