Port of FUSE-NTFS to FreeBSD (sort of)

[Csaba Henk]

On 2006-07-15, Ulrich Spoerlein <uspoerlein at gmail.com> wrote:
> the FUSE NTFS team has release a new version of its NTFS driver which
> promises to deliver write support for NTFS to FreeBSD.
> http://sourceforge.net/mailarchive/forum.php?thread_id=3D23836054&forum_id=
>=3D2697
>
> I made a port of the driver and fixed some build errors, but the port is
> still not working (for me), as it is running into an infinite loop.
>
> If some people would like to take it from here, I'd be glad to hand the
> port over, as I don't have that much time. At least all the boring stuff
> (pkg-descr, pkg-plist) has been taken care of.
>
> Here's further debugging info:
>
> Mounting the fuse device will result in an infinite loop in
> ntfs_attr_pread calling ntfs_pread unsuccessfully over and over again:
>
> (gdb) bt
> #0  ntfs_attr_pread (na=3D0x805e100, pos=3D476846, count=3D3354, b=3D0x8083=
> 000) at attrib.c:887
> #1  0x080497f3 in ntfs_fuse_get_nr_free_clusters (vol=3D0x8054100) at ntfs-=
> 3g.c:200
> #2  0x080498f1 in ntfs_fuse_statfs (path=3D0x480b62db "/", sfs=3D0xbfbfe600=
> ) at ntfs-3g.c:254
> #3  0x480b1cb1 in fuse_statfs () from /usr/local/lib/libfuse.so.2

My bet is that it's not a FUSE issue (neither kernel, nor lib). The bug
is apparently triggered below the fuselib level. I think it's either
some platform-related subtlety or a plain bug in the ntfs-3g code.

I also made a try with ntfs-3g, but, as I don't have real ntfs
partitions, I only tried with a quickly "mkntfs -fF"-d file. With that,
it works fine.

So, the misbehaviour is not easy to reproduce by our current knowledge,
that is, no other interested party can continue the work from where you
are.

I suggest you to go over one (or more) of the following possibilities:

 - Make a try with several ntfs volumes. If it works with most of them,
   send a pr for adding the port, and user feedback can help in tracking
   down the bug. (Btw, I'd suggest fusefs-ntfs3g or
   fusefs-ntfs-3g or fusefs-ntfs_3g as the port name -- I think
   including "3g" is necessary to make it unambigous what's we are
   dealing with.) 

 - Try to mount the same ntfs volume from Linux (if you don't have Linux
   on your box, you can still do it with a livecd). If the same thing
   happens, it's a bug in ntfs-3g, and you can report upstream (although
   the author is on a vacation ATM, as you probably know).

 - If gdb fails to uncover the reasons, fail back to plain old printf
   debug. Use the "-odebug,no_detach" mount options. Then the fs daemon
   won't go background and won't swallow output, so if you insert printfs
   you can make use of them. Moreover, the daemon will produce a lot of 
   debug output without needing to touch the code.

Regards,
Csaba