3 files changed, 53 insertions, 6 deletions
diff --git a/libnetfs/init-init.c b/libnetfs/init-init.c
index e98b6562..a088ad51 100644
--- a/libnetfs/init-init.c
+++ b/libnetfs/init-init.c
@@ -21,6 +21,9 @@
 
 #include "netfs.h"
 
+/* For safe inlining of netfs_node_netnode and netfs_netnode_node.  */
+size_t const _netfs_sizeof_struct_node = sizeof (struct node);
+
 pthread_spinlock_t netfs_node_refcnt_lock = PTHREAD_SPINLOCK_INITIALIZER;
 
 struct node *netfs_root_node = 0;
diff --git a/libnetfs/make-node.c b/libnetfs/make-node.c
index f20ada18..6bd8109c 100644
--- a/libnetfs/make-node.c
+++ b/libnetfs/make-node.c
@@ -21,13 +21,9 @@
 #include "netfs.h"
 #include <hurd/fshelp.h>
 
-struct node *
-netfs_make_node (struct netnode *nn)
+static struct node *
+init_node (struct node *np, struct netnode *nn)
 {
-  struct node *np = malloc (sizeof (struct node));
-  if (! np)
-    return NULL;
-  
   np->nn = nn;
 
   pthread_mutex_init (&np->lock, NULL);
@@ -40,3 +36,24 @@ netfs_make_node (struct netnode *nn)
   
   return np;
 }
+
+struct node *
+netfs_make_node (struct netnode *nn)
+{
+  struct node *np = malloc (sizeof (struct node));
+  if (! np)
+    return NULL;
+
+  return init_node (np, nn);
+}
+
+struct node *
+netfs_make_node_alloc (size_t size)
+{
+  struct node *np = malloc (sizeof (struct node) + size);
+
+  if (np == NULL)
+    return NULL;
+
+  return init_node (np, netfs_node_netnode (np));
+}
diff --git a/libnetfs/netfs.h b/libnetfs/netfs.h
index aef4a3dd..fbe2c60d 100644
--- a/libnetfs/netfs.h
+++ b/libnetfs/netfs.h
@@ -372,6 +372,33 @@ extern int netfs_maxsymlinks;
    If an error occurs, NULL is returned.  */
 struct node *netfs_make_node (struct netnode *);
 
+/* Create a new node structure.  Also allocate SIZE bytes for the
+   netnode.  The address of the netnode can be obtained using
+   netfs_node_netnode.  The new node will have one hard reference and
+   no light references.  If an error occurs, NULL is returned.  */
+struct node *netfs_make_node_alloc (size_t size);
+
+/* To avoid breaking the ABI whenever sizeof (struct node) changes, we
+   explicitly provide the size.  The following two functions will use
+   this value for offset calculations.  */
+extern const size_t _netfs_sizeof_struct_node;
+
+/* Return the address of the netnode for NODE.  NODE must have been
+   allocated using netfs_make_node_alloc.  */
+static inline struct netnode *
+netfs_node_netnode (struct node *node)
+{
+  return (struct netnode *) ((char *) node + _netfs_sizeof_struct_node);
+}
+
+/* Return the address of the node for NETNODE.  NETNODE must have been
+   allocated using netfs_make_node_alloc.  */
+static inline struct node *
+netfs_netnode_node (struct netnode *netnode)
+{
+  return (struct node *) ((char *) netnode - _netfs_sizeof_struct_node);
+}
+
 /* Whenever node->references is to be touched, this lock must be
    held.  Cf. netfs_nrele, netfs_nput, netfs_nref and netfs_drop_node.  */
 extern pthread_spinlock_t netfs_node_refcnt_lock;