new libports patch series

6 files changed, 1464 insertions, 0 deletions

diff --git a/debian/patches/0001-libports-use-a-single-hash-table.patch b/debian/patches/0001-libports-use-a-single-hash-table.patch
new file mode 100644
index 00000000..492a4cab
--- /dev/null
+++ b/debian/patches/0001-libports-use-a-single-hash-table.patch
@@ -0,0 +1,619 @@
+From 27741dca90e3a6070727fffc22d3105653a33747 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 1/5] 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.
+
+The 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           | 21 +++++++++++++++------
+ libports/claim-right.c              |  6 ++++--
+ libports/class-iterate.c            | 10 +---------
+ libports/complete-deallocate.c      |  8 +++-----
+ libports/create-bucket.c            |  7 -------
+ libports/create-class.c             |  1 -
+ libports/create-internal.c          |  9 +++------
+ libports/destroy-right.c            |  6 +++---
+ libports/import-port.c              |  9 +++------
+ libports/inhibit-all-rpcs.c         | 27 +++++++++++++--------------
+ libports/inhibit-bucket-rpcs.c      |  7 +++++--
+ libports/inhibit-class-rpcs.c       | 27 ++++++++++++++++++---------
+ libports/init.c                     |  7 ++++++-
+ libports/lookup-port.c              | 21 ++++++++-------------
+ libports/ports.h                    | 11 ++++++-----
+ libports/reallocate-from-external.c | 16 ++++++++++------
+ libports/reallocate-port.c          | 10 +++++++---
+ libports/transfer-right.c           | 20 +++++++++++++-------
+ 18 files changed, 118 insertions(+), 105 deletions(-)
+
+diff --git a/libports/bucket-iterate.c b/libports/bucket-iterate.c
+index babc204..d5f590e 100644
+--- a/libports/bucket-iterate.c
++++ b/libports/bucket-iterate.c
+@@ -36,35 +36,44 @@ _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 (_ports_htable.nr_items == 0)
+     {
+-      pthread_mutex_unlock (&_ports_lock);
++      pthread_mutex_unlock (&_ports_htable_lock);
+       return 0;
+     }
+ 
+-  nr_items = bucket->htable.nr_items;
++  nr_items = _ports_htable.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 (&_ports_htable, arg)
+     {
+       struct port_info *const pi = arg;
+ 
+-      if (class == 0 || pi->class == class)
++      if ((bucket == NULL || pi->bucket == bucket)
++          && (class == NULL || pi->class == class))
+ 	{
+ 	  pi->refcnt++;
+ 	  p[n] = pi;
+ 	  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.  */
+diff --git a/libports/claim-right.c b/libports/claim-right.c
+index 4851ea3..f453a82 100644
+--- a/libports/claim-right.c
++++ b/libports/claim-right.c
+@@ -34,10 +34,12 @@ ports_claim_right (void *portstruct)
+   if (ret == MACH_PORT_NULL)
+     return ret;
+ 
+-  pthread_mutex_lock (&_ports_lock);
+-  hurd_ihash_locp_remove (&pi->bucket->htable, pi->hentry);
++  pthread_mutex_lock (&_ports_htable_lock);
++  hurd_ihash_locp_remove (&_ports_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..5cfcfc8 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 (NULL, class, fun);
+ }
+diff --git a/libports/complete-deallocate.c b/libports/complete-deallocate.c
+index 8ce095b..1371d92 100644
+--- a/libports/complete-deallocate.c
++++ b/libports/complete-deallocate.c
+@@ -29,16 +29,14 @@ _ports_complete_deallocate (struct port_info *pi)
+ 
+   if (pi->port_right)
+     {
+-      hurd_ihash_locp_remove (&pi->bucket->htable, pi->hentry);
++      pthread_mutex_lock (&_ports_htable_lock);
++      hurd_ihash_locp_remove (&_ports_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..9f6821d 100644
+--- a/libports/create-bucket.c
++++ b/libports/create-bucket.c
+@@ -46,13 +46,6 @@ ports_create_bucket ()
+       return NULL;
+     }
+ 
+-  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..e773dd6 100644
+--- a/libports/create-internal.c
++++ b/libports/create-internal.c
+@@ -81,15 +81,12 @@ _ports_create_port_internal (struct port_class *class,
+       goto loop;
+     }
+ 
+-  err = hurd_ihash_add (&bucket->htable, port, pi);
++  pthread_mutex_lock (&_ports_htable_lock);
++  err = hurd_ihash_add (&_ports_htable, port, pi);
++  pthread_mutex_unlock (&_ports_htable_lock);
+   if (err)
+     goto lose;
+ 
+-  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..6ba7302 100644
+--- a/libports/destroy-right.c
++++ b/libports/destroy-right.c
+@@ -30,12 +30,12 @@ ports_destroy_right (void *portstruct)
+ 
+   if (pi->port_right != MACH_PORT_NULL)
+     {
+-      pthread_mutex_lock (&_ports_lock);
+-      hurd_ihash_locp_remove (&pi->bucket->htable, pi->hentry);
++      pthread_mutex_lock (&_ports_htable_lock);
++      hurd_ihash_locp_remove (&_ports_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..d0b2ea4 100644
+--- a/libports/import-port.c
++++ b/libports/import-port.c
+@@ -75,15 +75,12 @@ ports_import_port (struct port_class *class, struct port_bucket *bucket,
+       goto loop;
+     }
+ 
+-  err = hurd_ihash_add (&bucket->htable, port, pi);
++  pthread_mutex_lock (&_ports_htable_lock);
++  err = hurd_ihash_add (&_ports_htable, port, pi);
++  pthread_mutex_unlock (&_ports_htable_lock);
+   if (err)
+     goto lose;
+ 
+-  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..ed3e29d 100644
+--- a/libports/inhibit-bucket-rpcs.c
++++ b/libports/inhibit-bucket-rpcs.c
+@@ -35,10 +35,13 @@ ports_inhibit_bucket_rpcs (struct port_bucket *bucket)
+     {
+       int this_one = 0;
+ 
+-      HURD_IHASH_ITERATE (&bucket->htable, portstruct)
++      pthread_mutex_lock (&_ports_htable_lock);
++      HURD_IHASH_ITERATE (&_ports_htable, portstruct)
+ 	{
+ 	  struct rpc_info *rpc;
+ 	  struct port_info *pi = portstruct;
++	  if (pi->bucket != bucket)
++	    continue;
+ 
+ 	  for (rpc = pi->current_rpcs; rpc; rpc = rpc->next)
+ 	    {
+@@ -49,7 +52,7 @@ 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..8fbc7e8 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, hentry));
++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..9c5f14d 100644
+--- a/libports/ports.h
++++ b/libports/ports.h
+@@ -48,7 +48,6 @@ 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 */
+ };
+ typedef struct port_info *port_info_t;
+ 
+@@ -61,11 +60,9 @@ typedef struct port_info *port_info_t;
+ struct port_bucket
+ {
+   mach_port_t portset;
+-  struct hurd_ihash htable;
+   int rpcs;
+   int flags;
+   int count;
+-  struct port_bucket *next;
+ };
+ /* FLAGS above are the following: */
+ #define PORT_BUCKET_INHIBITED	PORTS_INHIBITED
+@@ -78,7 +75,6 @@ struct port_class
+ {
+   int flags;
+   int rpcs;
+-  struct port_info *ports;
+   int count;
+   void (*clean_routine) (void *);
+   void (*dropweak_routine) (void *);
+@@ -402,7 +398,12 @@ 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..bbcf9ba 100644
+--- a/libports/reallocate-from-external.c
++++ b/libports/reallocate-from-external.c
+@@ -43,8 +43,10 @@ ports_reallocate_from_external (void *portstruct, mach_port_t receive)
+ 			    MACH_PORT_RIGHT_RECEIVE, -1);
+   assert_perror (err);
+ 
+-  hurd_ihash_locp_remove (&pi->bucket->htable, pi->hentry);
+-  
++  pthread_mutex_lock (&_ports_htable_lock);
++  hurd_ihash_locp_remove (&_ports_htable, pi->hentry);
++  pthread_mutex_unlock (&_ports_htable_lock);
++
+   if ((pi->flags & PORT_HAS_SENDRIGHTS) && !stat.mps_srights)
+     {
+       dropref = 1;
+@@ -59,11 +61,13 @@ 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);
+-  assert_perror (err);
++
++  pthread_mutex_lock (&_ports_htable_lock);
++  err = hurd_ihash_add (&_ports_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..99c4041 100644
+--- a/libports/reallocate-port.c
++++ b/libports/reallocate-port.c
+@@ -36,7 +36,9 @@ ports_reallocate_port (void *portstruct)
+ 			    MACH_PORT_RIGHT_RECEIVE, -1);
+   assert_perror (err);
+ 
+-  hurd_ihash_locp_remove (&pi->bucket->htable, pi->hentry);
++  pthread_mutex_lock (&_ports_htable_lock);
++  hurd_ihash_locp_remove (&_ports_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 +50,11 @@ ports_reallocate_port (void *portstruct)
+     }
+   pi->cancel_threshold = 0;
+   pi->mscount = 0;
+-  err = hurd_ihash_add (&pi->bucket->htable, pi->port_right, pi);
+-  assert_perror (err);
++  pthread_mutex_lock (&_ports_htable_lock);
++  err = hurd_ihash_add (&_ports_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..5a7653d 100644
+--- a/libports/transfer-right.c
++++ b/libports/transfer-right.c
+@@ -41,7 +41,9 @@ ports_transfer_right (void *tostruct,
+   port = frompi->port_right;
+   if (port != MACH_PORT_NULL)
+     {
+-      hurd_ihash_locp_remove (&frompi->bucket->htable, frompi->hentry);
++      pthread_mutex_lock (&_ports_htable_lock);
++      hurd_ihash_locp_remove (&_ports_htable, frompi->hentry);
++      pthread_mutex_unlock (&_ports_htable_lock);
+       frompi->port_right = MACH_PORT_NULL;
+       if (frompi->flags & PORT_HAS_SENDRIGHTS)
+ 	{
+@@ -54,7 +56,9 @@ ports_transfer_right (void *tostruct,
+   /* Destroy the existing right in TOPI. */
+   if (topi->port_right != MACH_PORT_NULL)
+     {
+-      hurd_ihash_locp_remove (&topi->bucket->htable, topi->hentry);
++      pthread_mutex_lock (&_ports_htable_lock);
++      hurd_ihash_locp_remove (&_ports_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 +78,14 @@ 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)
+     {
+-      err = hurd_ihash_add (&topi->bucket->htable, port, topi);
++      pthread_mutex_lock (&_ports_htable_lock);
++      err = hurd_ihash_add (&_ports_htable, port, topi);
++      pthread_mutex_unlock (&_ports_htable_lock);
+       assert_perror (err);
+       if (topi->bucket != frompi->bucket)
+         {
+@@ -86,9 +94,7 @@ 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.rc0
+
diff --git a/debian/patches/0002-include-add-lock-less-reference-counting-primitives.patch b/debian/patches/0002-include-add-lock-less-reference-counting-primitives.patch
new file mode 100644
index 00000000..145d340e
--- /dev/null
+++ b/debian/patches/0002-include-add-lock-less-reference-counting-primitives.patch
@@ -0,0 +1,175 @@
+From 8faea20349dc1d8cfd0117d28a3f1271083192d0 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 2/5] include: add lock-less reference counting primitives
+
+* include/refcount.h: New file.
+---
+ include/refcount.h | 155 +++++++++++++++++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 155 insertions(+)
+ create mode 100644 include/refcount.h
+
+diff --git a/include/refcount.h b/include/refcount.h
+new file mode 100644
+index 0000000..946938a
+--- /dev/null
++++ b/include/refcount.h
+@@ -0,0 +1,155 @@
++/* 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 <stdint.h>
++
++/* Simple reference counting.  */
++
++/* An opaque type.  You must not access these values directly.  */
++typedef uint32_t refcount_t;
++
++/* Initialize REF with REFERENCES.  */
++static inline void
++refcount_init (refcount_t *ref, uint32_t references)
++{
++  *ref = references;
++}
++
++/* Increment REF.  Return the result of the operation.  */
++static inline uint32_t
++refcount_ref (refcount_t *ref)
++{
++  return __atomic_add_fetch (ref, 1, __ATOMIC_RELAXED);
++}
++
++/* Decrement REF.  Return the result of the operation.  */
++static inline uint32_t
++refcount_deref (refcount_t *ref)
++{
++  return __atomic_sub_fetch (ref, 1, __ATOMIC_RELAXED);
++}
++
++/* Return REF.  */
++static inline uint32_t
++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 uint64_t refcounts_t;
++
++/* Instead, the functions manipulating refcounts_t values write the
++   results into this kind of objects.  */
++struct references {
++  uint32_t hard;
++  uint32_t weak;
++};
++
++union _references {
++  struct references refs;
++  refcounts_t rc;
++};
++
++/* Initialize REF with HARD and WEAK references.  */
++static inline void
++refcounts_init (refcounts_t *ref, uint32_t hard, uint32_t weak)
++{
++  ((union _references *) ref)->refs =
++    (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.  */
++static inline void
++refcounts_ref (refcounts_t *ref, struct references *result)
++{
++  const union _references op = { .refs = { .hard = 1 } };
++  refcounts_t r = __atomic_add_fetch (ref, op.rc, __ATOMIC_RELAXED);
++  if (result)
++    ((union _references *) result)->rc = r;
++}
++
++/* Decrement the hard reference count of REF.  If RESULT is not NULL,
++   the result of the operation is written there.  */
++static inline void
++refcounts_deref (refcounts_t *ref, struct references *result)
++{
++  const union _references op = { .refs = { .hard = 1 } };
++  refcounts_t r = __atomic_sub_fetch (ref, op.rc, __ATOMIC_RELAXED);
++  if (result)
++    ((union _references *) result)->rc = r;
++}
++
++/* Increment the weak reference count of REF.  If RESULT is not NULL,
++   the result of the operation is written there.  */
++static inline void
++refcounts_ref_weak (refcounts_t *ref, struct references *result)
++{
++  const union _references op = { .refs = { .weak = 1 } };
++  refcounts_t r = __atomic_add_fetch (ref, op.rc, __ATOMIC_RELAXED);
++  if (result)
++    ((union _references *) result)->rc = r;
++}
++
++/* Decrement the weak reference count of REF.  If RESULT is not NULL,
++   the result of the operation is written there.  */
++static inline void
++refcounts_deref_weak (refcounts_t *ref, struct references *result)
++{
++  const union _references op = { .refs = { .weak = 1 } };
++  refcounts_t r = __atomic_sub_fetch (ref, op.rc, __ATOMIC_RELAXED);
++  if (result)
++    ((union _references *) result)->rc = r;
++}
++
++/* Store the current reference counts of REF in RESULT.  */
++static inline void
++refcounts_references (refcounts_t *ref, struct references *result)
++{
++  ((union _references *) result)->rc =
++    __atomic_load_n (ref, __ATOMIC_RELAXED);
++}
++
++/* Return the hard reference count of REF.  */
++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.  */
++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.rc0
+
diff --git a/debian/patches/0003-libports-lock-less-reference-counting-for-port_info-.patch b/debian/patches/0003-libports-lock-less-reference-counting-for-port_info-.patch
new file mode 100644
index 00000000..9c5754ed
--- /dev/null
+++ b/debian/patches/0003-libports-lock-less-reference-counting-for-port_info-.patch
@@ -0,0 +1,346 @@
+From 2644982be8c7d742f7d5be02ab9211c72bd356d5 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 3/5] libports: lock-less reference counting for port_info
+ objects
+
+* libports/refcount.h: New file with reference counting primitives.
+* 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      | 15 +++++++++++++++
+ 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, 58 insertions(+), 53 deletions(-)
+
+diff --git a/libports/bucket-iterate.c b/libports/bucket-iterate.c
+index d5f590e..2a2b2b6 100644
+--- a/libports/bucket-iterate.c
++++ b/libports/bucket-iterate.c
+@@ -35,7 +35,6 @@ _ports_bucket_class_iterate (struct port_bucket *bucket,
+   size_t i, n, nr_items;
+   error_t err;
+ 
+-  pthread_mutex_lock (&_ports_lock);
+   pthread_mutex_lock (&_ports_htable_lock);
+ 
+   if (_ports_htable.nr_items == 0)
+@@ -60,13 +59,12 @@ _ports_bucket_class_iterate (struct port_bucket *bucket,
+       if ((bucket == NULL || pi->bucket == bucket)
+           && (class == NULL || 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 1371d92..6c9074a 100644
+--- a/libports/complete-deallocate.c
++++ b/libports/complete-deallocate.c
+@@ -29,14 +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->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 e773dd6..9e3824d 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 d0b2ea4..e250b0e 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..dd38f55 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 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 before we release our hard reference.
++     The order is important here to prevent a race.  */
++  if (pi->class->dropweak_routine)
++    refcounts_ref_weak (&pi->refcounts, NULL);
++
++  refcounts_deref (&pi->refcounts, &result);
++
++  if (pi->class->dropweak_routine)
+     {
+-      pthread_mutex_unlock (&_ports_lock);
+-      (*pi->class->dropweak_routine) (pi);
+-      trieddroppingweakrefs = 1;
+-      goto retry;
++      if (result.hard == 0 && result.weak > 1)
++        (*pi->class->dropweak_routine) (pi);
++      refcounts_deref_weak (&pi->refcounts, &result);
+     }
+-  
+-  assert (pi->refcnt);
+ 
+-  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 9c5f14d..116e920 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 bbcf9ba..5ee579d 100644
+--- a/libports/reallocate-from-external.c
++++ b/libports/reallocate-from-external.c
+@@ -55,7 +55,7 @@ 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 5a7653d..d3ff0f4 100644
+--- a/libports/transfer-right.c
++++ b/libports/transfer-right.c
+@@ -70,7 +70,7 @@ 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.rc0
+
diff --git a/debian/patches/0004-libdiskfs-lock-less-reference-counting-for-peropen-o.patch b/debian/patches/0004-libdiskfs-lock-less-reference-counting-for-peropen-o.patch
new file mode 100644
index 00000000..cd84b4bc
--- /dev/null
+++ b/debian/patches/0004-libdiskfs-lock-less-reference-counting-for-peropen-o.patch
@@ -0,0 +1,143 @@
+From 51331c90f52801c9f65a002629dff5f9e4fec90d 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 4/5] 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 8151ddc..ae1a150 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;
+@@ -792,12 +793,12 @@ 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.rc0
+
diff --git a/debian/patches/0005-libtrivfs-lock-less-reference-counting-for-trivfs_pr.patch b/debian/patches/0005-libtrivfs-lock-less-reference-counting-for-trivfs_pr.patch
new file mode 100644
index 00000000..d32acdd0
--- /dev/null
+++ b/debian/patches/0005-libtrivfs-lock-less-reference-counting-for-trivfs_pr.patch
@@ -0,0 +1,176 @@
+From af1a321ffb5df24b3a5fa866ab2aa9c5b03f358c 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 5/5] libtrivfs: lock-less reference counting for trivfs_protid
+ objects
+
+* libtrivfs/trivfs.h (struct trivfs_protid): Use refcount_t for field
+refcnt.
+(struct trivfs_control): Remove unused field lock.
+* libtrivfs/open.c (trivfs_open): Initialize refcnt.
+* libtrivfs/io-reauthenticate.c (trivfs_S_io_reauthenticate): Adjust
+accordingly.
+* libtrivfs/io-restrict-auth.c (trivfs_S_io_restrict_auth): Likewise.
+* libtrivfs/protid-clean.c (trivfs_clean_protid): Likewise.
+* libtrivfs/protid-dup.c (trivfs_protid_dup): Likewise.
+* libtrivfs/cntl-create.c (trivfs_create_control): Drop the mutex
+initialization.
+* libtrivfs/peropen-make.c (trivfs_make_peropen): Initialize refcnt.
+* libtrivfs/peropen-rele.c (trivfs_release_peropen): Adjust accordingly.
+* libtrivfs/protid-make.c (trivfs_start_protid): Likewise.  Also, the
+node must no longer be locked, adjust comment accordingly.
+(trivfs_create_protid): 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      | 25 ++++++++++++++-----------
+ libtrivfs/protid-dup.c        |  5 +----
+ libtrivfs/trivfs.h            |  4 ++--
+ 7 files changed, 20 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..815e731 100644
+--- a/libtrivfs/protid-clean.c
++++ b/libtrivfs/protid-clean.c
+@@ -31,19 +31,22 @@ 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_protid_destroy_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.rc0
+
diff --git a/debian/patches/series b/debian/patches/series
index 7462b249..5913ebff 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -41,3 +41,8 @@ xkb-compat.patch
 mach-defpager-protected-payload.patch
 
 #ext2fs-cache-superblock.patch
+0001-libports-use-a-single-hash-table.patch
+0002-include-add-lock-less-reference-counting-primitives.patch
+0003-libports-lock-less-reference-counting-for-port_info-.patch
+0004-libdiskfs-lock-less-reference-counting-for-peropen-o.patch
+0005-libtrivfs-lock-less-reference-counting-for-trivfs_pr.patch