sshfs and permissions

[Pierre Penninckx <ibizapeanut@gmail.com>]

Hi all,

I'm using sshfs to access files on my server and it works great.
However I have a problem with permissions.

But first, my setup:
I have a server where I put all my
movies/musics/pictures/documents/backups of laptops/git projects.
It works with raid1 and lvm so it is quite secure and infinitely
scalable (well... I still need to buy hard drives).
This server will be accessible mostly by my family, some friends and
maybe some co-workers.
Every service one can access will be under /srv (/srv/movies,
/srv/pictures, etc.) or under /home/<username>.
Most of the computers are laptops. I have a Mac, my mom has a linux
OS, and my sister who lives in another house has a windows OS.

I'd like a quite basic permission system:
Family can do anything on the files but delete other's files;
Friends can only add or read;
And some friends will be able to write to git projects.
I don't explicitly need a chrooted environment.
I managed to do everything through ACLs apart making friends add
things and not delete other things:
in fact this would work if the sticky bit (chmod +t) could be
inherited when creating a new directory but it is not :/

So like I said I didn't manage to make permission 100% work through
sshfs, though it works on the server or through DokanFS.
The ACL on the /srv/movies folder is:
# file: movies
# owner: root
# group: videos
# flags: -s-
user::rwx
group::rwx
other::r-x
default:user::rwx
default:group::rwx
default:other::r-x
(and the default user umask is 0022)

When creating a file in this directory while connect through the
server (or with DokanFS), the file has these permissions:
rw-rw-r-- fine.
But when creating it through sshfs it have:
rw-r--r-- bad.
And rwxr-xr-x for folders.

First, thanks for reading my long post.
Second, do you have any suggestions ?
I don't really know what to test.

Thanks,
Ibiz