diff options
Diffstat (limited to 'nuttx/fs/fs_rewinddir.c')
-rw-r--r-- | nuttx/fs/fs_rewinddir.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/nuttx/fs/fs_rewinddir.c b/nuttx/fs/fs_rewinddir.c new file mode 100644 index 000000000..a0e2be7d8 --- /dev/null +++ b/nuttx/fs/fs_rewinddir.c @@ -0,0 +1,145 @@ +/**************************************************************************** + * 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); + } +} |