1 files changed, 136 insertions, 0 deletions
diff --git a/libtreefs/dir-hooks.c b/libtreefs/dir-hooks.c
new file mode 100644
index 00000000..5c54039a
--- /dev/null
+++ b/libtreefs/dir-hooks.c
@@ -0,0 +1,136 @@
+/* Default hooks for directory nodes
+
+   Copyright (C) 1995 Free Software Foundation, Inc.
+
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+
+   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., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include <sys/fcntl.h>
+
+#include "treefs.h"
+
+/* ---------------------------------------------------------------- */
+
+/* Return in CHILD a new node with one reference, presumably a possible child
+   of DIR, with a mode MODE.  All attempts to create a new node go through
+   this hook, so it may be overridden to easily control creation (e.g.,
+   replacing it with a hook that always returns EPERM).  Note that this
+   routine doesn't actually enter the child into the directory, or give the
+   node a non-zero link count, that should be done by the caller.  */
+error_t
+_treefs_dir_create_child (struct treefs_node *dir, 
+			   mode_t mode, struct treefs_auth *auth,
+			   struct treefs_node **child)
+{
+  error_t err;
+
+  if (!treefs_node_isdir (dir))
+    return ENOTDIR;
+
+  err = treefs_fsys_create_node (dir->fsys, dir, mode, auth, child);
+  if (err)
+    return err;
+
+  return 0;
+}
+
+/* ---------------------------------------------------------------- */
+
+/* Lookup NAME in DIR, returning the result in CHILD; AUTH should be used to
+   do authentication.  FLAGS is the open flags; if FLAGS contains O_CREAT,
+   and NAME is not found, then an entry should be created with a mode of
+   CREATE_MODE (which includes the S_IFMT bits, e.g., S_IFREG means a normal
+   file), unless O_EXCL is also set, in which case EEXIST should be returned.
+   Possible special errors returned include: EAGAIN -- result would be the
+   parent of our filesystem root.  */
+error_t
+_treefs_dir_lookup (struct treefs_node *dir, char *name,
+		    struct treefs_auth *auth,
+		    int flags, int create_mode,
+		    struct treefs_node **child)
+{
+  error_t err;
+
+  if (strcmp (name, "..") == 0 && dir == dir->fsys->root)
+    /* Whoops, the result is above our heads.  */
+    err = EAGAIN;
+  else
+    /* See if we've got an in-core entry for this file.  */
+    err = treefs_mdir_get (dir, name, child);
+
+  if (err == 0 && (flags & O_EXCL))
+    return EEXIST;
+
+  if (err == ENOENT)
+    /* See if there's some other way of getting this file.  */
+    err = treefs_dir_noent (dir, name, auth, flags, create_mode, child);
+
+  if (err == ENOENT && (flags & O_CREAT))
+    /* No such file, but the user wants to create it.  */
+    {
+      err = treefs_dir_create_child (dir, create_mode, auth, child);
+      if (!err)
+	{
+	  err = treefs_dir_link (dir, name, *child, auth);
+	  if (err)
+	    treefs_node_unref (*child);
+	}
+    }
+
+  return err;
+}
+
+/* ---------------------------------------------------------------- */
+
+/* Link the node CHILD into DIR as NAME, using AUTH to check authentication.
+   DIR should be locked and CHILD shouldn't be.  The default hook puts it
+   into DIR's in-core directory, and uses a reference to CHILD.  */
+error_t
+_treefs_dir_link (struct treefs_node *dir, char *name,
+		  struct treefs_node *child, struct treefs_auth *auth)
+{
+  struct treefs_node *old_child;
+  error_t err = treefs_node_mod_link_count (child, 1);
+  if (!err)
+    {
+      err = treefs_mdir_add (dir, name, child, &old_child);
+      if (err)
+	/* back out */
+	treefs_node_mod_link_count (child, -1);
+      else if (old_child)
+	treefs_node_mod_link_count (old_child, -1);
+    }
+  return err;
+}
+
+/* Remove the entry NAME from DIR, using AUTH to check authentication.  DIR
+   should be locked.  The default hook removes NAME from DIR's in-core
+   directory.  */
+error_t
+_treefs_dir_unlink (struct treefs_node *dir, char *name,
+		    struct treefs_auth *auth)
+{
+  struct treefs_node *old_child;
+  error_t err = treefs_mdir_remove (dir, name, &old_child);
+  if (!err && old_child)
+    {
+      treefs_node_mod_link_count (old_child, -1);
+      treefs_node_unref (old_child);
+    }
+  return err;
+}