137 lines
3.6 KiB
C
137 lines
3.6 KiB
C
/****************************************************************************
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* fs/vfs/fs_dup2.c
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <unistd.h>
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#include <sched.h>
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#include <assert.h>
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#include <errno.h>
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#include "inode/inode.h"
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: file_dup2
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*
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* Description:
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* Assign an inode to a specific files structure. This is the heart of
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* dup2.
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*
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* Equivalent to the non-standard dup2() function except that it
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* accepts struct file instances instead of file descriptors and it does
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* not set the errno variable.
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*
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* Returned Value:
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* Zero (OK) is returned on success; a negated errno value is return on
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* any failure.
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*
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****************************************************************************/
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int file_dup2(FAR struct file *filep1, FAR struct file *filep2)
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{
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FAR struct inode *inode;
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struct file temp;
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int ret;
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if (filep1 == NULL || filep1->f_inode == NULL || filep2 == NULL)
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{
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return -EBADF;
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}
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if (filep1 == filep2)
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{
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return OK;
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}
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/* Increment the reference count on the contained inode */
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inode = filep1->f_inode;
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ret = inode_addref(inode);
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if (ret < 0)
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{
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return ret;
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}
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/* Then clone the file structure */
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temp.f_oflags = filep1->f_oflags;
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temp.f_pos = filep1->f_pos;
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temp.f_inode = inode;
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temp.f_priv = NULL;
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/* Call the open method on the file, driver, mountpoint so that it
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* can maintain the correct open counts.
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*/
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if (inode->u.i_ops)
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{
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#ifndef CONFIG_DISABLE_MOUNTPOINT
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if (INODE_IS_MOUNTPT(inode))
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{
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/* Dup the open file on the in the new file structure */
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if (inode->u.i_mops->dup)
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{
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ret = inode->u.i_mops->dup(filep1, &temp);
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}
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}
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else
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#endif
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{
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/* (Re-)open the pseudo file or device driver */
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temp.f_priv = filep1->f_priv;
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if (inode->u.i_ops->open)
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{
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ret = inode->u.i_ops->open(&temp);
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}
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}
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/* Handle open failures */
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if (ret < 0)
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{
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inode_release(inode);
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return ret;
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}
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}
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/* If there is already an inode contained in the new file structure,
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* close the file and release the inode.
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*/
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ret = file_close(filep2);
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DEBUGASSERT(ret == 0);
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/* Return the file structure */
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memcpy(filep2, &temp, sizeof(temp));
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return OK;
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}
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