Created the most basic one-node libnetfs-based stackable translator.

The filter is going to be an ordinary translator in most
regards, save for its attitude towards the translators
sitting on the real filesystem node associated with the
mirror on which the filter is sitting (see README).

1 files changed, 166 insertions, 0 deletions

diff --git a/node.c b/node.c
new file mode 100644
index 000000000..33ff2777e
--- /dev/null
+++ b/node.c
@@ -0,0 +1,166 @@
+/*----------------------------------------------------------------------------*/
+/*node.c*/
+/*----------------------------------------------------------------------------*/
+/*Implementation of node management strategies*/
+/*----------------------------------------------------------------------------*/
+/*Based on the code of unionfs translator.*/
+/*----------------------------------------------------------------------------*/
+/*Copyright (C) 2001, 2002, 2005, 2008 Free Software Foundation, Inc.
+  Written by Sergiu Ivanov <unlimitedscolobb@gmail.com>.
+
+  This program 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 of the
+  License, or * (at your option) any later version.
+
+  This program 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 02111-1307
+  USA.*/
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+#define _GNU_SOURCE 1
+/*----------------------------------------------------------------------------*/
+#include <stdlib.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <stdio.h>
+/*----------------------------------------------------------------------------*/
+#include "debug.h"
+#include "node.h"
+#include "filter.h"
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Global Variables----------------------------------------------------*/
+/*The lock protecting the underlying filesystem*/
+struct mutex ulfs_lock = MUTEX_INITIALIZER;
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Functions-----------------------------------------------------------*/
+/*Derives a new node from `lnode` and adds a reference to `lnode`*/
+error_t
+node_create
+	(
+	node_t ** node	/*store the result here*/
+	)
+	{
+	error_t err = 0;
+
+	/*Create a new netnode*/
+	netnode_t * netnode_new = malloc(sizeof(netnode_t));
+	
+	/*If the memory could not be allocated*/
+	if(netnode_new == NULL)
+		err = ENOMEM;
+	else
+		{
+		/*create a new node from the netnode*/
+		node_t * node_new = netfs_make_node(netnode_new);
+		
+		/*If the creation failed*/
+		if(node_new == NULL)
+			{
+			/*set the error code*/
+			err = ENOMEM;
+
+			/*destroy the netnode created above*/
+			free(netnode_new);
+			
+			/*stop*/
+			return err;
+			}
+		
+		/*store the result of creation in the second parameter*/
+		*node = node_new;
+		}
+		
+	/*Return the result of operations*/
+	return err;
+	}/*node_create*/
+/*----------------------------------------------------------------------------*/
+/*Destroys the specified node and removes a light reference from the
+	associated light node*/
+void
+node_destroy
+	(
+	node_t * np
+	)
+	{
+	/*Destroy the port to the underlying filesystem allocated to the node*/
+	PORT_DEALLOC(np->nn->port);
+	
+	/*Free the netnode and the node itself*/
+	free(np->nn);
+	free(np);
+	}/*node_destroy*/
+/*----------------------------------------------------------------------------*/
+/*Creates the root node and the corresponding lnode*/
+error_t
+node_create_root
+	(
+	node_t ** root_node	/*store the result here*/
+	)
+	{
+	error_t err;
+
+	/*Try to create a node*/
+	node_t * node;
+	err = node_create(&node);
+	if(err)
+		return err;
+		
+	/*Store the result in the parameter*/
+	*root_node = node;
+	
+	/*Return the result*/
+	return err;
+	}/*node_create_root*/
+/*----------------------------------------------------------------------------*/
+/*Initializes the port to the underlying filesystem for the root node*/
+error_t
+node_init_root
+	(
+	mach_port_t underlying,	/*the port to the underlying node*/
+	node_t * node						/*the root node*/
+	)
+	{
+	error_t err = 0;
+
+	/*Acquire a lock for operations on the underlying filesystem*/
+	mutex_lock(&ulfs_lock);
+	
+	/*Store the specified port in the node*/
+	node->nn->port = underlying;
+	
+	LOG_MSG("node_init_root: Port: 0x%ld", (unsigned long)node->nn->port);
+	
+	/*Stat the root node*/
+	err = io_stat(node->nn->port, &node->nn_stat);
+	if(err)
+		{
+		/*deallocate the port*/
+		PORT_DEALLOC(node->nn->port);
+		
+		LOG_MSG("node_init_root: Could not stat the root node.");
+		
+		/*unlock the mutex and exit*/
+		mutex_unlock(&ulfs_lock);
+		return err;
+		}
+
+	/*Release the lock for operations on the undelying filesystem*/
+	mutex_unlock(&ulfs_lock);
+	
+	/*Return the result of operations*/
+	return err;
+	}/*node_init_root*/
+/*----------------------------------------------------------------------------*/