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/****************************************************************************
* fs/fs_registerreserve.c
*
* Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/kmalloc.h>
#include <nuttx/fs/fs.h>
#include "fs_internal.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Public Variables
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: inode_namelen
****************************************************************************/
static int inode_namelen(FAR const char *name)
{
const char *tmp = name;
while(*tmp && *tmp != '/') tmp++;
return tmp - name;
}
/****************************************************************************
* Name: inode_namecpy
****************************************************************************/
static void inode_namecpy(char *dest, const char *src)
{
while(*src && *src != '/') *dest++ = *src++;
*dest='\0';
}
/****************************************************************************
* Name: inode_alloc
****************************************************************************/
static FAR struct inode *inode_alloc(FAR const char *name)
{
int namelen = inode_namelen(name);
FAR struct inode *node = (FAR struct inode*)kzalloc(FSNODE_SIZE(namelen));
if (node)
{
inode_namecpy(node->i_name, name);
}
return node;
}
/****************************************************************************
* Name: inode_insert
****************************************************************************/
static void inode_insert(FAR struct inode *node,
FAR struct inode *peer,
FAR struct inode *parent)
{
/* If peer is non-null, then new node simply goes to the right
* of that peer node.
*/
if (peer)
{
node->i_peer = peer->i_peer;
peer->i_peer = node;
}
/* If parent is non-null, then it must go at the head of its
* list of children.
*/
else if (parent)
{
node->i_peer = parent->i_child;
parent->i_child = node;
}
/* Otherwise, this must be the new root_inode */
else
{
node->i_peer = root_inode;
root_inode = node;
}
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: inode_reserve
*
* Description:
* Reserve an (initialized) inode the pseudo file system.
*
* NOTE: Caller must hold the inode semaphore
*
* Input parameters:
* path - The path to the inode to create
* inode - The location to return the inode pointer
*
* Returned Value:
* Zero on success (with the inode point in 'inode'); A negated errno
* value is returned on failure:
*
* EINVAL - 'path' is invalid for this operation
* EEXIST - An inode already exists at 'path'
* ENOMEM - Failed to allocate in-memory resources for the operation
*
****************************************************************************/
int inode_reserve(FAR const char *path, FAR struct inode **inode)
{
const char *name = path;
FAR struct inode *left;
FAR struct inode *parent;
/* Assume failure */
DEBUGASSERT(path && inode);
*inode = NULL;
/* Handle paths that are interpreted as the root directory */
if (!*path || path[0] != '/')
{
return -EINVAL;
}
/* Find the location to insert the new subtree */
if (inode_search(&name, &left, &parent, (FAR const char **)NULL) != NULL)
{
/* It is an error if the node already exists in the tree */
return -EEXIST;
}
/* Now we now where to insert the subtree */
for (;;)
{
FAR struct inode *node;
/* Create a new node -- we need to know if this is the
* the leaf node or some intermediary. We can find this
* by looking at the next name.
*/
FAR const char *next_name = inode_nextname(name);
if (*next_name)
{
/* Insert an operationless node */
node = inode_alloc(name);
if (node)
{
inode_insert(node, left, parent);
/* Set up for the next time through the loop */
name = next_name;
left = NULL;
parent = node;
continue;
}
}
else
{
node = inode_alloc(name);
if (node)
{
inode_insert(node, left, parent);
*inode = node;
return OK;
}
}
/* We get here on failures to allocate node memory */
return -ENOMEM;
}
}
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