/****************************************************************************
* fs/fs_rewinddir.c
*
* Copyright (C) 2007-2009, 2011 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 <dirent.h>
#include <errno.h>
#include <nuttx/fs/fs.h>
#include <nuttx/fs/dirent.h>
#include "fs_internal.h"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: rewindpseudodir
****************************************************************************/
static inline void rewindpseudodir(struct fs_dirent_s *idir)
{
struct inode *prev;
inode_semtake();
/* Reset the position to the beginning */
prev = idir->u.pseudo.fd_next; /* (Save to delete later) */
idir->u.pseudo.fd_next = idir->fd_root; /* The next node to visit */
idir->fd_position = 0; /* Reset position */
/* Increment the reference count on the root=next node. We
* should now have two references on the inode.
*/
idir->fd_root->i_crefs++;
inode_semgive();
/* Then release the reference to the old next inode */
if (prev)
{
inode_release(prev);
}
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: rewinddir
*
* Description:
* The rewinddir() function resets the position of the
* directory stream dir to the beginning of the directory.
*
* Inputs:
* dirp -- An instance of type DIR created by a previous
* call to opendir();
*
* Return:
* None
*
****************************************************************************/
void rewinddir(FAR DIR *dirp)
{
struct fs_dirent_s *idir = (struct fs_dirent_s *)dirp;
#ifndef CONFIG_DISABLE_MOUNTPOINT
struct inode *inode;
#endif
/* Sanity checks */
if (!idir || !idir->fd_root)
{
return;
}
/* The way we handle the readdir depends on the type of inode
* that we are dealing with.
*/
#ifndef CONFIG_DISABLE_MOUNTPOINT
inode = idir->fd_root;
if (INODE_IS_MOUNTPT(inode))
{
/* The node is a file system mointpoint. Verify that the mountpoint
* supports the rewinddir() method
*/
if (inode->u.i_mops && inode->u.i_mops->rewinddir)
{
/* Perform the rewinddir() operation */
inode->u.i_mops->rewinddir(inode, idir);
}
}
else
#endif
{
/* The node is part of the root pseudo file system */
rewindpseudodir(idir);
}
}
