151 lines
4.8 KiB
C
151 lines
4.8 KiB
C
/****************************************************************************
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* fs/dirent/fs_rewinddir.c
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*
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* Copyright (C) 2007-2009, 2011, 2014 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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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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inode_semtake();
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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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