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Diffstat (limited to 'nuttx/fs/fs_foreachinode.c')
-rw-r--r-- | nuttx/fs/fs_foreachinode.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/nuttx/fs/fs_foreachinode.c b/nuttx/fs/fs_foreachinode.c new file mode 100644 index 000000000..08630263b --- /dev/null +++ b/nuttx/fs/fs_foreachinode.c @@ -0,0 +1,233 @@ +/**************************************************************************** + * fs/fs_foreachinode.c + * + * Copyright (C) 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 <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> + +#include <nuttx/fs/fs.h> + +#include "fs_internal.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 Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Variables + ****************************************************************************/ + +/**************************************************************************** + * 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. + * + ****************************************************************************/ + +int foreach_inodelevel(FAR struct inode *node, 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 looop 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 psuedo-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 *)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 */ + + inode_semtake(); + ret = foreach_inodelevel(root_inode, info); + inode_semgive(); + + /* Free the info structure and return the result */ + + 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 */ + + inode_semtake(); + ret = foreach_inodelevel(root_inode, &info); + inode_semgive(); + + return ret; + +#endif +} + |