Re: mountpoint information a get_sb

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

On Thu, Nov 23, 2006 at 01:51:24PM +0000, Mathieu Dube wrote:
> On Thu, 2006-11-23 at 18:32 +0000, Al Viro wrote:
> 
> > It might be mounted at any number of places, including 0.  Moreover,
> > it might be mounted at some place only to be immediately moved
> > elsewhere.
> > 
> > The question makes no sense.
> 
> Im sorry Im fairly new to this.
> 
> youre saying there is no way to know the mount point unless its already
> mounted?

I am saying that it can be mounted in any number of places at the same
time.
 
> for instance in kernel 2.2 you had a d_covers pointer to the dentry the
> mount would be placed on?

Kept in struct vfsmount since 2.4 and there can be many of those for the
same superblock.

> I need to know the subtree that will be made invisible once the fs is
> mounted

If you rely on something becoming invisible - you've got a problem.
It might be mounted elsewhere and not obscured there by anything.

If you want pass it *some* subtree, just pass it explicitly in the
options, but be ready to have it changed later on (stuff might be
mounted there, unmounted, moved around, etc.)

More details of what you are trying to do would be useful...