nuttx/fs/inode/fs_inodefind.c
chenrun1 4cec713dbf fs_inode:Change the type of i_crefs to atomic_int
Summary:
  1.Modified the i_crefs from int16_t to atomic_int
  2.Modified the i_crefs add, delete, read, and initialize interfaces to atomic operations
The purpose of this change is to avoid deadlock in cross-core scenarios, where A Core blocks B Core’s request for a write operation to A Core when A Core requests a read operation to B Core.

Signed-off-by: chenrun1 <chenrun1@xiaomi.com>
2024-09-23 14:07:03 +08:00

80 lines
2.5 KiB
C

/****************************************************************************
* fs/inode/fs_inodefind.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/fs/fs.h>
#include "inode/inode.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: inode_find
*
* Description:
* This is called from the open() logic to get a reference to the inode
* associated with a path. This is accomplished by calling inode_search().
* inode_find() is a simple wrapper around inode_search(). The primary
* difference between inode_find() and inode_search is that inode_find()
* will lock the inode tree and increment the reference count on the inode.
*
****************************************************************************/
int inode_find(FAR struct inode_search_s *desc)
{
int ret;
/* Find the node matching the path. If found, increment the count of
* references on the node.
*/
ret = inode_lock();
if (ret < 0)
{
return ret;
}
ret = inode_search(desc);
if (ret >= 0)
{
/* Found it */
FAR struct inode *node = desc->node;
DEBUGASSERT(node != NULL);
/* Increment the reference count on the inode */
atomic_fetch_add(&node->i_crefs, 1);
}
inode_unlock();
return ret;
}