nuttx/fs/vfs/fs_dup.c
Xiang Xiao 604eea453b fs/vfs: Let caller control whether add the reference count of inode in file_allocate
to simplify the caller in some special case

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
2022-10-28 10:12:08 +02:00

117 lines
3.1 KiB
C

/****************************************************************************
* fs/vfs/fs_dup.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 <unistd.h>
#include <sched.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/fs/fs.h>
#include "inode/inode.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: file_dup
*
* Description:
* Equivalent to the standard dup() function except that it
* accepts a struct file instance instead of a file descriptor.
*
* Returned Value:
* The new file descriptor is returned on success; a negated errno value
* is returned on any failure.
*
****************************************************************************/
int file_dup(FAR struct file *filep, int minfd)
{
struct file filep2;
int fd2;
int ret;
/* Let file_dup2() do the real work */
memset(&filep2, 0, sizeof(filep2));
ret = file_dup2(filep, &filep2);
if (ret < 0)
{
return ret;
}
/* Then allocate a new file descriptor for the inode */
fd2 = file_allocate(filep2.f_inode, filep2.f_oflags,
filep2.f_pos, filep2.f_priv, minfd, false);
if (fd2 < 0)
{
file_close(&filep2);
return fd2;
}
return fd2;
}
/****************************************************************************
* Name: dup
*
* Description:
* Clone a file or socket descriptor to an arbitrary descriptor number
*
****************************************************************************/
int dup(int fd)
{
FAR struct file *filep;
int ret;
/* Get the file structure corresponding to the file descriptor. */
ret = fs_getfilep(fd, &filep);
if (ret < 0)
{
goto err;
}
DEBUGASSERT(filep != NULL);
/* Let file_dup() do the real work */
ret = file_dup(filep, 0);
if (ret < 0)
{
goto err;
}
return ret;
err:
set_errno(-ret);
return ERROR;
}