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Diffstat (limited to 'nuttx/fs/fs_foreachmountpoint.c')
| -rw-r--r-- | nuttx/fs/fs_foreachmountpoint.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/nuttx/fs/fs_foreachmountpoint.c b/nuttx/fs/fs_foreachmountpoint.c new file mode 100644 index 000000000..e7a620650 --- /dev/null +++ b/nuttx/fs/fs_foreachmountpoint.c @@ -0,0 +1,177 @@ +/**************************************************************************** + * 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 psuedo-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 |