nuttx/fs/dirent/fs_rewinddir.c
Gregory Nutt a4d6af8343 Check return from nxsem_wait_initialize()
Resolution of Issue 619 will require multiple steps, this part of the first step in that resolution:  Every call to nxsem_wait_uninterruptible() must handle the return value from nxsem_wait_uninterruptible properly.  This commit is only for those files under fs/inode.  Utility functions under fs/incode were modified so the changes do extend to other fs/ sub-directories as well.
2020-03-30 01:33:31 +01:00

141 lines
4.1 KiB
C

/****************************************************************************
* fs/dirent/fs_rewinddir.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <dirent.h>
#include <errno.h>
#include <nuttx/fs/fs.h>
#include <nuttx/fs/dirent.h>
#include "inode/inode.h"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: rewindpseudodir
****************************************************************************/
static inline void rewindpseudodir(struct fs_dirent_s *idir)
{
struct inode *prev;
int ret;
ret = inode_semtake();
if (ret < 0)
{
return;
}
/* 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.
*
* Input Parameters:
* dirp -- An instance of type DIR created by a previous
* call to opendir();
*
* Returned Value:
* None
*
****************************************************************************/
void rewinddir(FAR DIR *dirp)
{
struct fs_dirent_s *idir = (struct fs_dirent_s *)dirp;
#ifndef CONFIG_DISABLE_MOUNTPOINT
struct inode *inode;
#endif
/* Verify that we were provided with a valid directory structure,
* A special case is when we enumerate an "empty", unused inode (fd_root
* == 0). That is an inode in the pseudo-filesystem that has no
* operations and no children. This is a "dangling" directory entry that
* has lost its children.
*/
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);
}
}