encode_fh: have inode but no dentry

[Dan Magenheimer <dan.magenheimer@oracle.com>]

Hi Aneesh --

I see you are continuing with encode_fh related
development so I thought I would bring this up
with you.

I have a need to call the encode_fh op in a
situation where I have an inode but not a dentry,
and calling d_find_alias(inode) sometimes returns
NULL.  In my usage, connectable is always zero, so
having just the inode should be sufficient to get
useful results from encode_fh, at least for the
filesystems I've looked at.

What I'd like to see is the generic interface to
encode_fh extended to support this situation,
probably by passing inode as another parameter,
perhaps specified so that it can only be non-NULL
if connectable==0 and dentry==NULL.

Such a change would require a patch that touched
nearly every filesystem so it's clearly not to
be taken lightly.

Any thoughts on this?

Thanks,
Dan