From c16eed2cb64089bf7d958db0fe85352f4ceefb4d 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: 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: Adjust accordingly.
* 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.
---
 libdiskfs/node-nputl.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

(limited to 'libdiskfs/node-nputl.c')

diff --git a/libdiskfs/node-nputl.c b/libdiskfs/node-nputl.c
index 19596654..8dac16e3 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);
 }
-- 
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