add patch series

15 files changed, 6013 insertions, 0 deletions

diff --git a/debian/patches/0001-include-add-lock-less-reference-counting-primitives.patch b/debian/patches/0001-include-add-lock-less-reference-counting-primitives.patch
new file mode 100644
index 00000000..350f7d7e
--- /dev/null
+++ b/debian/patches/0001-include-add-lock-less-reference-counting-primitives.patch
@@ -0,0 +1,283 @@
+From e83aa1db431019801a055ea0280bc7468e49cbaf Mon Sep 17 00:00:00 2001
+From: Justus Winter <4winter@informatik.uni-hamburg.de>
+Date: Tue, 6 May 2014 19:52:04 +0200
+Subject: [PATCH 01/14] include: add lock-less reference counting primitives
+
+* include/refcount.h: New file.
+---
+ include/refcount.h | 263 +++++++++++++++++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 263 insertions(+)
+ create mode 100644 include/refcount.h
+
+diff --git a/include/refcount.h b/include/refcount.h
+new file mode 100644
+index 0000000..5c3302d
+--- /dev/null
++++ b/include/refcount.h
+@@ -0,0 +1,263 @@
++/* Lock-less reference counting primitives
++
++   Copyright (C) 2014 Free Software Foundation, Inc.
++
++   Written by Justus Winter <4winter@informatik.uni-hamburg.de>
++
++   This file is part of the GNU Hurd.
++
++   The GNU Hurd is free software; you can redistribute it and/or
++   modify it under the terms of the GNU General Public License as
++   published by the Free Software Foundation; either version 2, or (at
++   your option) any later version.
++
++   The GNU Hurd is distributed in the hope that it will be useful, but
++   WITHOUT ANY WARRANTY; without even the implied warranty of
++   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
++   General Public License for more details.
++
++   You should have received a copy of the GNU General Public License
++   along with the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.  */
++
++#ifndef _HURD_REFCOUNT_H_
++#define _HURD_REFCOUNT_H_
++
++#include <assert.h>
++#include <limits.h>
++#include <stdint.h>
++
++/* Simple reference counting.  */
++
++/* An opaque type.  You must not access these values directly.  */
++typedef unsigned int refcount_t;
++
++/* Initialize REF with REFERENCES.  */
++static inline void
++refcount_init (refcount_t *ref, unsigned int references)
++{
++  *ref = references;
++}
++
++/* Increment REF.  Return the result of the operation.  This function
++   uses atomic operations.  It is not required to serialize calls to
++   this function.  */
++static inline unsigned int
++refcount_ref (refcount_t *ref)
++{
++  unsigned int r;
++  r = __atomic_add_fetch (ref, 1, __ATOMIC_RELAXED);
++  assert (r != UINT_MAX || !"refcount overflowed!");
++  return r;
++}
++
++/* Decrement REF.  Return the result of the operation.  This function
++   uses atomic operations.  It is not required to serialize calls to
++   this function.  */
++static inline unsigned int
++refcount_deref (refcount_t *ref)
++{
++  unsigned int r;
++  r = __atomic_sub_fetch (ref, 1, __ATOMIC_RELAXED);
++  assert (r != UINT_MAX || !"refcount underflowed!");
++  return r;
++}
++
++/* Return REF.  This function uses atomic operations.  It is not
++   required to serialize calls to this function.  */
++static inline unsigned int
++refcount_references (refcount_t *ref)
++{
++  return __atomic_load_n (ref, __ATOMIC_RELAXED);
++}
++
++/* Reference counting with weak references.  */
++
++/* An opaque type.  You must not access these values directly.  */
++typedef union _references refcounts_t;
++
++/* Instead, the functions manipulating refcounts_t values write the
++   results into this kind of objects.  */
++struct references {
++  /* We chose the layout of this struct so that when it is used in the
++     union _references, the hard reference counts occupy the least
++     significant bits.  We rely on this layout for atomic promotion
++     and demotion of references.  See refcounts_promote and
++     refcounts_demote for details.  */
++#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
++  uint32_t hard;
++  uint32_t weak;
++#else
++  uint32_t weak;
++  uint32_t hard;
++#endif
++};
++
++/* We use a union to convert struct reference values to uint64_t which
++   we can manipulate atomically.  While this behavior is not
++   guaranteed by the C standard, it is supported by all major
++   compilers.  */
++union _references {
++  struct references references;
++  uint64_t value;
++};
++
++/* Initialize REF with HARD and WEAK references.  */
++static inline void
++refcounts_init (refcounts_t *ref, uint32_t hard, uint32_t weak)
++{
++  ref->references = (struct references) { .hard = hard, .weak = weak };
++}
++
++/* Increment the hard reference count of REF.  If RESULT is not NULL,
++   the result of the operation is written there.  This function uses
++   atomic operations.  It is not required to serialize calls to this
++   function.  */
++static inline void
++refcounts_ref (refcounts_t *ref, struct references *result)
++{
++  const union _references op = { .references = { .hard = 1 } };
++  union _references r;
++  r.value = __atomic_add_fetch (&ref->value, op.value, __ATOMIC_RELAXED);
++  assert (r.references.hard != UINT32_MAX || !"refcount overflowed!");
++  if (result)
++    *result = r.references;
++}
++
++/* Decrement the hard reference count of REF.  If RESULT is not NULL,
++   the result of the operation is written there.  This function uses
++   atomic operations.  It is not required to serialize calls to this
++   function.  */
++static inline void
++refcounts_deref (refcounts_t *ref, struct references *result)
++{
++  const union _references op = { .references = { .hard = 1 } };
++  union _references r;
++  r.value = __atomic_sub_fetch (&ref->value, op.value, __ATOMIC_RELAXED);
++  assert (r.references.hard != UINT32_MAX || !"refcount underflowed!");
++  if (result)
++    *result = r.references;
++}
++
++/* Promote a weak reference to a hard reference.  If RESULT is not
++   NULL, the result of the operation is written there.  This function
++   uses atomic operations.  It is not required to serialize calls to
++   this function.  */
++static inline void
++refcounts_promote (refcounts_t *ref, struct references *result)
++{
++  /* To promote a weak reference, we need to atomically subtract 1
++     from the weak reference count, and add 1 to the hard reference
++     count.
++
++     We can subtract by 1 by adding the two's complement of 1 = ~0 to
++     a fixed-width value, discarding the overflow.
++
++     We do the same in our uint64_t value, but we have chosen the
++     layout of struct references so that when it is used in the union
++     _references, the weak reference counts occupy the most
++     significant bits.  When we add ~0 to the weak references, the
++     overflow will be discarded as unsigned arithmetic is modulo 2^n.
++     So we just add a hard reference.  In combination, this is the
++     desired operation.  */
++  const union _references op =
++    { .references = { .weak = ~0, .hard = 1} };
++  union _references r;
++  r.value = __atomic_add_fetch (&ref->value, op.value, __ATOMIC_RELAXED);
++  assert (r.references.hard != UINT32_MAX || !"refcount overflowed!");
++  assert (r.references.weak != UINT32_MAX || !"refcount underflowed!");
++  if (result)
++    *result = r.references;
++}
++
++/* Demote a hard reference to a weak reference.  If RESULT is not
++   NULL, the result of the operation is written there.  This function
++   uses atomic operations.  It is not required to serialize calls to
++   this function.  */
++static inline void
++refcounts_demote (refcounts_t *ref, struct references *result)
++{
++  /* To demote a hard reference, we need to atomically subtract 1 from
++     the hard reference count, and add 1 to the weak reference count.
++
++     We can subtract by 1 by adding the two's complement of 1 = ~0 to
++     a fixed-width value, discarding the overflow.
++
++     We do the same in our uint64_t value, but we have chosen the
++     layout of struct references so that when it is used in the union
++     _references, the hard reference counts occupy the least
++     significant bits.  When we add ~0 to the hard references, it will
++     overflow into the weak references.  This is the desired
++     operation.  */
++  const union _references op = { .references = { .hard = ~0 } };
++  union _references r;
++  r.value = __atomic_add_fetch (&ref->value, op.value, __ATOMIC_RELAXED);
++  assert (r.references.hard != UINT32_MAX || !"refcount underflowed!");
++  assert (r.references.weak != UINT32_MAX || !"refcount overflowed!");
++  if (result)
++    *result = r.references;
++}
++
++/* Increment the weak reference count of REF.  If RESULT is not NULL,
++   the result of the operation is written there.  This function uses
++   atomic operations.  It is not required to serialize calls to this
++   function.  */
++static inline void
++refcounts_ref_weak (refcounts_t *ref, struct references *result)
++{
++  const union _references op = { .references = { .weak = 1 } };
++  union _references r;
++  r.value = __atomic_add_fetch (&ref->value, op.value, __ATOMIC_RELAXED);
++  assert (r.references.weak != UINT32_MAX || !"refcount overflowed!");
++  if (result)
++    *result = r.references;
++}
++
++/* Decrement the weak reference count of REF.  If RESULT is not NULL,
++   the result of the operation is written there.  This function uses
++   atomic operations.  It is not required to serialize calls to this
++   function.  */
++static inline void
++refcounts_deref_weak (refcounts_t *ref, struct references *result)
++{
++  const union _references op = { .references = { .weak = 1 } };
++  union _references r;
++  r.value = __atomic_sub_fetch (&ref->value, op.value, __ATOMIC_RELAXED);
++  assert (r.references.weak != UINT32_MAX || !"refcount underflowed!");
++  if (result)
++    *result = r.references;
++}
++
++/* Store the current reference counts of REF in RESULT.  This function
++   uses atomic operations.  It is not required to serialize calls to
++   this function.  */
++static inline void
++refcounts_references (refcounts_t *ref, struct references *result)
++{
++  union _references r;
++  r.value =__atomic_load_n (&ref->value, __ATOMIC_RELAXED);
++  *result = r.references;
++}
++
++/* Return the hard reference count of REF.  This function uses atomic
++   operations.  It is not required to serialize calls to this
++   function.  */
++static inline uint32_t
++refcounts_hard_references (refcounts_t *ref)
++{
++  struct references result;
++  refcounts_references (ref, &result);
++  return result.hard;
++}
++
++/* Return the weak reference count of REF.  This function uses atomic
++   operations.  It is not required to serialize calls to this
++   function.  */
++static inline uint32_t
++refcounts_weak_references (refcounts_t *ref)
++{
++  struct references result;
++  refcounts_references (ref, &result);
++  return result.weak;
++}
++
++#endif /* _HURD_REFCOUNT_H_ */
+-- 
+2.0.0.rc2
+
diff --git a/debian/patches/0002-trans-fakeroot-override-fshelp_isowner.patch b/debian/patches/0002-trans-fakeroot-override-fshelp_isowner.patch
new file mode 100644
index 00000000..8754dd15
--- /dev/null
+++ b/debian/patches/0002-trans-fakeroot-override-fshelp_isowner.patch
@@ -0,0 +1,50 @@
+From ce90f0add260f7d8fb248b9ab688d86b282e8200 Mon Sep 17 00:00:00 2001
+From: Justus Winter <4winter@informatik.uni-hamburg.de>
+Date: Mon, 19 May 2014 16:46:33 +0200
+Subject: [PATCH 02/14] trans/fakeroot: override fshelp_isowner
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+As of recently, fakeroot would fail to create symlinks:
+
+% fakeroot-hurd ln -s foo a
+ln: failed to create symbolic link ‘a’: Operation not permitted
+
+Fix this by overriding fshelp_isowner.
+
+Various netfs functions will call fshelp_isowner to check whether USER
+is allowed to do some operation.  As fakeroot is not running within
+the fakeauth'ed environment, USER contains the real user.
+
+I have no explanation why this ever worked.
+
+* trans/fakeroot.c (fshelp_isowner): New function.
+---
+ trans/fakeroot.c | 10 ++++++++++
+ 1 file changed, 10 insertions(+)
+
+diff --git a/trans/fakeroot.c b/trans/fakeroot.c
+index d3addc1..32a34ec 100644
+--- a/trans/fakeroot.c
++++ b/trans/fakeroot.c
+@@ -469,6 +469,16 @@ netfs_validate_stat (struct node *np, struct iouser *cred)
+   return 0;
+ }
+ 
++/* Various netfs functions will call fshelp_isowner to check whether
++   USER is allowed to do some operation.  As fakeroot is not running
++   within the fakeauth'ed environment, USER contains the real
++   user.  Hence, we override this check.  */
++error_t
++fshelp_isowner (struct stat *st, struct iouser *user)
++{
++  return 0;
++}
++
+ error_t
+ netfs_attempt_chown (struct iouser *cred, struct node *np,
+ 		     uid_t uid, uid_t gid)
+-- 
+2.0.0.rc2
+
diff --git a/debian/patches/0003-librbtree-add-a-red-black-tree-implementation.patch b/debian/patches/0003-librbtree-add-a-red-black-tree-implementation.patch
new file mode 100644
index 00000000..d2e625bd
--- /dev/null
+++ b/debian/patches/0003-librbtree-add-a-red-black-tree-implementation.patch
@@ -0,0 +1,1181 @@
+From c5615b30ec661f66fff1b2733c30cd2b0efd31c5 Mon Sep 17 00:00:00 2001
+From: Justus Winter <4winter@informatik.uni-hamburg.de>
+Date: Fri, 16 May 2014 20:21:48 +0200
+Subject: [PATCH 03/14] librbtree: add a red-black tree implementation
+
+Red-black trees offer search, insert, and delete operations with worst
+case runtime in O(log n).  They are also very space efficient.
+
+This is an verbatim copy from git://git.sceen.net/rbraun/librbraun.git
+as of 45fef4ad.  Only macros.h has been slightly amended.  This file
+defines two macros, which are also defined in cthreads.h.  Undefine
+the macros first to work around this problem.
+
+* librbtree/Makefile: New file.
+* librbtree/rbtree.c: Likewise.
+* librbtree/rbtree.h: Likewise.
+* librbtree/rbtree_i.h: Likewise.
+* librbtree/macros.h: Likewise.  Also, undefine MACRO_{BEGIN,END}.
+* Makefile (lib-subdirs): Add librbtree.
+---
+ Makefile             |   3 +
+ librbtree/Makefile   |  27 +++
+ librbtree/macros.h   |  70 ++++++++
+ librbtree/rbtree.c   | 498 +++++++++++++++++++++++++++++++++++++++++++++++++++
+ librbtree/rbtree.h   | 310 ++++++++++++++++++++++++++++++++
+ librbtree/rbtree_i.h | 196 ++++++++++++++++++++
+ 6 files changed, 1104 insertions(+)
+ create mode 100644 librbtree/Makefile
+ create mode 100644 librbtree/macros.h
+ create mode 100644 librbtree/rbtree.c
+ create mode 100644 librbtree/rbtree.h
+ create mode 100644 librbtree/rbtree_i.h
+
+diff --git a/Makefile b/Makefile
+index 106f2f6..8a0be83 100644
+--- a/Makefile
++++ b/Makefile
+@@ -46,6 +46,9 @@ endif
+ # Other directories
+ other-subdirs = hurd doc config release include
+ 
++# XXX
++lib-subdirs += librbtree
++
+ # All the subdirectories together
+ subdirs = $(lib-subdirs) $(prog-subdirs) $(other-subdirs)
+ 
+diff --git a/librbtree/Makefile b/librbtree/Makefile
+new file mode 100644
+index 0000000..0f33358
+--- /dev/null
++++ b/librbtree/Makefile
+@@ -0,0 +1,27 @@
++#   Copyright (C) 2014 Free Software Foundation, Inc.
++#
++#   This file is part of the GNU Hurd.
++#
++#   The GNU Hurd is free software; you can redistribute it and/or
++#   modify it under the terms of the GNU General Public License as
++#   published by the Free Software Foundation; either version 2, or (at
++#   your option) any later version.
++#
++#   The GNU Hurd is distributed in the hope that it will be useful, but
++#   WITHOUT ANY WARRANTY; without even the implied warranty of
++#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
++#   General Public License for more details.
++#
++#   You should have received a copy of the GNU General Public License
++#   along with the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.
++
++dir := librbtree
++makemode := library
++
++libname := librbtree
++SRCS = rbtree.c
++installhdrs = rbtree.h rbtree_i.h macros.h
++
++OBJS = $(SRCS:.c=.o)
++
++include ../Makeconf
+diff --git a/librbtree/macros.h b/librbtree/macros.h
+new file mode 100644
+index 0000000..f0960a3
+--- /dev/null
++++ b/librbtree/macros.h
+@@ -0,0 +1,70 @@
++/*
++ * Copyright (c) 2009, 2010 Richard Braun.
++ * All rights reserved.
++ *
++ * Redistribution and use in source and binary forms, with or without
++ * modification, are permitted provided that the following conditions
++ * are met:
++ * 1. Redistributions of source code must retain the above copyright
++ *    notice, this list of conditions and the following disclaimer.
++ * 2. Redistributions in binary form must reproduce the above copyright
++ *    notice, this list of conditions and the following disclaimer in the
++ *    documentation and/or other materials provided with the distribution.
++ *
++ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
++ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
++ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
++ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
++ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
++ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
++ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
++ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
++ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
++ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
++ *
++ *
++ * Helper macros.
++ */
++
++#ifndef _MACROS_H
++#define _MACROS_H
++
++#include <stddef.h>
++
++#undef MACRO_BEGIN
++#undef MACRO_END
++#define MACRO_BEGIN     ({
++#define MACRO_END       })
++
++#define XQUOTE(x)       #x
++#define QUOTE(x)        XQUOTE(x)
++
++#define STRLEN(x)       (sizeof(x) - 1)
++#define ARRAY_SIZE(x)   (sizeof(x) / sizeof((x)[0]))
++
++#define MIN(a, b)       ((a) < (b) ? (a) : (b))
++#define MAX(a, b)       ((a) > (b) ? (a) : (b))
++
++#define P2ALIGNED(x, a) (((x) & ((a) - 1)) == 0)
++#define ISP2(x)         P2ALIGNED(x, x)
++#define P2ALIGN(x, a)   ((x) & -(a))
++#define P2ROUND(x, a)   (-(-(x) & -(a)))
++#define P2END(x, a)     (-(~(x) & -(a)))
++
++#define structof(ptr, type, member) \
++    ((type *)((char *)(ptr) - offsetof(type, member)))
++
++#define alignof(x)      __alignof__(x)
++
++#define likely(expr)    __builtin_expect(!!(expr), 1)
++#define unlikely(expr)  __builtin_expect(!!(expr), 0)
++
++#define barrier()       asm volatile("" : : : "memory")
++
++#define __noreturn      __attribute__((noreturn))
++#define __aligned(x)    __attribute__((aligned(x)))
++
++#define __format_printf(fmt, args) \
++    __attribute__((format(printf, fmt, args)))
++
++#endif /* _MACROS_H */
+diff --git a/librbtree/rbtree.c b/librbtree/rbtree.c
+new file mode 100644
+index 0000000..969a18d
+--- /dev/null
++++ b/librbtree/rbtree.c
+@@ -0,0 +1,498 @@
++/*
++ * Copyright (c) 2010, 2012 Richard Braun.
++ * All rights reserved.
++ *
++ * Redistribution and use in source and binary forms, with or without
++ * modification, are permitted provided that the following conditions
++ * are met:
++ * 1. Redistributions of source code must retain the above copyright
++ *    notice, this list of conditions and the following disclaimer.
++ * 2. Redistributions in binary form must reproduce the above copyright
++ *    notice, this list of conditions and the following disclaimer in the
++ *    documentation and/or other materials provided with the distribution.
++ *
++ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
++ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
++ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
++ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
++ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
++ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
++ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
++ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
++ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
++ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
++ */
++
++#include <assert.h>
++#include <stddef.h>
++
++#include "macros.h"
++#include "rbtree.h"
++#include "rbtree_i.h"
++
++/*
++ * Return the index of a node in the children array of its parent.
++ *
++ * The parent parameter must not be NULL, and must be the parent of the
++ * given node.
++ */
++static inline int
++rbtree_node_index(const struct rbtree_node *node,
++                  const struct rbtree_node *parent)
++{
++    assert(parent != NULL);
++    assert((node == NULL) || (rbtree_node_parent(node) == parent));
++
++    if (parent->children[RBTREE_LEFT] == node)
++        return RBTREE_LEFT;
++
++    assert(parent->children[RBTREE_RIGHT] == node);
++
++    return RBTREE_RIGHT;
++}
++
++/*
++ * Return the color of a node.
++ */
++static inline int
++rbtree_node_color(const struct rbtree_node *node)
++{
++    return node->parent & RBTREE_COLOR_MASK;
++}
++
++/*
++ * Return true if the node is red.
++ */
++static inline int
++rbtree_node_is_red(const struct rbtree_node *node)
++{
++    return rbtree_node_color(node) == RBTREE_COLOR_RED;
++}
++
++/*
++ * Return true if the node is black.
++ */
++static inline int
++rbtree_node_is_black(const struct rbtree_node *node)
++{
++    return rbtree_node_color(node) == RBTREE_COLOR_BLACK;
++}
++
++/*
++ * Set the parent of a node, retaining its current color.
++ */
++static inline void
++rbtree_node_set_parent(struct rbtree_node *node, struct rbtree_node *parent)
++{
++    assert(rbtree_node_check_alignment(node));
++    assert(rbtree_node_check_alignment(parent));
++
++    node->parent = (unsigned long)parent | (node->parent & RBTREE_COLOR_MASK);
++}
++
++/*
++ * Set the color of a node, retaining its current parent.
++ */
++static inline void
++rbtree_node_set_color(struct rbtree_node *node, int color)
++{
++    assert((color & ~RBTREE_COLOR_MASK) == 0);
++    node->parent = (node->parent & RBTREE_PARENT_MASK) | color;
++}
++
++/*
++ * Set the color of a node to red, retaining its current parent.
++ */
++static inline void
++rbtree_node_set_red(struct rbtree_node *node)
++{
++    rbtree_node_set_color(node, RBTREE_COLOR_RED);
++}
++
++/*
++ * Set the color of a node to black, retaining its current parent.
++ */
++static inline void
++rbtree_node_set_black(struct rbtree_node *node)
++{
++    rbtree_node_set_color(node, RBTREE_COLOR_BLACK);
++}
++
++/*
++ * Return the left-most deepest child node of the given node.
++ */
++static struct rbtree_node *
++rbtree_node_find_deepest(struct rbtree_node *node)
++{
++    struct rbtree_node *parent;
++
++    assert(node != NULL);
++
++    for (;;) {
++        parent = node;
++        node = node->children[RBTREE_LEFT];
++
++        if (node == NULL) {
++            node = parent->children[RBTREE_RIGHT];
++
++            if (node == NULL)
++                return parent;
++        }
++    }
++}
++
++/*
++ * Perform a tree rotation, rooted at the given node.
++ *
++ * The direction parameter defines the rotation direction and is either
++ * RBTREE_LEFT or RBTREE_RIGHT.
++ */
++static void
++rbtree_rotate(struct rbtree *tree, struct rbtree_node *node, int direction)
++{
++    struct rbtree_node *parent, *rnode;
++    int left, right;
++
++    left = direction;
++    right = 1 - left;
++    parent = rbtree_node_parent(node);
++    rnode = node->children[right];
++
++    node->children[right] = rnode->children[left];
++
++    if (rnode->children[left] != NULL)
++        rbtree_node_set_parent(rnode->children[left], node);
++
++    rnode->children[left] = node;
++    rbtree_node_set_parent(rnode, parent);
++
++    if (unlikely(parent == NULL))
++        tree->root = rnode;
++    else
++        parent->children[rbtree_node_index(node, parent)] = rnode;
++
++    rbtree_node_set_parent(node, rnode);
++}
++
++void
++rbtree_insert_rebalance(struct rbtree *tree, struct rbtree_node *parent,
++                        int index, struct rbtree_node *node)
++{
++    struct rbtree_node *grand_parent, *uncle, *tmp;
++    int left, right;
++
++    assert(rbtree_node_check_alignment(parent));
++    assert(rbtree_node_check_alignment(node));
++
++    node->parent = (unsigned long)parent | RBTREE_COLOR_RED;
++    node->children[RBTREE_LEFT] = NULL;
++    node->children[RBTREE_RIGHT] = NULL;
++
++    if (unlikely(parent == NULL))
++        tree->root = node;
++    else
++        parent->children[index] = node;
++
++    for (;;) {
++        if (parent == NULL) {
++            rbtree_node_set_black(node);
++            break;
++        }
++
++        if (rbtree_node_is_black(parent))
++            break;
++
++        grand_parent = rbtree_node_parent(parent);
++        assert(grand_parent != NULL);
++
++        left = rbtree_node_index(parent, grand_parent);
++        right = 1 - left;
++
++        uncle = grand_parent->children[right];
++
++        /*
++         * Uncle is red. Flip colors and repeat at grand parent.
++         */
++        if ((uncle != NULL) && rbtree_node_is_red(uncle)) {
++            rbtree_node_set_black(uncle);
++            rbtree_node_set_black(parent);
++            rbtree_node_set_red(grand_parent);
++            node = grand_parent;
++            parent = rbtree_node_parent(node);
++            continue;
++        }
++
++        /*
++         * Node is the right child of its parent. Rotate left at parent.
++         */
++        if (parent->children[right] == node) {
++            rbtree_rotate(tree, parent, left);
++            tmp = node;
++            node = parent;
++            parent = tmp;
++        }
++
++        /*
++         * Node is the left child of its parent. Handle colors, rotate right
++         * at grand parent, and leave.
++         */
++        rbtree_node_set_black(parent);
++        rbtree_node_set_red(grand_parent);
++        rbtree_rotate(tree, grand_parent, right);
++        break;
++    }
++
++    assert(rbtree_node_is_black(tree->root));
++}
++
++void
++rbtree_remove(struct rbtree *tree, struct rbtree_node *node)
++{
++    struct rbtree_node *child, *parent, *brother;
++    int color, left, right;
++
++    if (node->children[RBTREE_LEFT] == NULL)
++        child = node->children[RBTREE_RIGHT];
++    else if (node->children[RBTREE_RIGHT] == NULL)
++        child = node->children[RBTREE_LEFT];
++    else {
++        struct rbtree_node *successor;
++
++        /*
++         * Two-children case: replace the node with its successor.
++         */
++
++        successor = node->children[RBTREE_RIGHT];
++
++        while (successor->children[RBTREE_LEFT] != NULL)
++            successor = successor->children[RBTREE_LEFT];
++
++        color = rbtree_node_color(successor);
++        child = successor->children[RBTREE_RIGHT];
++        parent = rbtree_node_parent(node);
++
++        if (unlikely(parent == NULL))
++            tree->root = successor;
++        else
++            parent->children[rbtree_node_index(node, parent)] = successor;
++
++        parent = rbtree_node_parent(successor);
++
++        /*
++         * Set parent directly to keep the original color.
++         */
++        successor->parent = node->parent;
++        successor->children[RBTREE_LEFT] = node->children[RBTREE_LEFT];
++        rbtree_node_set_parent(successor->children[RBTREE_LEFT], successor);
++
++        if (node == parent)
++            parent = successor;
++        else {
++            successor->children[RBTREE_RIGHT] = node->children[RBTREE_RIGHT];
++            rbtree_node_set_parent(successor->children[RBTREE_RIGHT],
++                                   successor);
++            parent->children[RBTREE_LEFT] = child;
++
++            if (child != NULL)
++                rbtree_node_set_parent(child, parent);
++        }
++
++        goto update_color;
++    }
++
++    /*
++     * Node has at most one child.
++     */
++
++    color = rbtree_node_color(node);
++    parent = rbtree_node_parent(node);
++
++    if (child != NULL)
++        rbtree_node_set_parent(child, parent);
++
++    if (unlikely(parent == NULL))
++        tree->root = child;
++    else
++        parent->children[rbtree_node_index(node, parent)] = child;
++
++    /*
++     * The node has been removed, update the colors. The child pointer can
++     * be NULL, in which case it is considered a black leaf.
++     */
++update_color:
++    if (color == RBTREE_COLOR_RED)
++        return;
++
++    for (;;) {
++        if ((child != NULL) && rbtree_node_is_red(child)) {
++            rbtree_node_set_black(child);
++            break;
++        }
++
++        if (parent == NULL)
++            break;
++
++        left = rbtree_node_index(child, parent);
++        right = 1 - left;
++
++        brother = parent->children[right];
++
++        /*
++         * Brother is red. Recolor and rotate left at parent so that brother
++         * becomes black.
++         */
++        if (rbtree_node_is_red(brother)) {
++            rbtree_node_set_black(brother);
++            rbtree_node_set_red(parent);
++            rbtree_rotate(tree, parent, left);
++            brother = parent->children[right];
++        }
++
++        /*
++         * Brother has no red child. Recolor and repeat at parent.
++         */
++        if (((brother->children[RBTREE_LEFT] == NULL)
++             || rbtree_node_is_black(brother->children[RBTREE_LEFT]))
++            && ((brother->children[RBTREE_RIGHT] == NULL)
++                || rbtree_node_is_black(brother->children[RBTREE_RIGHT]))) {
++            rbtree_node_set_red(brother);
++            child = parent;
++            parent = rbtree_node_parent(child);
++            continue;
++        }
++
++        /*
++         * Brother's right child is black. Recolor and rotate right at brother.
++         */
++        if ((brother->children[right] == NULL)
++            || rbtree_node_is_black(brother->children[right])) {
++            rbtree_node_set_black(brother->children[left]);
++            rbtree_node_set_red(brother);
++            rbtree_rotate(tree, brother, right);
++            brother = parent->children[right];
++        }
++
++        /*
++         * Brother's left child is black. Exchange parent and brother colors
++         * (we already know brother is black), set brother's right child black,
++         * rotate left at parent and leave.
++         */
++        rbtree_node_set_color(brother, rbtree_node_color(parent));
++        rbtree_node_set_black(parent);
++        rbtree_node_set_black(brother->children[right]);
++        rbtree_rotate(tree, parent, left);
++        break;
++    }
++
++    assert((tree->root == NULL) || rbtree_node_is_black(tree->root));
++}
++
++struct rbtree_node *
++rbtree_nearest(struct rbtree_node *parent, int index, int direction)
++{
++    assert(rbtree_check_index(direction));
++
++    if (parent == NULL)
++        return NULL;
++
++    assert(rbtree_check_index(index));
++
++    if (index != direction)
++        return parent;
++
++    return rbtree_walk(parent, direction);
++}
++
++struct rbtree_node *
++rbtree_firstlast(const struct rbtree *tree, int direction)
++{
++    struct rbtree_node *prev, *cur;
++
++    assert(rbtree_check_index(direction));
++
++    prev = NULL;
++
++    for (cur = tree->root; cur != NULL; cur = cur->children[direction])
++        prev = cur;
++
++    return prev;
++}
++
++struct rbtree_node *
++rbtree_walk(struct rbtree_node *node, int direction)
++{
++    int left, right;
++
++    assert(rbtree_check_index(direction));
++
++    left = direction;
++    right = 1 - left;
++
++    if (node == NULL)
++        return NULL;
++
++    if (node->children[left] != NULL) {
++        node = node->children[left];
++
++        while (node->children[right] != NULL)
++            node = node->children[right];
++    } else {
++        struct rbtree_node *parent;
++        int index;
++
++        for (;;) {
++            parent = rbtree_node_parent(node);
++
++            if (parent == NULL)
++                return NULL;
++
++            index = rbtree_node_index(node, parent);
++            node = parent;
++
++            if (index == right)
++                break;
++        }
++    }
++
++    return node;
++}
++
++struct rbtree_node *
++rbtree_postwalk_deepest(const struct rbtree *tree)
++{
++    struct rbtree_node *node;
++
++    node = tree->root;
++
++    if (node == NULL)
++        return NULL;
++
++    return rbtree_node_find_deepest(node);
++}
++
++struct rbtree_node *
++rbtree_postwalk_unlink(struct rbtree_node *node)
++{
++    struct rbtree_node *parent;
++    int index;
++
++    if (node == NULL)
++        return NULL;
++
++    assert(node->children[RBTREE_LEFT] == NULL);
++    assert(node->children[RBTREE_RIGHT] == NULL);
++
++    parent = rbtree_node_parent(node);
++
++    if (parent == NULL)
++        return NULL;
++
++    index = rbtree_node_index(node, parent);
++    parent->children[index] = NULL;
++    node = parent->children[RBTREE_RIGHT];
++
++    if (node == NULL)
++        return parent;
++
++    return rbtree_node_find_deepest(node);
++}
+diff --git a/librbtree/rbtree.h b/librbtree/rbtree.h
+new file mode 100644
+index 0000000..cbb519e
+--- /dev/null
++++ b/librbtree/rbtree.h
+@@ -0,0 +1,310 @@
++/*
++ * Copyright (c) 2010, 2011, 2012 Richard Braun.
++ * All rights reserved.
++ *
++ * Redistribution and use in source and binary forms, with or without
++ * modification, are permitted provided that the following conditions
++ * are met:
++ * 1. Redistributions of source code must retain the above copyright
++ *    notice, this list of conditions and the following disclaimer.
++ * 2. Redistributions in binary form must reproduce the above copyright
++ *    notice, this list of conditions and the following disclaimer in the
++ *    documentation and/or other materials provided with the distribution.
++ *
++ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
++ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
++ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
++ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
++ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
++ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
++ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
++ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
++ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
++ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
++ *
++ *
++ * Red-black tree.
++ */
++
++#ifndef _RBTREE_H
++#define _RBTREE_H
++
++#include <assert.h>
++#include <stddef.h>
++
++#include "macros.h"
++
++/*
++ * Indexes of the left and right nodes in the children array of a node.
++ */
++#define RBTREE_LEFT     0
++#define RBTREE_RIGHT    1
++
++/*
++ * Red-black node.
++ */
++struct rbtree_node;
++
++/*
++ * Red-black tree.
++ */
++struct rbtree;
++
++/*
++ * Static tree initializer.
++ */
++#define RBTREE_INITIALIZER { NULL }
++
++#include "rbtree_i.h"
++
++/*
++ * Initialize a tree.
++ */
++static inline void
++rbtree_init(struct rbtree *tree)
++{
++    tree->root = NULL;
++}
++
++/*
++ * Initialize a node.
++ *
++ * A node is in no tree when its parent points to itself.
++ */
++static inline void
++rbtree_node_init(struct rbtree_node *node)
++{
++    assert(rbtree_node_check_alignment(node));
++
++    node->parent = (unsigned long)node | RBTREE_COLOR_RED;
++    node->children[RBTREE_LEFT] = NULL;
++    node->children[RBTREE_RIGHT] = NULL;
++}
++
++/*
++ * Return true if node is in no tree.
++ */
++static inline int
++rbtree_node_unlinked(const struct rbtree_node *node)
++{
++    return rbtree_node_parent(node) == node;
++}
++
++/*
++ * Macro that evaluates to the address of the structure containing the
++ * given node based on the given type and member.
++ */
++#define rbtree_entry(node, type, member) structof(node, type, member)
++
++/*
++ * Return true if tree is empty.
++ */
++static inline int
++rbtree_empty(const struct rbtree *tree)
++{
++    return tree->root == NULL;
++}
++
++/*
++ * Look up a node in a tree.
++ *
++ * Note that implementing the lookup algorithm as a macro gives two benefits:
++ * First, it avoids the overhead of a callback function. Next, the type of the
++ * cmp_fn parameter isn't rigid. The only guarantee offered by this
++ * implementation is that the key parameter is the first parameter given to
++ * cmp_fn. This way, users can pass only the value they need for comparison
++ * instead of e.g. allocating a full structure on the stack.
++ *
++ * See rbtree_insert().
++ */
++#define rbtree_lookup(tree, key, cmp_fn)                \
++MACRO_BEGIN                                             \
++    struct rbtree_node *___cur;                         \
++    int ___diff;                                        \
++                                                        \
++    ___cur = (tree)->root;                              \
++                                                        \
++    while (___cur != NULL) {                            \
++        ___diff = cmp_fn(key, ___cur);                  \
++                                                        \
++        if (___diff == 0)                               \
++            break;                                      \
++                                                        \
++        ___cur = ___cur->children[rbtree_d2i(___diff)]; \
++    }                                                   \
++                                                        \
++    ___cur;                                             \
++MACRO_END
++
++/*
++ * Look up a node or one of its nearest nodes in a tree.
++ *
++ * This macro essentially acts as rbtree_lookup() but if no entry matched
++ * the key, an additional step is performed to obtain the next or previous
++ * node, depending on the direction (left or right).
++ *
++ * The constraints that apply to the key parameter are the same as for
++ * rbtree_lookup().
++ */
++#define rbtree_lookup_nearest(tree, key, cmp_fn, dir)       \
++MACRO_BEGIN                                                 \
++    struct rbtree_node *___cur, *___prev;                   \
++    int ___diff, ___index;                                  \
++                                                            \
++    ___prev = NULL;                                         \
++    ___index = -1;                                          \
++    ___cur = (tree)->root;                                  \
++                                                            \
++    while (___cur != NULL) {                                \
++        ___diff = cmp_fn(key, ___cur);                      \
++                                                            \
++        if (___diff == 0)                                   \
++            break;                                          \
++                                                            \
++        ___prev = ___cur;                                   \
++        ___index = rbtree_d2i(___diff);                     \
++        ___cur = ___cur->children[___index];                \
++    }                                                       \
++                                                            \
++    if (___cur == NULL)                                     \
++        ___cur = rbtree_nearest(___prev, ___index, dir);    \
++                                                            \
++    ___cur;                                                 \
++MACRO_END
++
++/*
++ * Insert a node in a tree.
++ *
++ * This macro performs a standard lookup to obtain the insertion point of
++ * the given node in the tree (it is assumed that the inserted node never
++ * compares equal to any other entry in the tree) and links the node. It
++ * then checks red-black rules violations, and rebalances the tree if
++ * necessary.
++ *
++ * Unlike rbtree_lookup(), the cmp_fn parameter must compare two complete
++ * entries, so it is suggested to use two different comparison inline
++ * functions, such as myobj_cmp_lookup() and myobj_cmp_insert(). There is no
++ * guarantee about the order of the nodes given to the comparison function.
++ *
++ * See rbtree_lookup().
++ */
++#define rbtree_insert(tree, node, cmp_fn)                   \
++MACRO_BEGIN                                                 \
++    struct rbtree_node *___cur, *___prev;                   \
++    int ___diff, ___index;                                  \
++                                                            \
++    ___prev = NULL;                                         \
++    ___index = -1;                                          \
++    ___cur = (tree)->root;                                  \
++                                                            \
++    while (___cur != NULL) {                                \
++        ___diff = cmp_fn(node, ___cur);                     \
++        assert(___diff != 0);                               \
++        ___prev = ___cur;                                   \
++        ___index = rbtree_d2i(___diff);                     \
++        ___cur = ___cur->children[___index];                \
++    }                                                       \
++                                                            \
++    rbtree_insert_rebalance(tree, ___prev, ___index, node); \
++MACRO_END
++
++/*
++ * Look up a node/slot pair in a tree.
++ *
++ * This macro essentially acts as rbtree_lookup() but in addition to a node,
++ * it also returns a slot, which identifies an insertion point in the tree.
++ * If the returned node is NULL, the slot can be used by rbtree_insert_slot()
++ * to insert without the overhead of an additional lookup. The slot is a
++ * simple unsigned long integer.
++ *
++ * The constraints that apply to the key parameter are the same as for
++ * rbtree_lookup().
++ */
++#define rbtree_lookup_slot(tree, key, cmp_fn, slot) \
++MACRO_BEGIN                                         \
++    struct rbtree_node *___cur, *___prev;           \
++    int ___diff, ___index;                          \
++                                                    \
++    ___prev = NULL;                                 \
++    ___index = 0;                                   \
++    ___cur = (tree)->root;                          \
++                                                    \
++    while (___cur != NULL) {                        \
++        ___diff = cmp_fn(key, ___cur);              \
++                                                    \
++        if (___diff == 0)                           \
++            break;                                  \
++                                                    \
++        ___prev = ___cur;                           \
++        ___index = rbtree_d2i(___diff);             \
++        ___cur = ___cur->children[___index];        \
++    }                                               \
++                                                    \
++    (slot) = rbtree_slot(___prev, ___index);        \
++    ___cur;                                         \
++MACRO_END
++
++/*
++ * Insert a node at an insertion point in a tree.
++ *
++ * This macro essentially acts as rbtree_insert() except that it doesn't
++ * obtain the insertion point with a standard lookup. The insertion point
++ * is obtained by calling rbtree_lookup_slot(). In addition, the new node
++ * must not compare equal to an existing node in the tree (i.e. the slot
++ * must denote a NULL node).
++ */
++static inline void
++rbtree_insert_slot(struct rbtree *tree, unsigned long slot,
++                   struct rbtree_node *node)
++{
++    struct rbtree_node *parent;
++    int index;
++
++    parent = rbtree_slot_parent(slot);
++    index = rbtree_slot_index(slot);
++    rbtree_insert_rebalance(tree, parent, index, node);
++}
++
++/*
++ * Remove a node from a tree.
++ *
++ * After completion, the node is stale.
++ */
++void rbtree_remove(struct rbtree *tree, struct rbtree_node *node);
++
++/*
++ * Return the first node of a tree.
++ */
++#define rbtree_first(tree) rbtree_firstlast(tree, RBTREE_LEFT)
++
++/*
++ * Return the last node of a tree.
++ */
++#define rbtree_last(tree) rbtree_firstlast(tree, RBTREE_RIGHT)
++
++/*
++ * Return the node previous to the given node.
++ */
++#define rbtree_prev(node) rbtree_walk(node, RBTREE_LEFT)
++
++/*
++ * Return the node next to the given node.
++ */
++#define rbtree_next(node) rbtree_walk(node, RBTREE_RIGHT)
++
++/*
++ * Forge a loop to process all nodes of a tree, removing them when visited.
++ *
++ * This macro can only be used to destroy a tree, so that the resources used
++ * by the entries can be released by the user. It basically removes all nodes
++ * without doing any color checking.
++ *
++ * After completion, all nodes and the tree root member are stale.
++ */
++#define rbtree_for_each_remove(tree, node, tmp)         \
++for (node = rbtree_postwalk_deepest(tree),              \
++     tmp = rbtree_postwalk_unlink(node);                \
++     node != NULL;                                      \
++     node = tmp, tmp = rbtree_postwalk_unlink(node))    \
++
++#endif /* _RBTREE_H */
+diff --git a/librbtree/rbtree_i.h b/librbtree/rbtree_i.h
+new file mode 100644
+index 0000000..eb1619f
+--- /dev/null
++++ b/librbtree/rbtree_i.h
+@@ -0,0 +1,196 @@
++/*
++ * Copyright (c) 2010, 2011, 2012 Richard Braun.
++ * All rights reserved.
++ *
++ * Redistribution and use in source and binary forms, with or without
++ * modification, are permitted provided that the following conditions
++ * are met:
++ * 1. Redistributions of source code must retain the above copyright
++ *    notice, this list of conditions and the following disclaimer.
++ * 2. Redistributions in binary form must reproduce the above copyright
++ *    notice, this list of conditions and the following disclaimer in the
++ *    documentation and/or other materials provided with the distribution.
++ *
++ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
++ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
++ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
++ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
++ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
++ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
++ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
++ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
++ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
++ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
++ */
++
++#ifndef _RBTREE_I_H
++#define _RBTREE_I_H
++
++#include <assert.h>
++#include <stddef.h>
++
++#include "macros.h"
++
++/*
++ * Red-black node structure.
++ *
++ * To reduce the number of branches and the instruction cache footprint,
++ * the left and right child pointers are stored in an array, and the symmetry
++ * of most tree operations is exploited by using left/right variables when
++ * referring to children.
++ *
++ * In addition, this implementation assumes that all nodes are 4-byte aligned,
++ * so that the least significant bit of the parent member can be used to store
++ * the color of the node. This is true for all modern 32 and 64 bits
++ * architectures, as long as the nodes aren't embedded in structures with
++ * special alignment constraints such as member packing.
++ */
++struct rbtree_node {
++    unsigned long parent;
++    struct rbtree_node *children[2];
++};
++
++/*
++ * Red-black tree structure.
++ */
++struct rbtree {
++    struct rbtree_node *root;
++};
++
++/*
++ * Masks applied on the parent member of a node to obtain either the
++ * color or the parent address.
++ */
++#define RBTREE_COLOR_MASK   0x1UL
++#define RBTREE_PARENT_MASK  (~0x3UL)
++
++/*
++ * Node colors.
++ */
++#define RBTREE_COLOR_RED    0
++#define RBTREE_COLOR_BLACK  1
++
++/*
++ * Masks applied on slots to obtain either the child index or the parent
++ * address.
++ */
++#define RBTREE_SLOT_INDEX_MASK  0x1UL
++#define RBTREE_SLOT_PARENT_MASK (~RBTREE_SLOT_INDEX_MASK)
++
++/*
++ * Return true if the given index is a valid child index.
++ */
++static inline int
++rbtree_check_index(int index)
++{
++    return index == (index & 1);
++}
++
++/*
++ * Convert the result of a comparison into an index in the children array
++ * (0 or 1).
++ *
++ * This function is mostly used when looking up a node.
++ */
++static inline int
++rbtree_d2i(int diff)
++{
++    return !(diff <= 0);
++}
++
++/*
++ * Return true if the given pointer is suitably aligned.
++ */
++static inline int
++rbtree_node_check_alignment(const struct rbtree_node *node)
++{
++    return ((unsigned long)node & (~RBTREE_PARENT_MASK)) == 0;
++}
++
++/*
++ * Return the parent of a node.
++ */
++static inline struct rbtree_node *
++rbtree_node_parent(const struct rbtree_node *node)
++{
++    return (struct rbtree_node *)(node->parent & RBTREE_PARENT_MASK);
++}
++
++/*
++ * Translate an insertion point into a slot.
++ */
++static inline unsigned long
++rbtree_slot(struct rbtree_node *parent, int index)
++{
++    assert(rbtree_node_check_alignment(parent));
++    assert(rbtree_check_index(index));
++    return (unsigned long)parent | index;
++}
++
++/*
++ * Extract the parent address from a slot.
++ */
++static inline struct rbtree_node *
++rbtree_slot_parent(unsigned long slot)
++{
++    return (struct rbtree_node *)(slot & RBTREE_SLOT_PARENT_MASK);
++}
++
++/*
++ * Extract the index from a slot.
++ */
++static inline int
++rbtree_slot_index(unsigned long slot)
++{
++    return slot & RBTREE_SLOT_INDEX_MASK;
++}
++
++/*
++ * Insert a node in a tree, rebalancing it if necessary.
++ *
++ * The index parameter is the index in the children array of the parent where
++ * the new node is to be inserted. It is ignored if the parent is NULL.
++ *
++ * This function is intended to be used by the rbtree_insert() macro only.
++ */
++void rbtree_insert_rebalance(struct rbtree *tree, struct rbtree_node *parent,
++                             int index, struct rbtree_node *node);
++
++/*
++ * Return the previous or next node relative to a location in a tree.
++ *
++ * The parent and index parameters define the location, which can be empty.
++ * The direction parameter is either RBTREE_LEFT (to obtain the previous
++ * node) or RBTREE_RIGHT (to obtain the next one).
++ */
++struct rbtree_node * rbtree_nearest(struct rbtree_node *parent, int index,
++                                    int direction);
++
++/*
++ * Return the first or last node of a tree.
++ *
++ * The direction parameter is either RBTREE_LEFT (to obtain the first node)
++ * or RBTREE_RIGHT (to obtain the last one).
++ */
++struct rbtree_node * rbtree_firstlast(const struct rbtree *tree, int direction);
++
++/*
++ * Return the node next to, or previous to the given node.
++ *
++ * The direction parameter is either RBTREE_LEFT (to obtain the previous node)
++ * or RBTREE_RIGHT (to obtain the next one).
++ */
++struct rbtree_node * rbtree_walk(struct rbtree_node *node, int direction);
++
++/*
++ * Return the left-most deepest node of a tree, which is the starting point of
++ * the postorder traversal performed by rbtree_for_each_remove().
++ */
++struct rbtree_node * rbtree_postwalk_deepest(const struct rbtree *tree);
++
++/*
++ * Unlink a node from its tree and return the next (right) node in postorder.
++ */
++struct rbtree_node * rbtree_postwalk_unlink(struct rbtree_node *node);
++
++#endif /* _RBTREE_I_H */
+-- 
+2.0.0.rc2
+
diff --git a/debian/patches/0004-librdxtree-add-a-radix-tree-implementation.patch b/debian/patches/0004-librdxtree-add-a-radix-tree-implementation.patch
new file mode 100644
index 00000000..29294c26
--- /dev/null
+++ b/debian/patches/0004-librdxtree-add-a-radix-tree-implementation.patch
@@ -0,0 +1,1439 @@
+From 70e7e9a7c30a01caf33b89f599b561900a91ac88 Mon Sep 17 00:00:00 2001
+From: Justus Winter <4winter@informatik.uni-hamburg.de>
+Date: Mon, 19 May 2014 18:42:30 +0200
+Subject: [PATCH 04/14] librdxtree: add a radix tree implementation
+
+Radix trees offer search, insert, and delete operations in time linear
+in the size of the key.  They are also very cache efficient.
+
+This is an verbatim copy from git://git.sceen.net/rbraun/librbraun.git
+as of 45fef4ad.  Only macros.h has been slightly amended.  This file
+defines two macros, which are also defined in cthreads.h.  Undefine
+the macros first to work around this problem.
+
+* librdxtree/Makefile: New file.
+* librdxtree/rdxtree.c: Likewise.
+* librdxtree/rdxtree.h: Likewise.
+* librdxtree/rdxtree_i.h: Likewise.
+* librdxtree/error.c: Likewise.
+* librdxtree/error.h: Likewise.
+* librdxtree/macros.h: Likewise.  Also, undefine MACRO_{BEGIN,END}.
+* Makefile (lib-subdirs): Add librdxtree.
+---
+ Makefile               |   1 +
+ librdxtree/Makefile    |  27 ++
+ librdxtree/error.c     |  94 ++++++
+ librdxtree/error.h     |  84 +++++
+ librdxtree/macros.h    |  70 +++++
+ librdxtree/rdxtree.c   | 808 +++++++++++++++++++++++++++++++++++++++++++++++++
+ librdxtree/rdxtree.h   | 195 ++++++++++++
+ librdxtree/rdxtree_i.h |  65 ++++
+ 8 files changed, 1344 insertions(+)
+ create mode 100644 librdxtree/Makefile
+ create mode 100644 librdxtree/error.c
+ create mode 100644 librdxtree/error.h
+ create mode 100644 librdxtree/macros.h
+ create mode 100644 librdxtree/rdxtree.c
+ create mode 100644 librdxtree/rdxtree.h
+ create mode 100644 librdxtree/rdxtree_i.h
+
+diff --git a/Makefile b/Makefile
+index 8a0be83..53dac72 100644
+--- a/Makefile
++++ b/Makefile
+@@ -48,6 +48,7 @@ other-subdirs = hurd doc config release include
+ 
+ # XXX
+ lib-subdirs += librbtree
++lib-subdirs += librdxtree
+ 
+ # All the subdirectories together
+ subdirs = $(lib-subdirs) $(prog-subdirs) $(other-subdirs)
+diff --git a/librdxtree/Makefile b/librdxtree/Makefile
+new file mode 100644
+index 0000000..c9d3c9d
+--- /dev/null
++++ b/librdxtree/Makefile
+@@ -0,0 +1,27 @@
++#   Copyright (C) 2014 Free Software Foundation, Inc.
++#
++#   This file is part of the GNU Hurd.
++#
++#   The GNU Hurd is free software; you can redistribute it and/or
++#   modify it under the terms of the GNU General Public License as
++#   published by the Free Software Foundation; either version 2, or (at
++#   your option) any later version.
++#
++#   The GNU Hurd is distributed in the hope that it will be useful, but
++#   WITHOUT ANY WARRANTY; without even the implied warranty of
++#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
++#   General Public License for more details.
++#
++#   You should have received a copy of the GNU General Public License
++#   along with the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.
++
++dir := librdxtree
++makemode := library
++
++libname := librdxtree
++SRCS = rdxtree.c
++installhdrs = rdxtree.h rdxtree_i.h macros.h
++
++OBJS = $(SRCS:.c=.o)
++
++include ../Makeconf
+diff --git a/librdxtree/error.c b/librdxtree/error.c
+new file mode 100644
+index 0000000..dcc574f
+--- /dev/null
++++ b/librdxtree/error.c
+@@ -0,0 +1,94 @@
++/*
++ * Copyright (c) 2009, 2010 Richard Braun.
++ * All rights reserved.
++ *
++ * Redistribution and use in source and binary forms, with or without
++ * modification, are permitted provided that the following conditions
++ * are met:
++ * 1. Redistributions of source code must retain the above copyright
++ *    notice, this list of conditions and the following disclaimer.
++ * 2. Redistributions in binary form must reproduce the above copyright
++ *    notice, this list of conditions and the following disclaimer in the
++ *    documentation and/or other materials provided with the distribution.
++ *
++ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
++ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
++ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
++ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
++ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
++ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
++ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
++ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
++ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
++ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
++ */
++
++#include <errno.h>
++#include <stdio.h>
++#include <stdlib.h>
++
++#include "error.h"
++#include "macros.h"
++
++/*
++ * Error message table.
++ *
++ * This table must be consistent with the enum defined in error.h.
++ */
++static const char *errormsg_table[] = {
++    "success",
++    "unknown error",
++    "invalid argument",
++    "not enough space",
++    "invalid format",
++    "not enough resources",
++    "operation not permitted",
++    "resource busy",
++    "memory limit exceeded",
++    "operation timed out",
++    "operation would block",
++    "entry not found",
++    "internal memory allocator failure"
++};
++
++#define ERRORMSG_TABLE_SIZE ARRAY_SIZE(errormsg_table)
++
++const char *
++error_str(unsigned int error)
++{
++    if (error >= ERRORMSG_TABLE_SIZE)
++        return "invalid error code";
++
++    return errormsg_table[error];
++}
++
++unsigned int
++error_from_errno(int errno_code)
++{
++    switch (errno_code) {
++    case 0:
++        return ERR_SUCCESS;
++    case EINVAL:
++        return ERR_INVAL;
++    case ENOMEM:
++        return ERR_NOMEM;
++    case EAGAIN:
++        return ERR_NORES;
++    case EPERM:
++        return ERR_PERM;
++    case EBUSY:
++        return ERR_BUSY;
++    case ETIMEDOUT:
++        return ERR_TIMEDOUT;
++    default:
++        fprintf(stderr, "unable to translate errno code (%d)\n", errno_code);
++        return ERR_UNKNOWN;
++    }
++}
++
++void
++error_die(unsigned int error)
++{
++    fprintf(stderr, "process terminating, reason: %s\n", error_str(error));
++    abort();
++}
+diff --git a/librdxtree/error.h b/librdxtree/error.h
+new file mode 100644
+index 0000000..81babf7
+--- /dev/null
++++ b/librdxtree/error.h
+@@ -0,0 +1,84 @@
++/*
++ * Copyright (c) 2009, 2010 Richard Braun.
++ * All rights reserved.
++ *
++ * Redistribution and use in source and binary forms, with or without
++ * modification, are permitted provided that the following conditions
++ * are met:
++ * 1. Redistributions of source code must retain the above copyright
++ *    notice, this list of conditions and the following disclaimer.
++ * 2. Redistributions in binary form must reproduce the above copyright
++ *    notice, this list of conditions and the following disclaimer in the
++ *    documentation and/or other materials provided with the distribution.
++ *
++ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
++ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
++ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
++ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
++ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
++ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
++ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
++ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
++ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
++ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
++ */
++
++#ifndef _ERROR_H
++#define _ERROR_H
++
++#include "macros.h"
++
++/*
++ * List of errors this library can return.
++ *
++ * ERR_SUCCESS is guaranteed to be 0, allowing code such as :
++ *
++ * error = do_smth();
++ *
++ * if (error) {
++ *     ...;
++ * }
++ */
++enum {
++    ERR_SUCCESS,
++    ERR_UNKNOWN,
++    ERR_INVAL,
++    ERR_NOMEM,
++    ERR_FORMAT,
++    ERR_NORES,
++    ERR_PERM,
++    ERR_BUSY,
++    ERR_MEMLIM,
++    ERR_TIMEDOUT,
++    ERR_WOULDBLOCK,
++    ERR_LOOKUP,
++    ERR_MEM_CACHE
++};
++
++/*
++ * Return the message matching the given error.
++ *
++ * The returned address points to a statically allocated, read only,
++ * null-terminated string literal. The caller must not attempt to use it
++ * for anything else than error reporting.
++ */
++const char * error_str(unsigned int error);
++
++/*
++ * Map standard error codes to error values.
++ *
++ * This function accepts a subset of the standard error codes in errno.h.
++ * When called, and if the errno value is handled, it will return the
++ * corresponding ERR_xxx code. Otherwise ERR_UNKNOWN is returned.
++ */
++unsigned int error_from_errno(int errno_code);
++
++/*
++ * Exit the current process, reporting an error.
++ *
++ * This function will report the given error and make the process exit,
++ * using the error code as the exit() parameter.
++ */
++void __noreturn error_die(unsigned int error);
++
++#endif /* _ERROR_H */
+diff --git a/librdxtree/macros.h b/librdxtree/macros.h
+new file mode 100644
+index 0000000..f0960a3
+--- /dev/null
++++ b/librdxtree/macros.h
+@@ -0,0 +1,70 @@
++/*
++ * Copyright (c) 2009, 2010 Richard Braun.
++ * All rights reserved.
++ *
++ * Redistribution and use in source and binary forms, with or without
++ * modification, are permitted provided that the following conditions
++ * are met:
++ * 1. Redistributions of source code must retain the above copyright
++ *    notice, this list of conditions and the following disclaimer.
++ * 2. Redistributions in binary form must reproduce the above copyright
++ *    notice, this list of conditions and the following disclaimer in the
++ *    documentation and/or other materials provided with the distribution.
++ *
++ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
++ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
++ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
++ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
++ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
++ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
++ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
++ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
++ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
++ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
++ *
++ *
++ * Helper macros.
++ */
++
++#ifndef _MACROS_H
++#define _MACROS_H
++
++#include <stddef.h>
++
++#undef MACRO_BEGIN
++#undef MACRO_END
++#define MACRO_BEGIN     ({
++#define MACRO_END       })
++
++#define XQUOTE(x)       #x
++#define QUOTE(x)        XQUOTE(x)
++
++#define STRLEN(x)       (sizeof(x) - 1)
++#define ARRAY_SIZE(x)   (sizeof(x) / sizeof((x)[0]))
++
++#define MIN(a, b)       ((a) < (b) ? (a) : (b))
++#define MAX(a, b)       ((a) > (b) ? (a) : (b))
++
++#define P2ALIGNED(x, a) (((x) & ((a) - 1)) == 0)
++#define ISP2(x)         P2ALIGNED(x, x)
++#define P2ALIGN(x, a)   ((x) & -(a))
++#define P2ROUND(x, a)   (-(-(x) & -(a)))
++#define P2END(x, a)     (-(~(x) & -(a)))
++
++#define structof(ptr, type, member) \
++    ((type *)((char *)(ptr) - offsetof(type, member)))
++
++#define alignof(x)      __alignof__(x)
++
++#define likely(expr)    __builtin_expect(!!(expr), 1)
++#define unlikely(expr)  __builtin_expect(!!(expr), 0)
++
++#define barrier()       asm volatile("" : : : "memory")
++
++#define __noreturn      __attribute__((noreturn))
++#define __aligned(x)    __attribute__((aligned(x)))
++
++#define __format_printf(fmt, args) \
++    __attribute__((format(printf, fmt, args)))
++
++#endif /* _MACROS_H */
+diff --git a/librdxtree/rdxtree.c b/librdxtree/rdxtree.c
+new file mode 100644
+index 0000000..36fd09f
+--- /dev/null
++++ b/librdxtree/rdxtree.c
+@@ -0,0 +1,808 @@
++/*
++ * Copyright (c) 2013 Richard Braun.
++ *
++ * This program is free software: you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation, either version 3 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
++ */
++
++/*
++ * Copyright (c) 2011 Richard Braun.
++ * All rights reserved.
++ *
++ * Redistribution and use in source and binary forms, with or without
++ * modification, are permitted provided that the following conditions
++ * are met:
++ * 1. Redistributions of source code must retain the above copyright
++ *    notice, this list of conditions and the following disclaimer.
++ * 2. Redistributions in binary form must reproduce the above copyright
++ *    notice, this list of conditions and the following disclaimer in the
++ *    documentation and/or other materials provided with the distribution.
++ *
++ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
++ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
++ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
++ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
++ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
++ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
++ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
++ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
++ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
++ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
++ */
++
++#include <assert.h>
++#include <limits.h>
++#include <stddef.h>
++#include <stdlib.h>
++#include <string.h>
++
++#include "error.h"
++#include "macros.h"
++#include "rdxtree.h"
++#include "rdxtree_i.h"
++
++/*
++ * Mask applied on an entry to obtain its address.
++ */
++#define RDXTREE_ENTRY_ADDR_MASK (~0x3UL)
++
++/*
++ * Global properties used to shape radix trees.
++ */
++#define RDXTREE_RADIX       6
++#define RDXTREE_RADIX_SIZE  (1UL << RDXTREE_RADIX)
++#define RDXTREE_RADIX_MASK  (RDXTREE_RADIX_SIZE - 1)
++
++#if RDXTREE_RADIX < 6
++typedef unsigned long rdxtree_bm_t;
++#define rdxtree_ffs(x) __builtin_ffsl(x)
++#elif RDXTREE_RADIX == 6 /* RDXTREE_RADIX < 6 */
++typedef unsigned long long rdxtree_bm_t;
++#define rdxtree_ffs(x) __builtin_ffsll(x)
++#else /* RDXTREE_RADIX < 6 */
++#error "radix too high"
++#endif /* RDXTREE_RADIX < 6 */
++
++/*
++ * Allocation bitmap size in bits.
++ */
++#define RDXTREE_BM_SIZE (sizeof(rdxtree_bm_t) * CHAR_BIT)
++
++/*
++ * Empty/full allocation bitmap words.
++ */
++#define RDXTREE_BM_EMPTY    ((rdxtree_bm_t)0)
++#define RDXTREE_BM_FULL \
++    ((~(rdxtree_bm_t)0) >> (RDXTREE_BM_SIZE - RDXTREE_RADIX_SIZE))
++
++/*
++ * These macros can be replaced by actual functions in an environment
++ * that provides lockless synchronization such as RCU.
++ */
++#define llsync_assign_ptr(ptr, value)   ((ptr) = (value))
++#define llsync_read_ptr(ptr)            (ptr)
++
++/*
++ * Radix tree node.
++ *
++ * The height of a tree is the number of nodes to traverse until stored
++ * pointers are reached. A height of 0 means the entries of a node (or the
++ * tree root) directly point to stored pointers.
++ *
++ * The index is valid if and only if the parent isn't NULL.
++ *
++ * Concerning the allocation bitmap, a bit is set when the node it denotes,
++ * or one of its children, can be used to allocate an entry. Conversely, a bit
++ * is clear when the matching node and all of its children have no free entry.
++ *
++ * In order to support safe lockless lookups, in particular during a resize,
++ * each node includes the height of its subtree, which is invariant during
++ * the entire node lifetime. Since the tree height does vary, it can't be
++ * used to determine whether the tree root is a node or a stored pointer.
++ * This implementation assumes that all nodes and stored pointers are at least
++ * 4-byte aligned, and uses the least significant bit of entries to indicate
++ * the pointer type. This bit is set for internal nodes, and clear for stored
++ * pointers so that they can be accessed from slots without conversion.
++ */
++struct rdxtree_node {
++    struct rdxtree_node *parent;
++    unsigned int index;
++    unsigned int height;
++    unsigned int nr_entries;
++    rdxtree_bm_t alloc_bm;
++    void *entries[RDXTREE_RADIX_SIZE];
++};
++
++#ifdef RDXTREE_ENABLE_NODE_CREATION_FAILURES
++unsigned int rdxtree_fail_node_creation_threshold;
++unsigned int rdxtree_nr_node_creations;
++#endif /* RDXTREE_ENABLE_NODE_CREATION_FAILURES */
++
++static inline int
++rdxtree_check_alignment(const void *ptr)
++{
++    return ((unsigned long)ptr & ~RDXTREE_ENTRY_ADDR_MASK) == 0;
++}
++
++static inline void *
++rdxtree_entry_addr(void *entry)
++{
++    return (void *)((unsigned long)entry & RDXTREE_ENTRY_ADDR_MASK);
++}
++
++static inline int
++rdxtree_entry_is_node(const void *entry)
++{
++    return ((unsigned long)entry & 1) != 0;
++}
++
++static inline void *
++rdxtree_node_to_entry(struct rdxtree_node *node)
++{
++    return (void *)((unsigned long)node | 1);
++}
++
++static int
++rdxtree_node_create(struct rdxtree_node **nodep, unsigned int height)
++{
++    struct rdxtree_node *node;
++
++#ifdef RDXTREE_ENABLE_NODE_CREATION_FAILURES
++    if (rdxtree_fail_node_creation_threshold != 0) {
++        rdxtree_nr_node_creations++;
++
++        if (rdxtree_nr_node_creations == rdxtree_fail_node_creation_threshold)
++            return ERR_NOMEM;
++    }
++#endif /* RDXTREE_ENABLE_NODE_CREATION_FAILURES */
++
++    node = malloc(sizeof(*node));
++
++    if (node == NULL)
++        return ERR_NOMEM;
++
++    assert(rdxtree_check_alignment(node));
++    node->parent = NULL;
++    node->height = height;
++    node->nr_entries = 0;
++    node->alloc_bm = RDXTREE_BM_FULL;
++    memset(node->entries, 0, sizeof(node->entries));
++    *nodep = node;
++    return 0;
++}
++
++static void
++rdxtree_node_schedule_destruction(struct rdxtree_node *node)
++{
++    /*
++     * This function is intended to use the appropriate interface to defer
++     * destruction until all read-side references are dropped in an
++     * environment that provides lockless synchronization.
++     *
++     * Otherwise, it simply "schedules" destruction immediately.
++     */
++    free(node);
++}
++
++static inline void
++rdxtree_node_link(struct rdxtree_node *node, struct rdxtree_node *parent,
++                  unsigned int index)
++{
++    node->parent = parent;
++    node->index = index;
++}
++
++static inline void
++rdxtree_node_unlink(struct rdxtree_node *node)
++{
++    assert(node->parent != NULL);
++    node->parent = NULL;
++}
++
++static inline int
++rdxtree_node_full(struct rdxtree_node *node)
++{
++    return (node->nr_entries == ARRAY_SIZE(node->entries));
++}
++
++static inline int
++rdxtree_node_empty(struct rdxtree_node *node)
++{
++    return (node->nr_entries == 0);
++}
++
++static inline void
++rdxtree_node_insert(struct rdxtree_node *node, unsigned int index,
++                    void *entry)
++{
++    assert(index < ARRAY_SIZE(node->entries));
++    assert(node->entries[index] == NULL);
++
++    node->nr_entries++;
++    llsync_assign_ptr(node->entries[index], entry);
++}
++
++static inline void
++rdxtree_node_insert_node(struct rdxtree_node *node, unsigned int index,
++                         struct rdxtree_node *child)
++{
++    rdxtree_node_insert(node, index, rdxtree_node_to_entry(child));
++}
++
++static inline void
++rdxtree_node_remove(struct rdxtree_node *node, unsigned int index)
++{
++    assert(index < ARRAY_SIZE(node->entries));
++    assert(node->entries[index] != NULL);
++
++    node->nr_entries--;
++    llsync_assign_ptr(node->entries[index], NULL);
++}
++
++static inline void *
++rdxtree_node_find(struct rdxtree_node *node, unsigned int index, int get_slot)
++{
++    void *ptr;
++
++    while (index < ARRAY_SIZE(node->entries)) {
++        ptr = rdxtree_entry_addr(node->entries[index]);
++
++        if (ptr != NULL)
++            return get_slot ? (void *)&node->entries[index] : ptr;
++
++        index++;
++    }
++
++    return NULL;
++}
++
++static inline void
++rdxtree_node_bm_set(struct rdxtree_node *node, unsigned int index)
++{
++    node->alloc_bm |= (rdxtree_bm_t)1 << index;
++}
++
++static inline void
++rdxtree_node_bm_clear(struct rdxtree_node *node, unsigned int index)
++{
++    node->alloc_bm &= ~((rdxtree_bm_t)1 << index);
++}
++
++static inline int
++rdxtree_node_bm_is_set(struct rdxtree_node *node, unsigned int index)
++{
++    return (node->alloc_bm & ((rdxtree_bm_t)1 << index));
++}
++
++static inline int
++rdxtree_node_bm_empty(struct rdxtree_node *node)
++{
++    return (node->alloc_bm == RDXTREE_BM_EMPTY);
++}
++
++static inline unsigned int
++rdxtree_node_bm_first(struct rdxtree_node *node)
++{
++    return rdxtree_ffs(node->alloc_bm) - 1;
++}
++
++static inline unsigned long long
++rdxtree_max_key(unsigned int height)
++{
++    size_t shift;
++
++    shift = RDXTREE_RADIX * height;
++
++    if (likely(shift < (sizeof(unsigned long long) * CHAR_BIT)))
++        return (1ULL << shift) - 1;
++    else
++        return ~0ULL;
++}
++
++static void
++rdxtree_shrink(struct rdxtree *tree)
++{
++    struct rdxtree_node *node;
++    void *entry;
++
++    while (tree->height > 0) {
++        node = rdxtree_entry_addr(tree->root);
++
++        if (node->nr_entries != 1)
++            break;
++
++        entry = node->entries[0];
++
++        if (entry == NULL)
++            break;
++
++        tree->height--;
++
++        if (tree->height > 0)
++            rdxtree_node_unlink(rdxtree_entry_addr(entry));
++
++        llsync_assign_ptr(tree->root, entry);
++        rdxtree_node_schedule_destruction(node);
++    }
++}
++
++static int
++rdxtree_grow(struct rdxtree *tree, unsigned long long key)
++{
++    struct rdxtree_node *root, *node;
++    unsigned int new_height;
++    int error;
++
++    new_height = tree->height + 1;
++
++    while (key > rdxtree_max_key(new_height))
++        new_height++;
++
++    if (tree->root == NULL) {
++        tree->height = new_height;
++        return ERR_SUCCESS;
++    }
++
++    root = rdxtree_entry_addr(tree->root);
++
++    do {
++        error = rdxtree_node_create(&node, tree->height);
++
++        if (error) {
++            rdxtree_shrink(tree);
++            return error;
++        }
++
++        if (tree->height == 0)
++            rdxtree_node_bm_clear(node, 0);
++        else {
++            rdxtree_node_link(root, node, 0);
++
++            if (rdxtree_node_bm_empty(root))
++                rdxtree_node_bm_clear(node, 0);
++        }
++
++        rdxtree_node_insert(node, 0, tree->root);
++        tree->height++;
++        llsync_assign_ptr(tree->root, rdxtree_node_to_entry(node));
++        root = node;
++    } while (new_height > tree->height);
++
++    return ERR_SUCCESS;
++}
++
++static void
++rdxtree_cleanup(struct rdxtree *tree, struct rdxtree_node *node)
++{
++    struct rdxtree_node *prev;
++
++    for (;;) {
++        if (likely(!rdxtree_node_empty(node))) {
++            if (unlikely(node->parent == NULL))
++                rdxtree_shrink(tree);
++
++            break;
++        }
++
++        if (node->parent == NULL) {
++            tree->height = 0;
++            llsync_assign_ptr(tree->root, NULL);
++            rdxtree_node_schedule_destruction(node);
++            break;
++        }
++
++        prev = node;
++        node = node->parent;
++        rdxtree_node_unlink(prev);
++        rdxtree_node_remove(node, prev->index);
++        rdxtree_node_schedule_destruction(prev);
++    }
++}
++
++static void
++rdxtree_insert_bm_clear(struct rdxtree_node *node, unsigned int index)
++{
++    for (;;) {
++        rdxtree_node_bm_clear(node, index);
++
++        if (!rdxtree_node_full(node) || (node->parent == NULL))
++            break;
++
++        index = node->index;
++        node = node->parent;
++    }
++}
++
++int
++rdxtree_insert_common(struct rdxtree *tree, unsigned long long key,
++                      void *ptr, void ***slotp)
++{
++    struct rdxtree_node *node, *prev;
++    unsigned int height, shift, index = index;
++    int error;
++
++    assert(ptr != NULL);
++    assert(rdxtree_check_alignment(ptr));
++
++    if (unlikely(key > rdxtree_max_key(tree->height))) {
++        error = rdxtree_grow(tree, key);
++
++        if (error)
++            return error;
++    }
++
++    height = tree->height;
++
++    if (unlikely(height == 0)) {
++        if (tree->root != NULL)
++            return ERR_BUSY;
++
++        llsync_assign_ptr(tree->root, ptr);
++
++        if (slotp != NULL)
++            *slotp = &tree->root;
++
++        return ERR_SUCCESS;
++    }
++
++    node = rdxtree_entry_addr(tree->root);
++    shift = (height - 1) * RDXTREE_RADIX;
++    prev = NULL;
++
++    do {
++        if (node == NULL) {
++            error = rdxtree_node_create(&node, height - 1);
++
++            if (error) {
++                if (prev == NULL)
++                    tree->height = 0;
++                else
++                    rdxtree_cleanup(tree, prev);
++
++                return error;
++            }
++
++            if (prev == NULL)
++                llsync_assign_ptr(tree->root, rdxtree_node_to_entry(node));
++            else {
++                rdxtree_node_link(node, prev, index);
++                rdxtree_node_insert_node(prev, index, node);
++            }
++        }
++
++        prev = node;
++        index = (unsigned int)(key >> shift) & RDXTREE_RADIX_MASK;
++        node = rdxtree_entry_addr(prev->entries[index]);
++        shift -= RDXTREE_RADIX;
++        height--;
++    } while (height > 0);
++
++    if (unlikely(node != NULL))
++        return ERR_BUSY;
++
++    rdxtree_node_insert(prev, index, ptr);
++    rdxtree_insert_bm_clear(prev, index);
++
++    if (slotp != NULL)
++        *slotp = &prev->entries[index];
++
++    return ERR_SUCCESS;
++}
++
++int
++rdxtree_insert_alloc_common(struct rdxtree *tree, void *ptr,
++                            unsigned long long *keyp, void ***slotp)
++{
++    struct rdxtree_node *node, *prev;
++    unsigned long long key;
++    unsigned int height, shift, index = index;
++    int error;
++
++    assert(ptr != NULL);
++    assert(rdxtree_check_alignment(ptr));
++
++    height = tree->height;
++
++    if (unlikely(height == 0)) {
++        if (tree->root == NULL) {
++            llsync_assign_ptr(tree->root, ptr);
++            *keyp = 0;
++
++            if (slotp != NULL)
++                *slotp = &tree->root;
++
++            return ERR_SUCCESS;
++        }
++
++        goto grow;
++    }
++
++    node = rdxtree_entry_addr(tree->root);
++    key = 0;
++    shift = (height - 1) * RDXTREE_RADIX;
++    prev = NULL;
++
++    do {
++        if (node == NULL) {
++            error = rdxtree_node_create(&node, height - 1);
++
++            if (error) {
++                rdxtree_cleanup(tree, prev);
++                return error;
++            }
++
++            rdxtree_node_link(node, prev, index);
++            rdxtree_node_insert_node(prev, index, node);
++        }
++
++        prev = node;
++        index = rdxtree_node_bm_first(node);
++
++        if (index == (unsigned int)-1)
++            goto grow;
++
++        key |= (unsigned long long)index << shift;
++        node = rdxtree_entry_addr(node->entries[index]);
++        shift -= RDXTREE_RADIX;
++        height--;
++    } while (height > 0);
++
++    rdxtree_node_insert(prev, index, ptr);
++    rdxtree_insert_bm_clear(prev, index);
++
++    if (slotp != NULL)
++        *slotp = &prev->entries[index];
++
++    goto out;
++
++grow:
++    key = rdxtree_max_key(height) + 1;
++    error = rdxtree_insert_common(tree, key, ptr, slotp);
++
++    if (error)
++        return error;
++
++out:
++    *keyp = key;
++    return ERR_SUCCESS;
++}
++
++static void
++rdxtree_remove_bm_set(struct rdxtree_node *node, unsigned int index)
++{
++    do {
++        rdxtree_node_bm_set(node, index);
++
++        if (node->parent == NULL)
++            break;
++
++        index = node->index;
++        node = node->parent;
++    } while (!rdxtree_node_bm_is_set(node, index));
++}
++
++void *
++rdxtree_remove(struct rdxtree *tree, unsigned long long key)
++{
++    struct rdxtree_node *node, *prev;
++    unsigned int height, shift, index;
++
++    height = tree->height;
++
++    if (unlikely(key > rdxtree_max_key(height)))
++        return NULL;
++
++    node = rdxtree_entry_addr(tree->root);
++
++    if (unlikely(height == 0)) {
++        llsync_assign_ptr(tree->root, NULL);
++        return node;
++    }
++
++    shift = (height - 1) * RDXTREE_RADIX;
++
++    do {
++        if (node == NULL)
++            return NULL;
++
++        prev = node;
++        index = (unsigned int)(key >> shift) & RDXTREE_RADIX_MASK;
++        node = rdxtree_entry_addr(node->entries[index]);
++        shift -= RDXTREE_RADIX;
++        height--;
++    } while (height > 0);
++
++    if (node == NULL)
++        return NULL;
++
++    rdxtree_node_remove(prev, index);
++    rdxtree_remove_bm_set(prev, index);
++    rdxtree_cleanup(tree, prev);
++    return node;
++}
++
++void *
++rdxtree_lookup_common(const struct rdxtree *tree, unsigned long long key,
++                      int get_slot)
++{
++    struct rdxtree_node *node, *prev;
++    unsigned int height, shift, index;
++    void *entry;
++
++    entry = llsync_read_ptr(tree->root);
++
++    if (entry == NULL) {
++        node = NULL;
++        height = 0;
++    } else {
++        node = rdxtree_entry_addr(entry);
++        height = rdxtree_entry_is_node(entry) ? node->height + 1 : 0;
++    }
++
++    if (key > rdxtree_max_key(height))
++        return NULL;
++
++    if (height == 0) {
++        if (node == NULL)
++            return NULL;
++
++        return get_slot ? (void *)&tree->root : node;
++    }
++
++    shift = (height - 1) * RDXTREE_RADIX;
++
++    do {
++        if (node == NULL)
++            return NULL;
++
++        prev = node;
++        index = (unsigned int)(key >> shift) & RDXTREE_RADIX_MASK;
++        entry = llsync_read_ptr(node->entries[index]);
++        node = rdxtree_entry_addr(entry);
++        shift -= RDXTREE_RADIX;
++        height--;
++    } while (height > 0);
++
++    if (node == NULL)
++        return NULL;
++
++    return get_slot ? (void *)&prev->entries[index] : node;
++}
++
++void *
++rdxtree_replace_slot(void **slot, void *ptr)
++{
++    void *old;
++
++    assert(ptr != NULL);
++    assert(rdxtree_check_alignment(ptr));
++
++    old = *slot;
++    assert(old != NULL);
++    assert(rdxtree_check_alignment(old));
++    llsync_assign_ptr(*slot, ptr);
++    return old;
++}
++
++static struct rdxtree_node *
++rdxtree_walk(struct rdxtree *tree, struct rdxtree_node *node)
++{
++    struct rdxtree_node *prev, *child;
++    unsigned int height, index;
++
++    if (node == NULL) {
++        height = tree->height;
++        node = rdxtree_entry_addr(tree->root);
++
++        while (height > 1) {
++            node = rdxtree_node_find(node, 0, 0);
++            height--;
++        }
++
++        return node;
++    }
++
++    height = 0;
++
++    for (;;) {
++        prev = node->parent;
++
++        if (prev == NULL)
++            return NULL;
++
++        index = node->index;
++        child = rdxtree_node_find(prev, index + 1, 0);
++
++        if (child != NULL)
++            break;
++
++        height++;
++        node = prev;
++    }
++
++    node = child;
++
++    while (height > 0) {
++        node = rdxtree_node_find(node, 0, 0);
++        height--;
++    }
++
++    return node;
++}
++
++void *
++rdxtree_iter_next(struct rdxtree *tree, struct rdxtree_iter *iter)
++{
++    unsigned int index;
++
++    if (tree->height == 0) {
++        if (iter->slot != NULL)
++            return NULL;
++
++        iter->slot = &tree->root;
++        return *iter->slot;
++    }
++
++    if (iter->node != NULL) {
++        index = iter->slot - ((struct rdxtree_node *)iter->node)->entries;
++        iter->slot = rdxtree_node_find(iter->node, index + 1, 1);
++    }
++
++    if (iter->slot == NULL) {
++        iter->node = rdxtree_walk(tree, iter->node);
++
++        if (iter->node != NULL)
++            iter->slot = rdxtree_node_find(iter->node, 0, 1);
++    }
++
++    if (iter->slot == NULL)
++        return NULL;
++
++    return *iter->slot;
++}
++
++void
++rdxtree_remove_all(struct rdxtree *tree)
++{
++    struct rdxtree_node *node, *parent, *next;
++    unsigned int height, index;
++
++    height = tree->height;
++
++    if (height == 0) {
++        if (tree->root != NULL)
++            llsync_assign_ptr(tree->root, NULL);
++
++        return;
++    }
++
++    node = rdxtree_walk(tree, NULL);
++
++    do {
++        next = rdxtree_walk(tree, node);
++
++        parent = node->parent;
++
++        if (parent != NULL) {
++            index = node->index;
++            rdxtree_node_remove(parent, index);
++            rdxtree_remove_bm_set(parent, index);
++            rdxtree_cleanup(tree, parent);
++            node->parent = NULL;
++        }
++
++        rdxtree_node_schedule_destruction(node);
++
++        node = next;
++    } while (node != NULL);
++}
+diff --git a/librdxtree/rdxtree.h b/librdxtree/rdxtree.h
+new file mode 100644
+index 0000000..8ccfa25
+--- /dev/null
++++ b/librdxtree/rdxtree.h
+@@ -0,0 +1,195 @@
++/*
++ * Copyright (c) 2013 Richard Braun.
++ *
++ * This program is free software: you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation, either version 3 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
++ */
++
++/*
++ * Copyright (c) 2011 Richard Braun.
++ * All rights reserved.
++ *
++ * Redistribution and use in source and binary forms, with or without
++ * modification, are permitted provided that the following conditions
++ * are met:
++ * 1. Redistributions of source code must retain the above copyright
++ *    notice, this list of conditions and the following disclaimer.
++ * 2. Redistributions in binary form must reproduce the above copyright
++ *    notice, this list of conditions and the following disclaimer in the
++ *    documentation and/or other materials provided with the distribution.
++ *
++ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
++ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
++ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
++ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
++ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
++ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
++ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
++ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
++ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
++ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
++ *
++ *
++ * Radix tree.
++ *
++ * In addition to the standard insertion operation, this implementation
++ * can allocate keys for the caller at insertion time.
++ */
++
++#ifndef _RDXTREE_H
++#define _RDXTREE_H
++
++#include <stddef.h>
++
++/*
++ * Radix tree.
++ */
++struct rdxtree;
++
++/*
++ * Radix tree iterator.
++ */
++struct rdxtree_iter;
++
++/*
++ * Static tree initializer.
++ */
++#define RDXTREE_INITIALIZER { 0, NULL }
++
++#include "rdxtree_i.h"
++
++/*
++ * Initialize a tree.
++ */
++static inline void
++rdxtree_init(struct rdxtree *tree)
++{
++    tree->height = 0;
++    tree->root = NULL;
++}
++
++/*
++ * Insert a pointer in a tree.
++ *
++ * The ptr parameter must not be NULL.
++ */
++static inline int
++rdxtree_insert(struct rdxtree *tree, unsigned long long key, void *ptr)
++{
++    return rdxtree_insert_common(tree, key, ptr, NULL);
++}
++
++/*
++ * Insert a pointer in a tree and obtain its slot.
++ *
++ * The ptr and slotp parameters must not be NULL. If successful, the slot of
++ * the newly inserted pointer is stored at the address pointed to by the slotp
++ * parameter.
++ */
++static inline int
++rdxtree_insert_slot(struct rdxtree *tree, unsigned long long key, void *ptr,
++                    void ***slotp)
++{
++    return rdxtree_insert_common(tree, key, ptr, slotp);
++}
++
++/*
++ * Insert a pointer in a tree, for which a new key is allocated.
++ *
++ * The ptr and keyp parameters must not be NULL. The newly allocated key is
++ * stored at the address pointed to by the keyp parameter.
++ */
++static inline int
++rdxtree_insert_alloc(struct rdxtree *tree, void *ptr, unsigned long long *keyp)
++{
++    return rdxtree_insert_alloc_common(tree, ptr, keyp, NULL);
++}
++
++/*
++ * Insert a pointer in a tree, for which a new key is allocated, and obtain
++ * its slot.
++ *
++ * The ptr, keyp and slotp parameters must not be NULL. The newly allocated
++ * key is stored at the address pointed to by the keyp parameter while the
++ * slot of the inserted pointer is stored at the address pointed to by the
++ * slotp parameter.
++ */
++static inline int
++rdxtree_insert_alloc_slot(struct rdxtree *tree, void *ptr,
++                          unsigned long long *keyp, void ***slotp)
++{
++    return rdxtree_insert_alloc_common(tree, ptr, keyp, slotp);
++}
++
++/*
++ * Remove a pointer from a tree.
++ *
++ * The matching pointer is returned if successful, NULL otherwise.
++ */
++void * rdxtree_remove(struct rdxtree *tree, unsigned long long key);
++
++/*
++ * Look up a pointer in a tree.
++ *
++ * The matching pointer is returned if successful, NULL otherwise.
++ */
++static inline void *
++rdxtree_lookup(const struct rdxtree *tree, unsigned long long key)
++{
++    return rdxtree_lookup_common(tree, key, 0);
++}
++
++/*
++ * Look up a slot in a tree.
++ *
++ * A slot is a pointer to a stored pointer in a tree. It can be used as
++ * a placeholder for fast replacements to avoid multiple lookups on the same
++ * key.
++ *
++ * A slot for the matching pointer is returned if successful, NULL otherwise.
++ *
++ * See rdxtree_replace_slot().
++ */
++static inline void **
++rdxtree_lookup_slot(const struct rdxtree *tree, unsigned long long key)
++{
++    return rdxtree_lookup_common(tree, key, 1);
++}
++
++/*
++ * Replace a pointer in a tree.
++ *
++ * The ptr parameter must not be NULL. The previous pointer is returned.
++ *
++ * See rdxtree_lookup_slot().
++ */
++void * rdxtree_replace_slot(void **slot, void *ptr);
++
++/*
++ * Forge a loop to process all pointers of a tree.
++ */
++#define rdxtree_for_each(tree, iter, ptr)                           \
++for (rdxtree_iter_init(iter), ptr = rdxtree_iter_next(tree, iter);  \
++     ptr != NULL;                                                   \
++     ptr = rdxtree_iter_next(tree, iter))
++
++/*
++ * Remove all pointers from a tree.
++ *
++ * The common way to destroy a tree and its pointers is to loop over all
++ * the pointers using rdxtree_for_each(), freeing them, then call this
++ * function.
++ */
++void rdxtree_remove_all(struct rdxtree *tree);
++
++#endif /* _RDXTREE_H */
+diff --git a/librdxtree/rdxtree_i.h b/librdxtree/rdxtree_i.h
+new file mode 100644
+index 0000000..4761beb
+--- /dev/null
++++ b/librdxtree/rdxtree_i.h
+@@ -0,0 +1,65 @@
++/*
++ * Copyright (c) 2013 Richard Braun.
++ *
++ * This program is free software: you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation, either version 3 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
++ */
++
++#ifndef _RDXTREE_I_H
++#define _RDXTREE_I_H
++
++/*
++ * Radix tree.
++ */
++struct rdxtree {
++    unsigned int height;
++    void *root;
++};
++
++/*
++ * Radix tree iterator.
++ */
++struct rdxtree_iter {
++    void *node;
++    void **slot;
++};
++
++/*
++ * Initialize an iterator.
++ */
++static inline void
++rdxtree_iter_init(struct rdxtree_iter *iter)
++{
++    iter->node = NULL;
++    iter->slot = NULL;
++}
++
++int rdxtree_insert_common(struct rdxtree *tree, unsigned long long key,
++                          void *ptr, void ***slotp);
++
++int rdxtree_insert_alloc_common(struct rdxtree *tree, void *ptr,
++                                unsigned long long *keyp, void ***slotp);
++
++void * rdxtree_lookup_common(const struct rdxtree *tree, unsigned long long key,
++                             int get_slot);
++
++/*
++ * Walk over pointers in a tree.
++ *
++ * Move the iterator to the next pointer in the given tree.
++ *
++ * The next pointer is returned if there is one, NULL otherwise.
++ */
++void * rdxtree_iter_next(struct rdxtree *tree, struct rdxtree_iter *iter);
++
++#endif /* _RDXTREE_I_H */
+-- 
+2.0.0.rc2
+
diff --git a/debian/patches/0005-libdiskfs-lock-less-reference-counting-for-peropen-o.patch b/debian/patches/0005-libdiskfs-lock-less-reference-counting-for-peropen-o.patch
new file mode 100644
index 00000000..d7dc9660
--- /dev/null
+++ b/debian/patches/0005-libdiskfs-lock-less-reference-counting-for-peropen-o.patch
@@ -0,0 +1,143 @@
+From 53c4f43835fa824b6e70a5fe8c5d08f2c312f9e9 Mon Sep 17 00:00:00 2001
+From: Justus Winter <4winter@informatik.uni-hamburg.de>
+Date: Tue, 6 May 2014 18:58:10 +0200
+Subject: [PATCH 05/14] libdiskfs: lock-less reference counting for peropen
+ objects
+
+* libdiskfs/diskfs.h (struct peropen): Use refcount_t for field refcnt.
+* libdiskfs/peropen-make.c (diskfs_make_peropen): Initialize refcnt.
+* libdiskfs/peropen-rele.c (diskfs_release_peropen): Adjust accordingly.
+* libdiskfs/protid-make.c (diskfs_start_protid): Likewise.  Also, the
+node must no longer be locked, adjust comment accordingly.
+(diskfs_create_protid): Likewise.
+---
+ libdiskfs/diskfs.h       |  7 ++++---
+ libdiskfs/peropen-make.c |  2 +-
+ libdiskfs/peropen-rele.c | 21 ++++++++++-----------
+ libdiskfs/protid-make.c  |  8 ++++----
+ 4 files changed, 19 insertions(+), 19 deletions(-)
+
+diff --git a/libdiskfs/diskfs.h b/libdiskfs/diskfs.h
+index a3f860d..acd1910 100644
+--- a/libdiskfs/diskfs.h
++++ b/libdiskfs/diskfs.h
+@@ -28,6 +28,7 @@
+ #include <hurd/iohelp.h>
+ #include <idvec.h>
+ #include <features.h>
++#include <refcount.h>
+ 
+ #ifdef DISKFS_DEFINE_EXTERN_INLINE
+ #define DISKFS_EXTERN_INLINE
+@@ -57,7 +58,7 @@ struct peropen
+ {
+   int filepointer;
+   int lock_status;
+-  int refcnt;
++  refcount_t refcnt;
+   int openstat;
+ 
+   struct node *np;
+@@ -817,12 +818,12 @@ diskfs_create_node (struct node *dir, const char *name, mode_t mode,
+ 		    struct dirstat *ds);
+ 
+ /* Create and return a protid for an existing peropen PO in CRED,
+-   referring to user USER.  The node PO->np must be locked. */
++   referring to user USER.  */
+ error_t diskfs_create_protid (struct peropen *po, struct iouser *user,
+ 			      struct protid **cred);
+ 
+ /* Build and return in CRED a protid which has no user identification, for
+-   peropen PO.  The node PO->np must be locked.  */
++   peropen PO.  */
+ error_t diskfs_start_protid (struct peropen *po, struct protid **cred);
+ 
+ /* Finish building protid CRED started with diskfs_start_protid;
+diff --git a/libdiskfs/peropen-make.c b/libdiskfs/peropen-make.c
+index eba037f..6d5ca01 100644
+--- a/libdiskfs/peropen-make.c
++++ b/libdiskfs/peropen-make.c
+@@ -31,7 +31,7 @@ diskfs_make_peropen (struct node *np, int flags, struct peropen *context,
+ 
+   po->filepointer = 0;
+   po->lock_status = LOCK_UN;
+-  po->refcnt = 0;
++  refcount_init (&po->refcnt, 0);
+   po->openstat = flags;
+   po->np = np;
+   po->path = NULL;
+diff --git a/libdiskfs/peropen-rele.c b/libdiskfs/peropen-rele.c
+index d3f7492..877137b 100644
+--- a/libdiskfs/peropen-rele.c
++++ b/libdiskfs/peropen-rele.c
+@@ -22,13 +22,8 @@
+ void
+ diskfs_release_peropen (struct peropen *po)
+ {
+-  pthread_mutex_lock (&po->np->lock);
+-
+-  if (--po->refcnt)
+-    {
+-      pthread_mutex_unlock (&po->np->lock);
+-      return;
+-    }
++  if (refcount_deref (&po->refcnt) > 0)
++    return;
+ 
+   if (po->root_parent)
+     mach_port_deallocate (mach_task_self (), po->root_parent);
+@@ -40,10 +35,14 @@ diskfs_release_peropen (struct peropen *po)
+     mach_port_deallocate (mach_task_self (), po->shadow_root_parent);
+ 
+   if (po->lock_status != LOCK_UN)
+-    fshelp_acquire_lock (&po->np->userlock, &po->lock_status,
+-			 &po->np->lock, LOCK_UN);
+-
+-  diskfs_nput (po->np);
++    {
++      pthread_mutex_lock (&po->np->lock);
++      fshelp_acquire_lock (&po->np->userlock, &po->lock_status,
++                           &po->np->lock, LOCK_UN);
++      diskfs_nput (po->np);
++    }
++  else
++    diskfs_nrele (po->np);
+ 
+   free (po->path);
+   free (po);
+diff --git a/libdiskfs/protid-make.c b/libdiskfs/protid-make.c
+index b39b92a..22aaa2e 100644
+--- a/libdiskfs/protid-make.c
++++ b/libdiskfs/protid-make.c
+@@ -20,7 +20,7 @@
+ #include <assert.h>
+ 
+ /* Build and return in CRED a protid which has no user identification, for
+-   peropen PO.  The node PO->np must be locked.  */
++   peropen PO.  */
+ error_t
+ diskfs_start_protid (struct peropen *po, struct protid **cred)
+ {
+@@ -29,7 +29,7 @@ diskfs_start_protid (struct peropen *po, struct protid **cred)
+ 				 sizeof (struct protid), cred);
+   if (! err)
+     {
+-      po->refcnt++;
++      refcount_ref (&po->refcnt);
+       (*cred)->po = po;
+       (*cred)->shared_object = MACH_PORT_NULL;
+       (*cred)->mapped = 0;
+@@ -55,8 +55,8 @@ diskfs_finish_protid (struct protid *cred, struct iouser *user)
+   assert_perror (err);
+ }
+ 
+-/* Create and return a protid for an existing peropen PO in CRED for USER.
+-   The node PO->np must be locked. */
++/* Create and return a protid for an existing peropen PO in CRED for
++   USER.  */
+ error_t
+ diskfs_create_protid (struct peropen *po, struct iouser *user,
+ 		      struct protid **cred)
+-- 
+2.0.0.rc2
+
diff --git a/debian/patches/0006-libtrivfs-lock-less-reference-counting-for-trivfs_pe.patch b/debian/patches/0006-libtrivfs-lock-less-reference-counting-for-trivfs_pe.patch
new file mode 100644
index 00000000..8c1f0b41
--- /dev/null
+++ b/debian/patches/0006-libtrivfs-lock-less-reference-counting-for-trivfs_pe.patch
@@ -0,0 +1,172 @@
+From b4a8cde9dd82168454f2ab7543f16a80ca7b568e Mon Sep 17 00:00:00 2001
+From: Justus Winter <4winter@informatik.uni-hamburg.de>
+Date: Tue, 6 May 2014 19:07:13 +0200
+Subject: [PATCH 06/14] libtrivfs: lock-less reference counting for
+ trivfs_peropen objects
+
+* libtrivfs/trivfs.h (struct trivfs_peropen): Use refcount_t for field
+refcnt.
+(struct trivfs_control): Remove unused field lock.
+* libtrivfs/cntl-create.c (trivfs_create_control): Drop the mutex
+initialization.
+* libtrivfs/io-reauthenticate.c (trivfs_S_io_reauthenticate): Adjust
+accordingly.
+* libtrivfs/io-restrict-auth.c (trivfs_S_io_restrict_auth): Likewise.
+* libtrivfs/open.c (trivfs_open): Initialize refcnt.
+* libtrivfs/protid-clean.c (trivfs_clean_protid): Likewise.
+* libtrivfs/protid-dup.c (trivfs_protid_dup): Likewise.
+---
+ libtrivfs/cntl-create.c       |  1 -
+ libtrivfs/io-reauthenticate.c |  5 +----
+ libtrivfs/io-restrict-auth.c  |  4 +---
+ libtrivfs/open.c              |  2 +-
+ libtrivfs/protid-clean.c      | 26 +++++++++++++++-----------
+ libtrivfs/protid-dup.c        |  5 +----
+ libtrivfs/trivfs.h            |  4 ++--
+ 7 files changed, 21 insertions(+), 26 deletions(-)
+
+diff --git a/libtrivfs/cntl-create.c b/libtrivfs/cntl-create.c
+index 910daf3..eb9a834 100644
+--- a/libtrivfs/cntl-create.c
++++ b/libtrivfs/cntl-create.c
+@@ -85,7 +85,6 @@ trivfs_create_control (mach_port_t underlying,
+ 	}
+ 
+       (*control)->hook = 0;
+-      pthread_mutex_init (&(*control)->lock, NULL);
+     }
+ 
+ out:
+diff --git a/libtrivfs/io-reauthenticate.c b/libtrivfs/io-reauthenticate.c
+index 7677697..df0ed2e 100644
+--- a/libtrivfs/io-reauthenticate.c
++++ b/libtrivfs/io-reauthenticate.c
+@@ -62,11 +62,8 @@ trivfs_S_io_reauthenticate (struct trivfs_protid *cred,
+     newcred->isroot = 1;
+ 
+   newcred->hook = cred->hook;
+-
+-  pthread_mutex_lock (&cred->po->cntl->lock);
+   newcred->po = cred->po;
+-  newcred->po->refcnt++;
+-  pthread_mutex_unlock (&cred->po->cntl->lock);
++  refcount_ref (&newcred->po->refcnt);
+ 
+   do
+     err = io_restrict_auth (newcred->po->cntl->underlying, &newcred->realnode,
+diff --git a/libtrivfs/io-restrict-auth.c b/libtrivfs/io-restrict-auth.c
+index 65b4fd6..39670fe 100644
+--- a/libtrivfs/io-restrict-auth.c
++++ b/libtrivfs/io-restrict-auth.c
+@@ -110,10 +110,8 @@ trivfs_S_io_restrict_auth (struct trivfs_protid *cred,
+     }
+ 
+   newcred->isroot = 0;
+-  pthread_mutex_lock (&cred->po->cntl->lock);
+   newcred->po = cred->po;
+-  newcred->po->refcnt++;
+-  pthread_mutex_unlock (&cred->po->cntl->lock);
++  refcount_ref (&newcred->po->refcnt);
+   if (cred->isroot && idvec_contains (user->uids, 0))
+     newcred->isroot = 1;
+   newcred->user = user;
+diff --git a/libtrivfs/open.c b/libtrivfs/open.c
+index f64d2ff..97e70a1 100644
+--- a/libtrivfs/open.c
++++ b/libtrivfs/open.c
+@@ -40,7 +40,7 @@ trivfs_open (struct trivfs_control *cntl,
+ 
+   ports_port_ref (cntl);
+ 
+-  po->refcnt = 1;
++  refcount_init (&po->refcnt, 1);
+   po->cntl = cntl;
+   po->openmodes = flags;
+   po->hook = 0;
+diff --git a/libtrivfs/protid-clean.c b/libtrivfs/protid-clean.c
+index f98da6a..cce736d 100644
+--- a/libtrivfs/protid-clean.c
++++ b/libtrivfs/protid-clean.c
+@@ -31,19 +31,23 @@ trivfs_clean_protid (void *arg)
+     (*trivfs_protid_destroy_hook) (cred);
+ 
+   /* If we hold the only reference to the peropen, try to get rid of it. */
+-  pthread_mutex_lock (&cntl->lock);
+-  if (cred->po->refcnt == 1 && trivfs_peropen_destroy_hook)
++  if (refcount_deref (&cred->po->refcnt) == 0)
+     {
+-      pthread_mutex_unlock (&cntl->lock);
+-      (*trivfs_peropen_destroy_hook) (cred->po);
+-      pthread_mutex_lock (&cntl->lock);
++      if (trivfs_peropen_destroy_hook)
++        {
++          /* Reaquire a reference while we call the hook.  */
++          refcount_ref (&cred->po->refcnt);
++          (*trivfs_peropen_destroy_hook) (cred->po);
++          if (refcount_deref (&cred->po->refcnt) == 0)
++            goto free_po;
++        }
++      else
++        {
++        free_po:
++          ports_port_deref (cntl);
++          free (cred->po);
++        }
+     }
+-  if (--cred->po->refcnt == 0)
+-    {
+-      ports_port_deref (cntl);
+-      free (cred->po);
+-    }
+-  pthread_mutex_unlock (&cntl->lock);
+ 
+   iohelp_free_iouser (cred->user);
+ 
+diff --git a/libtrivfs/protid-dup.c b/libtrivfs/protid-dup.c
+index 6169603..75f3ca8 100644
+--- a/libtrivfs/protid-dup.c
++++ b/libtrivfs/protid-dup.c
+@@ -35,11 +35,8 @@ trivfs_protid_dup (struct trivfs_protid *cred, struct trivfs_protid **dup)
+ 
+   if (! err)
+     {
+-      pthread_mutex_lock (&cred->po->cntl->lock);
+       new->po = cred->po;
+-      new->po->refcnt++;
+-      pthread_mutex_unlock (&cred->po->cntl->lock);
+-
++      refcount_ref (&new->po->refcnt);
+       new->isroot = cred->isroot;
+ 
+       err = iohelp_dup_iouser (&new->user, cred->user);
+diff --git a/libtrivfs/trivfs.h b/libtrivfs/trivfs.h
+index bb456ff..8902338 100644
+--- a/libtrivfs/trivfs.h
++++ b/libtrivfs/trivfs.h
+@@ -24,6 +24,7 @@
+ #include <mach/mach.h>
+ #include <hurd/ports.h>
+ #include <hurd/iohelp.h>
++#include <refcount.h>
+ 
+ struct trivfs_protid
+ {
+@@ -41,14 +42,13 @@ struct trivfs_peropen
+ {
+   void *hook;			/* for user use */
+   int openmodes;
+-  int refcnt;
++  refcount_t refcnt;
+   struct trivfs_control *cntl;
+ };
+ 
+ struct trivfs_control
+ {
+   struct port_info pi;
+-  pthread_mutex_t lock;
+   struct port_class *protid_class;
+   struct port_bucket *protid_bucket;
+   mach_port_t filesys_id;
+-- 
+2.0.0.rc2
+
diff --git a/debian/patches/0007-libports-use-a-single-hash-table.patch b/debian/patches/0007-libports-use-a-single-hash-table.patch
new file mode 100644
index 00000000..18faad6c
--- /dev/null
+++ b/debian/patches/0007-libports-use-a-single-hash-table.patch
@@ -0,0 +1,650 @@
+From 5f8234bc694db5633260805f1c690113f8674642 Mon Sep 17 00:00:00 2001
+From: Justus Winter <4winter@informatik.uni-hamburg.de>
+Date: Sat, 3 May 2014 03:53:41 +0200
+Subject: [PATCH 07/14] libports: use a single hash table
+
+Previously, libports used a hash table per port bucket.  This makes
+looking up a port difficult if one does not know the port bucket, as
+one has to iterate over all buckets and do a hash table lookup each.
+
+Having to iterate over the buckets makes it necessary to keep a list
+of all buckets, which has to be updated and protected by a lock as
+well.
+
+Also, the current code in _ports_bucket_class_iterate iterates over
+the hash table associated with the bucket given.  When
+ports_class_iterate calls this common function, it obtains a reference
+to the bucket from one of the ports in the given class.  This will not
+work if a class contains ports in different port buckets.  This
+limitation is not documented as far as I can see.  Again, having to
+maintain this list has its cost and requires serialization.
+
+Use a single hash table instead.  Furthermore, serialize access to it
+using a separate lock.  Remove the linked lists of all buckets and all
+ports in a class.
+
+* libports/bucket-iterate.c (ports_bucket_iterate): Acquire
+_ports_htable_lock.  Also, generalize ports_bucket_iterate to treat
+the bucket argument the same way as the class argument.
+* libports/class-iterate.c (ports_class_iterate): Just call the
+generalized _ports_bucket_class_iterate with NULL as class.
+* libports/ports.h (struct port_info): Remove the port class links.
+(struct port_bucket): Remove the hash table, and the all buckets link.
+(_ports_all_buckets): Remove declaration.
+(_ports_htable): New global hash table.
+(_ports_htable_lock): Protected by this lock.
+* libports/claim-right.c: Adjust accordingly.
+* libports/complete-deallocate.c: Likewise.
+* libports/create-bucket.c: Likewise.
+* libports/create-class.c: Likewise.
+* libports/create-internal.c: Likewise.
+* libports/destroy-right.c: Likewise.
+* libports/import-port.c: Likewise.
+* libports/lookup-port.c: Likewise.
+* libports/reallocate-from-external.c: Likewise.
+* libports/reallocate-port.c: Likewise.
+* libports/transfer-right.c: Likewise.
+* libports/inhibit-all-rpcs.c: Iterate over the hash table.
+* libports/inhibit-bucket-rpcs.c: Likewise, but filter using bucket.
+* libports/inhibit-class-rpcs.c: Likewise, but filter using class.
+* libports/init.c (_ports_htable): Initialize.
+(_ports_htable_lock): Likewise.
+---
+ libports/bucket-iterate.c           | 22 +++++++++++++++-------
+ libports/claim-right.c              |  5 ++++-
+ libports/class-iterate.c            | 10 +---------
+ libports/complete-deallocate.c      |  7 +++----
+ libports/create-bucket.c            |  6 ------
+ libports/create-class.c             |  1 -
+ libports/create-internal.c          | 19 +++++++++++++------
+ libports/destroy-right.c            |  5 +++--
+ libports/import-port.c              | 19 +++++++++++++------
+ libports/inhibit-all-rpcs.c         | 27 +++++++++++++--------------
+ libports/inhibit-bucket-rpcs.c      |  3 ++-
+ libports/inhibit-class-rpcs.c       | 27 ++++++++++++++++++---------
+ libports/init.c                     |  7 ++++++-
+ libports/lookup-port.c              | 21 ++++++++-------------
+ libports/ports.h                    | 13 ++++++++-----
+ libports/reallocate-from-external.c | 15 +++++++++++----
+ libports/reallocate-port.c          |  9 ++++++++-
+ libports/transfer-right.c           | 18 ++++++++++++++----
+ 18 files changed, 140 insertions(+), 94 deletions(-)
+
+diff --git a/libports/bucket-iterate.c b/libports/bucket-iterate.c
+index babc204..06d8f7d 100644
+--- a/libports/bucket-iterate.c
++++ b/libports/bucket-iterate.c
+@@ -25,7 +25,7 @@
+ /* Internal entrypoint for both ports_bucket_iterate and ports_class_iterate.
+    If CLASS is non-null, call FUN only for ports in that class.  */
+ error_t
+-_ports_bucket_class_iterate (struct port_bucket *bucket,
++_ports_bucket_class_iterate (struct hurd_ihash *ht,
+ 			     struct port_class *class,
+ 			     error_t (*fun)(void *))
+ {
+@@ -36,23 +36,24 @@ _ports_bucket_class_iterate (struct port_bucket *bucket,
+   error_t err;
+ 
+   pthread_mutex_lock (&_ports_lock);
++  pthread_mutex_lock (&_ports_htable_lock);
+ 
+-  if (bucket->htable.nr_items == 0)
++  if (ht->nr_items == 0)
+     {
+-      pthread_mutex_unlock (&_ports_lock);
++      pthread_mutex_unlock (&_ports_htable_lock);
+       return 0;
+     }
+ 
+-  nr_items = bucket->htable.nr_items;
++  nr_items = ht->nr_items;
+   p = malloc (nr_items * sizeof *p);
+   if (p == NULL)
+     {
+-      pthread_mutex_unlock (&_ports_lock);
++      pthread_mutex_unlock (&_ports_htable_lock);
+       return ENOMEM;
+     }
+ 
+   n = 0;
+-  HURD_IHASH_ITERATE (&bucket->htable, arg)
++  HURD_IHASH_ITERATE (ht, arg)
+     {
+       struct port_info *const pi = arg;
+ 
+@@ -63,8 +64,15 @@ _ports_bucket_class_iterate (struct port_bucket *bucket,
+ 	  n++;
+ 	}
+     }
++  pthread_mutex_unlock (&_ports_htable_lock);
+   pthread_mutex_unlock (&_ports_lock);
+ 
++  if (n == 0)
++    {
++      free (p);
++      return 0;
++    }
++
+   if (n != nr_items)
+     {
+       /* We allocated too much.  Release unused memory.  */
+@@ -89,5 +97,5 @@ error_t
+ ports_bucket_iterate (struct port_bucket *bucket,
+ 		      error_t (*fun)(void *))
+ {
+-  return _ports_bucket_class_iterate (bucket, 0, fun);
++  return _ports_bucket_class_iterate (&bucket->htable, NULL, fun);
+ }
+diff --git a/libports/claim-right.c b/libports/claim-right.c
+index 4851ea3..11cc3ad 100644
+--- a/libports/claim-right.c
++++ b/libports/claim-right.c
+@@ -34,10 +34,13 @@ ports_claim_right (void *portstruct)
+   if (ret == MACH_PORT_NULL)
+     return ret;
+ 
+-  pthread_mutex_lock (&_ports_lock);
++  pthread_mutex_lock (&_ports_htable_lock);
++  hurd_ihash_locp_remove (&_ports_htable, pi->ports_htable_entry);
+   hurd_ihash_locp_remove (&pi->bucket->htable, pi->hentry);
++  pthread_mutex_unlock (&_ports_htable_lock);
+   err = mach_port_move_member (mach_task_self (), ret, MACH_PORT_NULL);
+   assert_perror (err);
++  pthread_mutex_lock (&_ports_lock);
+   pi->port_right = MACH_PORT_NULL;
+   if (pi->flags & PORT_HAS_SENDRIGHTS)
+     {
+diff --git a/libports/class-iterate.c b/libports/class-iterate.c
+index 1f8878a..df33818 100644
+--- a/libports/class-iterate.c
++++ b/libports/class-iterate.c
+@@ -23,13 +23,5 @@ error_t
+ ports_class_iterate (struct port_class *class,
+ 		     error_t (*fun)(void *))
+ {
+-  pthread_mutex_lock (&_ports_lock);
+-  if (class->ports != 0)
+-    {
+-      struct port_bucket *bucket = class->ports->bucket;
+-      pthread_mutex_unlock (&_ports_lock);
+-      return _ports_bucket_class_iterate (bucket, class, fun);
+-    }
+-  pthread_mutex_unlock (&_ports_lock);
+-  return 0;
++  return _ports_bucket_class_iterate (&_ports_htable, class, fun);
+ }
+diff --git a/libports/complete-deallocate.c b/libports/complete-deallocate.c
+index 8ce095b..50548ec 100644
+--- a/libports/complete-deallocate.c
++++ b/libports/complete-deallocate.c
+@@ -29,16 +29,15 @@ _ports_complete_deallocate (struct port_info *pi)
+ 
+   if (pi->port_right)
+     {
++      pthread_mutex_lock (&_ports_htable_lock);
++      hurd_ihash_locp_remove (&_ports_htable, pi->ports_htable_entry);
+       hurd_ihash_locp_remove (&pi->bucket->htable, pi->hentry);
++      pthread_mutex_unlock (&_ports_htable_lock);
+       mach_port_mod_refs (mach_task_self (), pi->port_right,
+ 			  MACH_PORT_RIGHT_RECEIVE, -1);
+       pi->port_right = MACH_PORT_NULL;
+     }
+ 
+-  *pi->prevp = pi->next;
+-  if (pi->next)
+-    pi->next->prevp = pi->prevp;
+-
+   pi->bucket->count--;
+   pi->class->count--;
+ 
+diff --git a/libports/create-bucket.c b/libports/create-bucket.c
+index 52d50c3..2c5f1b6 100644
+--- a/libports/create-bucket.c
++++ b/libports/create-bucket.c
+@@ -48,11 +48,5 @@ ports_create_bucket ()
+ 
+   hurd_ihash_init (&ret->htable, offsetof (struct port_info, hentry));
+   ret->rpcs = ret->flags = ret->count = 0;
+-
+-  pthread_mutex_lock (&_ports_lock);
+-  ret->next = _ports_all_buckets;
+-  _ports_all_buckets = ret;
+-  pthread_mutex_unlock (&_ports_lock);
+-
+   return ret;
+ }
+diff --git a/libports/create-class.c b/libports/create-class.c
+index 12c8add..782f52b 100644
+--- a/libports/create-class.c
++++ b/libports/create-class.c
+@@ -39,7 +39,6 @@ ports_create_class (void (*clean_routine)(void *),
+   cl->dropweak_routine = dropweak_routine;
+   cl->flags = 0;
+   cl->rpcs = 0;
+-  cl->ports = NULL;
+   cl->count = 0;
+   cl->uninhibitable_rpcs = ports_default_uninhibitable_rpcs;
+ 
+diff --git a/libports/create-internal.c b/libports/create-internal.c
+index 8551297..2981e74 100644
+--- a/libports/create-internal.c
++++ b/libports/create-internal.c
+@@ -81,15 +81,22 @@ _ports_create_port_internal (struct port_class *class,
+       goto loop;
+     }
+ 
++  pthread_mutex_lock (&_ports_htable_lock);
++  err = hurd_ihash_add (&_ports_htable, port, pi);
++  if (err)
++    {
++      pthread_mutex_unlock (&_ports_htable_lock);
++      goto lose;
++    }
+   err = hurd_ihash_add (&bucket->htable, port, pi);
+   if (err)
+-    goto lose;
++    {
++      hurd_ihash_locp_remove (&_ports_htable, pi->ports_htable_entry);
++      pthread_mutex_unlock (&_ports_htable_lock);
++      goto lose;
++    }
++  pthread_mutex_unlock (&_ports_htable_lock);
+ 
+-  pi->next = class->ports;
+-  pi->prevp = &class->ports;
+-  if (class->ports)
+-    class->ports->prevp = &pi->next;
+-  class->ports = pi;
+   bucket->count++;
+   class->count++;
+   pthread_mutex_unlock (&_ports_lock);
+diff --git a/libports/destroy-right.c b/libports/destroy-right.c
+index 65e19c7..aff7c02 100644
+--- a/libports/destroy-right.c
++++ b/libports/destroy-right.c
+@@ -30,12 +30,13 @@ ports_destroy_right (void *portstruct)
+ 
+   if (pi->port_right != MACH_PORT_NULL)
+     {
+-      pthread_mutex_lock (&_ports_lock);
++      pthread_mutex_lock (&_ports_htable_lock);
++      hurd_ihash_locp_remove (&_ports_htable, pi->ports_htable_entry);
+       hurd_ihash_locp_remove (&pi->bucket->htable, pi->hentry);
++      pthread_mutex_unlock (&_ports_htable_lock);
+       err = mach_port_mod_refs (mach_task_self (), pi->port_right,
+ 				MACH_PORT_RIGHT_RECEIVE, -1);
+       assert_perror (err);
+-      pthread_mutex_unlock (&_ports_lock);
+ 
+       pi->port_right = MACH_PORT_NULL;
+ 
+diff --git a/libports/import-port.c b/libports/import-port.c
+index 226f47e..91afaa7 100644
+--- a/libports/import-port.c
++++ b/libports/import-port.c
+@@ -75,15 +75,22 @@ ports_import_port (struct port_class *class, struct port_bucket *bucket,
+       goto loop;
+     }
+ 
++  pthread_mutex_lock (&_ports_htable_lock);
++  err = hurd_ihash_add (&_ports_htable, port, pi);
++  if (err)
++    {
++      pthread_mutex_unlock (&_ports_htable_lock);
++      goto lose;
++    }
+   err = hurd_ihash_add (&bucket->htable, port, pi);
+   if (err)
+-    goto lose;
++    {
++      hurd_ihash_locp_remove (&_ports_htable, pi->ports_htable_entry);
++      pthread_mutex_unlock (&_ports_htable_lock);
++      goto lose;
++    }
++  pthread_mutex_unlock (&_ports_htable_lock);
+ 
+-  pi->next = class->ports;
+-  pi->prevp = &class->ports;
+-  if (class->ports)
+-    class->ports->prevp = &pi->next;
+-  class->ports = pi;
+   bucket->count++;
+   class->count++;
+   pthread_mutex_unlock (&_ports_lock);
+diff --git a/libports/inhibit-all-rpcs.c b/libports/inhibit-all-rpcs.c
+index d4a54ba..83c291f 100644
+--- a/libports/inhibit-all-rpcs.c
++++ b/libports/inhibit-all-rpcs.c
+@@ -36,24 +36,23 @@ ports_inhibit_all_rpcs ()
+       struct port_bucket *bucket;
+       int this_one = 0;
+ 
+-      for (bucket = _ports_all_buckets; bucket; bucket = bucket->next)
++      pthread_mutex_lock (&_ports_htable_lock);
++      HURD_IHASH_ITERATE (&_ports_htable, portstruct)
+ 	{
+-	  HURD_IHASH_ITERATE (&bucket->htable, portstruct)
++	  struct rpc_info *rpc;
++	  struct port_info *pi = portstruct;
++
++	  for (rpc = pi->current_rpcs; rpc; rpc = rpc->next)
+ 	    {
+-	      struct rpc_info *rpc;
+-	      struct port_info *pi = portstruct;
+-	  
+-	      for (rpc = pi->current_rpcs; rpc; rpc = rpc->next)
+-		{
+-		  /* Avoid cancelling the calling thread if it's currently
+-		     handling a RPC.  */
+-		  if (rpc->thread == hurd_thread_self ())
+-		    this_one = 1;
+-		  else
+-		    hurd_thread_cancel (rpc->thread);
+-		}
++	      /* Avoid cancelling the calling thread if it's currently
++		 handling a RPC.  */
++	      if (rpc->thread == hurd_thread_self ())
++		this_one = 1;
++	      else
++		hurd_thread_cancel (rpc->thread);
+ 	    }
+ 	}
++      pthread_mutex_unlock (&_ports_htable_lock);
+ 
+       while (_ports_total_rpcs > this_one)
+ 	{
+diff --git a/libports/inhibit-bucket-rpcs.c b/libports/inhibit-bucket-rpcs.c
+index 965aa03..8c5a486 100644
+--- a/libports/inhibit-bucket-rpcs.c
++++ b/libports/inhibit-bucket-rpcs.c
+@@ -35,6 +35,7 @@ ports_inhibit_bucket_rpcs (struct port_bucket *bucket)
+     {
+       int this_one = 0;
+ 
++      pthread_mutex_lock (&_ports_htable_lock);
+       HURD_IHASH_ITERATE (&bucket->htable, portstruct)
+ 	{
+ 	  struct rpc_info *rpc;
+@@ -49,7 +50,7 @@ ports_inhibit_bucket_rpcs (struct port_bucket *bucket)
+ 		hurd_thread_cancel (rpc->thread);
+ 	    }
+ 	}
+-
++      pthread_mutex_unlock (&_ports_htable_lock);
+ 
+       while (bucket->rpcs > this_one)
+ 	{
+diff --git a/libports/inhibit-class-rpcs.c b/libports/inhibit-class-rpcs.c
+index 7ee8653..1580bdb 100644
+--- a/libports/inhibit-class-rpcs.c
++++ b/libports/inhibit-class-rpcs.c
+@@ -36,15 +36,24 @@ ports_inhibit_class_rpcs (struct port_class *class)
+       struct rpc_info *rpc;
+       int this_one = 0;
+ 
+-      for (pi = class->ports; pi; pi = pi->next)
+-	for (rpc = pi->current_rpcs; rpc; rpc = rpc->next)
+-	  {
+-	    /* Avoid cancelling the calling thread.  */
+-	    if (rpc->thread == hurd_thread_self ())
+-	      this_one = 1;
+-	    else
+-	      hurd_thread_cancel (rpc->thread);
+-	  }
++      pthread_mutex_lock (&_ports_htable_lock);
++      HURD_IHASH_ITERATE (&_ports_htable, portstruct)
++	{
++	  struct rpc_info *rpc;
++	  struct port_info *pi = portstruct;
++	  if (pi->class != class)
++	    continue;
++
++	  for (rpc = pi->current_rpcs; rpc; rpc = rpc->next)
++	    {
++	      /* Avoid cancelling the calling thread.  */
++	      if (rpc->thread == hurd_thread_self ())
++		this_one = 1;
++	      else
++		hurd_thread_cancel (rpc->thread);
++	    }
++	}
++      pthread_mutex_unlock (&_ports_htable_lock);
+ 
+       while (class->rpcs > this_one)
+ 	{
+diff --git a/libports/init.c b/libports/init.c
+index 3ef5388..d3aa90c 100644
+--- a/libports/init.c
++++ b/libports/init.c
+@@ -19,9 +19,14 @@
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+ 
+ #include "ports.h"
++#include <stddef.h>
+ 
+ pthread_mutex_t _ports_lock = PTHREAD_MUTEX_INITIALIZER;
+ pthread_cond_t _ports_block = PTHREAD_COND_INITIALIZER;
+-struct port_bucket *_ports_all_buckets;
++
++struct hurd_ihash _ports_htable =
++  HURD_IHASH_INITIALIZER (offsetof (struct port_info, ports_htable_entry));
++pthread_mutex_t _ports_htable_lock = PTHREAD_MUTEX_INITIALIZER;
++
+ int _ports_total_rpcs;
+ int _ports_flags;
+diff --git a/libports/lookup-port.c b/libports/lookup-port.c
+index f79f6f0..fbb13ef 100644
+--- a/libports/lookup-port.c
++++ b/libports/lookup-port.c
+@@ -26,26 +26,21 @@ ports_lookup_port (struct port_bucket *bucket,
+ 		   mach_port_t port,
+ 		   struct port_class *class)
+ {
+-  struct port_info *pi = 0;
+-  
++  struct port_info *pi;
++
+   pthread_mutex_lock (&_ports_lock);
++  pthread_mutex_lock (&_ports_htable_lock);
+ 
+-  if (bucket)
+-    pi = hurd_ihash_find (&bucket->htable, port);
+-  else
+-    for (bucket = _ports_all_buckets; bucket; bucket = bucket->next)
+-      {
+-	pi = hurd_ihash_find (&bucket->htable, port);
+-	if (pi)
+-	  break;
+-      }
+-  
+-  if (pi && class && pi->class != class)
++  pi = hurd_ihash_find (&_ports_htable, port);
++  if (pi
++      && ((class && pi->class != class)
++          || (bucket && pi->bucket != bucket)))
+     pi = 0;
+ 
+   if (pi)
+     pi->refcnt++;
+ 
++  pthread_mutex_unlock (&_ports_htable_lock);
+   pthread_mutex_unlock (&_ports_lock);
+   
+   return pi;
+diff --git a/libports/ports.h b/libports/ports.h
+index 7f13124..c29d78a 100644
+--- a/libports/ports.h
++++ b/libports/ports.h
+@@ -48,7 +48,7 @@ struct port_info
+   struct rpc_info *current_rpcs;
+   struct port_bucket *bucket;
+   hurd_ihash_locp_t hentry;
+-  struct port_info *next, **prevp; /* links on port_class list */
++  hurd_ihash_locp_t ports_htable_entry;
+ };
+ typedef struct port_info *port_info_t;
+ 
+@@ -65,7 +65,6 @@ struct port_bucket
+   int rpcs;
+   int flags;
+   int count;
+-  struct port_bucket *next;
+ };
+ /* FLAGS above are the following: */
+ #define PORT_BUCKET_INHIBITED	PORTS_INHIBITED
+@@ -78,7 +77,6 @@ struct port_class
+ {
+   int flags;
+   int rpcs;
+-  struct port_info *ports;
+   int count;
+   void (*clean_routine) (void *);
+   void (*dropweak_routine) (void *);
+@@ -277,7 +275,7 @@ error_t ports_class_iterate (struct port_class *class,
+ 			     error_t (*fun)(void *port));
+ 
+ /* Internal entrypoint for above two.  */
+-error_t _ports_bucket_class_iterate (struct port_bucket *bucket,
++error_t _ports_bucket_class_iterate (struct hurd_ihash *ht,
+ 				     struct port_class *class,
+ 				     error_t (*fun)(void *port));
+ 
+@@ -402,7 +400,12 @@ extern kern_return_t
+ /* Private data */
+ extern pthread_mutex_t _ports_lock;
+ extern pthread_cond_t _ports_block;
+-extern struct port_bucket *_ports_all_buckets;
++
++/* A hash table mapping port names to port_info objects.  */
++extern struct hurd_ihash _ports_htable;
++/* Access to the hash table is protected by this lock.  */
++extern pthread_mutex_t _ports_htable_lock;
++
+ extern int _ports_total_rpcs;
+ extern int _ports_flags;
+ #define _PORTS_INHIBITED	PORTS_INHIBITED
+diff --git a/libports/reallocate-from-external.c b/libports/reallocate-from-external.c
+index 8cccb2a..678b5d9 100644
+--- a/libports/reallocate-from-external.c
++++ b/libports/reallocate-from-external.c
+@@ -43,8 +43,11 @@ ports_reallocate_from_external (void *portstruct, mach_port_t receive)
+ 			    MACH_PORT_RIGHT_RECEIVE, -1);
+   assert_perror (err);
+ 
++  pthread_mutex_lock (&_ports_htable_lock);
++  hurd_ihash_locp_remove (&_ports_htable, pi->ports_htable_entry);
+   hurd_ihash_locp_remove (&pi->bucket->htable, pi->hentry);
+-  
++  pthread_mutex_unlock (&_ports_htable_lock);
++
+   if ((pi->flags & PORT_HAS_SENDRIGHTS) && !stat.mps_srights)
+     {
+       dropref = 1;
+@@ -59,11 +62,15 @@ ports_reallocate_from_external (void *portstruct, mach_port_t receive)
+   pi->port_right = receive;
+   pi->cancel_threshold = 0;
+   pi->mscount = stat.mps_mscount;
+-  
+-  err = hurd_ihash_add (&pi->bucket->htable, receive, pi);
++
++  pthread_mutex_lock (&_ports_htable_lock);
++  err = hurd_ihash_add (&_ports_htable, receive, pi);
+   assert_perror (err);
++  err = hurd_ihash_add (&pi->bucket->htable, receive, pi);
++  pthread_mutex_unlock (&_ports_htable_lock);
+   pthread_mutex_unlock (&_ports_lock);
+-  
++  assert_perror (err);
++
+   mach_port_move_member (mach_task_self (), receive, pi->bucket->portset);
+   
+   if (stat.mps_srights)
+diff --git a/libports/reallocate-port.c b/libports/reallocate-port.c
+index d2adaeb..4a719e4 100644
+--- a/libports/reallocate-port.c
++++ b/libports/reallocate-port.c
+@@ -36,7 +36,10 @@ ports_reallocate_port (void *portstruct)
+ 			    MACH_PORT_RIGHT_RECEIVE, -1);
+   assert_perror (err);
+ 
++  pthread_mutex_lock (&_ports_htable_lock);
++  hurd_ihash_locp_remove (&_ports_htable, pi->ports_htable_entry);
+   hurd_ihash_locp_remove (&pi->bucket->htable, pi->hentry);
++  pthread_mutex_unlock (&_ports_htable_lock);
+ 
+   err = mach_port_allocate (mach_task_self (), MACH_PORT_RIGHT_RECEIVE,
+ 			    &pi->port_right);
+@@ -48,9 +51,13 @@ ports_reallocate_port (void *portstruct)
+     }
+   pi->cancel_threshold = 0;
+   pi->mscount = 0;
+-  err = hurd_ihash_add (&pi->bucket->htable, pi->port_right, pi);
++  pthread_mutex_lock (&_ports_htable_lock);
++  err = hurd_ihash_add (&_ports_htable, pi->port_right, pi);
+   assert_perror (err);
++  err = hurd_ihash_add (&pi->bucket->htable, pi->port_right, pi);
++  pthread_mutex_unlock (&_ports_htable_lock);
+   pthread_mutex_unlock (&_ports_lock);
++  assert_perror (err);
+ 
+   err = mach_port_move_member (mach_task_self (), pi->port_right, 
+ 			       pi->bucket->portset);
+diff --git a/libports/transfer-right.c b/libports/transfer-right.c
+index 72488a9..3f23d93 100644
+--- a/libports/transfer-right.c
++++ b/libports/transfer-right.c
+@@ -41,7 +41,10 @@ ports_transfer_right (void *tostruct,
+   port = frompi->port_right;
+   if (port != MACH_PORT_NULL)
+     {
++      pthread_mutex_lock (&_ports_htable_lock);
++      hurd_ihash_locp_remove (&_ports_htable, frompi->ports_htable_entry);
+       hurd_ihash_locp_remove (&frompi->bucket->htable, frompi->hentry);
++      pthread_mutex_unlock (&_ports_htable_lock);
+       frompi->port_right = MACH_PORT_NULL;
+       if (frompi->flags & PORT_HAS_SENDRIGHTS)
+ 	{
+@@ -54,7 +57,10 @@ ports_transfer_right (void *tostruct,
+   /* Destroy the existing right in TOPI. */
+   if (topi->port_right != MACH_PORT_NULL)
+     {
++      pthread_mutex_lock (&_ports_htable_lock);
++      hurd_ihash_locp_remove (&_ports_htable, topi->ports_htable_entry);
+       hurd_ihash_locp_remove (&topi->bucket->htable, topi->hentry);
++      pthread_mutex_unlock (&_ports_htable_lock);
+       err = mach_port_mod_refs (mach_task_self (), topi->port_right,
+ 				MACH_PORT_RIGHT_RECEIVE, -1);
+       assert_perror (err);
+@@ -74,10 +80,16 @@ ports_transfer_right (void *tostruct,
+   topi->port_right = port;
+   topi->cancel_threshold = frompi->cancel_threshold;
+   topi->mscount = frompi->mscount;
+-  
++
++  pthread_mutex_unlock (&_ports_lock);
++
+   if (port)
+     {
++      pthread_mutex_lock (&_ports_htable_lock);
++      err = hurd_ihash_add (&_ports_htable, port, topi);
++      assert_perror (err);
+       err = hurd_ihash_add (&topi->bucket->htable, port, topi);
++      pthread_mutex_unlock (&_ports_htable_lock);
+       assert_perror (err);
+       if (topi->bucket != frompi->bucket)
+         {
+@@ -86,9 +98,7 @@ ports_transfer_right (void *tostruct,
+ 	  assert_perror (err);
+ 	}
+     }
+-  
+-  pthread_mutex_unlock (&_ports_lock);
+-  
++
+   /* Take care of any lowered reference counts. */
+   if (dereffrompi)
+     ports_port_deref (frompi);
+-- 
+2.0.0.rc2
+
diff --git a/debian/patches/0008-libports-lock-less-reference-counting-for-port_info-.patch b/debian/patches/0008-libports-lock-less-reference-counting-for-port_info-.patch
new file mode 100644
index 00000000..c4b63d69
--- /dev/null
+++ b/debian/patches/0008-libports-lock-less-reference-counting-for-port_info-.patch
@@ -0,0 +1,345 @@
+From 033ef517de7f127bb5c592d4eb70e6e91093df6a Mon Sep 17 00:00:00 2001
+From: Justus Winter <4winter@informatik.uni-hamburg.de>
+Date: Sat, 3 May 2014 01:02:35 +0200
+Subject: [PATCH 08/14] libports: lock-less reference counting for port_info
+ objects
+
+* libports/ports.h (struct port_info): Use the new type.
+* libports/lookup-port.c: No need to lock _ports_lock anymore.
+* libports/bucket-iterate.c: Likewise.
+* libports/complete-deallocate.c: Check if someone reacquired a
+reference through a hash table lookup.
+* libports/create-internal.c: Use the new reference counting primitives.
+* libports/get-right.c: Likewise.
+* libports/import-port.c: Likewise.
+* libports/port-deref-weak.c: Likewise.
+* libports/port-deref.c: Likewise.
+* libports/port-ref-weak.c: Likewise.
+* libports/port-ref.c: Likewise.
+* libports/reallocate-from-external.c: Likewise.
+* libports/transfer-right.c: Likewise.
+* utils/rpctrace.c: Likewise.
+---
+ libports/bucket-iterate.c           |  4 +---
+ libports/complete-deallocate.c      | 14 ++++++++++++++
+ libports/create-internal.c          |  3 +--
+ libports/get-right.c                |  2 +-
+ libports/import-port.c              |  3 +--
+ libports/lookup-port.c              |  6 ++----
+ libports/port-deref-weak.c          | 10 +++-------
+ libports/port-deref.c               | 34 ++++++++++++++++------------------
+ libports/port-ref-weak.c            |  8 +++-----
+ libports/port-ref.c                 |  8 +++-----
+ libports/ports.h                    |  4 ++--
+ libports/reallocate-from-external.c |  2 +-
+ libports/transfer-right.c           |  2 +-
+ utils/rpctrace.c                    | 10 ++++++++--
+ 14 files changed, 57 insertions(+), 53 deletions(-)
+
+diff --git a/libports/bucket-iterate.c b/libports/bucket-iterate.c
+index 06d8f7d..8a28827 100644
+--- a/libports/bucket-iterate.c
++++ b/libports/bucket-iterate.c
+@@ -35,7 +35,6 @@ _ports_bucket_class_iterate (struct hurd_ihash *ht,
+   size_t i, n, nr_items;
+   error_t err;
+ 
+-  pthread_mutex_lock (&_ports_lock);
+   pthread_mutex_lock (&_ports_htable_lock);
+ 
+   if (ht->nr_items == 0)
+@@ -59,13 +58,12 @@ _ports_bucket_class_iterate (struct hurd_ihash *ht,
+ 
+       if (class == 0 || pi->class == class)
+ 	{
+-	  pi->refcnt++;
++	  refcounts_ref (&pi->refcounts, NULL);
+ 	  p[n] = pi;
+ 	  n++;
+ 	}
+     }
+   pthread_mutex_unlock (&_ports_htable_lock);
+-  pthread_mutex_unlock (&_ports_lock);
+ 
+   if (n == 0)
+     {
+diff --git a/libports/complete-deallocate.c b/libports/complete-deallocate.c
+index 50548ec..a239957 100644
+--- a/libports/complete-deallocate.c
++++ b/libports/complete-deallocate.c
+@@ -29,15 +29,29 @@ _ports_complete_deallocate (struct port_info *pi)
+ 
+   if (pi->port_right)
+     {
++      struct references result;
++
+       pthread_mutex_lock (&_ports_htable_lock);
++      refcounts_references (&pi->refcounts, &result);
++      if (result.hard > 0 || result.weak > 0)
++        {
++          /* A reference was reacquired through a hash table lookup.
++             It's fine, we didn't touch anything yet. */
++          pthread_mutex_unlock (&_ports_htable_lock);
++          return;
++        }
++
+       hurd_ihash_locp_remove (&_ports_htable, pi->ports_htable_entry);
+       hurd_ihash_locp_remove (&pi->bucket->htable, pi->hentry);
+       pthread_mutex_unlock (&_ports_htable_lock);
++
+       mach_port_mod_refs (mach_task_self (), pi->port_right,
+ 			  MACH_PORT_RIGHT_RECEIVE, -1);
+       pi->port_right = MACH_PORT_NULL;
+     }
+ 
++  pthread_mutex_lock (&_ports_lock);
++
+   pi->bucket->count--;
+   pi->class->count--;
+ 
+diff --git a/libports/create-internal.c b/libports/create-internal.c
+index 2981e74..4f1e512 100644
+--- a/libports/create-internal.c
++++ b/libports/create-internal.c
+@@ -54,8 +54,7 @@ _ports_create_port_internal (struct port_class *class,
+     }
+ 
+   pi->class = class;
+-  pi->refcnt = 1;
+-  pi->weakrefcnt = 0;
++  refcounts_init (&pi->refcounts, 1, 0);
+   pi->cancel_threshold = 0;
+   pi->mscount = 0;
+   pi->flags = 0;
+diff --git a/libports/get-right.c b/libports/get-right.c
+index 89050c6..8681f46 100644
+--- a/libports/get-right.c
++++ b/libports/get-right.c
+@@ -41,7 +41,7 @@ ports_get_right (void *port)
+   if ((pi->flags & PORT_HAS_SENDRIGHTS) == 0)
+     {
+       pi->flags |= PORT_HAS_SENDRIGHTS;
+-      pi->refcnt++;
++      refcounts_ref (&pi->refcounts, NULL);
+       err = mach_port_request_notification (mach_task_self (),
+ 					    pi->port_right,
+ 					    MACH_NOTIFY_NO_SENDERS,
+diff --git a/libports/import-port.c b/libports/import-port.c
+index 91afaa7..8601d0e 100644
+--- a/libports/import-port.c
++++ b/libports/import-port.c
+@@ -48,8 +48,7 @@ ports_import_port (struct port_class *class, struct port_bucket *bucket,
+     return ENOMEM;
+   
+   pi->class = class;
+-  pi->refcnt = 1 + !!stat.mps_srights;
+-  pi->weakrefcnt = 0;
++  refcounts_init (&pi->refcounts, 1 + !!stat.mps_srights, 0);
+   pi->cancel_threshold = 0;
+   pi->mscount = stat.mps_mscount;
+   pi->flags = stat.mps_srights ? PORT_HAS_SENDRIGHTS : 0;
+diff --git a/libports/lookup-port.c b/libports/lookup-port.c
+index fbb13ef..1bf012f 100644
+--- a/libports/lookup-port.c
++++ b/libports/lookup-port.c
+@@ -28,7 +28,6 @@ ports_lookup_port (struct port_bucket *bucket,
+ {
+   struct port_info *pi;
+ 
+-  pthread_mutex_lock (&_ports_lock);
+   pthread_mutex_lock (&_ports_htable_lock);
+ 
+   pi = hurd_ihash_find (&_ports_htable, port);
+@@ -38,10 +37,9 @@ ports_lookup_port (struct port_bucket *bucket,
+     pi = 0;
+ 
+   if (pi)
+-    pi->refcnt++;
++    ports_port_ref (pi);
+ 
+   pthread_mutex_unlock (&_ports_htable_lock);
+-  pthread_mutex_unlock (&_ports_lock);
+-  
++
+   return pi;
+ }
+diff --git a/libports/port-deref-weak.c b/libports/port-deref-weak.c
+index beb4842..8432660 100644
+--- a/libports/port-deref-weak.c
++++ b/libports/port-deref-weak.c
+@@ -25,12 +25,8 @@ void
+ ports_port_deref_weak (void *portstruct)
+ {
+   struct port_info *pi = portstruct;
+-  
+-  pthread_mutex_lock (&_ports_lock);
+-  assert (pi->weakrefcnt);
+-  pi->weakrefcnt--;
+-  if (pi->refcnt == 0 && pi->weakrefcnt == 0)
++  struct references result;
++  refcounts_deref_weak (&pi->refcounts, &result);
++  if (result.hard == 0 && result.weak == 0)
+     _ports_complete_deallocate (pi);
+-  else
+-    pthread_mutex_unlock (&_ports_lock);
+ }
+diff --git a/libports/port-deref.c b/libports/port-deref.c
+index cf9b238..b97dd13 100644
+--- a/libports/port-deref.c
++++ b/libports/port-deref.c
+@@ -25,26 +25,24 @@ void
+ ports_port_deref (void *portstruct)
+ {
+   struct port_info *pi = portstruct;
+-  int trieddroppingweakrefs = 0;
+-
+- retry:
+-  
+-  pthread_mutex_lock (&_ports_lock);
+-  
+-  if (pi->refcnt == 1 && pi->weakrefcnt
+-      && pi->class->dropweak_routine && !trieddroppingweakrefs)
++  struct references result;
++
++  if (pi->class->dropweak_routine)
+     {
+-      pthread_mutex_unlock (&_ports_lock);
+-      (*pi->class->dropweak_routine) (pi);
+-      trieddroppingweakrefs = 1;
+-      goto retry;
++      /* If we need to call the dropweak routine, we need to hold one
++         reference while doing so.  We use a weak reference for this
++         purpose, which we acquire by demoting our hard reference to a
++         weak one.  */
++      refcounts_demote (&pi->refcounts, &result);
++
++      if (result.hard == 0 && result.weak > 1)
++        (*pi->class->dropweak_routine) (pi);
++
++      refcounts_deref_weak (&pi->refcounts, &result);
+     }
+-  
+-  assert (pi->refcnt);
++  else
++    refcounts_deref (&pi->refcounts, &result);
+ 
+-  pi->refcnt--;
+-  if (pi->refcnt == 0 && pi->weakrefcnt == 0)
++  if (result.hard == 0 && result.weak == 0)
+     _ports_complete_deallocate (pi);
+-  else
+-    pthread_mutex_unlock (&_ports_lock);
+ }
+diff --git a/libports/port-ref-weak.c b/libports/port-ref-weak.c
+index c7d3c69..e4b7fc8 100644
+--- a/libports/port-ref-weak.c
++++ b/libports/port-ref-weak.c
+@@ -25,9 +25,7 @@ void
+ ports_port_ref_weak (void *portstruct)
+ {
+   struct port_info *pi = portstruct;
+-  
+-  pthread_mutex_lock (&_ports_lock);
+-  assert (pi->refcnt || pi->weakrefcnt);
+-  pi->weakrefcnt++;
+-  pthread_mutex_unlock (&_ports_lock);
++  struct references result;
++  refcounts_ref_weak (&pi->refcounts, &result);
++  assert (result.hard > 0 || result.weak > 1);
+ }
+diff --git a/libports/port-ref.c b/libports/port-ref.c
+index 92b7118..761c50f 100644
+--- a/libports/port-ref.c
++++ b/libports/port-ref.c
+@@ -25,9 +25,7 @@ void
+ ports_port_ref (void *portstruct)
+ {
+   struct port_info *pi = portstruct;
+-  
+-  pthread_mutex_lock (&_ports_lock);
+-  assert (pi->refcnt || pi->weakrefcnt);
+-  pi->refcnt++;
+-  pthread_mutex_unlock (&_ports_lock);
++  struct references result;
++  refcounts_ref (&pi->refcounts, &result);
++  assert (result.hard > 1 || result.weak > 0);
+ }
+diff --git a/libports/ports.h b/libports/ports.h
+index c29d78a..3439443 100644
+--- a/libports/ports.h
++++ b/libports/ports.h
+@@ -27,6 +27,7 @@
+ #include <hurd/ihash.h>
+ #include <mach/notify.h>
+ #include <pthread.h>
++#include <refcount.h>
+ 
+ /* These are global values for common flags used in the various structures.
+    Not all of these are meaningful in all flag fields.  */
+@@ -39,8 +40,7 @@
+ struct port_info
+ {
+   struct port_class *class;
+-  int refcnt;
+-  int weakrefcnt;
++  refcounts_t refcounts;
+   mach_port_mscount_t mscount;
+   mach_msg_seqno_t cancel_threshold;
+   int flags;
+diff --git a/libports/reallocate-from-external.c b/libports/reallocate-from-external.c
+index 678b5d9..a912725 100644
+--- a/libports/reallocate-from-external.c
++++ b/libports/reallocate-from-external.c
+@@ -56,7 +56,7 @@ ports_reallocate_from_external (void *portstruct, mach_port_t receive)
+   else if (((pi->flags & PORT_HAS_SENDRIGHTS) == 0) && stat.mps_srights)
+     {
+       pi->flags |= PORT_HAS_SENDRIGHTS;
+-      pi->refcnt++;
++      refcounts_ref (&pi->refcounts, NULL);
+     }
+   
+   pi->port_right = receive;
+diff --git a/libports/transfer-right.c b/libports/transfer-right.c
+index 3f23d93..0e898ba 100644
+--- a/libports/transfer-right.c
++++ b/libports/transfer-right.c
+@@ -72,7 +72,7 @@ ports_transfer_right (void *tostruct,
+       else if (((topi->flags & PORT_HAS_SENDRIGHTS) == 0) && hassendrights)
+ 	{
+ 	  topi->flags |= PORT_HAS_SENDRIGHTS;
+-	  topi->refcnt++;
++	  refcounts_ref (&topi->refcounts, NULL);
+ 	}
+     }
+   
+diff --git a/utils/rpctrace.c b/utils/rpctrace.c
+index fc913e3..b11fea4 100644
+--- a/utils/rpctrace.c
++++ b/utils/rpctrace.c
+@@ -431,7 +431,9 @@ destroy_receiver_info (struct receiver_info *info)
+   while (send_wrapper)
+     {
+       struct sender_info *next = send_wrapper->next;
+-      assert (TRACED_INFO (send_wrapper)->pi.refcnt == 1);
++      assert (
++	refcounts_hard_references (&TRACED_INFO (send_wrapper)->pi.refcounts)
++	== 1);
+       /* Reset the receive_right of the send wrapper in advance to avoid
+        * destroy_receiver_info is called when the port info is destroyed. */
+       send_wrapper->receive_right = NULL;
+@@ -848,7 +850,11 @@ rewrite_right (mach_port_t *right, mach_msg_type_name_t *type,
+ 	    hurd_ihash_locp_remove (&traced_names, receiver_info->locp);
+ 
+ 	    send_wrapper2 = get_send_wrapper (receiver_info, dest, &rr);
+-	    assert (TRACED_INFO (send_wrapper2)->pi.refcnt == 1);
++	    assert (
++	      refcounts_hard_references (
++		&TRACED_INFO (send_wrapper2)->pi.refcounts)
++	      == 1);
++
+ 	    name = TRACED_INFO (send_wrapper2)->name;
+ 	    TRACED_INFO (send_wrapper2)->name = NULL;
+ 	    /* send_wrapper2 isn't destroyed normally, so we need to unlink
+-- 
+2.0.0.rc2
+
diff --git a/debian/patches/0009-ext2fs-use-a-seperate-lock-to-protect-nodehash.patch b/debian/patches/0009-ext2fs-use-a-seperate-lock-to-protect-nodehash.patch
new file mode 100644
index 00000000..38e796bd
--- /dev/null
+++ b/debian/patches/0009-ext2fs-use-a-seperate-lock-to-protect-nodehash.patch
@@ -0,0 +1,190 @@
+From cacd95554dd49069967018ed94f37a46d98c6085 Mon Sep 17 00:00:00 2001
+From: Justus Winter <4winter@informatik.uni-hamburg.de>
+Date: Tue, 13 May 2014 13:09:15 +0200
+Subject: [PATCH 09/14] ext2fs: use a seperate lock to protect nodehash
+
+Previously, ext2fs used diskfs_node_refcnt_lock to serialize access to
+the nodehash.
+
+Use a separate lock to protect nodehash.  Adjust the reference
+counting accordingly.  Every node in the nodehash carries a light
+reference.  When we are asked to give up that light reference, we
+reacquire our lock momentarily to check whether someone else
+reacquired a reference through the nodehash.
+
+* ext2fs/inode.c (nodehash_lock): New lock.
+(diskfs_cached_lookup): Use a separate lock to protect nodehash.
+Adjust the reference counting accordingly.
+(ifind): Likewise.
+(diskfs_node_iterate): Likewise.
+(diskfs_node_norefs): Move the code removing the node from nodehash...
+(diskfs_try_dropping_softrefs): ... here, where we check whether
+someone reacquired a reference, and if so hold on to our light
+reference.
+---
+ ext2fs/inode.c | 68 ++++++++++++++++++++++++++++++++++++++++++----------------
+ 1 file changed, 50 insertions(+), 18 deletions(-)
+
+diff --git a/ext2fs/inode.c b/ext2fs/inode.c
+index ed78265..aa070a2 100644
+--- a/ext2fs/inode.c
++++ b/ext2fs/inode.c
+@@ -46,8 +46,18 @@
+ #define	INOHASH(ino)	(((unsigned)(ino))%INOHSZ)
+ #endif
+ 
++/* The nodehash is a cache of nodes.
++
++   Access to nodehash and nodehash_nr_items is protected by
++   nodehash_lock.
++
++   Every node in the nodehash carries a light reference.  When we are
++   asked to give up that light reference, we reacquire our lock
++   momentarily to check whether someone else reacquired a reference
++   through the nodehash.  */
+ static struct node *nodehash[INOHSZ];
+ static size_t nodehash_nr_items;
++static pthread_mutex_t nodehash_lock = PTHREAD_MUTEX_INITIALIZER;
+ 
+ static error_t read_node (struct node *np);
+ 
+@@ -71,12 +81,12 @@ diskfs_cached_lookup (ino_t inum, struct node **npp)
+   struct node *np;
+   struct disknode *dn;
+ 
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
++  pthread_mutex_lock (&nodehash_lock);
+   for (np = nodehash[INOHASH(inum)]; np; np = np->dn->hnext)
+     if (np->cache_id == inum)
+       {
+-	np->references++;
+-	pthread_spin_unlock (&diskfs_node_refcnt_lock);
++	diskfs_nref (np);
++	pthread_mutex_unlock (&nodehash_lock);
+ 	pthread_mutex_lock (&np->lock);
+ 	*npp = np;
+ 	return 0;
+@@ -86,7 +96,7 @@ diskfs_cached_lookup (ino_t inum, struct node **npp)
+   dn = malloc (sizeof (struct disknode));
+   if (! dn)
+     {
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
++      pthread_mutex_unlock (&nodehash_lock);
+       return ENOMEM;
+     }
+   dn->dirents = 0;
+@@ -107,9 +117,10 @@ diskfs_cached_lookup (ino_t inum, struct node **npp)
+     dn->hnext->dn->hprevp = &dn->hnext;
+   dn->hprevp = &nodehash[INOHASH(inum)];
+   nodehash[INOHASH(inum)] = np;
++  diskfs_nref_light (np);
+   nodehash_nr_items += 1;
+ 
+-  pthread_spin_unlock (&diskfs_node_refcnt_lock);
++  pthread_mutex_unlock (&nodehash_lock);
+ 
+   /* Get the contents of NP off disk.  */
+   err = read_node (np);
+@@ -140,14 +151,13 @@ ifind (ino_t inum)
+ {
+   struct node *np;
+ 
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
++  pthread_mutex_lock (&nodehash_lock);
+   for (np = nodehash[INOHASH(inum)]; np; np = np->dn->hnext)
+     {
+       if (np->cache_id != inum)
+ 	continue;
+ 
+-      assert (np->references);
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
++      pthread_mutex_unlock (&nodehash_lock);
+       return np;
+     }
+   assert (0);
+@@ -158,11 +168,6 @@ ifind (ino_t inum)
+ void
+ diskfs_node_norefs (struct node *np)
+ {
+-  *np->dn->hprevp = np->dn->hnext;
+-  if (np->dn->hnext)
+-    np->dn->hnext->dn->hprevp = np->dn->hprevp;
+-  nodehash_nr_items -= 1;
+-
+   if (np->dn->dirents)
+     free (np->dn->dirents);
+   assert (!np->dn->pager);
+@@ -180,6 +185,33 @@ diskfs_node_norefs (struct node *np)
+ void
+ diskfs_try_dropping_softrefs (struct node *np)
+ {
++  pthread_mutex_lock (&nodehash_lock);
++  if (np->dn->hnext != NULL)
++    {
++      /* Check if someone reacquired a reference through the
++         nodehash.  */
++      unsigned int references;
++      pthread_spin_lock (&diskfs_node_refcnt_lock);
++      references = np->references;
++      pthread_spin_unlock (&diskfs_node_refcnt_lock);
++
++      if (references > 0)
++        {
++          /* A reference was reacquired through a hash table lookup.
++             It's fine, we didn't touch anything yet. */
++          pthread_mutex_unlock (&nodehash_lock);
++          return;
++        }
++
++      *np->dn->hprevp = np->dn->hnext;
++      if (np->dn->hnext)
++        np->dn->hnext->dn->hprevp = np->dn->hprevp;
++      np->dn->hnext = NULL;
++      nodehash_nr_items -= 1;
++      diskfs_nrele_light (np);
++    }
++  pthread_mutex_unlock (&nodehash_lock);
++
+   drop_pager_softrefs (np);
+ }
+ 
+@@ -556,12 +588,12 @@ diskfs_node_iterate (error_t (*fun)(struct node *))
+   size_t num_nodes;
+   struct node *node, **node_list, **p;
+ 
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
++  pthread_mutex_lock (&nodehash_lock);
+ 
+   /* We must copy everything from the hash table into another data structure
+      to avoid running into any problems with the hash-table being modified
+      during processing (normally we delegate access to hash-table with
+-     diskfs_node_refcnt_lock, but we can't hold this while locking the
++     nodehash_lock, but we can't hold this while locking the
+      individual node locks).  */
+   num_nodes = nodehash_nr_items;
+ 
+@@ -570,7 +602,7 @@ diskfs_node_iterate (error_t (*fun)(struct node *))
+   node_list = malloc (num_nodes * sizeof (struct node *));
+   if (node_list == NULL)
+     {
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
++      pthread_mutex_unlock (&nodehash_lock);
+       ext2_debug ("unable to allocate temporary node table");
+       return ENOMEM;
+     }
+@@ -580,10 +612,10 @@ diskfs_node_iterate (error_t (*fun)(struct node *))
+     for (node = nodehash[n]; node; node = node->dn->hnext)
+       {
+ 	*p++ = node;
+-	node->references++;
++	diskfs_nref (node);
+       }
+ 
+-  pthread_spin_unlock (&diskfs_node_refcnt_lock);
++  pthread_mutex_unlock (&nodehash_lock);
+ 
+   p = node_list;
+   while (num_nodes-- > 0)
+-- 
+2.0.0.rc2
+
diff --git a/debian/patches/0010-fatfs-use-a-seperate-lock-to-protect-nodehash.patch b/debian/patches/0010-fatfs-use-a-seperate-lock-to-protect-nodehash.patch
new file mode 100644
index 00000000..8614c7a6
--- /dev/null
+++ b/debian/patches/0010-fatfs-use-a-seperate-lock-to-protect-nodehash.patch
@@ -0,0 +1,222 @@
+From d387a9d5ce4974599e21ee623380c12e26164c0c Mon Sep 17 00:00:00 2001
+From: Justus Winter <4winter@informatik.uni-hamburg.de>
+Date: Tue, 13 May 2014 15:14:53 +0200
+Subject: [PATCH 10/14] fatfs: use a seperate lock to protect nodehash
+
+Previously, fatfs used diskfs_node_refcnt_lock to serialize access to
+the nodehash.
+
+Use a separate lock to protect nodehash.  Adjust the reference
+counting accordingly.  Every node in the nodehash carries a light
+reference.  When we are asked to give up that light reference, we
+reacquire our lock momentarily to check whether someone else
+reacquired a reference through the nodehash.
+
+* fatfs/inode.c (nodehash_lock): New lock.
+(diskfs_cached_lookup): Use a separate lock to protect nodehash.
+Adjust the reference counting accordingly.
+(ifind): Likewise.
+(diskfs_node_iterate): Likewise.
+(diskfs_node_norefs): Move the code removing the node from nodehash...
+(diskfs_try_dropping_softrefs): ... here, where we check whether
+someone reacquired a reference, and if so hold on to our light
+reference.
+---
+ fatfs/inode.c | 81 +++++++++++++++++++++++++++++++++++++++++------------------
+ 1 file changed, 57 insertions(+), 24 deletions(-)
+
+diff --git a/fatfs/inode.c b/fatfs/inode.c
+index ed6f3f0..8b3385b 100644
+--- a/fatfs/inode.c
++++ b/fatfs/inode.c
+@@ -44,8 +44,18 @@
+ #define INOHASH(ino)    (((unsigned)(ino))%INOHSZ)
+ #endif
+ 
++/* The nodehash is a cache of nodes.
++
++   Access to nodehash and nodehash_nr_items is protected by
++   nodehash_lock.
++
++   Every node in the nodehash carries a light reference.  When we are
++   asked to give up that light reference, we reacquire our lock
++   momentarily to check whether someone else reacquired a reference
++   through the nodehash.  */
+ static struct node *nodehash[INOHSZ];
+ static size_t nodehash_nr_items;
++static pthread_mutex_t nodehash_lock = PTHREAD_MUTEX_INITIALIZER;
+ 
+ static error_t read_node (struct node *np, vm_address_t buf);
+ 
+@@ -67,12 +77,12 @@ diskfs_cached_lookup (ino64_t inum, struct node **npp)
+   struct node *np;
+   struct disknode *dn;
+ 
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
++  pthread_mutex_lock (&nodehash_lock);
+   for (np = nodehash[INOHASH(inum)]; np; np = np->dn->hnext)
+     if (np->cache_id == inum)
+       {
+-        np->references++;
+-        pthread_spin_unlock (&diskfs_node_refcnt_lock);
++        diskfs_nref (np);
++        pthread_mutex_unlock (&nodehash_lock);
+         pthread_mutex_lock (&np->lock);
+         *npp = np;
+         return 0;
+@@ -82,7 +92,7 @@ diskfs_cached_lookup (ino64_t inum, struct node **npp)
+   dn = malloc (sizeof (struct disknode));
+   if (! dn)
+     {
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
++      pthread_mutex_unlock (&nodehash_lock);
+       return ENOMEM;
+     }
+   dn->pager = 0;
+@@ -107,10 +117,11 @@ diskfs_cached_lookup (ino64_t inum, struct node **npp)
+     dn->hnext->dn->hprevp = &dn->hnext;
+   dn->hprevp = &nodehash[INOHASH(inum)];
+   nodehash[INOHASH(inum)] = np;
++  diskfs_nref_light (np);
+   nodehash_nr_items += 1;
+ 
+-  pthread_spin_unlock (&diskfs_node_refcnt_lock);
+-  
++  pthread_mutex_unlock (&nodehash_lock);
++
+   /* Get the contents of NP off disk.  */
+   err = read_node (np, 0);
+ 
+@@ -133,12 +144,12 @@ diskfs_cached_lookup_in_dirbuf (int inum, struct node **npp, vm_address_t buf)
+   struct node *np;
+   struct disknode *dn;
+ 
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
++  pthread_mutex_lock (&nodehash_lock);
+   for (np = nodehash[INOHASH(inum)]; np; np = np->dn->hnext)
+     if (np->cache_id == inum)
+       {
+-        np->references++;
+-        pthread_spin_unlock (&diskfs_node_refcnt_lock);
++        diskfs_nref (np);
++        pthread_mutex_unlock (&nodehash_lock);
+         pthread_mutex_lock (&np->lock);
+         *npp = np;
+         return 0;
+@@ -148,7 +159,7 @@ diskfs_cached_lookup_in_dirbuf (int inum, struct node **npp, vm_address_t buf)
+   dn = malloc (sizeof (struct disknode));
+   if (! dn)
+     {
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
++      pthread_mutex_unlock (&nodehash_lock);
+       return ENOMEM;
+     }
+   dn->pager = 0;
+@@ -173,10 +184,11 @@ diskfs_cached_lookup_in_dirbuf (int inum, struct node **npp, vm_address_t buf)
+     dn->hnext->dn->hprevp = &dn->hnext;
+   dn->hprevp = &nodehash[INOHASH(inum)];
+   nodehash[INOHASH(inum)] = np;
++  diskfs_nref_light (np);
+   nodehash_nr_items += 1;
+ 
+-  pthread_spin_unlock (&diskfs_node_refcnt_lock);
+-  
++  pthread_mutex_unlock (&nodehash_lock);
++
+   /* Get the contents of NP off disk.  */
+   err = read_node (np, buf);
+ 
+@@ -196,14 +208,13 @@ ifind (ino_t inum)
+ {
+   struct node *np;
+ 
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
++  pthread_mutex_lock (&nodehash_lock);
+   for (np = nodehash[INOHASH(inum)]; np; np = np->dn->hnext)
+     {
+       if (np->cache_id != inum)
+         continue;
+ 
+-      assert (np->references);
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
++      pthread_mutex_unlock (&nodehash_lock);
+       return np;
+     }
+   assert (0);
+@@ -216,11 +227,6 @@ diskfs_node_norefs (struct node *np)
+ {
+   struct cluster_chain *last = np->dn->first;
+ 
+-  *np->dn->hprevp = np->dn->hnext;
+-  if (np->dn->hnext)
+-    np->dn->hnext->dn->hprevp = np->dn->hprevp;
+-  nodehash_nr_items -= 1;
+-
+   while (last)
+     {
+       struct cluster_chain *next = last->next;
+@@ -251,6 +257,33 @@ diskfs_node_norefs (struct node *np)
+ void
+ diskfs_try_dropping_softrefs (struct node *np)
+ {
++  pthread_mutex_lock (&nodehash_lock);
++  if (np->dn->hnext != NULL)
++    {
++      /* Check if someone reacquired a reference through the
++         nodehash.  */
++      unsigned int references;
++      pthread_spin_lock (&diskfs_node_refcnt_lock);
++      references = np->references;
++      pthread_spin_unlock (&diskfs_node_refcnt_lock);
++
++      if (references > 0)
++        {
++          /* A reference was reacquired through a hash table lookup.
++             It's fine, we didn't touch anything yet. */
++          pthread_mutex_unlock (&nodehash_lock);
++          return;
++        }
++
++      *np->dn->hprevp = np->dn->hnext;
++      if (np->dn->hnext)
++        np->dn->hnext->dn->hprevp = np->dn->hprevp;
++      np->dn->hnext = NULL;
++      nodehash_nr_items -= 1;
++      diskfs_nrele_light (np);
++    }
++  pthread_mutex_unlock (&nodehash_lock);
++
+   drop_pager_softrefs (np);
+ }
+ 
+@@ -554,12 +587,12 @@ diskfs_node_iterate (error_t (*fun)(struct node *))
+   size_t num_nodes;
+   struct node *node, **node_list, **p;
+ 
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
++  pthread_mutex_lock (&nodehash_lock);
+ 
+   /* We must copy everything from the hash table into another data structure
+      to avoid running into any problems with the hash-table being modified
+      during processing (normally we delegate access to hash-table with
+-     diskfs_node_refcnt_lock, but we can't hold this while locking the
++     nodehash_lock, but we can't hold this while locking the
+      individual node locks).  */
+ 
+   num_nodes = nodehash_nr_items;
+@@ -570,10 +603,10 @@ diskfs_node_iterate (error_t (*fun)(struct node *))
+     for (node = nodehash[n]; node; node = node->dn->hnext)
+       {
+         *p++ = node;
+-        node->references++;
++        diskfs_nref (node);
+       }
+ 
+-  pthread_spin_unlock (&diskfs_node_refcnt_lock);
++  pthread_mutex_unlock (&nodehash_lock);
+ 
+   p = node_list;
+   while (num_nodes-- > 0)
+-- 
+2.0.0.rc2
+
diff --git a/debian/patches/0011-isofs-use-a-seperate-lock-to-protect-node_cache.patch b/debian/patches/0011-isofs-use-a-seperate-lock-to-protect-node_cache.patch
new file mode 100644
index 00000000..c3717561
--- /dev/null
+++ b/debian/patches/0011-isofs-use-a-seperate-lock-to-protect-node_cache.patch
@@ -0,0 +1,222 @@
+From 9bc027b9b4cf6616eb9f25303390b4080a0bf53f Mon Sep 17 00:00:00 2001
+From: Justus Winter <4winter@informatik.uni-hamburg.de>
+Date: Tue, 13 May 2014 15:16:31 +0200
+Subject: [PATCH 11/14] isofs: use a seperate lock to protect node_cache
+
+Previously, isofs used diskfs_node_refcnt_lock to serialize access to
+the node_cache.
+
+Use a separate lock to protect node_cache.  Adjust the reference
+counting accordingly.  Every node in the node_cache carries a light
+reference.  When we are asked to give up that light reference, we
+reacquire our lock momentarily to check whether someone else
+reacquired a reference through the node_cache.
+
+* isofs/inode.c (node_cache_lock): New lock.
+(inode_cache_find): Use a separate lock to protect node_cache.
+Adjust the reference counting accordingly.
+(diskfs_cached_lookup): Likewise.
+(load_inode): Likewise.
+(cache_inode): Update comment accordingly.
+(diskfs_node_iterate): Likewise.
+(diskfs_node_norefs): Move the code removing the node from node_cache...
+(diskfs_try_dropping_softrefs): ... here, where we check whether
+someone reacquired a reference, and if so hold on to our light
+reference.
+---
+ isofs/inode.c | 72 +++++++++++++++++++++++++++++++++++++++++++----------------
+ 1 file changed, 53 insertions(+), 19 deletions(-)
+
+diff --git a/isofs/inode.c b/isofs/inode.c
+index cdc05ae..4f22086 100644
+--- a/isofs/inode.c
++++ b/isofs/inode.c
+@@ -48,9 +48,19 @@ struct node_cache
+   struct node *np;		/* if live */
+ };
+ 
++/* The node_cache is a cache of nodes.
++
++   Access to node_cache, node_cache_size, and node_cache_alloced is
++   protected by node_cache_lock.
++
++   Every node in the node_cache carries a light reference.  When we
++   are asked to give up that light reference, we reacquire our lock
++   momentarily to check whether someone else reacquired a reference
++   through the node_cache.  */
+ static int node_cache_size = 0;
+ static int node_cache_alloced = 0;
+ struct node_cache *node_cache = 0;
++static pthread_mutex_t node_cache_lock = PTHREAD_MUTEX_INITIALIZER;
+ 
+ /* Forward */
+ static error_t read_disknode (struct node *,
+@@ -58,7 +68,7 @@ static error_t read_disknode (struct node *,
+ 
+ 
+ /* See if node with identifier ID is in the cache.  If so, return it,
+-   with one additional reference. diskfs_node_refcnt_lock must be held
++   with one additional reference. node_cache_lock must be held
+    on entry to the call, and will be released iff the node was found
+    in the cache. */
+ void
+@@ -71,8 +81,8 @@ inode_cache_find (off_t id, struct node **npp)
+ 	&& node_cache[i].np)
+       {
+ 	*npp = node_cache[i].np;
+-	(*npp)->references++;
+-	pthread_spin_unlock (&diskfs_node_refcnt_lock);
++	diskfs_nref (*npp);
++	pthread_mutex_unlock (&node_cache_lock);
+ 	pthread_mutex_lock (&(*npp)->lock);
+ 	return;
+       }
+@@ -92,7 +102,7 @@ use_file_start_id (struct dirrect *record, struct rrip_lookup *rr)
+ }
+ 
+ /* Enter NP into the cache.  The directory entry we used is DR, the
+-   cached Rock-Ridge info RR. diskfs_node_refcnt_lock must be held. */
++   cached Rock-Ridge info RR. node_cache_lock must be held. */
+ void
+ cache_inode (struct node *np, struct dirrect *record,
+ 	    struct rrip_lookup *rr)
+@@ -155,7 +165,7 @@ diskfs_cached_lookup (ino_t id, struct node **npp)
+      to avoid presenting zero cache ID's. */
+   id--;
+ 
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
++  pthread_mutex_lock (&node_cache_lock);
+   assert (id < node_cache_size);
+ 
+   np = node_cache[id].np;
+@@ -174,7 +184,7 @@ diskfs_cached_lookup (ino_t id, struct node **npp)
+       dn = malloc (sizeof (struct disknode));
+       if (!dn)
+ 	{
+-	  pthread_spin_unlock (&diskfs_node_refcnt_lock);
++	  pthread_mutex_unlock (&node_cache_lock);
+ 	  release_rrip (&rr);
+ 	  return ENOMEM;
+ 	}
+@@ -185,16 +195,17 @@ diskfs_cached_lookup (ino_t id, struct node **npp)
+       if (!np)
+ 	{
+ 	  free (dn);
+-	  pthread_spin_unlock (&diskfs_node_refcnt_lock);
++	  pthread_mutex_unlock (&node_cache_lock);
+ 	  release_rrip (&rr);
+ 	  return ENOMEM;
+ 	}
+       np->cache_id = id + 1;	/* see above for rationale for increment */
+       pthread_mutex_lock (&np->lock);
+       c->np = np;
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
++      diskfs_nref_light (np);
++      pthread_mutex_unlock (&node_cache_lock);
+ 
+-      err = read_disknode (np, node_cache[id].dr, &rr);
++      err = read_disknode (np, dn->dr, &rr);
+       if (!err)
+ 	*npp = np;
+ 
+@@ -204,8 +215,8 @@ diskfs_cached_lookup (ino_t id, struct node **npp)
+     }
+ 
+ 
+-  np->references++;
+-  pthread_spin_unlock (&diskfs_node_refcnt_lock);
++  diskfs_nref (np);
++  pthread_mutex_unlock (&node_cache_lock);
+   pthread_mutex_lock (&np->lock);
+   *npp = np;
+   return 0;
+@@ -315,7 +326,7 @@ load_inode (struct node **npp, struct dirrect *record,
+   if (rr->valid & VALID_CL)
+     record = rr->realdirent;
+ 
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
++  pthread_mutex_lock (&node_cache_lock);
+ 
+   /* First check the cache */
+   if (use_file_start_id (record, rr))
+@@ -325,7 +336,7 @@ load_inode (struct node **npp, struct dirrect *record,
+ 
+   if (*npp)
+     {
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
++      pthread_mutex_unlock (&node_cache_lock);
+       return 0;
+     }
+ 
+@@ -333,7 +344,7 @@ load_inode (struct node **npp, struct dirrect *record,
+   dn = malloc (sizeof (struct disknode));
+   if (!dn)
+     {
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
++      pthread_mutex_unlock (&node_cache_lock);
+       return ENOMEM;
+     }
+   dn->fileinfo = 0;
+@@ -344,14 +355,14 @@ load_inode (struct node **npp, struct dirrect *record,
+   if (!np)
+     {
+       free (dn);
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
++      pthread_mutex_unlock (&node_cache_lock);
+       return ENOMEM;
+     }
+ 
+   pthread_mutex_lock (&np->lock);
+ 
+   cache_inode (np, record, rr);
+-  pthread_spin_unlock (&diskfs_node_refcnt_lock);
++  pthread_mutex_unlock (&node_cache_lock);
+ 
+   err = read_disknode (np, record, rr);
+   *npp = np;
+@@ -505,9 +516,6 @@ error_t (*diskfs_read_symlink_hook) (struct node *, char *)
+ void
+ diskfs_node_norefs (struct node *np)
+ {
+-  assert (node_cache[np->cache_id - 1].np == np);
+-  node_cache[np->cache_id - 1].np = 0;
+-
+   if (np->dn->translator)
+     free (np->dn->translator);
+ 
+@@ -521,6 +529,32 @@ diskfs_node_norefs (struct node *np)
+ void
+ diskfs_try_dropping_softrefs (struct node *np)
+ {
++  pthread_mutex_lock (&node_cache_lock);
++  if (np->cache_id != 0)
++    {
++      assert (node_cache[np->cache_id - 1].np == np);
++
++      /* Check if someone reacquired a reference through the
++         node_cache.  */
++      unsigned int references;
++      pthread_spin_lock (&diskfs_node_refcnt_lock);
++      references = np->references;
++      pthread_spin_unlock (&diskfs_node_refcnt_lock);
++
++      if (references > 0)
++        {
++          /* A reference was reacquired through a hash table lookup.
++             It's fine, we didn't touch anything yet. */
++          pthread_mutex_unlock (&node_cache_lock);
++          return;
++        }
++
++      node_cache[np->cache_id - 1].np = 0;
++      np->cache_id = 0;
++      diskfs_nrele_light (np);
++    }
++  pthread_mutex_unlock (&node_cache_lock);
++
+   drop_pager_softrefs (np);
+ }
+ 
+-- 
+2.0.0.rc2
+
diff --git a/debian/patches/0012-tmpfs-use-a-seperate-lock-to-protect-all_nodes.patch b/debian/patches/0012-tmpfs-use-a-seperate-lock-to-protect-all_nodes.patch
new file mode 100644
index 00000000..312fefc0
--- /dev/null
+++ b/debian/patches/0012-tmpfs-use-a-seperate-lock-to-protect-all_nodes.patch
@@ -0,0 +1,263 @@
+From 33b4c3d529229dcac21e4d49b9ae42d54718ca3b Mon Sep 17 00:00:00 2001
+From: Justus Winter <4winter@informatik.uni-hamburg.de>
+Date: Tue, 13 May 2014 15:35:42 +0200
+Subject: [PATCH 12/14] tmpfs: use a seperate lock to protect all_nodes
+
+Previously, tmpfs used diskfs_node_refcnt_lock to serialize access to
+the all_nodes and some other related global state related to memory
+consumption.
+
+Use a separate lock to protect all_nodes, and to the state related to
+memory consumption as this is updated during insertion and removal
+operations. Adjust the reference counting accordingly.  Every node in
+the all_nodes carries a light reference.  When we are asked to give up
+that light reference, we reacquire our lock momentarily to check
+whether someone else reacquired a reference through the all_nodes.
+
+* tmpfs/node.c (all_nodes_lock): New lock.
+(diskfs_alloc_node): Use a separate lock to protect all_nodes.
+Adjust the reference counting accordingly.
+(diskfs_free_node): Likewise.
+(diskfs_cached_lookup):Likewise.
+(diskfs_node_iterate): Likewise.
+(diskfs_node_norefs): Move the code removing the node from all_nodes...
+(diskfs_try_dropping_softrefs): ... here, where we check whether
+someone reacquired a reference, and if so hold on to our light
+reference.
+* tmpfs/tmpfs.c (diskfs_set_statfs): Use all_nodes_lock.
+* tmpfs/tmpfs.h (all_nodes_lock): New declaration.
+(adjust_used): Use all_nodes_lock.
+---
+ tmpfs/node.c  | 76 +++++++++++++++++++++++++++++++++++++++++++----------------
+ tmpfs/tmpfs.c |  4 ++--
+ tmpfs/tmpfs.h |  6 +++--
+ 3 files changed, 62 insertions(+), 24 deletions(-)
+
+diff --git a/tmpfs/node.c b/tmpfs/node.c
+index acc029a..74971ec 100644
+--- a/tmpfs/node.c
++++ b/tmpfs/node.c
+@@ -29,8 +29,18 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+ unsigned int num_files;
+ static unsigned int gen;
+ 
++/* all_nodes is a cache of nodes.
++
++   Access to all_nodes and all_nodes_nr_items is protected by
++   all_nodes_lock.
++
++   Every node in the all_nodes carries a light reference.  When we are
++   asked to give up that light reference, we reacquire our lock
++   momentarily to check whether someone else reacquired a reference
++   through the all_nodes.  */
+ struct node *all_nodes;
+ static size_t all_nodes_nr_items;
++pthread_mutex_t all_nodes_lock = PTHREAD_MUTEX_INITIALIZER;
+ 
+ error_t
+ diskfs_alloc_node (struct node *dp, mode_t mode, struct node **npp)
+@@ -40,18 +50,18 @@ diskfs_alloc_node (struct node *dp, mode_t mode, struct node **npp)
+   dn = calloc (1, sizeof *dn);
+   if (dn == 0)
+     return ENOSPC;
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
++  pthread_mutex_lock (&all_nodes_lock);
+   if (round_page (tmpfs_space_used + sizeof *dn) / vm_page_size
+       > tmpfs_page_limit)
+     {
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
++      pthread_mutex_unlock (&all_nodes_lock);
+       free (dn);
+       return ENOSPC;
+     }
+   dn->gen = gen++;
+   ++num_files;
+   tmpfs_space_used += sizeof *dn;
+-  pthread_spin_unlock (&diskfs_node_refcnt_lock);
++  pthread_mutex_unlock (&all_nodes_lock);
+ 
+   dn->type = IFTODT (mode & S_IFMT);
+   return diskfs_cached_lookup ((ino_t) (uintptr_t) dn, npp);
+@@ -75,15 +85,18 @@ diskfs_free_node (struct node *np, mode_t mode)
+       free (np->dn->u.lnk);
+       break;
+     }
++
++  pthread_mutex_lock (&all_nodes_lock);
+   *np->dn->hprevp = np->dn->hnext;
+   if (np->dn->hnext != 0)
+     np->dn->hnext->dn->hprevp = np->dn->hprevp;
+   all_nodes_nr_items -= 1;
+-  free (np->dn);
+-  np->dn = 0;
+-
+   --num_files;
+   tmpfs_space_used -= sizeof *np->dn;
++  pthread_mutex_unlock (&all_nodes_lock);
++
++  free (np->dn);
++  np->dn = 0;
+ }
+ 
+ void
+@@ -117,14 +130,6 @@ diskfs_node_norefs (struct node *np)
+ 	  np->dn->u.chr = np->dn_stat.st_rdev;
+ 	  break;
+ 	}
+-
+-      /* Remove this node from the cache list rooted at `all_nodes'.  */
+-      *np->dn->hprevp = np->dn->hnext;
+-      if (np->dn->hnext != 0)
+-	np->dn->hnext->dn->hprevp = np->dn->hprevp;
+-      all_nodes_nr_items -= 1;
+-      np->dn->hnext = 0;
+-      np->dn->hprevp = 0;
+     }
+ 
+   free (np);
+@@ -167,11 +172,14 @@ diskfs_cached_lookup (ino_t inum, struct node **npp)
+ 
+   assert (npp);
+ 
++  pthread_mutex_lock (&all_nodes_lock);
++
+   if (dn->hprevp != 0)		/* There is already a node.  */
+     {
+       np = *dn->hprevp;
+       assert (np->dn == dn);
+       assert (*dn->hprevp == np);
++      pthread_mutex_unlock (&all_nodes_lock);
+ 
+       diskfs_nref (np);
+     }
+@@ -183,14 +191,14 @@ diskfs_cached_lookup (ino_t inum, struct node **npp)
+       np = diskfs_make_node (dn);
+       np->cache_id = (ino_t) (uintptr_t) dn;
+ 
+-      pthread_spin_lock (&diskfs_node_refcnt_lock);
+       dn->hnext = all_nodes;
+       if (dn->hnext)
+ 	dn->hnext->dn->hprevp = &dn->hnext;
+       dn->hprevp = &all_nodes;
+       all_nodes = np;
+       all_nodes_nr_items += 1;
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
++      diskfs_nref_light (np);
++      pthread_mutex_unlock (&all_nodes_lock);
+ 
+       st = &np->dn_stat;
+       memset (st, 0, sizeof *st);
+@@ -229,12 +237,12 @@ diskfs_node_iterate (error_t (*fun) (struct node *))
+   size_t num_nodes;
+   struct node *node, **node_list, **p;
+ 
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
++  pthread_mutex_lock (&all_nodes_lock);
+ 
+   /* We must copy everything from the hash table into another data structure
+      to avoid running into any problems with the hash-table being modified
+      during processing (normally we delegate access to hash-table with
+-     diskfs_node_refcnt_lock, but we can't hold this while locking the
++     all_nodes_lock, but we can't hold this while locking the
+      individual node locks).  */
+ 
+   num_nodes = all_nodes_nr_items;
+@@ -243,10 +251,10 @@ diskfs_node_iterate (error_t (*fun) (struct node *))
+   for (node = all_nodes; node != 0; node = node->dn->hnext)
+     {
+       *p++ = node;
+-      node->references++;
++      diskfs_nref (node);
+     }
+ 
+-  pthread_spin_unlock (&diskfs_node_refcnt_lock);
++  pthread_mutex_unlock (&all_nodes_lock);
+ 
+   p = node_list;
+   while (num_nodes-- > 0)
+@@ -272,6 +280,34 @@ diskfs_node_iterate (error_t (*fun) (struct node *))
+ void
+ diskfs_try_dropping_softrefs (struct node *np)
+ {
++  pthread_mutex_lock (&all_nodes_lock);
++  if (np->dn->hnext != NULL)
++    {
++      /* Check if someone reacquired a reference through the
++         all_nodes.  */
++      unsigned int references;
++      pthread_spin_lock (&diskfs_node_refcnt_lock);
++      references = np->references;
++      pthread_spin_unlock (&diskfs_node_refcnt_lock);
++
++      if (references > 0)
++        {
++          /* A reference was reacquired through a hash table lookup.
++             It's fine, we didn't touch anything yet. */
++          pthread_mutex_unlock (&all_nodes_lock);
++          return;
++        }
++
++      /* Remove this node from the cache list rooted at `all_nodes'.  */
++      *np->dn->hprevp = np->dn->hnext;
++      if (np->dn->hnext != 0)
++	np->dn->hnext->dn->hprevp = np->dn->hprevp;
++      all_nodes_nr_items -= 1;
++      np->dn->hnext = NULL;
++      np->dn->hprevp = NULL;
++      diskfs_nrele_light (np);
++    }
++  pthread_mutex_unlock (&all_nodes_lock);
+ }
+ 
+ /* The user must define this funcction.  Node NP has some light
+diff --git a/tmpfs/tmpfs.c b/tmpfs/tmpfs.c
+index a45d343..024b818 100644
+--- a/tmpfs/tmpfs.c
++++ b/tmpfs/tmpfs.c
+@@ -67,10 +67,10 @@ diskfs_set_statfs (struct statfs *st)
+   st->f_bsize = vm_page_size;
+   st->f_blocks = tmpfs_page_limit;
+ 
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
++  pthread_mutex_lock (&all_nodes_lock);
+   st->f_files = num_files;
+   pages = round_page (tmpfs_space_used) / vm_page_size;
+-  pthread_spin_unlock (&diskfs_node_refcnt_lock);
++  pthread_mutex_unlock (&all_nodes_lock);
+ 
+   st->f_bfree = pages < tmpfs_page_limit ? tmpfs_page_limit - pages : 0;
+   st->f_bavail = st->f_bfree;
+diff --git a/tmpfs/tmpfs.h b/tmpfs/tmpfs.h
+index b3c636d..187249e 100644
+--- a/tmpfs/tmpfs.h
++++ b/tmpfs/tmpfs.h
+@@ -24,6 +24,7 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+ #include <sys/types.h>
+ #include <dirent.h>
+ #include <stdint.h>
++#include <pthread.h>
+ 
+ struct disknode
+ {
+@@ -71,15 +72,16 @@ struct tmpfs_dirent
+ 
+ extern unsigned int num_files;
+ extern off_t tmpfs_page_limit, tmpfs_space_used;
++extern pthread_mutex_t all_nodes_lock;
+ 
+ extern mach_port_t default_pager;
+ 
+ static inline void
+ adjust_used (off_t change)
+ {
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
++  pthread_mutex_lock (&all_nodes_lock);
+   tmpfs_space_used += change;
+-  pthread_spin_unlock (&diskfs_node_refcnt_lock);
++  pthread_mutex_unlock (&all_nodes_lock);
+ }
+ 
+ #endif
+-- 
+2.0.0.rc2
+
diff --git a/debian/patches/0013-libdiskfs-lock-less-reference-counting-of-nodes.patch b/debian/patches/0013-libdiskfs-lock-less-reference-counting-of-nodes.patch
new file mode 100644
index 00000000..ec071d36
--- /dev/null
+++ b/debian/patches/0013-libdiskfs-lock-less-reference-counting-of-nodes.patch
@@ -0,0 +1,531 @@
+From 9e27bff0a5b59d5179781d94a673c71467db5e86 Mon Sep 17 00:00:00 2001
+From: Justus Winter <4winter@informatik.uni-hamburg.de>
+Date: Wed, 14 May 2014 11:19:35 +0200
+Subject: [PATCH 13/14] libdiskfs: lock-less reference counting of nodes
+
+* libdiskfs/diskfs.h (struct node): Use refcounts_t for reference counting.
+(diskfs_node_refcnt_lock): Remove.
+(diskfs_node_norefs,diskfs_drop_node): Change comments accordingly.
+* libdiskfs/init-init.c: Likewise.
+* libdiskfs/node-drop.c: Likewise.
+* libdiskfs/node-make.c: Likewise.
+* libdiskfs/node-nput.c: Likewise.
+* libdiskfs/node-nputl.c: Likewise.
+* libdiskfs/node-nref.c: Likewise.
+* libdiskfs/node-nrefl.c: Likewise.
+* libdiskfs/node-nrele.c: Likewise.
+* libdiskfs/node-nrelel.c: Likewise.
+* ext2fs/inode.c: Likewise.
+* fatfs/inode.c: Likewise.
+* isofs/inode.c: Likewise.
+* tmpfs/node.c: Likewise.
+* doc/hurd.texi: Likewise.
+---
+ doc/hurd.texi           | 11 ++--------
+ ext2fs/inode.c          |  9 +++------
+ fatfs/inode.c           | 21 ++++++-------------
+ isofs/inode.c           |  9 +++------
+ libdiskfs/diskfs.h      | 12 ++++-------
+ libdiskfs/init-init.c   |  2 --
+ libdiskfs/node-drop.c   |  9 +++------
+ libdiskfs/node-make.c   |  3 +--
+ libdiskfs/node-nput.c   | 54 +++++++++++++++++++------------------------------
+ libdiskfs/node-nputl.c  | 12 ++++-------
+ libdiskfs/node-nref.c   | 10 ++++-----
+ libdiskfs/node-nrefl.c  |  6 +++---
+ libdiskfs/node-nrele.c  | 48 +++++++++++++++++++++----------------------
+ libdiskfs/node-nrelel.c |  9 +++------
+ tmpfs/node.c            |  9 +++------
+ 15 files changed, 83 insertions(+), 141 deletions(-)
+
+diff --git a/doc/hurd.texi b/doc/hurd.texi
+index 07ddfb4..6cafdb9 100644
+--- a/doc/hurd.texi
++++ b/doc/hurd.texi
+@@ -3780,10 +3780,6 @@ new thread and (eventually) get rid of the old one; the old thread won't
+ do any more syncs, regardless.
+ @end deftypefun
+ 
+-@deftypevar spin_lock_t diskfs_node_refcnt_lock
+-Pager reference count lock.
+-@end deftypevar
+-
+ @deftypevar int diskfs_readonly
+ Set to zero if the filesystem is currently writable.
+ @end deftypevar
+@@ -3818,9 +3814,7 @@ Every file or directory is a diskfs @dfn{node}.  The following functions
+ help your diskfs callbacks manage nodes and their references:
+ 
+ @deftypefun void diskfs_drop_node (@w{struct node *@var{np}})
+-Node @var{np} now has no more references; clean all state.  The
+-@var{diskfs_node_refcnt_lock} must be held, and will be released upon
+-return.  @var{np} must be locked.
++Node @var{np} now has no more references; clean all state.
+ @end deftypefun
+ 
+ @deftypefun void diskfs_node_update (@w{struct node *@var{np}}, @w{int @var{wait}})
+@@ -4236,14 +4230,13 @@ without real users.
+ @deftypefun void diskfs_try_dropping_softrefs (@w{struct node *@var{np}})
+ Node @var{np} has some light references, but has just lost its last hard
+ references.  Take steps so that if any light references can be freed,
+-they are.  Both @var{diskfs_node_refcnt_lock} and @var{np} are locked.
++they are.  @var{np} is locked.
+ This function will be called after @code{diskfs_lost_hardrefs}.
+ @end deftypefun
+ 
+ @deftypefun void diskfs_node_norefs (@w{struct node *@var{np}})
+ Node @var{np} has no more references; free local state, including
+ @code{*@var{np}} if it shouldn't be retained.
+-@var{diskfs_node_refcnt_lock} is held.
+ @end deftypefun
+ 
+ @deftypefun error_t diskfs_set_hypermetadata (@w{int @var{wait}}, @w{int @var{clean}})
+diff --git a/ext2fs/inode.c b/ext2fs/inode.c
+index aa070a2..7ec343f 100644
+--- a/ext2fs/inode.c
++++ b/ext2fs/inode.c
+@@ -190,12 +190,9 @@ diskfs_try_dropping_softrefs (struct node *np)
+     {
+       /* Check if someone reacquired a reference through the
+          nodehash.  */
+-      unsigned int references;
+-      pthread_spin_lock (&diskfs_node_refcnt_lock);
+-      references = np->references;
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
+-
+-      if (references > 0)
++      struct references result;
++      refcounts_references (&np->refcounts, &result);
++      if (result.hard > 0 || result.weak > 1)
+         {
+           /* A reference was reacquired through a hash table lookup.
+              It's fine, we didn't touch anything yet. */
+diff --git a/fatfs/inode.c b/fatfs/inode.c
+index 8b3385b..d5750b4 100644
+--- a/fatfs/inode.c
++++ b/fatfs/inode.c
+@@ -237,14 +237,8 @@ diskfs_node_norefs (struct node *np)
+   if (np->dn->translator)
+     free (np->dn->translator);
+ 
+-  /* It is safe to unlock diskfs_node_refcnt_lock here for a while because
+-     all references to the node have been deleted.  */
+   if (np->dn->dirnode)
+-    {
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
+-      diskfs_nrele (np->dn->dirnode);
+-      pthread_spin_lock (&diskfs_node_refcnt_lock);
+-    }
++    diskfs_nrele (np->dn->dirnode);
+ 
+   assert (!np->dn->pager);
+ 
+@@ -262,12 +256,9 @@ diskfs_try_dropping_softrefs (struct node *np)
+     {
+       /* Check if someone reacquired a reference through the
+          nodehash.  */
+-      unsigned int references;
+-      pthread_spin_lock (&diskfs_node_refcnt_lock);
+-      references = np->references;
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
+-
+-      if (references > 0)
++      struct references result;
++      refcounts_references (&np->refcounts, &result);
++      if (result.hard > 0 || result.weak > 1)
+         {
+           /* A reference was reacquired through a hash table lookup.
+              It's fine, we didn't touch anything yet. */
+@@ -372,7 +363,7 @@ read_node (struct node *np, vm_address_t buf)
+   /* Files in fatfs depend on the directory that hold the file.  */
+   np->dn->dirnode = dp;
+   if (dp)
+-    dp->references++;
++    refcounts_ref (&dp->refcounts, NULL);
+ 
+   pthread_rwlock_rdlock (&np->dn->dirent_lock);
+ 
+@@ -814,7 +805,7 @@ diskfs_alloc_node (struct node *dir, mode_t mode, struct node **node)
+ 
+   /* FIXME: We know that readnode couldn't put this in.  */
+   np->dn->dirnode = dir;
+-  dir->references++;
++  refcounts_ref (&dir->refcounts, NULL);
+ 
+   *node = np;
+   return 0;
+diff --git a/isofs/inode.c b/isofs/inode.c
+index 4f22086..b36a289 100644
+--- a/isofs/inode.c
++++ b/isofs/inode.c
+@@ -536,12 +536,9 @@ diskfs_try_dropping_softrefs (struct node *np)
+ 
+       /* Check if someone reacquired a reference through the
+          node_cache.  */
+-      unsigned int references;
+-      pthread_spin_lock (&diskfs_node_refcnt_lock);
+-      references = np->references;
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
+-
+-      if (references > 0)
++      struct references result;
++      refcounts_references (&np->refcounts, &result);
++      if (result.hard > 0 || result.weak > 1)
+         {
+           /* A reference was reacquired through a hash table lookup.
+              It's fine, we didn't touch anything yet. */
+diff --git a/libdiskfs/diskfs.h b/libdiskfs/diskfs.h
+index acd1910..e10e75e 100644
+--- a/libdiskfs/diskfs.h
++++ b/libdiskfs/diskfs.h
+@@ -96,8 +96,7 @@ struct node
+ 
+   pthread_mutex_t lock;
+ 
+-  int references;		/* hard references */
+-  int light_references;		/* light references */
++  refcounts_t refcounts;
+ 
+   mach_port_t sockaddr;		/* address for S_IFSOCK shortcut */
+ 
+@@ -201,8 +200,6 @@ extern volatile struct mapped_time_value *diskfs_mtime;
+    be done by format independent code. */
+ extern int diskfs_synchronous;
+ 
+-extern pthread_spinlock_t diskfs_node_refcnt_lock;
+-
+ extern int pager_port_type;
+ 
+ /* Whether the filesystem is currently writable or not. */
+@@ -451,7 +448,7 @@ error_t diskfs_alloc_node (struct node *dp, mode_t mode, struct node **np);
+ void diskfs_free_node (struct node *np, mode_t mode);
+ 
+ /* Node NP has no more references; free local state, including *NP
+-   if it isn't to be retained.  diskfs_node_refcnt_lock is held. */
++   if it isn't to be retained.  */
+ void diskfs_node_norefs (struct node *np);
+ 
+ /* The user must define this function.  Node NP has some light
+@@ -614,9 +611,8 @@ void diskfs_spawn_first_thread (ports_demuxer_type demuxer);
+    diskfs_init_completed once it has a valid proc and auth port. */
+ void diskfs_start_bootstrap ();
+ 
+-/* Node NP now has no more references; clean all state.  The
+-   _diskfs_node_refcnt_lock must be held, and will be released
+-   upon return.  NP must be locked.  */
++/* Node NP now has no more references; clean all state.  NP must be
++   locked.  */
+ void diskfs_drop_node (struct node *np);
+ 
+ /* Set on disk fields from NP->dn_stat; update ctime, atime, and mtime
+diff --git a/libdiskfs/init-init.c b/libdiskfs/init-init.c
+index 35be7ed..976b4e8 100644
+--- a/libdiskfs/init-init.c
++++ b/libdiskfs/init-init.c
+@@ -37,8 +37,6 @@ int _diskfs_noatime;
+ 
+ struct hurd_port _diskfs_exec_portcell;
+ 
+-pthread_spinlock_t diskfs_node_refcnt_lock = PTHREAD_SPINLOCK_INITIALIZER;
+-
+ pthread_spinlock_t _diskfs_control_lock = PTHREAD_SPINLOCK_INITIALIZER;
+ int _diskfs_ncontrol_ports;
+ 
+diff --git a/libdiskfs/node-drop.c b/libdiskfs/node-drop.c
+index 83eb590..fab3cfa 100644
+--- a/libdiskfs/node-drop.c
++++ b/libdiskfs/node-drop.c
+@@ -31,9 +31,8 @@ free_modreqs (struct modreq *mr)
+ }
+ 
+ 
+-/* Node NP now has no more references; clean all state.  The
+-   diskfs_node_refcnt_lock must be held, and will be released
+-   upon return.  NP must be locked.  */
++/* Node NP now has no more references; clean all state.  NP must be
++   locked.  */
+ void
+ diskfs_drop_node (struct node *np)
+ {
+@@ -60,8 +59,7 @@ diskfs_drop_node (struct node *np)
+ 	     and an nput.  The next time through, this routine
+ 	     will notice that the size is zero, and not have to
+ 	     do anything. */
+-	  np->references++;
+-	  pthread_spin_unlock (&diskfs_node_refcnt_lock);
++	  refcounts_ref (&np->refcounts, NULL);
+ 	  diskfs_truncate (np, 0);
+ 	  
+ 	  /* Force allocsize to zero; if truncate consistently fails this
+@@ -94,5 +92,4 @@ diskfs_drop_node (struct node *np)
+   assert (!np->sockaddr);
+ 
+   diskfs_node_norefs (np);
+-  pthread_spin_unlock (&diskfs_node_refcnt_lock);
+ }
+diff --git a/libdiskfs/node-make.c b/libdiskfs/node-make.c
+index ff0cc0d..c7ca3b0 100644
+--- a/libdiskfs/node-make.c
++++ b/libdiskfs/node-make.c
+@@ -29,8 +29,7 @@ init_node (struct node *np, struct disknode *dn)
+   np->dn_stat_dirty = 0;
+ 
+   pthread_mutex_init (&np->lock, NULL);
+-  np->references = 1;
+-  np->light_references = 0;
++  refcounts_init (&np->refcounts, 1, 0);
+   np->owner = 0;
+   np->sockaddr = MACH_PORT_NULL;
+ 
+diff --git a/libdiskfs/node-nput.c b/libdiskfs/node-nput.c
+index 5043ad1..2935ae2 100644
+--- a/libdiskfs/node-nput.c
++++ b/libdiskfs/node-nput.c
+@@ -26,56 +26,44 @@
+ void
+ diskfs_nput (struct node *np)
+ {
+-  int tried_drop_softrefs = 0;
++  struct references result;
+ 
+- loop:
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
+-  assert (np->references);
+-  np->references--;
+-  if (np->references + np->light_references == 0)
+-    diskfs_drop_node (np);
+-  else if (np->references == 0 && !tried_drop_softrefs)
+-    {
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
++  /* While we call the diskfs_try_dropping_softrefs, we need to hold
++     one reference.  We use a weak reference for this purpose, which
++     we acquire by demoting our hard reference to a weak one.  */
++  refcounts_demote (&np->refcounts, &result);
+ 
++  if (result.hard == 0)
++    {
+       /* This is our cue that something akin to "last process closes file"
+ 	 in the POSIX.1 sense happened, so make sure any pending node time
+ 	 updates now happen in a timely fashion.  */
+       diskfs_set_node_times (np);
+-
+       diskfs_lost_hardrefs (np);
+       if (!np->dn_stat.st_nlink)
+ 	{
+-	  /* There are no links.  If there are soft references that
+-	     can be dropped, we can't let them postpone deallocation.
+-	     So attempt to drop them.  But that's a user-supplied
+-	     routine, which might result in further recursive calls to
+-	     the ref-counting system.  So we have to reacquire our
+-	     reference around the call to forestall disaster. */
+-	  pthread_spin_lock (&diskfs_node_refcnt_lock);
+-	  np->references++;
+-	  pthread_spin_unlock (&diskfs_node_refcnt_lock);
+-
+ 	  if (np->sockaddr != MACH_PORT_NULL)
+ 	    {
+ 	      mach_port_deallocate (mach_task_self (), np->sockaddr);
+ 	      np->sockaddr = MACH_PORT_NULL;
+ 	    }
+ 
++	  /* There are no links.  If there are soft references that
++	     can be dropped, we can't let them postpone deallocation.
++	     So attempt to drop them.  But that's a user-supplied
++	     routine, which might result in further recursive calls to
++	     the ref-counting system.  This is not a problem, as we
++	     hold a weak reference ourselves. */
+ 	  diskfs_try_dropping_softrefs (np);
+-
+-	  /* But there's no value in looping forever in this
+-	     routine; only try to drop soft refs once. */
+-	  tried_drop_softrefs = 1;
+-
+-	  /* Now we can drop the reference back... */
+-	  goto loop;
+ 	}
+       pthread_mutex_unlock (&np->lock);
+     }
+-  else
+-    {
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
+-      pthread_mutex_unlock (&np->lock);
+-    }
++
++  /* Finally get rid of our reference.  */
++  refcounts_deref_weak (&np->refcounts, &result);
++
++  if (result.hard == 0 && result.weak == 0)
++    diskfs_drop_node (np);
++
++  pthread_mutex_unlock (&np->lock);
+ }
+diff --git a/libdiskfs/node-nputl.c b/libdiskfs/node-nputl.c
+index 1959665..8dac16e 100644
+--- a/libdiskfs/node-nputl.c
++++ b/libdiskfs/node-nputl.c
+@@ -25,14 +25,10 @@
+ void
+ diskfs_nput_light (struct node *np)
+ {
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
+-  assert (np->light_references);
+-  np->light_references--;
+-  if (np->references + np->light_references == 0)
++  struct references result;
++  refcounts_deref_weak (&np->refcounts, &result);
++  if (result.hard == 0 && result.weak == 0)
+     diskfs_drop_node (np);
+   else
+-    {
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
+-      pthread_mutex_unlock (&np->lock);
+-    }
++    pthread_mutex_unlock (&np->lock);
+ }
+diff --git a/libdiskfs/node-nref.c b/libdiskfs/node-nref.c
+index 13cea05..89ffa4f 100644
+--- a/libdiskfs/node-nref.c
++++ b/libdiskfs/node-nref.c
+@@ -26,12 +26,10 @@
+ void
+ diskfs_nref (struct node *np)
+ {
+-  int new_hardref;
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
+-  np->references++;
+-  new_hardref = (np->references == 1);
+-  pthread_spin_unlock (&diskfs_node_refcnt_lock);
+-  if (new_hardref)
++  struct references result;
++  refcounts_ref (&np->refcounts, &result);
++  assert (result.hard > 1 || result.weak > 0);
++  if (result.hard == 1)
+     {
+       pthread_mutex_lock (&np->lock);
+       diskfs_new_hardrefs (np);
+diff --git a/libdiskfs/node-nrefl.c b/libdiskfs/node-nrefl.c
+index 9692247..b7af409 100644
+--- a/libdiskfs/node-nrefl.c
++++ b/libdiskfs/node-nrefl.c
+@@ -24,7 +24,7 @@
+ void
+ diskfs_nref_light (struct node *np)
+ {
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
+-  np->light_references++;
+-  pthread_spin_unlock (&diskfs_node_refcnt_lock);
++  struct references result;
++  refcounts_ref_weak (&np->refcounts, &result);
++  assert (result.hard > 0 || result.weak > 1);
+ }
+diff --git a/libdiskfs/node-nrele.c b/libdiskfs/node-nrele.c
+index cc68089..d962846 100644
+--- a/libdiskfs/node-nrele.c
++++ b/libdiskfs/node-nrele.c
+@@ -28,38 +28,36 @@
+ void
+ diskfs_nrele (struct node *np)
+ {
+-  int tried_drop_softrefs = 0;
++  struct references result;
+ 
+- loop:
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
+-  assert (np->references);
+-  np->references--;
+-  if (np->references + np->light_references == 0)
+-    {
+-      pthread_mutex_lock (&np->lock);
+-      diskfs_drop_node (np);
+-    }
+-  else if (np->references == 0)
++  /* While we call the diskfs_try_dropping_softrefs, we need to hold
++     one reference.  We use a weak reference for this purpose, which
++     we acquire by demoting our hard reference to a weak one.  */
++  refcounts_demote (&np->refcounts, &result);
++
++  if (result.hard == 0)
+     {
+       pthread_mutex_lock (&np->lock);
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
+       diskfs_lost_hardrefs (np);
+-      if (!np->dn_stat.st_nlink && !tried_drop_softrefs)
++      if (!np->dn_stat.st_nlink)
+ 	{
+-	  /* Same issue here as in nput; see that for explanation */
+-	  pthread_spin_lock (&diskfs_node_refcnt_lock);
+-	  np->references++;
+-	  pthread_spin_unlock (&diskfs_node_refcnt_lock);
+-
++	  /* There are no links.  If there are soft references that
++	     can be dropped, we can't let them postpone deallocation.
++	     So attempt to drop them.  But that's a user-supplied
++	     routine, which might result in further recursive calls to
++	     the ref-counting system.  This is not a problem, as we
++	     hold a weak reference ourselves. */
+ 	  diskfs_try_dropping_softrefs (np);
+-	  tried_drop_softrefs = 1;
+-
+-	  /* Now we can drop the reference back... */
+-	  pthread_mutex_unlock (&np->lock);
+-	  goto loop;
+ 	}
+       pthread_mutex_unlock (&np->lock);
+     }
+-  else
+-    pthread_spin_unlock (&diskfs_node_refcnt_lock);
++
++  /* Finally get rid of our reference.  */
++  refcounts_deref_weak (&np->refcounts, &result);
++
++  if (result.hard == 0 && result.weak == 0)
++    {
++      pthread_mutex_lock (&np->lock);
++      diskfs_drop_node (np);
++    }
+ }
+diff --git a/libdiskfs/node-nrelel.c b/libdiskfs/node-nrelel.c
+index ee53b22..dc4f920 100644
+--- a/libdiskfs/node-nrelel.c
++++ b/libdiskfs/node-nrelel.c
+@@ -26,14 +26,11 @@
+ void
+ diskfs_nrele_light (struct node *np)
+ {
+-  pthread_spin_lock (&diskfs_node_refcnt_lock);
+-  assert (np->light_references);
+-  np->light_references--;
+-  if (np->references + np->light_references == 0)
++  struct references result;
++  refcounts_deref_weak (&np->refcounts, &result);
++  if (result.hard == 0 && result.weak == 0)
+     {
+       pthread_mutex_lock (&np->lock);
+       diskfs_drop_node (np);
+     }
+-  else
+-    pthread_spin_unlock (&diskfs_node_refcnt_lock);
+ }
+diff --git a/tmpfs/node.c b/tmpfs/node.c
+index 74971ec..275bb3c 100644
+--- a/tmpfs/node.c
++++ b/tmpfs/node.c
+@@ -285,12 +285,9 @@ diskfs_try_dropping_softrefs (struct node *np)
+     {
+       /* Check if someone reacquired a reference through the
+          all_nodes.  */
+-      unsigned int references;
+-      pthread_spin_lock (&diskfs_node_refcnt_lock);
+-      references = np->references;
+-      pthread_spin_unlock (&diskfs_node_refcnt_lock);
+-
+-      if (references > 0)
++      struct references result;
++      refcounts_references (&np->refcounts, &result);
++      if (result.hard > 0 || result.weak > 1)
+         {
+           /* A reference was reacquired through a hash table lookup.
+              It's fine, we didn't touch anything yet. */
+-- 
+2.0.0.rc2
+
diff --git a/debian/patches/0014-ext2fs-use-librdxtree-for-the-nodehash.patch b/debian/patches/0014-ext2fs-use-librdxtree-for-the-nodehash.patch
new file mode 100644
index 00000000..fb3ca46e
--- /dev/null
+++ b/debian/patches/0014-ext2fs-use-librdxtree-for-the-nodehash.patch
@@ -0,0 +1,308 @@
+From a02756d13bc21f7a12573a71b38a08ef7b02e8a6 Mon Sep 17 00:00:00 2001
+From: Justus Winter <4winter@informatik.uni-hamburg.de>
+Date: Wed, 14 May 2014 15:30:19 +0200
+Subject: [PATCH 14/14] ext2fs: use librdxtree for the nodehash
+
+Previously, a lookup of a node through nodehash took O(N / INOHSZ).
+With INOHSZ being a constant (512) this is linear in N.  Use a radix
+tree instead, which gives us a lookup in time linear with the size of
+keys.
+
+* ext2fs/inode.c (INOHSZ, INOHASH): Remove.
+(nodehash): Use a radix tree.
+(inode_init): Remove.
+(diskfs_cached_lookup): Adjust accordingly.
+(ifind, diskfs_try_dropping_softrefs, diskfs_node_iterate): Likewise.
+* ext2fs/ext2fs.h (struct disknode): Remove list pointers.
+* ext2fs/ext2fs.c (main): Drop inode_init.
+---
+ ext2fs/Makefile |   2 +-
+ ext2fs/ext2fs.c |   2 -
+ ext2fs/ext2fs.h |   4 +-
+ ext2fs/inode.c  | 121 +++++++++++++++++++++-----------------------------------
+ 4 files changed, 48 insertions(+), 81 deletions(-)
+
+diff --git a/ext2fs/Makefile b/ext2fs/Makefile
+index 8d2e68c..f93d696 100644
+--- a/ext2fs/Makefile
++++ b/ext2fs/Makefile
+@@ -23,7 +23,7 @@ target = ext2fs
+ SRCS = balloc.c dir.c ext2fs.c getblk.c hyper.c ialloc.c \
+        inode.c pager.c pokel.c truncate.c storeinfo.c msg.c xinl.c
+ OBJS = $(SRCS:.c=.o)
+-HURDLIBS = diskfs pager iohelp fshelp store ports ihash shouldbeinlibc
++HURDLIBS = diskfs pager iohelp fshelp store ports ihash rdxtree shouldbeinlibc
+ OTHERLIBS = -lpthread $(and $(HAVE_LIBBZ2),-lbz2) $(and $(HAVE_LIBZ),-lz)
+ 
+ include ../Makeconf
+diff --git a/ext2fs/ext2fs.c b/ext2fs/ext2fs.c
+index 128b6ed..0409dfb 100644
+--- a/ext2fs/ext2fs.c
++++ b/ext2fs/ext2fs.c
+@@ -185,8 +185,6 @@ main (int argc, char **argv)
+ 
+   map_hypermetadata ();
+ 
+-  inode_init ();
+-
+   /* Set diskfs_root_node to the root inode. */
+   err = diskfs_cached_lookup (EXT2_ROOT_INO, &diskfs_root_node);
+   if (err)
+diff --git a/ext2fs/ext2fs.h b/ext2fs/ext2fs.h
+index 3422af2..8eaa846 100644
+--- a/ext2fs/ext2fs.h
++++ b/ext2fs/ext2fs.h
+@@ -26,6 +26,7 @@
+ #include <hurd/store.h>
+ #include <hurd/diskfs.h>
+ #include <hurd/ihash.h>
++#include <hurd/rdxtree.h>
+ #include <assert.h>
+ #include <pthread.h>
+ #include <sys/mman.h>
+@@ -159,9 +160,6 @@ struct disknode
+      each DIRBLKSIZE piece of the directory. */
+   int *dirents;
+ 
+-  /* Links on hash list. */
+-  struct node *hnext, **hprevp;
+-
+   /* Lock to lock while fiddling with this inode's block allocation info.  */
+   pthread_rwlock_t alloc_lock;
+ 
+diff --git a/ext2fs/inode.c b/ext2fs/inode.c
+index 7ec343f..fea39ae 100644
+--- a/ext2fs/inode.c
++++ b/ext2fs/inode.c
+@@ -20,6 +20,7 @@
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+ 
+ #include "ext2fs.h"
++#include <stddef.h>
+ #include <string.h>
+ #include <unistd.h>
+ #include <stdio.h>
+@@ -39,13 +40,6 @@
+ #define UF_IMMUTABLE 0
+ #endif
+ 
+-#define	INOHSZ	512
+-#if	((INOHSZ&(INOHSZ-1)) == 0)
+-#define	INOHASH(ino)	((ino)&(INOHSZ-1))
+-#else
+-#define	INOHASH(ino)	(((unsigned)(ino))%INOHSZ)
+-#endif
+-
+ /* The nodehash is a cache of nodes.
+ 
+    Access to nodehash and nodehash_nr_items is protected by
+@@ -55,23 +49,14 @@
+    asked to give up that light reference, we reacquire our lock
+    momentarily to check whether someone else reacquired a reference
+    through the nodehash.  */
+-static struct node *nodehash[INOHSZ];
++static struct rdxtree nodecache = RDXTREE_INITIALIZER;
+ static size_t nodehash_nr_items;
+-static pthread_mutex_t nodehash_lock = PTHREAD_MUTEX_INITIALIZER;
++static pthread_mutex_t nodecache_lock = PTHREAD_RWLOCK_INITIALIZER;
+ 
+ static error_t read_node (struct node *np);
+ 
+ pthread_spinlock_t generation_lock = PTHREAD_SPINLOCK_INITIALIZER;
+ 
+-/* Initialize the inode hash table. */
+-void
+-inode_init ()
+-{
+-  int n;
+-  for (n = 0; n < INOHSZ; n++)
+-    nodehash[n] = 0;
+-}
+-
+ /* Fetch inode INUM, set *NPP to the node structure;
+    gain one user reference and lock the node.  */
+ error_t
+@@ -81,46 +66,40 @@ diskfs_cached_lookup (ino_t inum, struct node **npp)
+   struct node *np;
+   struct disknode *dn;
+ 
+-  pthread_mutex_lock (&nodehash_lock);
+-  for (np = nodehash[INOHASH(inum)]; np; np = np->dn->hnext)
+-    if (np->cache_id == inum)
+-      {
+-	diskfs_nref (np);
+-	pthread_mutex_unlock (&nodehash_lock);
+-	pthread_mutex_lock (&np->lock);
+-	*npp = np;
+-	return 0;
+-      }
+-
+-  /* Format specific data for the new node.  */
+-  dn = malloc (sizeof (struct disknode));
+-  if (! dn)
++  pthread_rwlock_rdlock (&nodecache_lock);
++  np = rdxtree_lookup (&nodecache, inum);
++  if (np != NULL)
++    {
++      diskfs_nref (np);
++      pthread_rwlock_unlock (&nodecache_lock);
++      pthread_mutex_lock (&np->lock);
++      *npp = np;
++      return 0;
++    }
++  pthread_rwlock_unlock (&nodecache_lock);
++
++  /* Create the new node.  */
++  np = diskfs_make_node_alloc (sizeof *dn);
++  if (np == NULL)
+     {
+-      pthread_mutex_unlock (&nodehash_lock);
++      pthread_mutex_unlock (&nodecache_lock);
+       return ENOMEM;
+     }
++  np->cache_id = inum;
++  dn = diskfs_node_disknode (np);
+   dn->dirents = 0;
+   dn->dir_idx = 0;
+   dn->pager = 0;
+   pthread_rwlock_init (&dn->alloc_lock, NULL);
+   pokel_init (&dn->indir_pokel, diskfs_disk_pager, disk_cache);
+-
+-  /* Create the new node.  */
+-  np = diskfs_make_node (dn);
+-  np->cache_id = inum;
+-
+   pthread_mutex_lock (&np->lock);
+ 
+   /* Put NP in NODEHASH.  */
+-  dn->hnext = nodehash[INOHASH(inum)];
+-  if (dn->hnext)
+-    dn->hnext->dn->hprevp = &dn->hnext;
+-  dn->hprevp = &nodehash[INOHASH(inum)];
+-  nodehash[INOHASH(inum)] = np;
+   diskfs_nref_light (np);
++  pthread_rwlock_wrlock (&nodecache_lock);
++  rdxtree_insert (&nodecache, inum, np);
+   nodehash_nr_items += 1;
+-
+-  pthread_mutex_unlock (&nodehash_lock);
++  pthread_rwlock_unlock (&nodecache_lock);
+ 
+   /* Get the contents of NP off disk.  */
+   err = read_node (np);
+@@ -151,16 +130,12 @@ ifind (ino_t inum)
+ {
+   struct node *np;
+ 
+-  pthread_mutex_lock (&nodehash_lock);
+-  for (np = nodehash[INOHASH(inum)]; np; np = np->dn->hnext)
+-    {
+-      if (np->cache_id != inum)
+-	continue;
++  pthread_rwlock_rdlock (&nodecache_lock);
++  np = rdxtree_lookup (&nodecache, inum);
++  pthread_rwlock_unlock (&nodecache_lock);
+ 
+-      pthread_mutex_unlock (&nodehash_lock);
+-      return np;
+-    }
+-  assert (0);
++  assert (np);
++  return np;
+ }
+ 
+ /* The last reference to a node has gone away; drop
+@@ -176,7 +151,6 @@ diskfs_node_norefs (struct node *np)
+   pokel_inherit (&global_pokel, &np->dn->indir_pokel);
+   pokel_finalize (&np->dn->indir_pokel);
+ 
+-  free (np->dn);
+   free (np);
+ }
+ 
+@@ -185,8 +159,8 @@ diskfs_node_norefs (struct node *np)
+ void
+ diskfs_try_dropping_softrefs (struct node *np)
+ {
+-  pthread_mutex_lock (&nodehash_lock);
+-  if (np->dn->hnext != NULL)
++  pthread_rwlock_wrlock (&nodecache_lock);
++  if (np->cache_id != 0)
+     {
+       /* Check if someone reacquired a reference through the
+          nodehash.  */
+@@ -196,18 +170,16 @@ diskfs_try_dropping_softrefs (struct node *np)
+         {
+           /* A reference was reacquired through a hash table lookup.
+              It's fine, we didn't touch anything yet. */
+-          pthread_mutex_unlock (&nodehash_lock);
++          pthread_rwlock_unlock (&nodecache_lock);
+           return;
+         }
+ 
+-      *np->dn->hprevp = np->dn->hnext;
+-      if (np->dn->hnext)
+-        np->dn->hnext->dn->hprevp = np->dn->hprevp;
+-      np->dn->hnext = NULL;
++      rdxtree_remove (&nodecache, np->cache_id);
+       nodehash_nr_items -= 1;
++      np->cache_id = 0;
+       diskfs_nrele_light (np);
+     }
+-  pthread_mutex_unlock (&nodehash_lock);
++  pthread_rwlock_unlock (&nodecache_lock);
+ 
+   drop_pager_softrefs (np);
+ }
+@@ -581,16 +553,16 @@ error_t
+ diskfs_node_iterate (error_t (*fun)(struct node *))
+ {
+   error_t err = 0;
+-  int n;
++  struct rdxtree_iter iter;
+   size_t num_nodes;
+   struct node *node, **node_list, **p;
+ 
+-  pthread_mutex_lock (&nodehash_lock);
++  pthread_rwlock_rdlock (&nodecache_lock);
+ 
+   /* We must copy everything from the hash table into another data structure
+      to avoid running into any problems with the hash-table being modified
+      during processing (normally we delegate access to hash-table with
+-     nodehash_lock, but we can't hold this while locking the
++     nodecache_lock, but we can't hold this while locking the
+      individual node locks).  */
+   num_nodes = nodehash_nr_items;
+ 
+@@ -599,20 +571,19 @@ diskfs_node_iterate (error_t (*fun)(struct node *))
+   node_list = malloc (num_nodes * sizeof (struct node *));
+   if (node_list == NULL)
+     {
+-      pthread_mutex_unlock (&nodehash_lock);
++      pthread_rwlock_unlock (&nodecache_lock);
+       ext2_debug ("unable to allocate temporary node table");
+       return ENOMEM;
+     }
+ 
+   p = node_list;
+-  for (n = 0; n < INOHSZ; n++)
+-    for (node = nodehash[n]; node; node = node->dn->hnext)
+-      {
+-	*p++ = node;
+-	diskfs_nref (node);
+-      }
+-
+-  pthread_mutex_unlock (&nodehash_lock);
++  rdxtree_for_each (&nodecache, &iter, node)
++    {
++      *p++ = node;
++      diskfs_nref (node);
++    }
++
++  pthread_rwlock_unlock (&nodecache_lock);
+ 
+   p = node_list;
+   while (num_nodes-- > 0)
+-- 
+2.0.0.rc2
+
diff --git a/debian/patches/series b/debian/patches/series
index 6f1da5d7..fb6f1325 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -42,3 +42,17 @@ mach-defpager-protected-payload.patch
 
 #0010-libihash-make-the-locp-offset-mechanism-more-flexibl.patch
 #0011-trans-fakeroot-use-the-indirection-mechanism-for-loc.patch
+0001-include-add-lock-less-reference-counting-primitives.patch
+0002-trans-fakeroot-override-fshelp_isowner.patch
+0003-librbtree-add-a-red-black-tree-implementation.patch
+0004-librdxtree-add-a-radix-tree-implementation.patch
+0005-libdiskfs-lock-less-reference-counting-for-peropen-o.patch
+0006-libtrivfs-lock-less-reference-counting-for-trivfs_pe.patch
+0007-libports-use-a-single-hash-table.patch
+0008-libports-lock-less-reference-counting-for-port_info-.patch
+0009-ext2fs-use-a-seperate-lock-to-protect-nodehash.patch
+0010-fatfs-use-a-seperate-lock-to-protect-nodehash.patch
+0011-isofs-use-a-seperate-lock-to-protect-node_cache.patch
+0012-tmpfs-use-a-seperate-lock-to-protect-all_nodes.patch
+0013-libdiskfs-lock-less-reference-counting-of-nodes.patch
+0014-ext2fs-use-librdxtree-for-the-nodehash.patch