nuttx/fs/vfs/fs_dupfd.c
Gregory Nutt a4d6af8343 Check return from nxsem_wait_initialize()
Resolution of Issue 619 will require multiple steps, this part of the first step in that resolution:  Every call to nxsem_wait_uninterruptible() must handle the return value from nxsem_wait_uninterruptible properly.  This commit is only for those files under fs/inode.  Utility functions under fs/incode were modified so the changes do extend to other fs/ sub-directories as well.
2020-03-30 01:33:31 +01:00

137 lines
3.8 KiB
C

/****************************************************************************
* fs/vfs/fs_dupfd.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 <sched.h>
#include <errno.h>
#include <assert.h>
#include <nuttx/fs/fs.h>
#include "inode/inode.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define DUP_ISOPEN(filep) (filep->f_inode != NULL)
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: file_dup
*
* Description:
* Equivalent to the non-standard fs_dupfd() function except that it
* accepts a struct file instance instead of a file descriptor and does
* not set the errno variable.
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is returned on
* any failure.
*
****************************************************************************/
int file_dup(FAR struct file *filep, int minfd)
{
int fd2;
int ret;
/* Verify that fd is a valid, open file descriptor */
if (!DUP_ISOPEN(filep))
{
return -EBADF;
}
/* Increment the reference count on the contained inode */
ret = inode_addref(filep->f_inode);
if (ret < 0)
{
return ret;
}
/* Then allocate a new file descriptor for the inode */
fd2 = files_allocate(filep->f_inode, filep->f_oflags, filep->f_pos, minfd);
if (fd2 < 0)
{
inode_release(filep->f_inode);
return -EMFILE;
}
return fd2;
}
/****************************************************************************
* Name: fs_dupfd OR dup
*
* Description:
* Clone a file descriptor 'fd' to an arbitrary descriptor number (any
* value greater than or equal to 'minfd'). If socket descriptors are
* implemented, then this is called by dup() for the case of file
* descriptors. If socket descriptors are not implemented, then this
* function IS dup().
*
* Returned Value:
* fs_dupfd is sometimes an OS internal function and sometimes is a direct
* substitute for dup(). So it must return an errno value as though it
* were dup().
*
****************************************************************************/
int fs_dupfd(int fd, int minfd)
{
FAR struct file *filep;
int ret;
/* Get the file structure corresponding to the file descriptor. */
ret = fs_getfilep(fd, &filep);
if (ret < 0)
{
goto errout;
}
DEBUGASSERT(filep != NULL);
/* Let file_dup() do the real work */
ret = file_dup(filep, minfd);
if (ret < 0)
{
goto errout;
}
return ret;
errout:
set_errno(-ret);
return ERROR;
}