Re: [PATCH][CFT] per-process namespaces for Linux

[Werner Almesberger]

Alexander Viro wrote:
> No. Just an overmount.

Ah, too bad. Union mounts would have been really elegant (allowing the
operation to be repeated without residues, and also allowing umounting
of the covered FS as a sanity check). But I guess there's no way to
implement them without performance penalty ...

> Is it worth emptying?

Probably not ... the only interesting case would be if you could completely
umount it.

> BTW, Werner - could you take a look at the
> prepare_namespace()/handle_initrd()?

Okay, I'll have a look.

> That's our late boot process taken into one place. I'm really not happy
> about the following:

Agreed on all three counts. Also, change_root might just die by evolution,
just like most of NFS-root-from-initrd (using change_root) died.

What we need is a migration plan. Right now, it seems that most people
still use change_root. Hopefully they read the little message I left them
in linux/Documentation/initrd.txt:

  Current kernels still support it, but you should _not_ rely on its
  continued availability.

So with some luck, distributors will switch to pivot_root sometime soon,
when deploying 2.4. So if we drop all the old junk in 2.5, the amount of
letter bombs should be small ;-)

> Again, current patch reproduces the behaviour of the main tree.

Since you've already done all the work ... ;-) It's good if we can make
one change at a time.

- Werner

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 / Werner Almesberger, ICA, EPFL, CH           [e-mail] /
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