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- /****************************************************************************
- * fs/inode/fs_registerreserve.c
- *
- * Copyright (C) 2007-2009, 2011-2012, 2015, 2017 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 "inode/inode.h"
- /****************************************************************************
- * 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 *)kmm_zalloc(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 = g_root_inode;
- g_root_inode = node;
- }
- }
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: inode_reserve
- *
- * Description:
- * Reserve an (initialized) inode the pseudo file system. The initial
- * reference count on the new inode is zero.
- *
- * 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
- *
- * Assumptions:
- * Caller must hold the inode semaphore
- *
- ****************************************************************************/
- int inode_reserve(FAR const char *path, FAR struct inode **inode)
- {
- struct inode_search_s desc;
- FAR struct inode *left;
- FAR struct inode *parent;
- FAR const char *name;
- int ret;
- /* Assume failure */
- DEBUGASSERT(path != NULL && inode != NULL);
- *inode = NULL;
- /* Handle paths that are interpreted as the root directory */
- if (path[0] == '\0' || path[0] != '/')
- {
- return -EINVAL;
- }
- /* Find the location to insert the new subtree */
- SETUP_SEARCH(&desc, path, false);
- ret = inode_search(&desc);
- if (ret >= 0)
- {
- /* It is an error if the node already exists in the tree (or if it
- * lies within a mountpoint, we don't distinguish here).
- */
- ret = -EEXIST;
- goto errout_with_search;
- }
- /* Now we now where to insert the subtree */
- name = desc.path;
- left = desc.peer;
- parent = desc.parent;
- 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 *nextname = inode_nextname(name);
- if (*nextname != '\0')
- {
- /* Insert an operationless node */
- node = inode_alloc(name);
- if (node != NULL)
- {
- inode_insert(node, left, parent);
- /* Set up for the next time through the loop */
- name = nextname;
- left = NULL;
- parent = node;
- continue;
- }
- }
- else
- {
- node = inode_alloc(name);
- if (node != NULL)
- {
- inode_insert(node, left, parent);
- *inode = node;
- ret = OK;
- break;
- }
- }
- /* We get here on failures to allocate node memory */
- ret = -ENOMEM;
- break;
- }
- errout_with_search:
- RELEASE_SEARCH(&desc);
- return ret;
- }
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