Re: [fuse-devel] Incompatible mount data

[Miklos S. <mi...@sz...>]

> now that davfs2 is running with fuse kernel module version 5.x, I am 
> testing with version 7.x.
> 
> Unfortunately I had to notice that the mount data of this two versions 
> are incompatible. While option 'group_id' is mandatory with version 7.x, 
> it is not allowed with version 5.x. So it is impossible to communicate 
> with the fuse kernel module without evaluating the version in advance.
> 
> At the moment it looks like I have to leave this to the user, but that 
> is not very user friendly.
> 
> So I still believe some means to get the version from the running kernel 
> module (like the fcntl call of coda) would be a real useful feature.

The way fusermount deals with this problem is to first try the mount
with the 'group_id' option, and if that fails with EINVAL, try without
this option.  This isn't terribly elegant, but it should work.

Miklos