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/****************************************************************************
* fs/fs_foreachmountpoint.c
*
* Copyright (C) 2012 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 <sys/statfs.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/fs/fs.h>
#include "fs_internal.h"
#ifndef CONFIG_DISABLE_MOUNTPOUNT
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
/* This structure just remembers the final consumer of the mountpoint
* information (and its argument).
*/
struct enum_mountpoint_s
{
foreach_mountpoint_t handler;
FAR void *arg;
};
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
static int mountpoint_filter(FAR struct inode *node,
FAR char dirpath[PATH_MAX], FAR void *arg)
{
FAR struct enum_mountpoint_s *info = (FAR struct enum_mountpoint_s *)arg;
struct statfs statbuf;
int pathlen;
int namlen;
int ret = OK;
DEBUGASSERT(node && info && info->handler);
/* Check if the inode is a mountpoint. Mountpoints must support statfs.
* If this one does not for some reason, then it will be ignored.
*
* The root node is a special case: It has no operations (u.i_mops == NULL)
*/
if (INODE_IS_MOUNTPT(node) && node->u.i_mops && node->u.i_mops->statfs)
{
/* Yes... get the full path to the inode by concatenating the inode
* name and the path to the directory containing the inode.
*/
pathlen = strlen(dirpath);
namlen = strlen(node->i_name) + 1;
/* Make sure that this would not exceed the maximum path length */
if (pathlen + namlen > PATH_MAX)
{
return -ENAMETOOLONG;
}
/* Append the inode name to the directory path */
sprintf(&dirpath[pathlen], "/%s", node->i_name);
/* Get the status of the file system */
ret = node->u.i_mops->statfs(node, &statbuf);
if (ret == OK)
{
/* And pass the full path and file system status to the handler */
ret = info->handler(dirpath, &statbuf, info->arg);
}
/* Truncate the path name back to the correct length */
dirpath[pathlen] = '\0';
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: foreach_mountpoint
*
* Description:
* Visit each mountpoint in the pseudo-file system. The traversal is
* terminated when the callback 'handler' returns a non-zero value, or when
* all of the mountpoints have been visited.
*
* This is just a front end "filter" to foreach_inode() that forwards only
* mountpoint inodes. It is intended to support the mount() command to
* when the mount command is used to enumerate mounts.
*
* NOTE 1: Use with caution... The pseudo-file system is locked throughout
* the traversal.
* NOTE 2: The search algorithm is recursive and could, in principle, use
* an indeterminant amount of stack space. This will not usually be a
* real work issue.
*
****************************************************************************/
int foreach_mountpoint(foreach_mountpoint_t handler, FAR void *arg)
{
struct enum_mountpoint_s info;
/* Let foreach_inode do the real work */
info.handler = handler;
info.arg = arg;
return foreach_inode(mountpoint_filter, (FAR void *)&info);
}
#endif
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