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/*----------------------------------------------------------------------------*/
/*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*/
/*----------------------------------------------------------------------------*/
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