[Tcl-soc2008] tcl-fuse: progress update

[Alexandros S. <al...@gm...>]

Hi all,

This is a progress update for the Tcl-Fuse project
(https://sourceforge.net/projects/tcl-fuse).

SINCE LAST UPDATE:

  * Implemented all the proxy functions that establish an interface
between: FUSE API <=> Tcl procedures
  * Completed the FuseVFS extension that fully exports Tcl's VFS to
userspace, via FUSE.
  * Preliminary API documentation in examples/fusetcl.tcl

FUSEVFS:

Code at: examples/fusevfs.tcl

The FuseVFS extension is implemented in Tcl using the tcl-fuse C
extension. It exports the Tcl's VFS on userspace, via FUSE. Based on
what it is provided by Tcl, the following FUSE operations have been
implemented and tested:
	getattr
	readdir
	readlink
	open
	read
	write
	rename
	mknod
	mkdir
	unlink
	rmdir
	chmod
	chown
	symlink
	link
	truncate
	access
	utimens
	truncate
	access
	flush
	fsync

Whereas the following were not implemented:
	statfs
	setxattr
	getxattr
	listxattr
	removexattr
	opendir
	releasedir
	fsyncdir
	create
	ftruncate
	fgetattr
	destroy
	lock
	bmap
	release
either because they weren't necessary (ftruncate, fgetattr, fsyncdir),
applicable (bmap), or the necessary information are not provided by Tcl
at all (statfs, setxattr, getxattr, listxattr, removexattr). For
example, Tcl's VFS does not support "exteded attributes", hence we
cannot provided them to FUSE.

An other limitation of Tcl's VFS is that it does not support create of
fifos, sockets, & device files, and hence it is not supported in FuseVFS
either.

The release, opendir, and releasedir operations are not necessary due to
the state-less nature of this implementation. A state-full version is
planned for implementation, which will have greater performance and more
thoroughly test tcl-fuse.

  * Implement a few subcommands of the "fuse" command, namely:
    delete, version, info & unmount.
  * Create Tcl cleanup procedures to automatically erase state.
  * Integration of FUSE events to Tcl's event loop
    and threading model.
  * Documentation (man page).

TO FETCH

svn checkout https://tcl-fuse.svn.sourceforge.net/svnroot/tcl-fuse

TO COMPILE

On 32bit:
    autoconf
    ./configure
    make
    sudo make install

On 64bit systems:
    autoconf
    PKG_CFLAGS="-D_FILE_OFFSET_BITS=64" \
     ./configure --with-tcl=/usr/lib64
    make
    sudo make install

Detailed instructions in README.tclfuse.

REQUIREMENTS:

  * Kernel with FUSE enabled (CONFIG_FUSE_FS)
  * Tcl 8.5
  * The user mounting a fuse filesystem must be in the "fuse" group (name
depends on the distro).

TO TRY IT OUT:

To mount the "hello" filesystem:

    cd <root of source code tree>
    tclsh examples/hello.tcl

To mount the FuseVFS filesystem that maps the root of Tcl's VFS:

    cd <root of source code tree>
    tclsh examples/test_fusevfs.tcl

In both cases the examples/mnt directory is where the filesystems will
get mounted.

Next status update will come after one or two weeks.

Regards,
Alexandros