add patch series

2 files changed, 236 insertions, 0 deletions

diff --git a/debian/patches/nodeihash0001-libdiskfs-use-ihash-for-the-node-cache.patch b/debian/patches/nodeihash0001-libdiskfs-use-ihash-for-the-node-cache.patch
new file mode 100644
index 00000000..6635dde9
--- /dev/null
+++ b/debian/patches/nodeihash0001-libdiskfs-use-ihash-for-the-node-cache.patch
@@ -0,0 +1,235 @@
+From 8a1b938b3ddd56548372fbd0f4d9fc182cc35c9f Mon Sep 17 00:00:00 2001
+From: Justus Winter <4winter@informatik.uni-hamburg.de>
+Date: Wed, 24 Jun 2015 02:30:01 +0200
+Subject: [PATCH hurd] libdiskfs: use ihash for the node cache
+
+Replace the hand-written hash table in the node cache with libihash.
+Libihash is a self-tuning hash table, whereas the previous code used a
+fixed number of buckets.
+
+* libdiskfs/Makefile (HURDLIBS): Link to `ihash'.
+* libdiskfs/diskfs.h (struct node): Remove bucket list, add slot pointer.
+* libdiskfs/node-cache.c (nodecache): New ihash table replacing the
+old `nodehash'.
+(lookup): Drop function.
+(diskfs_cached_lookup_context): Adapt accordingly.
+(diskfs_cached_ifind): Likewise.
+(diskfs_try_dropping_softrefs): Likewise.
+(diskfs_node_iterate): Likewise.
+---
+ libdiskfs/Makefile     |  2 +-
+ libdiskfs/diskfs.h     |  5 ++--
+ libdiskfs/node-cache.c | 80 +++++++++++++++++---------------------------------
+ 3 files changed, 31 insertions(+), 56 deletions(-)
+
+diff --git a/libdiskfs/Makefile b/libdiskfs/Makefile
+index 47b9339..803761d 100644
+--- a/libdiskfs/Makefile
++++ b/libdiskfs/Makefile
+@@ -61,7 +61,7 @@ MIGSTUBS = fsServer.o ioServer.o fsysServer.o exec_startupServer.o \
+ 	startup_notifyServer.o
+ OBJS = $(sort $(SRCS:.c=.o) $(MIGSTUBS))
+ 
+-HURDLIBS = fshelp iohelp store ports shouldbeinlibc pager
++HURDLIBS = fshelp iohelp store ports shouldbeinlibc pager ihash
+ LDLIBS += -lpthread
+ 
+ fsys-MIGSFLAGS = -imacros $(srcdir)/fsmutations.h -DREPLY_PORTS
+diff --git a/libdiskfs/diskfs.h b/libdiskfs/diskfs.h
+index 11fb0ad..106aeb0 100644
+--- a/libdiskfs/diskfs.h
++++ b/libdiskfs/diskfs.h
+@@ -25,6 +25,7 @@
+ #include <pthread.h>
+ #include <hurd/ports.h>
+ #include <hurd/fshelp.h>
++#include <hurd/ihash.h>
+ #include <hurd/iohelp.h>
+ #include <idvec.h>
+ #include <features.h>
+@@ -80,8 +81,8 @@ struct peropen
+    filesystem.  */
+ struct node
+ {
+-  /* Links on hash list. */
+-  struct node *hnext, **hprevp;
++  /* The slot we occupy in the node cache.  */
++  hurd_ihash_locp_t slot;
+ 
+   struct disknode *dn;
+ 
+diff --git a/libdiskfs/node-cache.c b/libdiskfs/node-cache.c
+index a76474a..07cd879 100644
+--- a/libdiskfs/node-cache.c
++++ b/libdiskfs/node-cache.c
+@@ -17,15 +17,10 @@
+    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/>.  */
+ 
+-#include "priv.h"
+-
+-#define	INOHSZ	8192
+-#if	((INOHSZ&(INOHSZ-1)) == 0)
+-#define	INOHASH(ino)	((ino)&(INOHSZ-1))
+-#else
+-#define	INOHASH(ino)	(((unsigned)(ino))%INOHSZ)
+-#endif
++#include <hurd/ihash.h>
+ 
++#include "priv.h"
++//XXX
+ /* The nodehash is a cache of nodes.
+ 
+    Access to nodehash and nodehash_nr_items is protected by
+@@ -35,8 +30,8 @@
+    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 struct hurd_ihash nodecache =
++  HURD_IHASH_INITIALIZER (offsetof (struct node, slot));
+ static pthread_rwlock_t nodecache_lock = PTHREAD_RWLOCK_INITIALIZER;
+ 
+ /* Initialize the inode hash table. */
+@@ -45,18 +40,6 @@ nodecache_init ()
+ {
+ }
+ 
+-/* Lookup node with inode number INUM.  Returns NULL if the node is
+-   not found in the node cache.  */
+-static struct node *
+-lookup (ino_t inum)
+-{
+-  struct node *np;
+-  for (np = nodehash[INOHASH(inum)]; np; np = np->hnext)
+-    if (np->cache_id == inum)
+-      return np;
+-  return NULL;
+-}
+-
+ /* Fetch inode INUM, set *NPP to the node structure;
+    gain one user reference and lock the node.  */
+ error_t __attribute__ ((weak))
+@@ -72,10 +55,12 @@ diskfs_cached_lookup_context (ino_t inum, struct node **npp,
+ 			      struct lookup_context *ctx)
+ {
+   error_t err;
+-  struct node *np, *tmp;
++  struct node *np;
++  hurd_ihash_locp_t slot;
+ 
+   pthread_rwlock_rdlock (&nodecache_lock);
+-  np = lookup (inum);
++  slot = hurd_ihash_locp_find (&nodecache, inum);
++  np = hurd_ihash_locp_value (slot);
+   if (np)
+     goto gotit;
+   pthread_rwlock_unlock (&nodecache_lock);
+@@ -89,22 +74,18 @@ diskfs_cached_lookup_context (ino_t inum, struct node **npp,
+ 
+   /* Put NP in NODEHASH.  */
+   pthread_rwlock_wrlock (&nodecache_lock);
+-  tmp = lookup (inum);
+-  if (tmp)
++  slot = hurd_ihash_locp_find (&nodecache, inum);
++  if (hurd_ihash_locp_value (slot))
+     {
+       /* We lost a race.  */
+       diskfs_nput (np);
+-      np = tmp;
++      np = hurd_ihash_locp_value (slot);
+       goto gotit;
+     }
+ 
+-  np->hnext = nodehash[INOHASH(inum)];
+-  if (np->hnext)
+-    np->hnext->hprevp = &np->hnext;
+-  np->hprevp = &nodehash[INOHASH(inum)];
+-  nodehash[INOHASH(inum)] = np;
++  err = hurd_ihash_locp_add (&nodecache, slot, inum, np);
++  assert_perror (err);
+   diskfs_nref_light (np);
+-  nodehash_nr_items += 1;
+   pthread_rwlock_unlock (&nodecache_lock);
+ 
+   /* Get the contents of NP off disk.  */
+@@ -133,7 +114,7 @@ diskfs_cached_ifind (ino_t inum)
+   struct node *np;
+ 
+   pthread_rwlock_rdlock (&nodecache_lock);
+-  np = lookup (inum);
++  np = hurd_ihash_find (&nodecache, inum);
+   pthread_rwlock_unlock (&nodecache_lock);
+ 
+   assert (np);
+@@ -144,7 +125,7 @@ void __attribute__ ((weak))
+ diskfs_try_dropping_softrefs (struct node *np)
+ {
+   pthread_rwlock_wrlock (&nodecache_lock);
+-  if (np->hprevp != NULL)
++  if (np->slot != NULL)
+     {
+       /* Check if someone reacquired a reference through the
+ 	 nodehash.  */
+@@ -159,12 +140,8 @@ diskfs_try_dropping_softrefs (struct node *np)
+ 	  return;
+ 	}
+ 
+-      *np->hprevp = np->hnext;
+-      if (np->hnext)
+-	np->hnext->hprevp = np->hprevp;
+-      np->hnext = NULL;
+-      np->hprevp = NULL;
+-      nodehash_nr_items -= 1;
++      hurd_ihash_locp_remove (&nodecache, np->slot);
++      np->slot = NULL;
+       diskfs_nrele_light (np);
+     }
+   pthread_rwlock_unlock (&nodecache_lock);
+@@ -179,7 +156,6 @@ error_t __attribute__ ((weak))
+ diskfs_node_iterate (error_t (*fun)(struct node *))
+ {
+   error_t err = 0;
+-  int n;
+   size_t num_nodes;
+   struct node *node, **node_list, **p;
+ 
+@@ -191,7 +167,7 @@ diskfs_node_iterate (error_t (*fun)(struct node *))
+      nodecache_lock, but we can't hold this while locking the
+      individual node locks).  */
+   /* XXX: Can we?  */
+-  num_nodes = nodehash_nr_items;
++  num_nodes = nodecache.nr_items;
+ 
+   /* TODO This method doesn't scale beyond a few dozen nodes and should be
+      replaced.  */
+@@ -203,17 +179,15 @@ diskfs_node_iterate (error_t (*fun)(struct node *))
+     }
+ 
+   p = node_list;
+-  for (n = 0; n < INOHSZ; n++)
+-    for (node = nodehash[n]; node; node = node->hnext)
+-      {
+-	*p++ = node;
+-
+-	/* We acquire a hard reference for node, but without using
+-	   diskfs_nref.	 We do this so that diskfs_new_hardrefs will not
+-	   get called.	*/
+-	refcounts_ref (&node->refcounts, NULL);
+-      }
++  HURD_IHASH_ITERATE (&nodecache, i)
++    {
++      *p++ = node = i;
+ 
++      /* We acquire a hard reference for node, but without using
++	 diskfs_nref.  We do this so that diskfs_new_hardrefs will not
++	 get called.  */
++      refcounts_ref (&node->refcounts, NULL);
++    }
+   pthread_rwlock_unlock (&nodecache_lock);
+ 
+   p = node_list;
+-- 
+2.1.4
+
diff --git a/debian/patches/series b/debian/patches/series
index 79228bfb..514b363b 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -58,3 +58,4 @@ ihash-as-cache0002-libihash-optimize-lookup-or-insert-operations.patch
 ihash-as-cache0003-libihash-prefer-performance-degradation-over-failure.patch
 ext2fs-optimize-bcache0001-ext2fs-improve-the-block-cache.patch
 ext2fs-optimize-bcache0002-ext2fs-disable-block-cache-debugging-by-default.patch
+nodeihash0001-libdiskfs-use-ihash-for-the-node-cache.patch