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- /****************************************************************************
- * fs/inode/fs_foreachinode.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 <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <errno.h>
- #include <nuttx/kmalloc.h>
- #include <nuttx/fs/fs.h>
- #include "inode/inode.h"
- /****************************************************************************
- * Pre-processor Definitions
- ****************************************************************************/
- /* Is it better to allocate the struct inode_path_s from the heap? or
- * from the stack? This decision depends on how often this is down and
- * how much stack space you can afford.
- */
- #define ENUM_INODE_ALLOC 1
- /****************************************************************************
- * Private Types
- ****************************************************************************/
- /* This structure manages the full path to the inode. */
- struct inode_path_s
- {
- foreach_inode_t handler;
- FAR void *arg;
- char path[CONFIG_PATH_MAX];
- };
- /****************************************************************************
- * Private Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: foreach_inodelevel
- *
- * Description:
- * This is the recursive 'heart' of foreach_inode. It will visit each
- * inode at this level in the hierarchy and recurse handle each inode
- * at the next level down.
- *
- * Assumptions:
- * The caller holds the inode semaphore.
- *
- ****************************************************************************/
- static int foreach_inodelevel(FAR struct inode *node,
- FAR struct inode_path_s *info)
- {
- int ret = OK;
- /* Visit each node at this level */
- for (; node; node = node->i_peer)
- {
- /* Give the next inode to the callback */
- ret = info->handler(node, info->path, info->arg);
- /* Break out of the loop early if the handler returns a non-zero
- * value.
- */
- if (ret != 0)
- {
- break;
- }
- /* If there is a level 'beneath' this one, then recurse to visit all
- * of the inodes at that level.
- */
- if (node->i_child)
- {
- /* Construct the path to the next level */
- int pathlen = strlen(info->path);
- int namlen = strlen(node->i_name) + 1;
- /* Make sure that this would not exceed the maximum path length */
- if (pathlen + namlen > PATH_MAX)
- {
- ret = -ENAMETOOLONG;
- break;
- }
- /* Append the path segment to this inode and recurse */
- sprintf(&info->path[pathlen], "/%s", node->i_name);
- ret = foreach_inodelevel(node->i_child, info);
- /* Truncate the path name back to the correct length */
- info->path[pathlen] = '\0';
- /* Return early if the handler at the lower level returned a non-
- * zero value
- */
- if (ret != 0)
- {
- break;
- }
- }
- }
- /* Return the result of the traversal. */
- return ret;
- }
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: foreach_inode
- *
- * Description:
- * Visit each inode in the pseudo-file system. The traversal is terminated
- * when the callback 'handler' returns a non-zero value, or when all of
- * the inodes have been visited.
- *
- * NOTE 1: Use with caution... The pseudo-file system is locked throughout
- * the traversal.
- * NOTE 2: The search algorithm is recursive and could, in principle, use
- * an indeterminant amount of stack space. This will not usually be a
- * real work issue.
- *
- ****************************************************************************/
- int foreach_inode(foreach_inode_t handler, FAR void *arg)
- {
- #ifdef ENUM_INODE_ALLOC
- FAR struct inode_path_s *info;
- int ret;
- /* Allocate the mountpoint info structure */
- info = (FAR struct inode_path_s *)kmm_malloc(sizeof(struct inode_path_s));
- if (!info)
- {
- return -ENOMEM;
- }
- /* Initialize the info structure */
- info->handler = handler;
- info->arg = arg;
- info->path[0] = '\0';
- /* Start the recursion at the root inode */
- ret = inode_semtake();
- if (ret >= 0)
- {
- ret = foreach_inodelevel(g_root_inode->i_child, info);
- inode_semgive();
- }
- /* Free the info structure and return the result */
- kmm_free(info);
- return ret;
- #else
- struct inode_path_s info;
- int ret;
- /* Initialize the info structure */
- info.handler = handler;
- info.arg = arg;
- info.path[0] = '\0';
- /* Start the recursion at the root inode */
- ret = inode_semtake();
- if (ret >= 0)
- {
- ret = foreach_inodelevel(g_root_inode->i_child, &info);
- inode_semgive();
- }
- return ret;
- #endif
- }
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