141 lines
4.1 KiB
C
141 lines
4.1 KiB
C
/****************************************************************************
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* fs/dirent/fs_rewinddir.c
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <dirent.h>
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#include <errno.h>
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#include <nuttx/fs/fs.h>
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#include <nuttx/fs/dirent.h>
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#include "inode/inode.h"
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Name: rewindpseudodir
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****************************************************************************/
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static inline void rewindpseudodir(struct fs_dirent_s *idir)
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{
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struct inode *prev;
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int ret;
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ret = inode_semtake();
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if (ret < 0)
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{
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return;
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}
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/* Reset the position to the beginning */
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prev = idir->u.pseudo.fd_next; /* (Save to delete later) */
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idir->u.pseudo.fd_next = idir->fd_root; /* The next node to visit */
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idir->fd_position = 0; /* Reset position */
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/* Increment the reference count on the root=next node. We
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* should now have two references on the inode.
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*/
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idir->fd_root->i_crefs++;
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inode_semgive();
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/* Then release the reference to the old next inode */
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if (prev)
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{
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inode_release(prev);
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}
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}
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: rewinddir
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*
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* Description:
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* The rewinddir() function resets the position of the
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* directory stream dir to the beginning of the directory.
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*
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* Input Parameters:
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* dirp -- An instance of type DIR created by a previous
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* call to opendir();
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*
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* Returned Value:
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* None
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*
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****************************************************************************/
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void rewinddir(FAR DIR *dirp)
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{
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struct fs_dirent_s *idir = (struct fs_dirent_s *)dirp;
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#ifndef CONFIG_DISABLE_MOUNTPOINT
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struct inode *inode;
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#endif
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/* Verify that we were provided with a valid directory structure,
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* A special case is when we enumerate an "empty", unused inode (fd_root
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* == 0). That is an inode in the pseudo-filesystem that has no
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* operations and no children. This is a "dangling" directory entry that
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* has lost its children.
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*/
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if (!idir || !idir->fd_root)
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{
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return;
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}
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/* The way we handle the readdir depends on the type of inode
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* that we are dealing with.
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*/
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#ifndef CONFIG_DISABLE_MOUNTPOINT
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inode = idir->fd_root;
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if (INODE_IS_MOUNTPT(inode))
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{
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/* The node is a file system mointpoint. Verify that the mountpoint
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* supports the rewinddir() method
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*/
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if (inode->u.i_mops && inode->u.i_mops->rewinddir)
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{
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/* Perform the rewinddir() operation */
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inode->u.i_mops->rewinddir(inode, idir);
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}
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}
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else
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#endif
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{
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/* The node is part of the root pseudo file system */
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rewindpseudodir(idir);
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}
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}
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