FUSE(用户文件系统)
一，fuse介绍
FUSE实现实现了内核与用户之间的隔离，用户想要写一个文件系统只需修改根据用户想要实现的操作来改写fuse提供的API就可以了，这里还要提一个挂载的概念，就是将一个目录添加到了另一个目录下（类似于U盘一样），然后。可以对这个目录中的数据进行操作，就是挂载
二，fuse安装
本文末尾有fuse-2.9.3.tar.gz 下载包
解压：tar -zxvf fuse-2.9.3.tar.gz
进入解压包：cd fuse-2.9.3
安装：./configure (后面可以加 --prefis=/目录 这样可以指定安装路径，有时候系统为64位时，文件会被安装到了/usr/local/bli)
编译:make
安装:make install
卸载摸个目录下的挂载：fusermount -u 目录
用python 编辑fuse需要安装fusepy
下载fusepy（本文附带fusepy-2.0.0.tar.gz的下载包）
解压：tar -zxvf fusepy
进入解压后的文件夹：cd fusepy-2.0.2
这时候你会看到setup.py
运行fusepy：python setup.py install
然后回到有你的修改好的文件的文件夹中（文件以.py结尾）
运行：python 文件名 挂载文件夹 挂载路径（这个文件夹要为空才行）
如：[root@localhost fuse]# python test.py /usr /nn（这里nn文件夹要为空哦）
然后你就看到程序“停止了”其实已经挂载成功了
重新打开一个窗口，进入你的挂载路径，然后ls,你会发现这个文件夹下面的目录和你挂载的文件夹目录一样
[root@localhost usr]# ls
bin etc fusetest games include java lib lib64 libexec local sbin share src tmp
[root@localhost usr]# cd /yjt/jj/
[root@localhost jj]# ls
bin etc fusetest games include java lib lib64 libexec local sbin share src tmp
[root@localhost jj]#
然后还可以里面的文件进行操作哦
三，fuse目录
1 ./doc 包含FUSE相关文档
2 ./include 包含了FUSE API头，对创建文件系统有用，主要用fuse.h
3 ./lib 存放FUSE库的示代示
4 ./util 包含了FUSE工具库的示代示
5 ./example 参考的示子
四，关于fuse API修改
如果你用的是C的话，必须对C相当了解这里重点说python的修改
主要用到了python的os，os.path两个库可以试着去先看一下这些库里面函数的用法API的修改会容易的多
如文件的重命名函数的重写
def rename(self, old, new):
return os.rename(self._full_path(old), self._full_path(new))
就只用调用os.rename（）这个函数就可以了
这里提供一个fuse的案例大家可以看一下
#!/usr/bin/env python
from __future__ import with_statement
import os
import sys
import errno
from fuse import FUSE, FuseOSError, Operations
class Passthrough(Operations):
def __init__(self, root):
self.root = root
# Helpers
# =======
def _full_path(self, partial):
if partial.startswith("/"):
partial = partial[1:]
path = os.path.join(self.root, partial)
return path
# Filesystem methods
# ==================
def access(self, path, mode):
full_path = self._full_path(path)
if not os.access(full_path, mode):
raise FuseOSError(errno.EACCES)
def chmod(self, path, mode):
full_path = self._full_path(path)
return os.chmod(full_path, mode)
def chown(self, path, uid, gid):
full_path = self._full_path(path)
return os.chown(full_path, uid, gid)
def getattr(self, path, fh=None):
full_path = self._full_path(path)
st = os.lstat(full_path)
return dict((key, getattr(st, key)) for key in ('st_atime', 'st_ctime',
'st_gid', 'st_mode', 'st_mtime', 'st_nlink', 'st_size', 'st_uid'))
def readdir(self, path, fh):
full_path = self._full_path(path)
dirents = ['.', '..']
if os.path.isdir(full_path):
dirents.extend(os.listdir(full_path))
for r in dirents:
yield r
def readlink(self, path):
pathname = os.readlink(self._full_path(path))
if pathname.startswith("/"):
# Path name is absolute, sanitize it.
return os.path.relpath(pathname, self.root)
else:
return pathname
def mknod(self, path, mode, dev):
return os.mknod(self._full_path(path), mode, dev)
def rmdir(self, path):
full_path = self._full_path(path)
return os.rmdir(full_path)
def mkdir(self, path, mode):
return os.mkdir(self._full_path(path), mode)
def statfs(self, path):
full_path = self._full_path(path)
stv = os.statvfs(full_path)
return dict((key, getattr(stv, key)) for key in ('f_bavail', 'f_bfree',
'f_blocks', 'f_bsize', 'f_favail', 'f_ffree', 'f_files', 'f_flag',
'f_frsize', 'f_namemax'))
def unlink(self, path):
return os.unlink(self._full_path(path))
def symlink(self, target, name):
return os.symlink(self._full_path(target), self._full_path(name))
def rename(self, old, new):
return os.rename(self._full_path(old), self._full_path(new))
def link(self, target, name):
return os.link(self._full_path(target), self._full_path(name))
def utimens(self, path, times=None):
return os.utime(self._full_path(path), times)
# File methods
# ============
def open(self, path, flags):
full_path = self._full_path(path)
return os.open(full_path, flags)
def create(self, path, mode, fi=None):
full_path = self._full_path(path)
return os.open(full_path, os.O_WRONLY | os.O_CREAT, mode)
def read(self, path, length, offset, fh):
os.lseek(fh, offset, os.SEEK_SET)
return os.read(fh, length)
def write(self, path, buf, offset, fh):
os.lseek(fh, offset, os.SEEK_SET)
return os.write(fh, buf)
def truncate(self, path, length, fh=None):
full_path = self._full_path(path)
with open(full_path, 'r+') as f:
f.truncate(length)
def flush(self, path, fh):
return os.fsync(fh)
def release(self, path, fh):
return os.close(fh)
def fsync(self, path, fdatasync, fh):
return self.flush(path, fh)
def main(mountpoint, root):
FUSE(Passthrough(root), mountpoint, foreground=True)
if __name__ == '__main__':
main(sys.argv[2], sys.argv[1])
将这一个代码复制，然后命名为.py文件,可能会有缩进的问题，大家修改一下，按照上面的提示
[root@localhost fuse]# python test.py /usr /nn
即可运行