incubator-nuttx/fs/vfs/fs_fstat.c

148 lines
4.6 KiB
C

/****************************************************************************
* fs/vfs/fs_fstat.c
*
* Copyright (C) 2017 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <unistd.h>
#include <sched.h>
#include <errno.h>
#include <nuttx/fs/fs.h>
#include "inode/inode.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: fstat
*
* Description:
* The fstat() function will obtain information about an open file
* associated with the file descriptor 'fd', and will write it to the area
* pointed to by 'buf'.
*
* The 'buf' argument is a pointer to a stat structure, as defined in
* <sys/stat.h>, into which information is placed concerning the file.
*
* Input Parameters:
* fd - The file descriptor associated with the open file of interest
* buf - The caller provide location in which to return information about
* the open file.
*
* Returned Value:
* Upon successful completion, 0 shall be returned. Otherwise, -1 shall be
* returned and errno set to indicate the error.
*
****************************************************************************/
int fstat(int fd, FAR struct stat *buf)
{
FAR struct file *filep;
FAR struct inode *inode;
int ret;
/* Did we get a valid file descriptor? */
if ((unsigned int)fd >= CONFIG_NFILE_DESCRIPTORS)
{
/* No networking... it is a bad descriptor in any event */
set_errno(EBADF);
return ERROR;
}
/* The descriptor is in a valid range to file descriptor... do the
* read. First, get the file structure. Note that on failure,
* fs_getfilep() will set the errno variable.
*/
filep = fs_getfilep(fd);
if (filep == NULL)
{
/* The errno value has already been set */
return ERROR;
}
/* Get the inode from the file structure */
inode = filep->f_inode;
DEBUGASSERT(inode != NULL);
/* The way we handle the stat depends on the type of inode that we
* are dealing with.
*/
#ifndef CONFIG_DISABLE_MOUNTPOINT
if (INODE_IS_MOUNTPT(inode))
{
/* The inode is a file system mointpoint. Verify that the mountpoint
* supports the fstat() method
*/
ret = -ENOSYS;
if (inode->u.i_mops && inode->u.i_mops->fstat)
{
/* Perform the fstat() operation */
ret = inode->u.i_mops->fstat(filep, buf);
}
}
else
#endif
{
/* The inode is part of the root pseudo file system. */
ret = inode_stat(inode, buf);
}
/* Check if the fstat operation was successful */
if (ret < 0)
{
set_errno(-ret);
return ERROR;
}
/* Successfully fstat'ed the file */
return OK;
}