Merge git://git.linux-nfs.org/pub/linux/nfs-2.6

* git://git.linux-nfs.org/pub/linux/nfs-2.6: (122 commits)
  sunrpc: drop BKL around wrap and unwrap
  NFSv4: Make sure unlock is really an unlock when cancelling a lock
  NLM: fix source address of callback to client
  SUNRPC client: add interface for binding to a local address
  SUNRPC server: record the destination address of a request
  SUNRPC: cleanup transport creation argument passing
  NFSv4: Make the NFS state model work with the nosharedcache mount option
  NFS: Error when mounting the same filesystem with different options
  NFS: Add the mount option "nosharecache"
  NFS: Add support for mounting NFSv4 file systems with string options
  NFS: Add final pieces to support in-kernel mount option parsing
  NFS: Introduce generic mount client API
  NFS: Add enums and match tables for mount option parsing
  NFS: Improve debugging output in NFS in-kernel mount client
  NFS: Clean up in-kernel NFS mount
  NFS: Remake nfsroot_mount as a permanent part of NFS client
  SUNRPC: Add a convenient default for the hostname when calling rpc_create()
  SUNRPC: Rename rpcb_getport to be consistent with new rpcb_getport_sync name
  SUNRPC: Rename rpcb_getport_external routine
  SUNRPC: Allow rpcbind requests to be interrupted by a signal.
  ...

14 files changed, 980 insertions, 660 deletions

diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index 9527f2bb174..aa55d0a03e6 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -13,17 +13,22 @@
 #include <linux/errno.h>
 #include <linux/sunrpc/clnt.h>
 #include <linux/spinlock.h>
+#include <linux/smp_lock.h>
 
 #ifdef RPC_DEBUG
 # define RPCDBG_FACILITY	RPCDBG_AUTH
 #endif
 
-static struct rpc_authops *	auth_flavors[RPC_AUTH_MAXFLAVOR] = {
+static DEFINE_SPINLOCK(rpc_authflavor_lock);
+static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
 	&authnull_ops,		/* AUTH_NULL */
 	&authunix_ops,		/* AUTH_UNIX */
 	NULL,			/* others can be loadable modules */
 };
 
+static LIST_HEAD(cred_unused);
+static unsigned long number_cred_unused;
+
 static u32
 pseudoflavor_to_flavor(u32 flavor) {
 	if (flavor >= RPC_AUTH_MAXFLAVOR)
@@ -32,55 +37,67 @@ pseudoflavor_to_flavor(u32 flavor) {
 }
 
 int
-rpcauth_register(struct rpc_authops *ops)
+rpcauth_register(const struct rpc_authops *ops)
 {
 	rpc_authflavor_t flavor;
+	int ret = -EPERM;
 
 	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
 		return -EINVAL;
-	if (auth_flavors[flavor] != NULL)
-		return -EPERM;		/* what else? */
-	auth_flavors[flavor] = ops;
-	return 0;
+	spin_lock(&rpc_authflavor_lock);
+	if (auth_flavors[flavor] == NULL) {
+		auth_flavors[flavor] = ops;
+		ret = 0;
+	}
+	spin_unlock(&rpc_authflavor_lock);
+	return ret;
 }
 
 int
-rpcauth_unregister(struct rpc_authops *ops)
+rpcauth_unregister(const struct rpc_authops *ops)
 {
 	rpc_authflavor_t flavor;
+	int ret = -EPERM;
 
 	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
 		return -EINVAL;
-	if (auth_flavors[flavor] != ops)
-		return -EPERM;		/* what else? */
-	auth_flavors[flavor] = NULL;
-	return 0;
+	spin_lock(&rpc_authflavor_lock);
+	if (auth_flavors[flavor] == ops) {
+		auth_flavors[flavor] = NULL;
+		ret = 0;
+	}
+	spin_unlock(&rpc_authflavor_lock);
+	return ret;
 }
 
 struct rpc_auth *
 rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
 {
 	struct rpc_auth		*auth;
-	struct rpc_authops	*ops;
+	const struct rpc_authops *ops;
 	u32			flavor = pseudoflavor_to_flavor(pseudoflavor);
 
 	auth = ERR_PTR(-EINVAL);
 	if (flavor >= RPC_AUTH_MAXFLAVOR)
 		goto out;
 
-	/* FIXME - auth_flavors[] really needs an rw lock,
-	 * and module refcounting. */
 #ifdef CONFIG_KMOD
 	if ((ops = auth_flavors[flavor]) == NULL)
 		request_module("rpc-auth-%u", flavor);
 #endif
-	if ((ops = auth_flavors[flavor]) == NULL)
+	spin_lock(&rpc_authflavor_lock);
+	ops = auth_flavors[flavor];
+	if (ops == NULL || !try_module_get(ops->owner)) {
+		spin_unlock(&rpc_authflavor_lock);
 		goto out;
+	}
+	spin_unlock(&rpc_authflavor_lock);
 	auth = ops->create(clnt, pseudoflavor);
+	module_put(ops->owner);
 	if (IS_ERR(auth))
 		return auth;
 	if (clnt->cl_auth)
-		rpcauth_destroy(clnt->cl_auth);
+		rpcauth_release(clnt->cl_auth);
 	clnt->cl_auth = auth;
 
 out:
@@ -88,7 +105,7 @@ out:
 }
 
 void
-rpcauth_destroy(struct rpc_auth *auth)
+rpcauth_release(struct rpc_auth *auth)
 {
 	if (!atomic_dec_and_test(&auth->au_count))
 		return;
@@ -97,11 +114,31 @@ rpcauth_destroy(struct rpc_auth *auth)
 
 static DEFINE_SPINLOCK(rpc_credcache_lock);
 
+static void
+rpcauth_unhash_cred_locked(struct rpc_cred *cred)
+{
+	hlist_del_rcu(&cred->cr_hash);
+	smp_mb__before_clear_bit();
+	clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
+}
+
+static void
+rpcauth_unhash_cred(struct rpc_cred *cred)
+{
+	spinlock_t *cache_lock;
+
+	cache_lock = &cred->cr_auth->au_credcache->lock;
+	spin_lock(cache_lock);
+	if (atomic_read(&cred->cr_count) == 0)
+		rpcauth_unhash_cred_locked(cred);
+	spin_unlock(cache_lock);
+}
+
 /*
  * Initialize RPC credential cache
  */
 int
-rpcauth_init_credcache(struct rpc_auth *auth, unsigned long expire)
+rpcauth_init_credcache(struct rpc_auth *auth)
 {
 	struct rpc_cred_cache *new;
 	int i;
@@ -111,8 +148,7 @@ rpcauth_init_credcache(struct rpc_auth *auth, unsigned long expire)
 		return -ENOMEM;
 	for (i = 0; i < RPC_CREDCACHE_NR; i++)
 		INIT_HLIST_HEAD(&new->hashtable[i]);
-	new->expire = expire;
-	new->nextgc = jiffies + (expire >> 1);
+	spin_lock_init(&new->lock);
 	auth->au_credcache = new;
 	return 0;
 }
@@ -121,13 +157,13 @@ rpcauth_init_credcache(struct rpc_auth *auth, unsigned long expire)
  * Destroy a list of credentials
  */
 static inline
-void rpcauth_destroy_credlist(struct hlist_head *head)
+void rpcauth_destroy_credlist(struct list_head *head)
 {
 	struct rpc_cred *cred;
 
-	while (!hlist_empty(head)) {
-		cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
-		hlist_del_init(&cred->cr_hash);
+	while (!list_empty(head)) {
+		cred = list_entry(head->next, struct rpc_cred, cr_lru);
+		list_del_init(&cred->cr_lru);
 		put_rpccred(cred);
 	}
 }
@@ -137,58 +173,95 @@ void rpcauth_destroy_credlist(struct hlist_head *head)
  * that are not referenced.
  */
 void
-rpcauth_free_credcache(struct rpc_auth *auth)
+rpcauth_clear_credcache(struct rpc_cred_cache *cache)
 {
-	struct rpc_cred_cache *cache = auth->au_credcache;
-	HLIST_HEAD(free);
-	struct hlist_node *pos, *next;
+	LIST_HEAD(free);
+	struct hlist_head *head;
 	struct rpc_cred	*cred;
 	int		i;
 
 	spin_lock(&rpc_credcache_lock);
+	spin_lock(&cache->lock);
 	for (i = 0; i < RPC_CREDCACHE_NR; 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);
+		head = &cache->hashtable[i];
+		while (!hlist_empty(head)) {
+			cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
+			get_rpccred(cred);
+			if (!list_empty(&cred->cr_lru)) {
+				list_del(&cred->cr_lru);
+				number_cred_unused--;
+			}
+			list_add_tail(&cred->cr_lru, &free);
+			rpcauth_unhash_cred_locked(cred);
 		}
 	}
+	spin_unlock(&cache->lock);
 	spin_unlock(&rpc_credcache_lock);
 	rpcauth_destroy_credlist(&free);
 }
 
-static void
-rpcauth_prune_expired(struct rpc_auth *auth, struct rpc_cred *cred, struct hlist_head *free)
+/*
+ * Destroy the RPC credential cache
+ */
+void
+rpcauth_destroy_credcache(struct rpc_auth *auth)
 {
-	if (atomic_read(&cred->cr_count) != 1)
-	       return;
-	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);
-		hlist_add_head(&cred->cr_hash, free);
+	struct rpc_cred_cache *cache = auth->au_credcache;
+
+	if (cache) {
+		auth->au_credcache = NULL;
+		rpcauth_clear_credcache(cache);
+		kfree(cache);
 	}
 }
 
 /*
  * Remove stale credentials. Avoid sleeping inside the loop.
  */
-static void
-rpcauth_gc_credcache(struct rpc_auth *auth, struct hlist_head *free)
+static int
+rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
 {
-	struct rpc_cred_cache *cache = auth->au_credcache;
-	struct hlist_node *pos, *next;
-	struct rpc_cred	*cred;
-	int		i;
+	spinlock_t *cache_lock;
+	struct rpc_cred *cred;
 
-	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, &cache->hashtable[i]) {
-			cred = hlist_entry(pos, struct rpc_cred, cr_hash);
-			rpcauth_prune_expired(auth, cred, free);
+	while (!list_empty(&cred_unused)) {
+		cred = list_entry(cred_unused.next, struct rpc_cred, cr_lru);
+		list_del_init(&cred->cr_lru);
+		number_cred_unused--;
+		if (atomic_read(&cred->cr_count) != 0)
+			continue;
+		cache_lock = &cred->cr_auth->au_credcache->lock;
+		spin_lock(cache_lock);
+		if (atomic_read(&cred->cr_count) == 0) {
+			get_rpccred(cred);
+			list_add_tail(&cred->cr_lru, free);
+			rpcauth_unhash_cred_locked(cred);
+			nr_to_scan--;
 		}
+		spin_unlock(cache_lock);
+		if (nr_to_scan == 0)
+			break;
 	}
-	cache->nextgc = jiffies + cache->expire;
+	return nr_to_scan;
+}
+
+/*
+ * Run memory cache shrinker.
+ */
+static int
+rpcauth_cache_shrinker(int nr_to_scan, gfp_t gfp_mask)
+{
+	LIST_HEAD(free);
+	int res;
+
+	if (list_empty(&cred_unused))
+		return 0;
+	spin_lock(&rpc_credcache_lock);
+	nr_to_scan = rpcauth_prune_expired(&free, nr_to_scan);
+	res = (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
+	spin_unlock(&rpc_credcache_lock);
+	rpcauth_destroy_credlist(&free);
+	return res;
 }
 
 /*
@@ -198,53 +271,56 @@ struct rpc_cred *
 rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
 		int flags)
 {
+	LIST_HEAD(free);
 	struct rpc_cred_cache *cache = auth->au_credcache;
-	HLIST_HEAD(free);
-	struct hlist_node *pos, *next;
-	struct rpc_cred	*new = NULL,
-			*cred = NULL;
+	struct hlist_node *pos;
+	struct rpc_cred	*cred = NULL,
+			*entry, *new;
 	int		nr = 0;
 
 	if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS))
 		nr = acred->uid & RPC_CREDCACHE_MASK;
-retry:
-	spin_lock(&rpc_credcache_lock);
-	if (time_before(cache->nextgc, jiffies))
-		rpcauth_gc_credcache(auth, &free);
-	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, flags)) {
-			hlist_del(&entry->cr_hash);
-			cred = entry;
-			break;
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(entry, pos, &cache->hashtable[nr], cr_hash) {
+		if (!entry->cr_ops->crmatch(acred, entry, flags))
+			continue;
+		spin_lock(&cache->lock);
+		if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
+			spin_unlock(&cache->lock);
+			continue;
 		}
-		rpcauth_prune_expired(auth, entry, &free);
+		cred = get_rpccred(entry);
+		spin_unlock(&cache->lock);
+		break;
 	}
-	if (new) {
-		if (cred)
-			hlist_add_head(&new->cr_hash, &free);
-		else
-			cred = new;
-	}
-	if (cred) {
-		hlist_add_head(&cred->cr_hash, &cache->hashtable[nr]);
-		get_rpccred(cred);
-	}
-	spin_unlock(&rpc_credcache_lock);
+	rcu_read_unlock();
 
-	rpcauth_destroy_credlist(&free);
+	if (cred != NULL)
+		goto found;
 
-	if (!cred) {
-		new = auth->au_ops->crcreate(auth, acred, flags);
-		if (!IS_ERR(new)) {
-#ifdef RPC_DEBUG
-			new->cr_magic = RPCAUTH_CRED_MAGIC;
-#endif
-			goto retry;
-		} else
-			cred = new;
-	} else if ((cred->cr_flags & RPCAUTH_CRED_NEW)
+	new = auth->au_ops->crcreate(auth, acred, flags);
+	if (IS_ERR(new)) {
+		cred = new;
+		goto out;
+	}
+
+	spin_lock(&cache->lock);
+	hlist_for_each_entry(entry, pos, &cache->hashtable[nr], cr_hash) {
+		if (!entry->cr_ops->crmatch(acred, entry, flags))
+			continue;
+		cred = get_rpccred(entry);
+		break;
+	}
+	if (cred == NULL) {
+		cred = new;
+		set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
+		hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
+	} else
+		list_add_tail(&new->cr_lru, &free);
+	spin_unlock(&cache->lock);
+found:
+	if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags)
 			&& cred->cr_ops->cr_init != NULL
 			&& !(flags & RPCAUTH_LOOKUP_NEW)) {
 		int res = cred->cr_ops->cr_init(auth, cred);
@@ -253,8 +329,9 @@ retry:
 			cred = ERR_PTR(res);
 		}
 	}
-
-	return (struct rpc_cred *) cred;
+	rpcauth_destroy_credlist(&free);
+out:
+	return cred;
 }
 
 struct rpc_cred *
@@ -275,10 +352,27 @@ rpcauth_lookupcred(struct rpc_auth *auth, int flags)
 	return ret;
 }
 
+void
+rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
+		  struct rpc_auth *auth, const struct rpc_credops *ops)
+{
+	INIT_HLIST_NODE(&cred->cr_hash);
+	INIT_LIST_HEAD(&cred->cr_lru);
+	atomic_set(&cred->cr_count, 1);
+	cred->cr_auth = auth;
+	cred->cr_ops = ops;
+	cred->cr_expire = jiffies;
+#ifdef RPC_DEBUG
+	cred->cr_magic = RPCAUTH_CRED_MAGIC;
+#endif
+	cred->cr_uid = acred->uid;
+}
+EXPORT_SYMBOL(rpcauth_init_cred);
+
 struct rpc_cred *
 rpcauth_bindcred(struct rpc_task *task)
 {
-	struct rpc_auth *auth = task->tk_auth;
+	struct rpc_auth *auth = task->tk_client->cl_auth;
 	struct auth_cred acred = {
 		.uid = current->fsuid,
 		.gid = current->fsgid,
@@ -288,7 +382,7 @@ rpcauth_bindcred(struct rpc_task *task)
 	int flags = 0;
 
 	dprintk("RPC: %5u looking up %s cred\n",
-		task->tk_pid, task->tk_auth->au_ops->au_name);
+		task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
 	get_group_info(acred.group_info);
 	if (task->tk_flags & RPC_TASK_ROOTCREDS)
 		flags |= RPCAUTH_LOOKUP_ROOTCREDS;
@@ -304,19 +398,42 @@ rpcauth_bindcred(struct rpc_task *task)
 void
 rpcauth_holdcred(struct rpc_task *task)
 {
-	dprintk("RPC: %5u holding %s cred %p\n",
-		task->tk_pid, task->tk_auth->au_ops->au_name,
-		task->tk_msg.rpc_cred);
-	if (task->tk_msg.rpc_cred)
-		get_rpccred(task->tk_msg.rpc_cred);
+	struct rpc_cred *cred = task->tk_msg.rpc_cred;
+	if (cred != NULL) {
+		get_rpccred(cred);
+		dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
+				cred->cr_auth->au_ops->au_name, cred);
+	}
 }
 
 void
 put_rpccred(struct rpc_cred *cred)
 {
-	cred->cr_expire = jiffies;
+	/* Fast path for unhashed credentials */
+	if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
+		goto need_lock;
+
 	if (!atomic_dec_and_test(&cred->cr_count))
 		return;
+	goto out_destroy;
+need_lock:
+	if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
+		return;
+	if (!list_empty(&cred->cr_lru)) {
+		number_cred_unused--;
+		list_del_init(&cred->cr_lru);
+	}
+	if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
+		rpcauth_unhash_cred(cred);
+	else if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
+		cred->cr_expire = jiffies;
+		list_add_tail(&cred->cr_lru, &cred_unused);
+		number_cred_unused++;
+		spin_unlock(&rpc_credcache_lock);
+		return;
+	}
+	spin_unlock(&rpc_credcache_lock);
+out_destroy:
 	cred->cr_ops->crdestroy(cred);
 }
 
@@ -326,7 +443,7 @@ rpcauth_unbindcred(struct rpc_task *task)
 	struct rpc_cred	*cred = task->tk_msg.rpc_cred;
 
 	dprintk("RPC: %5u releasing %s cred %p\n",
-		task->tk_pid, task->tk_auth->au_ops->au_name, cred);
+		task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 
 	put_rpccred(cred);
 	task->tk_msg.rpc_cred = NULL;
@@ -338,7 +455,7 @@ rpcauth_marshcred(struct rpc_task *task, __be32 *p)
 	struct rpc_cred	*cred = task->tk_msg.rpc_cred;
 
 	dprintk("RPC: %5u marshaling %s cred %p\n",
-		task->tk_pid, task->tk_auth->au_ops->au_name, cred);
+		task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 
 	return cred->cr_ops->crmarshal(task, p);
 }
@@ -349,7 +466,7 @@ rpcauth_checkverf(struct rpc_task *task, __be32 *p)
 	struct rpc_cred	*cred = task->tk_msg.rpc_cred;
 
 	dprintk("RPC: %5u validating %s cred %p\n",
-		task->tk_pid, task->tk_auth->au_ops->au_name, cred);
+		task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 
 	return cred->cr_ops->crvalidate(task, p);
 }
@@ -359,13 +476,17 @@ rpcauth_wrap_req(struct rpc_task *task, kxdrproc_t encode, void *rqstp,
 		__be32 *data, void *obj)
 {
 	struct rpc_cred *cred = task->tk_msg.rpc_cred;
+	int ret;
 
 	dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
 			task->tk_pid, cred->cr_ops->cr_name, cred);
 	if (cred->cr_ops->crwrap_req)
 		return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
 	/* By default, we encode the arguments normally. */
-	return encode(rqstp, data, obj);
+	lock_kernel();
+	ret = encode(rqstp, data, obj);
+	unlock_kernel();
+	return ret;
 }
 
 int
@@ -373,6 +494,7 @@ rpcauth_unwrap_resp(struct rpc_task *task, kxdrproc_t decode, void *rqstp,
 		__be32 *data, void *obj)
 {
 	struct rpc_cred *cred = task->tk_msg.rpc_cred;
+	int ret;
 
 	dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
 			task->tk_pid, cred->cr_ops->cr_name, cred);
@@ -380,7 +502,10 @@ rpcauth_unwrap_resp(struct rpc_task *task, kxdrproc_t decode, void *rqstp,
 		return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
 						   data, obj);
 	/* By default, we decode the arguments normally. */
-	return decode(rqstp, data, obj);
+	lock_kernel();
+	ret = decode(rqstp, data, obj);
+	unlock_kernel();
+	return ret;
 }
 
 int
@@ -390,7 +515,7 @@ rpcauth_refreshcred(struct rpc_task *task)
 	int err;
 
 	dprintk("RPC: %5u refreshing %s cred %p\n",
-		task->tk_pid, task->tk_auth->au_ops->au_name, cred);
+		task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 
 	err = cred->cr_ops->crrefresh(task);
 	if (err < 0)
@@ -401,17 +526,34 @@ rpcauth_refreshcred(struct rpc_task *task)
 void
 rpcauth_invalcred(struct rpc_task *task)
 {
+	struct rpc_cred *cred = task->tk_msg.rpc_cred;
+
 	dprintk("RPC: %5u invalidating %s cred %p\n",
-		task->tk_pid, task->tk_auth->au_ops->au_name, task->tk_msg.rpc_cred);
-	spin_lock(&rpc_credcache_lock);
-	if (task->tk_msg.rpc_cred)
-		task->tk_msg.rpc_cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
-	spin_unlock(&rpc_credcache_lock);
+		task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
+	if (cred)
+		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 }
 
 int
 rpcauth_uptodatecred(struct rpc_task *task)
 {
-	return !(task->tk_msg.rpc_cred) ||
-		(task->tk_msg.rpc_cred->cr_flags & RPCAUTH_CRED_UPTODATE);
+	struct rpc_cred *cred = task->tk_msg.rpc_cred;
+
+	return cred == NULL ||
+		test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
+}
+
+
+static struct shrinker *rpc_cred_shrinker;
+
+void __init rpcauth_init_module(void)
+{
+	rpc_init_authunix();
+	rpc_cred_shrinker = set_shrinker(DEFAULT_SEEKS, rpcauth_cache_shrinker);
+}
+
+void __exit rpcauth_remove_module(void)
+{
+	if (rpc_cred_shrinker != NULL)
+		remove_shrinker(rpc_cred_shrinker);
 }
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 4e4ccc5b6fe..baf4096d52d 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -54,9 +54,10 @@
 #include <linux/sunrpc/gss_api.h>
 #include <asm/uaccess.h>
 
-static struct rpc_authops authgss_ops;
+static const struct rpc_authops authgss_ops;
 
-static struct rpc_credops gss_credops;
+static const struct rpc_credops gss_credops;
+static const struct rpc_credops gss_nullops;
 
 #ifdef RPC_DEBUG
 # define RPCDBG_FACILITY	RPCDBG_AUTH
@@ -64,7 +65,6 @@ static struct rpc_credops gss_credops;
 
 #define NFS_NGROUPS	16
 
-#define GSS_CRED_EXPIRE		(60 * HZ)	/* XXX: reasonable? */
 #define GSS_CRED_SLACK		1024		/* XXX: unused */
 /* length of a krb5 verifier (48), plus data added before arguments when
  * using integrity (two 4-byte integers): */
@@ -79,19 +79,16 @@ static struct rpc_credops gss_credops;
 /* dump the buffer in `emacs-hexl' style */
 #define isprint(c)      ((c > 0x1f) && (c < 0x7f))
 
-static DEFINE_RWLOCK(gss_ctx_lock);
-
 struct gss_auth {
+	struct kref kref;
 	struct rpc_auth rpc_auth;
 	struct gss_api_mech *mech;
 	enum rpc_gss_svc service;
-	struct list_head upcalls;
 	struct rpc_clnt *client;
 	struct dentry *dentry;
-	spinlock_t lock;
 };
 
-static void gss_destroy_ctx(struct gss_cl_ctx *);
+static void gss_free_ctx(struct gss_cl_ctx *);
 static struct rpc_pipe_ops gss_upcall_ops;
 
 static inline struct gss_cl_ctx *
@@ -105,20 +102,24 @@ static inline void
 gss_put_ctx(struct gss_cl_ctx *ctx)
 {
 	if (atomic_dec_and_test(&ctx->count))
-		gss_destroy_ctx(ctx);
+		gss_free_ctx(ctx);
 }
 
+/* gss_cred_set_ctx:
+ * called by gss_upcall_callback and gss_create_upcall in order
+ * to set the gss context. The actual exchange of an old context
+ * and a new one is protected by the inode->i_lock.
+ */
 static void
 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 {
 	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 	struct gss_cl_ctx *old;
-	write_lock(&gss_ctx_lock);
+
 	old = gss_cred->gc_ctx;
-	gss_cred->gc_ctx = ctx;
-	cred->cr_flags |= RPCAUTH_CRED_UPTODATE;
-	cred->cr_flags &= ~RPCAUTH_CRED_NEW;
-	write_unlock(&gss_ctx_lock);
+	rcu_assign_pointer(gss_cred->gc_ctx, ctx);
+	set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
+	clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 	if (old)
 		gss_put_ctx(old);
 }
@@ -129,10 +130,10 @@ gss_cred_is_uptodate_ctx(struct rpc_cred *cred)
 	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 	int res = 0;
 
-	read_lock(&gss_ctx_lock);
-	if ((cred->cr_flags & RPCAUTH_CRED_UPTODATE) && gss_cred->gc_ctx)
+	rcu_read_lock();
+	if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) && gss_cred->gc_ctx)
 		res = 1;
-	read_unlock(&gss_ctx_lock);
+	rcu_read_unlock();
 	return res;
 }
 
@@ -171,10 +172,10 @@ gss_cred_get_ctx(struct rpc_cred *cred)
 	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 	struct gss_cl_ctx *ctx = NULL;
 
-	read_lock(&gss_ctx_lock);
+	rcu_read_lock();
 	if (gss_cred->gc_ctx)
 		ctx = gss_get_ctx(gss_cred->gc_ctx);
-	read_unlock(&gss_ctx_lock);
+	rcu_read_unlock();
 	return ctx;
 }
 
@@ -269,10 +270,10 @@ gss_release_msg(struct gss_upcall_msg *gss_msg)
 }
 
 static struct gss_upcall_msg *
-__gss_find_upcall(struct gss_auth *gss_auth, uid_t uid)
+__gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
 {
 	struct gss_upcall_msg *pos;
-	list_for_each_entry(pos, &gss_auth->upcalls, list) {
+	list_for_each_entry(pos, &rpci->in_downcall, list) {
 		if (pos->uid != uid)
 			continue;
 		atomic_inc(&pos->count);
@@ -290,24 +291,24 @@ __gss_find_upcall(struct gss_auth *gss_auth, uid_t uid)
 static inline struct gss_upcall_msg *
 gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
 {
+	struct inode *inode = gss_auth->dentry->d_inode;
+	struct rpc_inode *rpci = RPC_I(inode);
 	struct gss_upcall_msg *old;
 
-	spin_lock(&gss_auth->lock);
-	old = __gss_find_upcall(gss_auth, gss_msg->uid);
+	spin_lock(&inode->i_lock);
+	old = __gss_find_upcall(rpci, gss_msg->uid);
 	if (old == NULL) {
 		atomic_inc(&gss_msg->count);
-		list_add(&gss_msg->list, &gss_auth->upcalls);
+		list_add(&gss_msg->list, &rpci->in_downcall);
 	} else
 		gss_msg = old;
-	spin_unlock(&gss_auth->lock);
+	spin_unlock(&inode->i_lock);
 	return gss_msg;
 }
 
 static void
 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 {
-	if (list_empty(&gss_msg->list))
-		return;
 	list_del_init(&gss_msg->list);
 	rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 	wake_up_all(&gss_msg->waitqueue);
@@ -318,10 +319,14 @@ static void
 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 {
 	struct gss_auth *gss_auth = gss_msg->auth;
+	struct inode *inode = gss_auth->dentry->d_inode;
 
-	spin_lock(&gss_auth->lock);
-	__gss_unhash_msg(gss_msg);
-	spin_unlock(&gss_auth->lock);
+	if (list_empty(&gss_msg->list))
+		return;
+	spin_lock(&inode->i_lock);
+	if (!list_empty(&gss_msg->list))
+		__gss_unhash_msg(gss_msg);
+	spin_unlock(&inode->i_lock);
 }
 
 static void
@@ -330,16 +335,16 @@ gss_upcall_callback(struct rpc_task *task)
 	struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
 			struct gss_cred, gc_base);
 	struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
+	struct inode *inode = gss_msg->auth->dentry->d_inode;
 
-	BUG_ON(gss_msg == NULL);
+	spin_lock(&inode->i_lock);
 	if (gss_msg->ctx)
 		gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_get_ctx(gss_msg->ctx));
 	else
 		task->tk_status = gss_msg->msg.errno;
-	spin_lock(&gss_msg->auth->lock);
 	gss_cred->gc_upcall = NULL;
 	rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
-	spin_unlock(&gss_msg->auth->lock);
+	spin_unlock(&inode->i_lock);
 	gss_release_msg(gss_msg);
 }
 
@@ -386,11 +391,12 @@ static inline int
 gss_refresh_upcall(struct rpc_task *task)
 {
 	struct rpc_cred *cred = task->tk_msg.rpc_cred;
-	struct gss_auth *gss_auth = container_of(task->tk_client->cl_auth,
+	struct gss_auth *gss_auth = container_of(cred->cr_auth,
 			struct gss_auth, rpc_auth);
 	struct gss_cred *gss_cred = container_of(cred,
 			struct gss_cred, gc_base);
 	struct gss_upcall_msg *gss_msg;
+	struct inode *inode = gss_auth->dentry->d_inode;
 	int err = 0;
 
 	dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
@@ -400,7 +406,7 @@ gss_refresh_upcall(struct rpc_task *task)
 		err = PTR_ERR(gss_msg);
 		goto out;
 	}
-	spin_lock(&gss_auth->lock);
+	spin_lock(&inode->i_lock);
 	if (gss_cred->gc_upcall != NULL)
 		rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL, NULL);
 	else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
@@ -411,7 +417,7 @@ gss_refresh_upcall(struct rpc_task *task)
 		rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback, NULL);
 	} else
 		err = gss_msg->msg.errno;
-	spin_unlock(&gss_auth->lock);
+	spin_unlock(&inode->i_lock);
 	gss_release_msg(gss_msg);
 out:
 	dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
@@ -422,6 +428,7 @@ out:
 static inline int
 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 {
+	struct inode *inode = gss_auth->dentry->d_inode;
 	struct rpc_cred *cred = &gss_cred->gc_base;
 	struct gss_upcall_msg *gss_msg;
 	DEFINE_WAIT(wait);
@@ -435,12 +442,11 @@ gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 	}
 	for (;;) {
 		prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
-		spin_lock(&gss_auth->lock);
+		spin_lock(&inode->i_lock);
 		if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
-			spin_unlock(&gss_auth->lock);
 			break;
 		}
-		spin_unlock(&gss_auth->lock);
+		spin_unlock(&inode->i_lock);
 		if (signalled()) {
 			err = -ERESTARTSYS;
 			goto out_intr;
@@ -451,6 +457,7 @@ gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 		gss_cred_set_ctx(cred, gss_get_ctx(gss_msg->ctx));
 	else
 		err = gss_msg->msg.errno;
+	spin_unlock(&inode->i_lock);
 out_intr:
 	finish_wait(&gss_msg->waitqueue, &wait);
 	gss_release_msg(gss_msg);
@@ -489,12 +496,11 @@ gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 	const void *p, *end;
 	void *buf;
 	struct rpc_clnt *clnt;
-	struct gss_auth *gss_auth;
-	struct rpc_cred *cred;
 	struct gss_upcall_msg *gss_msg;
+	struct inode *inode = filp->f_path.dentry->d_inode;
 	struct gss_cl_ctx *ctx;
 	uid_t uid;
-	int err = -EFBIG;
+	ssize_t err = -EFBIG;
 
 	if (mlen > MSG_BUF_MAXSIZE)
 		goto out;
@@ -503,7 +509,7 @@ gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 	if (!buf)
 		goto out;
 
-	clnt = RPC_I(filp->f_path.dentry->d_inode)->private;
+	clnt = RPC_I(inode)->private;
 	err = -EFAULT;
 	if (copy_from_user(buf, src, mlen))
 		goto err;
@@ -519,43 +525,38 @@ gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 	ctx = gss_alloc_context();
 	if (ctx == NULL)
 		goto err;
-	err = 0;
-	gss_auth = container_of(clnt->cl_auth, struct gss_auth, rpc_auth);
-	p = gss_fill_context(p, end, ctx, gss_auth->mech);
+
+	err = -ENOENT;
+	/* Find a matching upcall */
+	spin_lock(&inode->i_lock);
+	gss_msg = __gss_find_upcall(RPC_I(inode), uid);
+	if (gss_msg == NULL) {
+		spin_unlock(&inode->i_lock);
+		goto err_put_ctx;
+	}
+	list_del_init(&gss_msg->list);
+	spin_unlock(&inode->i_lock);
+
+	p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 	if (IS_ERR(p)) {
 		err = PTR_ERR(p);
-		if (err != -EACCES)
-			goto err_put_ctx;
-	}
-	spin_lock(&gss_auth->lock);
-	gss_msg = __gss_find_upcall(gss_auth, uid);
-	if (gss_msg) {
-		if (err == 0 && gss_msg->ctx == NULL)
-			gss_msg->ctx = gss_get_ctx(ctx);
-		gss_msg->msg.errno = err;
-		__gss_unhash_msg(gss_msg);
-		spin_unlock(&gss_auth->lock);
-		gss_release_msg(gss_msg);
-	} else {
-		struct auth_cred acred = { .uid = uid };
-		spin_unlock(&gss_auth->lock);
-		cred = rpcauth_lookup_credcache(clnt->cl_auth, &acred, RPCAUTH_LOOKUP_NEW);
-		if (IS_ERR(cred)) {
-			err = PTR_ERR(cred);
-			goto err_put_ctx;
-		}
-		gss_cred_set_ctx(cred, gss_get_ctx(ctx));
+		gss_msg->msg.errno = (err == -EACCES) ? -EACCES : -EAGAIN;
+		goto err_release_msg;
 	}
-	gss_put_ctx(ctx);
-	kfree(buf);
-	dprintk("RPC:       gss_pipe_downcall returning length %Zu\n", mlen);
-	return mlen;
+	gss_msg->ctx = gss_get_ctx(ctx);
+	err = mlen;
+
+err_release_msg:
+	spin_lock(&inode->i_lock);
+	__gss_unhash_msg(gss_msg);
+	spin_unlock(&inode->i_lock);
+	gss_release_msg(gss_msg);
 err_put_ctx:
 	gss_put_ctx(ctx);
 err:
 	kfree(buf);
 out:
-	dprintk("RPC:       gss_pipe_downcall returning %d\n", err);
+	dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
 	return err;
 }
 
@@ -563,27 +564,21 @@ static void
 gss_pipe_release(struct inode *inode)
 {
 	struct rpc_inode *rpci = RPC_I(inode);
-	struct rpc_clnt *clnt;
-	struct rpc_auth *auth;
-	struct gss_auth *gss_auth;
+	struct gss_upcall_msg *gss_msg;
 
-	clnt = rpci->private;
-	auth = clnt->cl_auth;
-	gss_auth = container_of(auth, struct gss_auth, rpc_auth);
-	spin_lock(&gss_auth->lock);
-	while (!list_empty(&gss_auth->upcalls)) {
-		struct gss_upcall_msg *gss_msg;
+	spin_lock(&inode->i_lock);
+	while (!list_empty(&rpci->in_downcall)) {
 
-		gss_msg = list_entry(gss_auth->upcalls.next,
+		gss_msg = list_entry(rpci->in_downcall.next,
 				struct gss_upcall_msg, list);
 		gss_msg->msg.errno = -EPIPE;
 		atomi