d67e9f0ad9
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@2341 42af7a65-404d-4744-a932-0658087f49c3
120 lines
4.1 KiB
C
120 lines
4.1 KiB
C
/****************************************************************************
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* fs/fs_filedup.c
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*
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* Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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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 <sched.h>
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#include <errno.h>
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#include <nuttx/fs.h>
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#include "fs_internal.h"
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#if CONFIG_NFILE_DESCRIPTORS > 0
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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#define DUP_ISOPEN(fd, list) \
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((unsigned int)fd < CONFIG_NFILE_DESCRIPTORS && \
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list->fl_files[fd].f_inode != NULL)
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Global Functions
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****************************************************************************/
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/****************************************************************************
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* Name: file_dup OR dup
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*
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* Description:
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* Clone a file descriptor to an arbitray descriptor number. If socket
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* descriptors are implemented, then this is called by dup() for the case
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* of file descriptors. If socket descriptors are not implemented, then
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* this function IS dup().
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*
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****************************************************************************/
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int file_dup(int fildes, int minfd)
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{
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FAR struct filelist *list;
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int fildes2;
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/* Get the thread-specific file list */
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list = sched_getfiles();
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if (!list)
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{
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errno = EMFILE;
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return ERROR;
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}
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/* Verify that fildes is a valid, open file descriptor */
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if (!DUP_ISOPEN(fildes, list))
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{
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errno = EBADF;
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return ERROR;
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}
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/* Increment the reference count on the contained inode */
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inode_addref(list->fl_files[fildes].f_inode);
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/* Then allocate a new file descriptor for the inode */
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fildes2 = files_allocate(list->fl_files[fildes].f_inode,
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list->fl_files[fildes].f_oflags,
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list->fl_files[fildes].f_pos,
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minfd);
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if (fildes2 < 0)
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{
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errno = EMFILE;
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inode_release(list->fl_files[fildes].f_inode);
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return ERROR;
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}
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return fildes2;
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}
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#endif /* CONFIG_NFILE_DESCRIPTORS > 0 */
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