incubator-nuttx/fs/shm/shm_unlink.c

163 lines
3.9 KiB
C

/****************************************************************************
* fs/shm/shm_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 <stdio.h>
#include <assert.h>
#include <errno.h>
#include "inode/inode.h"
/****************************************************************************
* Private Functions
****************************************************************************/
static int file_shm_unlink(FAR const char *name)
{
FAR struct inode *inode;
struct inode_search_s desc;
char fullpath[sizeof(CONFIG_FS_SHMFS_VFS_PATH) + CONFIG_NAME_MAX + 2];
int ret;
/* Make sure that a non-NULL name is supplied */
if (!name)
{
return -ENOENT;
}
/* Remove any number of leading '/' */
while (*name == '/')
{
name++;
}
/* Empty name supplied? */
if (*name == '\0')
{
return -ENOENT;
}
/* Name too long? */
if (strnlen(name, CONFIG_NAME_MAX + 1) > CONFIG_NAME_MAX)
{
return -ENAMETOOLONG;
}
/* Get the full path to the shm object */
snprintf(fullpath, sizeof(fullpath),
CONFIG_FS_SHMFS_VFS_PATH "/%s", name);
/* Get the inode for this shm object */
SETUP_SEARCH(&desc, fullpath, false);
ret = inode_lock();
if (ret < 0)
{
goto errout_with_search;
}
ret = inode_find(&desc);
if (ret < 0)
{
/* There is no inode that includes in this path */
goto errout_with_sem;
}
/* Get the search results */
inode = desc.node;
DEBUGASSERT(inode != NULL);
/* Verify that what we found is, indeed, an shm inode */
if (!INODE_IS_SHM(inode))
{
ret = -ENOENT;
goto errout_with_inode;
}
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
if (inode->u.i_ops->unlink)
{
/* Notify the shmfs driver that it has been unlinked */
ret = inode->u.i_ops->unlink(inode);
if (ret < 0)
{
goto errout_with_inode;
}
}
#endif
/* Remove the old inode from the tree. If 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 have a
* reference on the inode. -EBUSY means that the inode was, indeed,
* unlinked but it could not be freed because there are references.
*/
if (ret == -EBUSY)
{
ret = OK;
}
DEBUGASSERT(ret == OK);
errout_with_inode:
inode_release(inode);
errout_with_sem:
inode_unlock();
errout_with_search:
RELEASE_SEARCH(&desc);
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
int shm_unlink(FAR const char *name)
{
int ret = file_shm_unlink(name);
if (ret < 0)
{
set_errno(-ret);
return ERROR;
}
return ret;
}