incubator-nuttx/fs/fs_findblockdriver.c

131 lines
4.4 KiB
C

/****************************************************************************
* fs/fs_openblockdriver.c
*
* Copyright (C) 2008 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* Redistribution and use in pathname and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of pathname 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 <sys/types.h>
#include <sys/mount.h>
#include <debug.h>
#include <errno.h>
#include <nuttx/fs.h>
#include "fs_internal.h"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: find_blockdriver
*
* Description:
* Return the inode of the block driver specified by 'pathname'
*
* Inputs:
* pathname - the full path to the block driver to be located
* mountflags - if MS_RDONLY is set, then driver must support write
* operations (see include/sys/mount.h)
* ppinode - address of the location to return the inode reference
*
* Return:
* Returns zero on success or a negated errno on failure:
*
* EINVAL - pathname or pinode is NULL
* ENOENT - No block driver of this name is registered
* ENOTBLK - The inode associated with the pathname is not a block driver
* EACCESS - The MS_RDONLY option was not set but this driver does not
* support write access
*
****************************************************************************/
int find_blockdriver(FAR const char *pathname, int mountflags, FAR struct inode **ppinode)
{
FAR struct inode *inode;
int ret = 0; /* Assume success */
/* Sanity checks */
#ifdef CONFIG_DEBUG
if (!pathname || !ppinode)
{
ret = -EINVAL;
goto errout;
}
#endif
/* Find the inode registered with this pathname */
inode = inode_find(pathname, NULL);
if (!inode)
{
fdbg("Failed to find %s\n", pathname);
ret = -ENOENT;
goto errout;
}
/* Verify that the inode is a block driver. */
if (!INODE_IS_BLOCK(inode))
{
fdbg("%s is not a block driver\n", pathname);
ret = -ENOTBLK;
goto errout_with_inode;
}
/* Make sure that the inode supports the requested access */
if (!inode->u.i_bops || !inode->u.i_bops->read ||
(!inode->u.i_bops->write && (mountflags & MS_RDONLY) == 0))
{
fdbg("%s does not support requested access\n", pathname);
ret = -EACCES;
goto errout_with_inode;
}
*ppinode = inode;
return OK;
errout_with_inode:
inode_release(inode);
errout:
return ret;
}