Re: FS-specified FSID for non-device based filesystems?

[Al Viro <viro@ftp.linux.org.uk>]

On Wed, Apr 19, 2006 at 02:15:41PM +0200, Miklos Szeredi wrote:
> > > because Al Viro pokes obvious holes in the scheme.
> > > 
> > > I cannot find anything in Documentation/filesystems/sysfs.txt, so:
> > > How is /sys/fs supposed to work?
> > 
> > I don't know, as I didn't create it.  I think one of the FUSE developers
> > did.
> 
> Yeah.  There are a couple of FUSE specific attributes under
> /sys/fs/fuse (documented in Documentation/filesystems/fuse.txt).
> 
> I'll put a pointer into sysfs.txt.

Speaking of obvious holes, what is
        /* Setting file->private_data can't race with other mount()
           instances, since BKL is held for ->get_sb() */
        if (file->private_data)
                return -EINVAL;
doing, seeing that the next thing you do is GFP_KERNEL allocations, which
would kill all hope to use BKL-based protection here?