incubator-nuttx/fs/vfs/fs_fstat.c

279 lines
7.9 KiB
C

/****************************************************************************
* fs/vfs/fs_fstat.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 <sys/stat.h>
#include <unistd.h>
#include <sched.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/fs/fs.h>
#include <nuttx/mtd/mtd.h>
#include "inode/inode.h"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: proxy_fstat
*
* Description:
* Check for special cases where the character driver is really just a
* proxy for the real, underlying MTD or block driver.
*
* NOTE: This must be done here rather than in the the common
* inode_stat() function because the filep reference must be available
* in order to call the character driver ioctl method.
*
* Input Parameters:
* filep - File structure instance
* inode - The inode associated with the file descriptor
* buf - The caller provide location in which to return information
* about the open file.
*
* Returned Value:
* Upon successful completion, 0 is returned. Otherwise, a negated errno
* value is returned.
*
****************************************************************************/
static int proxy_fstat(FAR struct file *filep, FAR struct inode *inode,
FAR struct stat *buf)
{
#ifdef CONFIG_MTD
struct mtd_geometry_s mtdgeo;
#endif
#ifndef CONFIG_DISABLE_MOUNTPOINT
struct geometry blkgeo;
#endif
int ret = -ENOENT;
/* Check if this is a valid character driver */
if (INODE_IS_DRIVER(inode) &&
inode->u.i_ops != NULL &&
inode->u.i_ops->ioctl != NULL)
{
#ifdef CONFIG_MTD
/* Check if this is a proxy for an MTD driver. In this case, both the
* MTDIOC_GEOMETRY ioctl and the BIOC_GEOMTRY will be supported by
* character driver.
*/
if (inode->u.i_ops->ioctl(filep, MTDIOC_GEOMETRY,
(unsigned long)((uintptr_t)&mtdgeo)) >= 0)
{
memset(buf, 0, sizeof(struct stat));
buf->st_mode = S_IFMTD;
buf->st_mode |= S_IROTH | S_IRGRP | S_IRUSR;
buf->st_mode |= S_IWOTH | S_IWGRP | S_IWUSR;
buf->st_size = mtdgeo.neraseblocks * mtdgeo.erasesize;
ret = OK;
}
#ifndef CONFIG_DISABLE_MOUNTPOINT
else
#endif
#endif
#ifndef CONFIG_DISABLE_MOUNTPOINT
/* Check if this is a proxy for a block driver. In this case, only
* the BIOC_GEOMETRY ioctl will be supported.
*/
if (inode->u.i_ops->ioctl(filep, BIOC_GEOMETRY,
(unsigned long)((uintptr_t)&blkgeo)) >= 0)
{
memset(buf, 0, sizeof(struct stat));
buf->st_mode = S_IFBLK;
if (inode->u.i_ops->read)
{
buf->st_mode |= S_IROTH | S_IRGRP | S_IRUSR;
}
if (inode->u.i_ops->write)
{
buf->st_mode |= S_IWOTH | S_IWGRP | S_IWUSR;
}
if (blkgeo.geo_available)
{
buf->st_size = blkgeo.geo_nsectors * blkgeo.geo_sectorsize;
}
ret = OK;
}
#endif
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: file_fstat
*
* Description:
* file_fstat() is an internal OS interface. It is functionally similar
* to the standard fstat() interface except:
*
* - It does not modify the errno variable,
* - It is not a cancellation point,
* - It does not handle socket descriptors, and
* - It accepts a file structure instance instead of file descriptor.
*
* Input Parameters:
* filep - File structure instance
* 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 file_fstat(FAR struct file *filep, FAR struct stat *buf)
{
FAR struct inode *inode;
int ret;
DEBUGASSERT(filep != NULL);
/* Get the inode from the file structure */
inode = filep->f_inode;
/* Was this file opened ? */
if (!inode)
{
return -EBADF;
}
/* 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 mountpoint. 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
#ifdef CONFIG_NET
if (INODE_IS_SOCKET(inode))
{
/* Let the networking logic handle the fstat() */
ret = psock_fstat(file_socket(filep), buf);
}
else
#endif
{
/* Check if the inode is a proxy for a block or MTD driver */
ret = proxy_fstat(filep, inode, buf);
if (ret < 0)
{
/* The inode is part of the root pseudo file system. */
ret = inode_stat(inode, buf, 0);
}
}
return ret;
}
/****************************************************************************
* 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;
int ret;
/* First, get the file structure. Note that on failure,
* fs_getfilep() will return the errno.
*/
ret = fs_getfilep(fd, &filep);
if (ret < 0)
{
goto errout;
}
/* Perform the fstat operation */
ret = file_fstat(filep, buf);
/* Check if the fstat operation was successful */
if (ret >= 0)
{
/* Successfully fstat'ed the file */
return OK;
}
errout:
set_errno(-ret);
return ERROR;
}