14 files changed, 605 insertions, 435 deletions

diff --git a/Documentation/keys-request-key.txt b/Documentation/keys-request-key.txt
index c1f64fdf84c..266955d23ee 100644
--- a/Documentation/keys-request-key.txt
+++ b/Documentation/keys-request-key.txt
@@ -20,6 +20,19 @@ or:
 					     const char *callout_string,
 					     void *aux);
 
+or:
+
+	struct key *request_key_async(const struct key_type *type,
+				      const char *description,
+				      const char *callout_string);
+
+or:
+
+	struct key *request_key_async_with_auxdata(const struct key_type *type,
+						   const char *description,
+						   const char *callout_string,
+						   void *aux);
+
 Or by userspace invoking the request_key system call:
 
 	key_serial_t request_key(const char *type,
@@ -32,10 +45,14 @@ does not need to link the key to a keyring to prevent it from being immediately
 destroyed.  The kernel interface returns a pointer directly to the key, and
 it's up to the caller to destroy the key.
 
-The request_key_with_auxdata() call is like the in-kernel request_key() call,
-except that it permits auxiliary data to be passed to the upcaller (the default
-is NULL).  This is only useful for those key types that define their own upcall
-mechanism rather than using /sbin/request-key.
+The request_key*_with_auxdata() calls are like the in-kernel request_key*()
+calls, except that they permit auxiliary data to be passed to the upcaller (the
+default is NULL).  This is only useful for those key types that define their
+own upcall mechanism rather than using /sbin/request-key.
+
+The two async in-kernel calls may return keys that are still in the process of
+being constructed.  The two non-async ones will wait for construction to
+complete first.
 
 The userspace interface links the key to a keyring associated with the process
 to prevent the key from going away, and returns the serial number of the key to
diff --git a/Documentation/keys.txt b/Documentation/keys.txt
index 947d57d5345..51652d39e61 100644
--- a/Documentation/keys.txt
+++ b/Documentation/keys.txt
@@ -4,7 +4,7 @@
 
 This service allows cryptographic keys, authentication tokens, cross-domain
 user mappings, and similar to be cached in the kernel for the use of
-filesystems other kernel services.
+filesystems and other kernel services.
 
 Keyrings are permitted; these are a special type of key that can hold links to
 other keys. Processes each have three standard keyring subscriptions that a
@@ -726,6 +726,15 @@ call, and the key released upon close. How to deal with conflicting keys due to
 two different users opening the same file is left to the filesystem author to
 solve.
 
+To access the key manager, the following header must be #included:
+
+	<linux/key.h>
+
+Specific key types should have a header file under include/keys/ that should be
+used to access that type.  For keys of type "user", for example, that would be:
+
+	<keys/user-type.h>
+
 Note that there are two different types of pointers to keys that may be
 encountered:
 
@@ -791,6 +800,36 @@ payload contents" for more information.
     passed to the key_type->request_key() op if it exists.
 
 
+(*) A key can be requested asynchronously by calling one of:
+
+	struct key *request_key_async(const struct key_type *type,
+				      const char *description,
+				      const char *callout_string);
+
+    or:
+
+	struct key *request_key_async_with_auxdata(const struct key_type *type,
+						   const char *description,
+						   const char *callout_string,
+					     	   void *aux);
+
+    which are asynchronous equivalents of request_key() and
+    request_key_with_auxdata() respectively.
+
+    These two functions return with the key potentially still under
+    construction.  To wait for contruction completion, the following should be
+    called:
+
+	int wait_for_key_construction(struct key *key, bool intr);
+
+    The function will wait for the key to finish being constructed and then
+    invokes key_validate() to return an appropriate value to indicate the state
+    of the key (0 indicates the key is usable).
+
+    If intr is true, then the wait can be interrupted by a signal, in which
+    case error ERESTARTSYS will be returned.
+
+
 (*) When it is no longer required, the key should be released using:
 
 	void key_put(struct key *key);
@@ -924,7 +963,11 @@ DEFINING A KEY TYPE
 
 A kernel service may want to define its own key type. For instance, an AFS
 filesystem might want to define a Kerberos 5 ticket key type. To do this, it
-author fills in a struct key_type and registers it with the system.
+author fills in a key_type struct and registers it with the system.
+
+Source files that implement key types should include the following header file:
+
+	<linux/key-type.h>
 
 The structure has a number of fields, some of which are mandatory:
 
@@ -1053,22 +1096,44 @@ The structure has a number of fields, some of which are mandatory:
      as might happen when the userspace buffer is accessed.
 
 
- (*) int (*request_key)(struct key *key, struct key *authkey, const char *op,
+ (*) int (*request_key)(struct key_construction *cons, const char *op,
 			void *aux);
 
-     This method is optional.  If provided, request_key() and
-     request_key_with_auxdata() will invoke this function rather than
-     upcalling to /sbin/request-key to operate upon a key of this type.
+     This method is optional.  If provided, request_key() and friends will
+     invoke this function rather than upcalling to /sbin/request-key to operate
+     upon a key of this type.
+
+     The aux parameter is as passed to request_key_async_with_auxdata() and
+     similar or is NULL otherwise.  Also passed are the construction record for
+     the key to be operated upon and the operation type (currently only
+     "create").
+
+     This method is permitted to return before the upcall is complete, but the
+     following function must be called under all circumstances to complete the
+     instantiation process, whether or not it succeeds, whether or not there's
+     an error:
+
+	void complete_request_key(struct key_construction *cons, int error);
+
+     The error parameter should be 0 on success, -ve on error.  The
+     construction record is destroyed by this action and the authorisation key
+     will be revoked.  If an error is indicated, the key under construction
+     will be negatively instantiated if it wasn't already instantiated.
+
+     If this method returns an error, that error will be returned to the
+     caller of request_key*().  complete_request_key() must be called prior to
+     returning.
+
+     The key under construction and the authorisation key can be found in the
+     key_construction struct pointed to by cons:
+
+     (*) struct key *key;
+
+     	 The key under construction.
 
-     The aux parameter is as passed to request_key_with_auxdata() or is NULL
-     otherwise.  Also passed are the key to be operated upon, the
-     authorisation key for this operation and the operation type (currently
-     only "create").
+     (*) struct key *authkey;
 
-     This function should return only when the upcall is complete.  Upon return
-     the authorisation key will be revoked, and the target key will be
-     negatively instantiated if it is still uninstantiated.  The error will be
-     returned to the caller of request_key*().
+     	 The authorisation key.
 
 
 ============================
diff --git a/Documentation/networking/rxrpc.txt b/Documentation/networking/rxrpc.txt
index cae231b1c13..c36b64b0020 100644
--- a/Documentation/networking/rxrpc.txt
+++ b/Documentation/networking/rxrpc.txt
@@ -857,3 +857,10 @@ The kernel interface functions are as follows:
 
      This is used to extract the error number from a message indicating either
      a local error occurred or a network error occurred.
+
+ (*) Allocate a null key for doing anonymous security.
+
+	struct key *rxrpc_get_null_key(const char *keyname);
+
+     This is used to allocate a null RxRPC key that can be used to indicate
+     anonymous security for a particular domain.
diff --git a/fs/afs/cell.c b/fs/afs/cell.c
index ccfa89f3525..970d38f3056 100644
--- a/fs/afs/cell.c
+++ b/fs/afs/cell.c
@@ -33,6 +33,7 @@ static struct afs_cell *afs_cell_root;
 static struct afs_cell *afs_cell_alloc(const char *name, char *vllist)
 {
 	struct afs_cell *cell;
+	struct key *key;
 	size_t namelen;
 	char keyname[4 + AFS_MAXCELLNAME + 1], *cp, *dp, *next;
 	int ret;
@@ -89,20 +90,14 @@ static struct afs_cell *afs_cell_alloc(const char *name, char *vllist)
 	do {
 		*dp++ = toupper(*cp);
 	} while (*cp++);
-	cell->anonymous_key = key_alloc(&key_type_rxrpc, keyname, 0, 0, current,
-					KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA);
-	if (IS_ERR(cell->anonymous_key)) {
-		_debug("no key");
-		ret = PTR_ERR(cell->anonymous_key);
-		goto error;
-	}
 
-	ret = key_instantiate_and_link(cell->anonymous_key, NULL, 0,
-				       NULL, NULL);
-	if (ret < 0) {
-		_debug("instantiate failed");
+	key = rxrpc_get_null_key(keyname);
+	if (IS_ERR(key)) {
+		_debug("no key");
+		ret = PTR_ERR(key);
 		goto error;
 	}
+	cell->anonymous_key = key;
 
 	_debug("anon key %p{%x}",
 	       cell->anonymous_key, key_serial(cell->anonymous_key));
diff --git a/include/keys/rxrpc-type.h b/include/keys/rxrpc-type.h
index e2ee73aef0e..4ea429b1875 100644
--- a/include/keys/rxrpc-type.h
+++ b/include/keys/rxrpc-type.h
@@ -19,4 +19,6 @@
  */
 extern struct key_type key_type_rxrpc;
 
+extern struct key *rxrpc_get_null_key(const char *);
+
 #endif /* _KEYS_USER_TYPE_H */
diff --git a/include/linux/key-type.h b/include/linux/key-type.h
new file mode 100644
index 00000000000..65833d4d599
--- /dev/null
+++ b/include/linux/key-type.h
@@ -0,0 +1,112 @@
+/* Definitions for key type implementations
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#ifndef _LINUX_KEY_TYPE_H
+#define _LINUX_KEY_TYPE_H
+
+#include <linux/key.h>
+
+#ifdef CONFIG_KEYS
+
+/*
+ * key under-construction record
+ * - passed to the request_key actor if supplied
+ */
+struct key_construction {
+	struct key	*key;	/* key being constructed */
+	struct key	*authkey;/* authorisation for key being constructed */
+};
+
+typedef int (*request_key_actor_t)(struct key_construction *key,
+				   const char *op, void *aux);
+
+/*
+ * kernel managed key type definition
+ */
+struct key_type {
+	/* name of the type */
+	const char *name;
+
+	/* default payload length for quota precalculation (optional)
+	 * - this can be used instead of calling key_payload_reserve(), that
+	 *   function only needs to be called if the real datalen is different
+	 */
+	size_t def_datalen;
+
+	/* instantiate a key of this type
+	 * - this method should call key_payload_reserve() to determine if the
+	 *   user's quota will hold the payload
+	 */
+	int (*instantiate)(struct key *key, const void *data, size_t datalen);
+
+	/* update a key of this type (optional)
+	 * - this method should call key_payload_reserve() to recalculate the
+	 *   quota consumption
+	 * - the key must be locked against read when modifying
+	 */
+	int (*update)(struct key *key, const void *data, size_t datalen);
+
+	/* match a key against a description */
+	int (*match)(const struct key *key, const void *desc);
+
+	/* clear some of the data from a key on revokation (optional)
+	 * - the key's semaphore will be write-locked by the caller
+	 */
+	void (*revoke)(struct key *key);
+
+	/* clear the data from a key (optional) */
+	void (*destroy)(struct key *key);
+
+	/* describe a key */
+	void (*describe)(const struct key *key, struct seq_file *p);
+
+	/* read a key's data (optional)
+	 * - permission checks will be done by the caller
+	 * - the key's semaphore will be readlocked by the caller
+	 * - should return the amount of data that could be read, no matter how
+	 *   much is copied into the buffer
+	 * - shouldn't do the copy if the buffer is NULL
+	 */
+	long (*read)(const struct key *key, char __user *buffer, size_t buflen);
+
+	/* handle request_key() for this type instead of invoking
+	 * /sbin/request-key (optional)
+	 * - key is the key to instantiate
+	 * - authkey is the authority to assume when instantiating this key
+	 * - op is the operation to be done, usually "create"
+	 * - the call must not return until the instantiation process has run
+	 *   its course
+	 */
+	request_key_actor_t request_key;
+
+	/* internal fields */
+	struct list_head	link;		/* link in types list */
+};
+
+extern struct key_type key_type_keyring;
+
+extern int register_key_type(struct key_type *ktype);
+extern void unregister_key_type(struct key_type *ktype);
+
+extern int key_payload_reserve(struct key *key, size_t datalen);
+extern int key_instantiate_and_link(struct key *key,
+				    const void *data,
+				    size_t datalen,
+				    struct key *keyring,
+				    struct key *instkey);
+extern int key_negate_and_link(struct key *key,
+			       unsigned timeout,
+			       struct key *keyring,
+			       struct key *instkey);
+extern void complete_request_key(struct key_construction *cons, int error);
+
+#endif /* CONFIG_KEYS */
+#endif /* _LINUX_KEY_TYPE_H */
diff --git a/include/linux/key.h b/include/linux/key.h
index a9220e75782..fcdbd5ed227 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -1,6 +1,6 @@
-/* key.h: authentication token and access key management
+/* Authentication token and access key management
  *
- * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004, 2007 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  *
  * This program is free software; you can redistribute it and/or
@@ -175,78 +175,6 @@ struct key {
 	} payload;
 };
 
-/*****************************************************************************/
-/*
- * kernel managed key type definition
- */
-typedef int (*request_key_actor_t)(struct key *key, struct key *authkey,
-				   const char *op, void *aux);
-
-struct key_type {
-	/* name of the type */
-	const char *name;
-
-	/* default payload length for quota precalculation (optional)
-	 * - this can be used instead of calling key_payload_reserve(), that
-	 *   function only needs to be called if the real datalen is different
-	 */
-	size_t def_datalen;
-
-	/* instantiate a key of this type
-	 * - this method should call key_payload_reserve() to determine if the
-	 *   user's quota will hold the payload
-	 */
-	int (*instantiate)(struct key *key, const void *data, size_t datalen);
-
-	/* update a key of this type (optional)
-	 * - this method should call key_payload_reserve() to recalculate the
-	 *   quota consumption
-	 * - the key must be locked against read when modifying
-	 */
-	int (*update)(struct key *key, const void *data, size_t datalen);
-
-	/* match a key against a description */
-	int (*match)(const struct key *key, const void *desc);
-
-	/* clear some of the data from a key on revokation (optional)
-	 * - the key's semaphore will be write-locked by the caller
-	 */
-	void (*revoke)(struct key *key);
-
-	/* clear the data from a key (optional) */
-	void (*destroy)(struct key *key);
-
-	/* describe a key */
-	void (*describe)(const struct key *key, struct seq_file *p);
-
-	/* read a key's data (optional)
-	 * - permission checks will be done by the caller
-	 * - the key's semaphore will be readlocked by the caller
-	 * - should return the amount of data that could be read, no matter how
-	 *   much is copied into the buffer
-	 * - shouldn't do the copy if the buffer is NULL
-	 */
-	long (*read)(const struct key *key, char __user *buffer, size_t buflen);
-
-	/* handle request_key() for this type instead of invoking
-	 * /sbin/request-key (optional)
-	 * - key is the key to instantiate
-	 * - authkey is the authority to assume when instantiating this key
-	 * - op is the operation to be done, usually "create"
-	 * - the call must not return until the instantiation process has run
-	 *   its course
-	 */
-	request_key_actor_t request_key;
-
-	/* internal fields */
-	struct list_head	link;		/* link in types list */
-};
-
-extern struct key_type key_type_keyring;
-
-extern int register_key_type(struct key_type *ktype);
-extern void unregister_key_type(struct key_type *ktype);
-
 extern struct key *key_alloc(struct key_type *type,
 			     const char *desc,
 			     uid_t uid, gid_t gid,
@@ -259,16 +187,6 @@ extern struct key *key_alloc(struct key_type *type,
 #define KEY_ALLOC_QUOTA_OVERRUN	0x0001	/* add to quota, permit even if overrun */
 #define KEY_ALLOC_NOT_IN_QUOTA	0x0002	/* not in quota */
 
-extern int key_payload_reserve(struct key *key, size_t datalen);
-extern int key_instantiate_and_link(struct key *key,
-				    const void *data,
-				    size_t datalen,
-				    struct key *keyring,
-				    struct key *instkey);
-extern int key_negate_and_link(struct key *key,
-			       unsigned timeout,
-			       struct key *keyring,
-			       struct key *instkey);
 extern void key_revoke(struct key *key);
 extern void key_put(struct key *key);
 
@@ -293,6 +211,17 @@ extern struct key *request_key_with_auxdata(struct key_type *type,
 					    const char *callout_info,
 					    void *aux);
 
+extern struct key *request_key_async(struct key_type *type,
+				     const char *description,
+				     const char *callout_info);
+
+extern struct key *request_key_async_with_auxdata(struct key_type *type,
+						  const char *description,
+						  const char *callout_info,
+						  void *aux);
+
+extern int wait_for_key_construction(struct key *key, bool intr);
+
 extern int key_validate(struct key *key);
 
 extern key_ref_t key_create_or_update(key_ref_t keyring,
@@ -328,8 +257,6 @@ extern int keyring_add_key(struct key *keyring,
 
 extern struct key *key_lookup(key_serial_t id);
 
-extern void keyring_replace_payload(struct key *key, void *replacement);
-
 #define key_serial(key) ((key) ? (key)->serial : 0)
 
 /*
diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index 0803f305ed0..c680017f5c8 100644
--- a/net/rxrpc/af_rxrpc.c
+++ b/net/rxrpc/af_rxrpc.c
@@ -14,6 +14,7 @@
 #include <linux/skbuff.h>
 #include <linux/poll.h>
 #include <linux/proc_fs.h>
+#include <linux/key-type.h>
 #include <net/net_namespace.h>
 #include <net/sock.h>
 #include <net/af_rxrpc.h>
diff --git a/net/rxrpc/ar-key.c b/net/rxrpc/ar-key.c
index 7e049ff6ae6..9a8ff684da7 100644
--- a/net/rxrpc/ar-key.c
+++ b/net/rxrpc/ar-key.c
@@ -15,7 +15,7 @@
 #include <linux/module.h>
 #include <linux/net.h>
 #include <linux/skbuff.h>
-#include <linux/key.h>
+#include <linux/key-type.h>
 #include <linux/crypto.h>
 #include <net/sock.h>
 #include <net/af_rxrpc.h>
@@ -40,7 +40,6 @@ struct key_type key_type_rxrpc = {
 	.destroy	= rxrpc_destroy,
 	.describe	= rxrpc_describe,
 };
-
 EXPORT_SYMBOL(key_type_rxrpc);
 
 /*
@@ -330,5 +329,32 @@ error:
 	_leave(" = -ENOMEM [ins %d]", ret);
 	return -ENOMEM;
 }
-
 EXPORT_SYMBOL(rxrpc_get_server_data_key);
+
+/**
+ * rxrpc_get_null_key - Generate a null RxRPC key
+ * @keyname: The name to give the key.
+ *
+ * Generate a null RxRPC key that can be used to indicate anonymous security is
+ * required for a particular domain.
+ */
+struct key *rxrpc_get_null_key(const char *keyname)
+{
+	struct key *key;
+	int ret;
+
+	key = key_alloc(&key_type_rxrpc, keyname, 0, 0, current,
+			KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA);
+	if (IS_ERR(key))
+		return key;
+
+	ret = key_instantiate_and_link(key, NULL, 0, NULL, NULL);
+	if (ret < 0) {
+		key_revoke(key);
+		key_put(key);
+		return ERR_PTR(ret);
+	}
+
+	return key;
+}
+EXPORT_SYMBOL(rxrpc_get_null_key);
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 1bb416f4bbc..d36d6939335 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -1,6 +1,6 @@
 /* internal.h: authentication token and access key management internal defs
  *
- * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2003-5, 2007 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  *
  * This program is free software; you can redistribute it and/or
@@ -12,17 +12,28 @@
 #ifndef _INTERNAL_H
 #define _INTERNAL_H
 
-#include <linux/key.h>
+#include <linux/key-type.h>
 #include <linux/key-ui.h>
 
-#if 0
-#define kenter(FMT, a...)	printk("==> %s("FMT")\n",__FUNCTION__ , ## a)
-#define kleave(FMT, a...)	printk("<== %s()"FMT"\n",__FUNCTION__ , ## a)
-#define kdebug(FMT, a...)	printk(FMT"\n" , ## a)
+static inline __attribute__((format(printf, 1, 2)))
+void no_printk(const char *fmt, ...)
+{
+}
+
+#ifdef __KDEBUG
+#define kenter(FMT, ...) \
+	printk(KERN_DEBUG "==> %s("FMT")\n", __FUNCTION__, ##__VA_ARGS__)
+#define kleave(FMT, ...) \
+	printk(KERN_DEBUG "<== %s()"FMT"\n", __FUNCTION__, ##__VA_ARGS__)
+#define kdebug(FMT, ...) \
+	printk(KERN_DEBUG "xxx" FMT"yyy\n", ##__VA_ARGS__)
 #else
-#define kenter(FMT, a...)	do {} while(0)
-#define kleave(FMT, a...)	do {} while(0)
-#define kdebug(FMT, a...)	do {} while(0)
+#define kenter(FMT, ...) \
+	no_printk(KERN_DEBUG "==> %s("FMT")\n", __FUNCTION__, ##__VA_ARGS__)
+#define kleave(FMT, ...) \
+	no_printk(KERN_DEBUG "<== %s()"FMT"\n", __FUNCTION__, ##__VA_ARGS__)
+#define kdebug(FMT, ...) \
+	no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
 #endif
 
 extern struct key_type key_type_user;
@@ -36,7 +47,7 @@ extern struct key_type key_type_user;
  */
 struct key_user {
 	struct rb_node		node;
-	struct list_head	consq;		/* construction queue */
+	struct mutex		cons_lock;	/* construction initiation lock */
 	spinlock_t		lock;
 	atomic_t		usage;		/* for accessing qnkeys & qnbytes */
 	atomic_t		nkeys;		/* number of keys */
@@ -62,7 +73,7 @@ extern void key_user_put(struct key_user *user);
 extern struct rb_root key_serial_tree;
 extern spinlock_t key_serial_lock;
 extern struct semaphore key_alloc_sem;
-extern struct rw_semaphore key_construction_sem;
+extern struct mutex key_construction_mutex;
 extern wait_queue_head_t request_key_conswq;
 
 
@@ -109,7 +120,7 @@ extern struct key *request_key_and_link(struct key_type *type,
 struct request_key_auth {
 	struct key		*target_key;
 	struct task_struct	*context;
-	const char		*callout_info;
+	char			*callout_info;
 	pid_t			pid;
 };
 
diff --git a/security/keys/key.c b/security/keys/key.c
index 01bbc6d9d19..fdd5ca6d89f 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -1,6 +1,6 @@
-/* key.c: basic authentication token and access key management
+/* Basic authentication token and access key management
  *
- * Copyright (C) 2004-6 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  *
  * This program is free software; you can redistribute it and/or
@@ -34,7 +34,7 @@ static void key_cleanup(struct work_struct *work);
 static DECLARE_WORK(key_cleanup_task, key_cleanup);
 
 /* we serialise key instantiation and link */
-DECLARE_RWSEM(key_construction_sem);
+DEFINE_MUTEX(key_construction_mutex);
 
 /* any key who's type gets unegistered will be re-typed to this */
 static struct key_type key_type_dead = {
@@ -104,7 +104,7 @@ struct key_user *key_user_lookup(uid_t uid)
 	candidate->qnkeys = 0;
 	candidate->qnbytes = 0;
 	spin_lock_init(&candidate->lock);
-	INIT_LIST_HEAD(&candidate->consq);
+	mutex_init(&candidate->cons_lock);
 
 	rb_link_node(&candidate->node, parent, p);
 	rb_insert_color(&candidate->node, &key_user_tree);
@@ -418,7 +418,7 @@ static int __key_instantiate_and_link(struct key *key,
 	awaken = 0;
 	ret = -EBUSY;
 
-	down_write(&key_construction_sem);
+	mutex_lock(&key_construction_mutex);
 
 	/* can't instantiate twice */
 	if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
@@ -443,11 +443,11 @@ static int __key_instantiate_and_link(struct key *key,
 		}
 	}
 
-	up_write(&key_construction_sem);
+	mutex_unlock(&key_construction_mutex);
 
 	/* wake up anyone waiting for a key to be constructed */
 	if (awaken)
-		wake_up_all(&request_key_conswq);
+		wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);
 
 	return ret;
 
@@ -500,7 +500,7 @@ int key_negate_and_link(struct key *key,
 	if (keyring)
 		down_write(&keyring->sem);
 
-	down_write(&key_construction_sem);
+	mutex_lock(&key_construction_mutex);
 
 	/* can't instantiate twice */
 	if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
@@ -525,14 +525,14 @@ int key_negate_and_link(struct key *key,
 			key_revoke(instkey);
 	}
 
-	up_write(&key_construction_sem);
+	mutex_unlock(&key_construction_mutex);
 
 	if (keyring)
 		up_write(&keyring->sem);
 
 	/* wake up anyone waiting for a key to be constructed */
 	if (awaken)
-		wake_up_all(&request_key_conswq);
+		wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);
 
 	return ret;
 
@@ -899,12 +899,14 @@ void key_revoke(struct key *key)
 {
 	key_check(key);
 
-	/* make sure no one's trying to change or use the key when we mark
-	 * it */
-	down_write(&key->sem);
-	set_bit(KEY_FLAG_REVOKED, &key->flags);
-
-	if (key->type->revoke)
+	/* make sure no one's trying to change or use the key when we mark it
+	 * - we tell lockdep that we might nest because we might be revoking an
+	 *   authorisation key whilst holding the sem on a key we've just
+	 *   instantiated
+	 */
+	down_write_nested(&key->sem, 1);
+	if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags) &&
+	    key->type->revoke)
 		key->type->revoke(key);
 
 	up_write(&key->sem);
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index b6f86808475..2a0eb946fc7 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -26,7 +26,7 @@ static DEFINE_MUTEX(key_session_mutex);
 /* the root user's tracking struct */
 struct key_user root_key_user = {
 	.usage		= ATOMIC_INIT(3),
-	.consq		= LIST_HEAD_INIT(root_key_user.consq),
+	.cons_lock	= __MUTEX_INITIALIZER(root_key_user.cons_lock),
 	.lock		= __SPIN_LOCK_UNLOCKED(root_key_user.lock),
 	.nkeys		= ATOMIC_INIT(2),
 	.nikeys		= ATOMIC_INIT(2),
@@ -679,8 +679,18 @@ key_ref_t lookup_user_key(struct task_struct *context, key_serial_t id,
 		break;
 	}
 
-	/* check the status */
-	if (perm) {
+	if (!partial) {
+		ret = wait_for_key_construction(key, true);
+		switch (ret) {
+		case -ERESTARTSYS:
+			goto invalid_key;
+		default:
+			if (perm)
+				goto invalid_key;
+		case 0:
+			break;
+		}
+	} else if (perm) {
 		ret = key_validate(key);
 		if (ret < 0)
 			goto invalid_key;
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 557500110a1..6381e616c47 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -1,6 +1,6 @@
-/* request_key.c: request a key from userspace
+/* Request a key from userspace
  *
- * Copyright (C) 2004-6 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  *
  * This program is free software; you can redistribute it and/or
@@ -18,27 +18,54 @@
 #include <linux/keyctl.h>
 #include "internal.h"
 
-struct key_construction {
-	struct list_head	link;	/* link in construction queue */
-	struct key		*key;	/* key being constructed */
-};
+/*
+ * wait_on_bit() sleep function for uninterruptible waiting
+ */
+static int key_wait_bit(void *flags)
+{
+	schedule();
+	return 0;
+}
+
+/*
+ * wait_on_bit() sleep function for interruptible waiting
+ */
+static int key_wait_bit_intr(void *flags)
+{
+	schedule();
+	return signal_pending(current) ? -ERESTARTSYS : 0;
+}
+
+/*
+ * call to complete the construction of a key
+ */
+void complete_request_key(struct key_construction *cons, int error)
+{
+	kenter("{%d,%d},%d", cons->key->serial, cons->authkey->serial, error);
 
-/* when waiting for someone else's keys, you get added to this */
-DECLARE_WAIT_QUEUE_HEAD(request_key_conswq);
+	if (error < 0)
+		key_negate_and_link(cons->key, key_negative_timeout, NULL,
+				    cons->authkey);
+	else
+		key_revoke(cons->authkey);
+
+	key_put(cons->key);
+	key_put(cons->authkey);
+	kfree(cons);
+}
+EXPORT_SYMBOL(complete_request_key);
 
-/*****************************************************************************/
 /*
  * request userspace finish the construction of a key
  * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>"
  */
-static int call_sbin_request_key(struct key *key,
-				 struct key *authkey,
+static int call_sbin_request_key(struct key_construction *cons,
 				 const char *op,
 				 void *aux)
 {
 	struct task_struct *tsk = current;
 	key_serial_t prkey, sskey;
-	struct key *keyring;
+	struct key *key = cons->key, *authkey = cons->authkey, *keyring;
 	char *argv[9], *envp[3], uid_str[12], gid_str[12];
 	char key_str[12], keyring_str[3][12];
 	char desc[20];
@@ -82,8 +109,7 @@ static int call_sbin_request_key(struct key *key,
 		rcu_read_lock();
 		sskey = rcu_dereference(tsk->signal->session_keyring)->serial;
 		rcu_read_unlock();
-	}
-	else {
+	} else {
 		sskey = tsk->user->session_keyring->serial;
 	}
 
@@ -110,228 +136,77 @@ static int call_sbin_request_key(struct key *key,
 	/* do it */
 	ret = call_usermodehelper_keys(argv[0], argv, envp, keyring,
 				       UMH_WAIT_PROC);
+	kdebug("usermode -> 0x%x", ret);
+	if (ret >= 0) {
+		/* ret is the exit/wait code */
+		if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags) ||
+		    key_validate(key) < 0)
+			ret = -ENOKEY;
+		else
+			/* ignore any errors from userspace if the key was
+			 * instantiated */
+			ret = 0;
+	}
 
 error_link:
 	key_put(keyring);
 
 error_alloc:
 	kleave(" = %d", ret);
+	complete_request_key(cons, ret);
 	return ret;
+}
 
-} /* end call_sbin_request_key() */
-
-/*****************************************************************************/
 /*
- * call out to userspace for the key
- * - called with the construction sem held, but the sem is dropped here
+ * call out to userspace for key construction
  * - we ignore program failure and go on key status instead
  */
-static struct key *__request_key_construction(struct key_type *type,
-					      const char *description,
-					      const char *callout_info,
-					      void *aux,
-					      unsigned long flags)
+static int construct_key(struct key *key, const char *callout_info, void *aux)
 {
+	struct key_construction *cons;
 	request_key_actor_t actor;
-	struct key_construction cons;
-	struct timespec now;
-	struct key *key, *authkey;
-	int ret, negated;
+	struct key *authkey;
+	int ret;
 
-	kenter("%s,%s,%s,%lx", type->name, description, callout_info, flags);
+	kenter("%d,%s,%p", key->serial, callout_info, aux);
 
-	/* create a key and add it to the queue */
-	key = key_alloc(type, description,
-			current->fsuid, current->fsgid, current, KEY_POS_ALL,
-			flags);
-	if (IS_ERR(key))
-		goto alloc_failed;
-
-	set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
-
-	cons.key = key;
-	list_add_tail(&cons.link, &key->user->consq);
-
-	/* we drop the construction sem here on behalf of the caller */
-	up_write(&key_construction_sem);
+	cons = kmalloc(sizeof(*cons), GFP_KERNEL);
+	if (!cons)
+		return -ENOMEM;
 
 	/* allocate an authorisation key */
 	authkey = request_key_auth_new(key, callout_info);
 	if (IS_ERR(authkey)) {
+		kfree(cons);
 		ret = PTR_ERR(authkey);
 		authkey = NULL;
-		goto alloc_authkey_failed;
-	}
-
-	/* make the call */
-	actor = call_sbin_request_key;
-	if (type->request_key)
-		actor = type->request_key;
-	ret = actor(key, authkey, "create", aux);
-	if (ret < 0)
-		goto request_failed;
-
-	/* if the key wasn't instantiated, then we want to give an error */
-	ret = -ENOKEY;
-	if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
-		goto request_failed;
-
-	key_revoke(authkey);