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+/****************************************************************************
+ * 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: rewindpsuedodir
+ ****************************************************************************/
+
+static inline void rewindpsuedodir(struct fs_dirent_s *idir)
+{
+ struct inode *prev;
+
+ inode_semtake();
+
+ /* Reset the position to the beginning */
+
+ prev = idir->u.psuedo.fd_next; /* (Save to delete later) */
+ idir->u.psuedo.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 psuedo file system */
+
+ rewindpsuedodir(idir);
+ }
+}