[CRIU] [PATCH 1/3] crtools: allow to use --inherit-fd on dump to mark inhereted descriptors

[Andrew Vagin]

On Thu, Nov 26, 2015 at 04:57:35PM +0300, Pavel Emelyanov wrote:
> On 11/26/2015 12:32 PM, Andrey Vagin wrote:
> > From: Andrew Vagin <avagin at virtuozzo.com>
> > 
> > Signed-off-by: Andrew Vagin <avagin at virtuozzo.com>
> > ---
> >  crtools.c       |  4 ----
> >  files.c         | 14 +++++++++-----
> >  include/files.h |  1 +
> >  3 files changed, 10 insertions(+), 9 deletions(-)
> > 
> > diff --git a/crtools.c b/crtools.c
> > index 123ad06..0a4b8b5 100644
> > --- a/crtools.c
> > +++ b/crtools.c
> > @@ -597,10 +597,6 @@ int main(int argc, char *argv[], char *envp[])
> >  		return 1;
> >  
> >  	if (!list_empty(&opts.inherit_fds)) {
> > -		if (strcmp(argv[optind], "restore")) {
> > -			pr_err("--inherit-fd is restore-only option\n");
> > -			return 1;
> > -		}
> 
> No, the inherit-fd should remain restore-only option. Justification:
> 
> The "external" file descriptor can be restored in may ways. E.g. for sockets
> we can connect() it by hands. For files we can pre-open one before going
> into chroot. Maybe other ways are possible. And for _any_ of them we can
> inherit it from the parent. Thus inheritance is _one_ of the ways to
> _restore_ things.
> 
> So the question is -- how to tell criu that some fd is "external" on dump.
> I suggest using other option(s) for this. Maybe provide the unified
> --external-fd one that looks like --inherit-fd. And obsolete the -x with
> it.

We can use this option or an option with another names. It doesn't matter.

> 
> -- Pavel