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- /****************************************************************************
- * fs/inode/fs_inodereserve.c
- *
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership. The
- * ASF licenses this file to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance with the
- * License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
- * License for the specific language governing permissions and limitations
- * under the License.
- *
- ****************************************************************************/
- /****************************************************************************
- * 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)
- {
- FAR struct inode *node;
- int namelen;
- namelen = inode_namelen(name);
- 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;
- }
- /* Then it must go at the head of parent's list of children. */
- else
- {
- DEBUGASSERT(parent != NULL);
- node->i_peer = parent->i_child;
- parent->i_child = node;
- }
- }
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: inode_root_reserve
- *
- * Description:
- * Reserve the root inode for the pseudo file system.
- *
- ****************************************************************************/
- void inode_root_reserve(void)
- {
- g_root_inode = inode_alloc("");
- }
- /****************************************************************************
- * 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;
- if (path[0] == '\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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