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Diffstat (limited to 'node.c')
| -rw-r--r-- | node.c | 166 |
1 files changed, 166 insertions, 0 deletions
@@ -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*/ +/*----------------------------------------------------------------------------*/ |