158 lines
4.4 KiB
C
158 lines
4.4 KiB
C
/****************************************************************************
|
|
* fs/mqueue/mq_unlink.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 <stdbool.h>
|
|
#include <stdio.h>
|
|
#include <mqueue.h>
|
|
#include <assert.h>
|
|
#include <errno.h>
|
|
|
|
#include <nuttx/mqueue.h>
|
|
|
|
#include "inode/inode.h"
|
|
#include "mqueue/mqueue.h"
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: mq_unlink
|
|
*
|
|
* Description:
|
|
* This function removes the message queue named by "mq_name." If one
|
|
* or more tasks have the message queue open when mq_unlink() is called,
|
|
* removal of the message queue is postponed until all references to the
|
|
* message queue have been closed.
|
|
*
|
|
* Input Parameters:
|
|
* mq_name - Name of the message queue
|
|
*
|
|
* Returned Value:
|
|
* None
|
|
*
|
|
* Assumptions:
|
|
*
|
|
****************************************************************************/
|
|
|
|
int mq_unlink(FAR const char *mq_name)
|
|
{
|
|
FAR struct inode *inode;
|
|
struct inode_search_s desc;
|
|
char fullpath[MAX_MQUEUE_PATH];
|
|
int errcode;
|
|
int ret;
|
|
|
|
/* Get the full path to the message queue */
|
|
|
|
snprintf(fullpath, MAX_MQUEUE_PATH, CONFIG_FS_MQUEUE_MPATH "/%s", mq_name);
|
|
|
|
/* Get the inode for this message queue. */
|
|
|
|
SETUP_SEARCH(&desc, fullpath, false);
|
|
|
|
sched_lock();
|
|
ret = inode_find(&desc);
|
|
if (ret < 0)
|
|
{
|
|
/* There is no inode that includes in this path */
|
|
|
|
errcode = -ret;
|
|
goto errout_with_search;
|
|
}
|
|
|
|
/* Get the search results */
|
|
|
|
inode = desc.node;
|
|
DEBUGASSERT(inode != NULL);
|
|
|
|
/* Verify that what we found is, indeed, a message queue */
|
|
|
|
if (!INODE_IS_MQUEUE(inode))
|
|
{
|
|
errcode = ENXIO;
|
|
goto errout_with_inode;
|
|
}
|
|
|
|
/* Refuse to unlink the inode if it has children. I.e., if it is
|
|
* functioning as a directory and the directory is not empty.
|
|
*/
|
|
|
|
ret = inode_semtake();
|
|
if (ret < 0)
|
|
{
|
|
errcode = -ret;
|
|
goto errout_with_inode;
|
|
}
|
|
|
|
if (inode->i_child != NULL)
|
|
{
|
|
errcode = ENOTEMPTY;
|
|
goto errout_with_semaphore;
|
|
}
|
|
|
|
/* Remove the old inode from the tree. Because we hold a reference count
|
|
* on the inode, it will not be deleted now. This will set the
|
|
* FSNODEFLAG_DELETED bit in the inode flags.
|
|
*/
|
|
|
|
ret = inode_remove(fullpath);
|
|
|
|
/* inode_remove() should always fail with -EBUSY because we hae a reference
|
|
* on the inode. -EBUSY means that the inode was, indeed, unlinked but
|
|
* thatis could not be freed because there are references.
|
|
*/
|
|
|
|
DEBUGASSERT(ret >= 0 || ret == -EBUSY);
|
|
UNUSED(ret);
|
|
|
|
/* Now we do not release the reference count in the normal way (by calling
|
|
* inode release. Rather, we call mq_inode_release(). mq_inode_release
|
|
* will decrement the reference count on the inode. But it will also free
|
|
* the message queue if that reference count decrements to zero. Since we
|
|
* hold one reference, that can only occur if the message queue is not
|
|
* in-use.
|
|
*/
|
|
|
|
inode_semgive();
|
|
mq_inode_release(inode);
|
|
RELEASE_SEARCH(&desc);
|
|
sched_unlock();
|
|
return OK;
|
|
|
|
errout_with_semaphore:
|
|
inode_semgive();
|
|
|
|
errout_with_inode:
|
|
inode_release(inode);
|
|
|
|
errout_with_search:
|
|
RELEASE_SEARCH(&desc);
|
|
set_errno(errcode);
|
|
sched_unlock();
|
|
return ERROR;
|
|
}
|