Use refcount_t for peropen reference counting in libnetfs.

* libnetfs/netfs.h: Use refcount_t.
* libnetfs/make-peropen.c: Initialize to 1 with refcount_init just like in libdiskfs.
* libnetfs/make-protid.c: Don't increment the count here. Do it like libdiskfs.
* libnetfs/io-duplicate.c: Add refcount_ref since netfs_make_protid no longer increments the refcount.
* libnetfs/io-reauthenticate.c: Likewise.
* libnetfs/io-restrict-auth.c: Likewise.
* libnetfs/release-peropen.c: Dereference without locking.

1 files changed, 18 insertions, 20 deletions

diff --git a/libnetfs/release-peropen.c b/libnetfs/release-peropen.c
index c206b438..01af97dd 100644
--- a/libnetfs/release-peropen.c
+++ b/libnetfs/release-peropen.c
@@ -24,29 +24,27 @@
 void
 netfs_release_peropen (struct peropen *po)
 {
+  if (refcount_deref (&po->refcnt) > 0)
+    return;
+
   pthread_mutex_lock (&po->np->lock);
-  if (--po->refcnt)
-    pthread_mutex_unlock (&po->np->lock);
-  else
-    {
-      if (po->root_parent)
-	mach_port_deallocate (mach_task_self (), po->root_parent);
+  if (po->root_parent)
+    mach_port_deallocate (mach_task_self (), po->root_parent);
 
-      if (po->shadow_root && po->shadow_root != po->np)
-	{
-	  pthread_mutex_lock (&po->shadow_root->lock);
-	  netfs_nput (po->shadow_root);
-	}
-      if (po->shadow_root_parent)
-	mach_port_deallocate (mach_task_self (), po->shadow_root_parent);
+  if (po->shadow_root && po->shadow_root != po->np)
+    {
+      pthread_mutex_lock (&po->shadow_root->lock);
+      netfs_nput (po->shadow_root);
+    }
+  if (po->shadow_root_parent)
+    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);
+  if (po->lock_status != LOCK_UN)
+    fshelp_acquire_lock (&po->np->userlock, &po->lock_status,
+			 &po->np->lock, LOCK_UN);
 
-      netfs_nput (po->np);
+  netfs_nput (po->np);
 
-      free (po->path);
-      free (po);
-    }
+  free (po->path);
+  free (po);
 }