KEYS: Deal with dead-type keys appropriately [try #6]

Allow keys for which the key type has been removed to be unlinked.  Currently
dead-type keys can only be disposed of by completely clearing the keyrings
that point to them.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/keys/key.c b/security/keys/key.c
index 4a1297d..3762d5b 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -642,10 +642,8 @@
 	goto error;
 
  found:
-	/* pretend it doesn't exist if it's dead */
-	if (atomic_read(&key->usage) == 0 ||
-	    test_bit(KEY_FLAG_DEAD, &key->flags) ||
-	    key->type == &key_type_dead)
+	/* pretend it doesn't exist if it is awaiting deletion */
+	if (atomic_read(&key->usage) == 0)
 		goto not_found;
 
 	/* this races with key_put(), but that doesn't matter since key_put()