Quoting Hans Reiser <[EMAIL PROTECTED]>:

> [EMAIL PROTECTED] wrote:
> 
> >Quoting Hans Reiser <[EMAIL PROTECTED]>:
> >
> >...
> >
> >  
> >
> >>[EMAIL PROTECTED] wrote:

[...]

> >>>
> >>>Quoting Hubert Chan <[EMAIL PROTECTED]>:

[...]

> >I would suggest that for every link to a file on a different filesystem,
> the
> >linking directory should store both an identifier for the child file's
> >filesystem and the child file's on-disk inumber on that filesystem.* The
> reverse
> >links would be stored in the same way. 
> >
> I can accept a patch that does this.

(ulp) ... yessir. Two things though: first, it's going to be a while before I
have any patches for you. When I said I wasn't even a passable Unix geek I
wasn't being modest. But rest assured I am now working frantically on this. :)

Second, before implementing hard linking across directories you're really going
to need two-way links between directories and their children. * You'll also need
explicit file deletion and if possible weak non-symbolic links (..loose links).

* More precisely, you'll need the call to discover the parents of a given file.
The actual reference from child to parent is only absolutely necessary for links
across filesystems; on internal links it's basically a performance optimisation.

[...]

> >This leaves one significant problem: what happens when a file is moved from
> one
> >filesystem to another? What will prevent the cross-filesystem hard links to
> the
> >file from breaking? Cleaning up cross-filesystem links after explicit file
> >deletion is a related but simpler problem. I think a good but not ideal
> solution
> >to this problem is possible. I'll go into detail if anyone is interested.
> >  
> >
> More interested in patches....

In any case, hard links across filesystems alone is a solid 80% solution. You
probably want to implement it first before adding moving across directories.

[...]

Leo.

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