用用户态文件系统(FUSE)解决假设ftp服务器时的编码问题

hellwolf

在假设ftp服务器时最讨厌的就是编码问题，在windows环境下，中文都是GB*的，而在Linux下UTF-8则使用的越来越广泛，为了解决这个矛盾，我写了个fuse-convmv用户态文件系统，现已经支持只读类的操作。
下面是软件的README文件：

Abstract
========

This is a filesystem client use the FUSE(Filesystem in
USErspace) interface to convert file name from one charset
to another.


Motivation
==========

Convmv(http://osx.freshmeat.net/projects/convmv/)is a
utility to converts filenames (not file content),
directories, and even whole filesystems to a different
encoding. Inspired by this tool, born was the convmvfs which
mirror a whole filesystem tree from one charset to another.

For example, in China there's a National Standard called
GB2312 which defined a charset to present most of the
Chinese character. And many ftp client used in China only
accept and show filename in GB2312. But in *nix world i18n
is more acceptable than l10n so many *nix server use UTF-8.
For example, there's a linux hosted box run a ftp server app
on it. The ftp server export /ftp/pub to anonymous access in
which all filenames are in UTF-8 charset. Now we can make a
directory called /ftp/pub_gb2312 and use our convmvfs tool to
mount a special fuse filesystem on /ftp/pub_gb2312, which
hotly convert the filename in /ftp/pub from UTF-8 to GB2312
but leave the contant unchanged.


Install
=======

First you need to download FUSE 2.5 or later from:

http://fuse.sourceforge.net

After installing FUSE, compile convmvfs the usual way:

./configure
make
make install (as root)

And you are ready to go.

If checking out from CVS for the first time also do
'autoreconf -iv' before doing './configure'.


How to use
==========

Once convmvfs is installed running it is very simple:

usage: convmvfs mountpoint [options]

general options:
-o opt,[opt...] mount options
-h --help print help
-V --version print version

FUSE options:
-d -o debug enable debug output (implies -f)
-f foreground operation
-s disable multi-threaded operation

-o allow_other allow access to other users
-o allow_root allow access to root
-o nonempty allow mounts over non-empty file/dir
-o default_permissions enable permission checking by kernel
-o fsname=NAME set filesystem name
-o large_read issue large read requests (2.4 only)
-o max_read=N set maximum size of read requests

-o hard_remove immediate removal (don't hide files)
-o use_ino let filesystem set inode numbers
-o readdir_ino try to fill in d_ino in readdir
-o direct_io use direct I/O
-o kernel_cache cache files in kernel
-o umask=M set file permissions (octal)
-o uid=N set file owner
-o gid=N set file group
-o entry_timeout=T cache timeout for names (1.0s)
-o negative_timeout=T cache timeout for deleted names (0.0s)
-o attr_timeout=T cache timeout for attributes (1.0s)

CONVMVFS options:
-o srcdir=PATH which directory to convert
-o icharset=CHARSET charset used in srcdir
-o ocharset=CHARSET charset used in mounted filesystem

Note:
* If you use normal user to mount file system be sure to have
r/w permision to /dev/fuse.

* use iconv --list to see which charsets are supported.

* to allow other user to access the mount point use allow_other option

Sample use:

* to mount
$convmvfs /ftp/pub_gbk -o srcdir=/ftp/pub, \
icharset=utf8,ocharset=gbk

* to umount
$fusermount -u /ftp/pub_gbk

___________________________________

举个应用例子，我在我的一个服务器上(debian sarge)配置有vsftp服务器。
1、首先安装Fuse>=2.5——不能使用debian sarge自带的，因为版本太老了。
2、编译安装后记住要设置每次开机都加载fuse内核模块，在debian下是修改/etc/modules文件。然后配置udev，让/dev/fuse文件的用户组为fuse（如果没有先添加这个用户组）：

1. 
   
2. #addgroup --system fuse
   
3. #cat /etc/udev/rules.d/40-fuse.rules
   
4. KERNEL="fuse", NAME="%k", MODE="0660",OWNER="root" GROUP="fuse"
   

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3、添加用户fuser属于组fuse
#adduser --ingroup fuse --disabled-password --no-create-home --system --shell /bin/sh fuser
4、修改/etc/fuse.conf添加：

1. 
   
2. # cat /etc/fuse.conf
   
3. user_allow_other
   

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5、然后就编译安装fuse-convmv（附件有)。
6、假设/home/ftp/pub中的所有文件名都是UTF-8编码的，现在新建一个/home/ftp/pub_gbk文件夹，并且将这个文件夹的属组设置为fuser。现在执行下列命令：

1. 
   
2. # su fuser -c '/usr/local/bin/convmvfs -o srcdir=/home/ftp/pub,icharset=utf8,ocharset=gbk,allow_other /home/ftp/pub_gbk'
   
3. srcdir=/home/ftp/pub/
   
4. icharset=utf8
   
5. ocharset=gbk
   

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成功后，访问ftp服务器，就会有pub和pub_gbk两个文件夹，其中pub是UTF-8编码的文件，pub_gbk是转换后的gbk编码文件名。

目前只支持读文件／读目录等操作，还不支持写入。欢迎大家与我一同交流。


P.S:0.1版本见附件

wwenyunkui2013

convmvfs 镜像以后，编码格式的确转换了，但是目录的context也变成了fusefs_t，而且不能修改，ftp客户端根本无法访问这个目录呀？？？
chcon  -t public_content_t /var/ftp/wenyk/
convmvfs /var/ftp/wenyk/ -o srcdir=/home/wenyk,icharset=UTF8,ocharset=gbk,nonempty

ls -Z /var/ftp/  
drwxr-xr-x. root  root  system_ubject_r:public_content_t:s0 pub
drwx------. wenyk wenyk system_ubject_r:fusefs_t:s0    wenyk
ftp://wenyk:wenyk@172.17.15.102

cannot change directory:/var/ftp/wenyk