Re: [Xen-devel] [PATCH for-4.5] xl: print message to stdout when (!debug && dryrun)

[Wei Liu <wei.liu2@xxxxxxxxxx>]

On Sat, Dec 13, 2014 at 01:37:16PM -0500, Konrad Rzeszutek Wilk wrote:
> On Sat, Dec 13, 2014 at 04:54:05PM +0000, Wei Liu wrote:
> > In commit d36a3734a ("xl: fix migration failure with xl migrate
> > --debug"), message is printed to stderr for both debug mode
> > and dryrun mode. That caused rdname() in xendomains fails to parse
> > domain name since it's expecting input from xl's stdout.
> > 
> > So this patch separates those two cases. If xl is running in debug mode,
> > then message is printed to stderr; if xl is running in dryrun mode and
> > debug is not enabled, message is printed to stdout. This will fix
> > xendomains and other scripts that use "xl create --dryrun", as well as
> > not re-introducing the old bug fixed in d36a3734a.
> > 
> > Reported-by: Mark Pryor <tlviewer@xxxxxxxxx>
> > Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
> > Cc: M A Young <m.a.young@xxxxxxxxxxxx>
> > Cc: Ian Campbell <ian.campbell@xxxxxxxxxx>
> > Cc: Konrad Wilk <konrad.wilk@xxxxxxxxxx>
> > ---
> > This is a regression, and this bug is so subtle that's a bit hard to
> > debug from user's point of view. So I think this should go into 4.5.
> > 
> > Mark posted a workaround in
> > <104017455.78913.1418434454763.JavaMail.yahoo@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> > but to be honest I don't think it's nice to have everyone patch their
> > scripts in order to work around this.
> > ---
> >  tools/libxl/xl_cmdimpl.c |    4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
> > index 3737c7e..0a5f7c8 100644
> > --- a/tools/libxl/xl_cmdimpl.c
> > +++ b/tools/libxl/xl_cmdimpl.c
> > @@ -2472,8 +2472,10 @@ static uint32_t create_domain(struct domain_create 
> > *dom_info)
> >          }
> >      }
> >  
> > -    if (debug || dom_info->dryrun)
> > +    if (debug)
> >          printf_info(default_output_format, -1, &d_config, stderr);
> > +    if (!debug && dom_info->dryrun)
> 
> Could this 'else if (dom_info->dry_run)' ?
> 
> I know that semantically it is exactly the same as the 'if (!debug ..)' but
> it just "feels" more proper? Thought since you are the maintainer in that
> area - your opinion on how you want to do that is of course authoritive.
> 

I don't have strong preference on this. I just happened to type in
whatever style that flowed though my mind at that particular point. If
Ian and you both feel strongly about this I can certainly resend. :-)

Wei.

> Regardless,
> 
> Release-Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> > +        printf_info(default_output_format, -1, &d_config, stdout);
> >  
> >      ret = 0;
> >      if (dom_info->dryrun)
> > -- 
> > 1.7.10.4
> > 

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel