incubator-nuttx/fs/inode/fs_inoderemove.c

158 lines
4.6 KiB
C

/****************************************************************************
* fs/inode/fs_inoderemove.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 <assert.h>
#include <errno.h>
#include <nuttx/kmalloc.h>
#include <nuttx/fs/fs.h>
#include "inode/inode.h"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: inode_unlink
*
* Description:
* Given a path, remove a the node from the in-memory, inode tree that the
* path refers to. This is normally done in preparation to removing or
* moving an inode.
*
* In symbolic links in the pseduo file system are enabled, then this
* logic will follow the symbolic links up until the terminal node. Then
* that link in removed. So if this the terminal node is a symbolic link,
* the symbolic link node will be removed, not the target of the link.
*
* Assumptions/Limitations:
* The caller must hold the inode semaphore
*
****************************************************************************/
static FAR struct inode *inode_unlink(FAR const char *path)
{
struct inode_search_s desc;
FAR struct inode *inode = NULL;
int ret;
/* Verify parameters. Ignore null paths */
if (path == NULL)
{
return NULL;
}
/* Find the node to unlink */
SETUP_SEARCH(&desc, path, true);
ret = inode_search(&desc);
if (ret >= 0)
{
inode = desc.node;
DEBUGASSERT(inode != NULL);
/* If peer is non-null, then remove the node from the right of
* of that peer node.
*/
if (desc.peer != NULL)
{
desc.peer->i_peer = inode->i_peer;
}
/* Then remove the node from head of the list of children. */
else
{
DEBUGASSERT(desc.parent != NULL);
desc.parent->i_child = inode->i_peer;
}
inode->i_peer = NULL;
inode->i_parent = NULL;
atomic_fetch_sub(&inode->i_crefs, 1);
}
RELEASE_SEARCH(&desc);
return inode;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: inode_remove
*
* Description:
* Given a path, remove a the node from the in-memory, inode tree that the
* path refers to and free all resources related to the inode. If the
* inode is in-use, then it will be unlinked, but will not be freed until
* the last reference to the inode is released.
*
* Assumptions/Limitations:
* The caller must hold the inode semaphore
*
****************************************************************************/
int inode_remove(FAR const char *path)
{
FAR struct inode *inode;
/* Find the inode and unlink it from the in-memory inode tree */
inode = inode_unlink(path);
if (inode)
{
/* Found it! But we cannot delete the inode if there are references
* to it
*/
if (atomic_load(&inode->i_crefs))
{
return -EBUSY;
}
else
{
/* And delete it now -- recursively to delete all of its children.
* Since it has been unlinked, then the peer pointer should be
* NULL.
*/
DEBUGASSERT(inode->i_peer == NULL);
inode_free(inode);
return OK;
}
}
/* The node does not exist */
return -ENOENT;
}