summaryrefslogtreecommitdiff
path: root/libdiskfs/node-nrele.c
diff options
context:
space:
mode:
Diffstat (limited to 'libdiskfs/node-nrele.c')
-rw-r--r--libdiskfs/node-nrele.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/libdiskfs/node-nrele.c b/libdiskfs/node-nrele.c
new file mode 100644
index 00000000..9dbc5d8c
--- /dev/null
+++ b/libdiskfs/node-nrele.c
@@ -0,0 +1,65 @@
+/*
+ Copyright (C) 1999 Free Software Foundation, Inc.
+ Written by Thomas Bushnell, BSG.
+
+ 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 this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. */
+
+#include "priv.h"
+
+/* Release a hard reference on NP. If NP is locked by anyone, then
+ this cannot be the last hard reference (because you must hold a
+ hard reference in order to hold the lock). If this is the last
+ hard reference and there are no links, then request soft references
+ to be dropped. */
+void
+diskfs_nrele (struct node *np)
+{
+ int tried_drop_softrefs = 0;
+
+ loop:
+ spin_lock (&diskfs_node_refcnt_lock);
+ assert (np->references);
+ np->references--;
+ if (np->references + np->light_references == 0)
+ {
+ mutex_lock (&np->lock);
+ diskfs_drop_node (np);
+ }
+ else if (np->references == 0)
+ {
+ mutex_lock (&np->lock);
+ spin_unlock (&diskfs_node_refcnt_lock);
+ diskfs_lost_hardrefs (np);
+ if (!np->dn_stat.st_nlink && !tried_drop_softrefs)
+ {
+ /* Same issue here as in nput; see that for explanation */
+ spin_lock (&diskfs_node_refcnt_lock);
+ np->references++;
+ spin_unlock (&diskfs_node_refcnt_lock);
+
+ diskfs_try_dropping_softrefs (np);
+ tried_drop_softrefs = 1;
+
+ /* Now we can drop the reference back... */
+ mutex_unlock (&np->lock);
+ goto loop;
+ }
+ mutex_unlock (&np->lock);
+ }
+ else
+ spin_unlock (&diskfs_node_refcnt_lock);
+}