Re: ecryptfs

[Michael Halcrow <mhalcrow@us.ibm.com>]

On Mon, Aug 07, 2006 at 08:13:10PM -0400, Shaya Potter wrote:
> On Mon, 2006-08-07 at 17:47 -0500, Michael Halcrow wrote:
> > On Mon, Aug 07, 2006 at 01:21:04PM -0400, Josef Sipek wrote:
> > > On Mon, Aug 07, 2006 at 11:31:15AM -0500, Michael Halcrow wrote:
> > > ...
> > > > Here is where I am thinking about going with crossing lower mount
> > > > points. This patch makes sure that there is a 1-to-1 mapping in
> > > > inode numbers between the stacked inodes and the lower inodes. It
> > > > maintains the association by modifying the struct inode to include
> > > > a back pointer from the lower inode to the stacked inode.
> > > 
> > > Do you maintain the inode numbers across mounts (of ecryptfs)? The
> > > patch doesn't look like it does.
> > 
> > Nope; this patch just aims to make sure that stacked and lower inodes
> > maintain a 1-to-1 relationship.
> 
> so that won't let your cross mount points.... i.e. the 2 underlying
> mountpoints can have the same inode numbers, couldn't they?

Two underlying mountpoints can have the sane inode number. This patch
will assign a unique inode number to each stacked inode while linking
to the stacked inode from the lower inode to keep a 1-to-1 mapping of
stacked and lower inodes. Something like this is necessary for
crossing mount points in the lower filesystem while handling hard
links right. There are other issues with regard to namespaces and what
not that still need to be addressed.

Mike