[Libguestfs] [PATCH nbdkit] nbd: Hide some state machine debugging behind a debug flag

[Richard W.M. Jones]

On Tue, May 10, 2022 at 08:45:50AM -0500, Eric Blake wrote:
> On Tue, May 10, 2022 at 10:43:04AM +0100, Richard W.M. Jones wrote:
> > When running virt-p2v which uses this plugin, the log file is consumed
> > by messages about state machine transitions and so on.  In a log file
> > that was shared with me, out of the 135,023 lines in total,
> > 94,653 (70%) were:
> > 
> >   nbdkit: debug: polling, dir=1
> > 
> > and 18,676 (14%) were:
> > 
> >   nbdkit: debug: cookie X completed state machine, status 0
> > 
> > This commit changes the logging so these state machine transitions are
> > only printed when you use the debug flag “-D nbd.verbose=1”.  I didn't
> > document this flag because it's likely only of use to developers who
> > are reading the code already.
> > 
> > There are some debug messages along error paths which are
> > (a) generally useful and (b) did not appear in the log file, so I left
> > those alone.
> > 
> > Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2083498
> > Reported-by: Ming Xie
> > ---
> >  plugins/nbd/nbd.c | 24 +++++++++++++++++-------
> >  1 file changed, 17 insertions(+), 7 deletions(-)
> 
> Reviewed-by: Eric Blake <eblake at redhat.com>

Thanks, that's commit 5a1908c461a8b45cc6d23e58e18149ee854ff300

Rich.

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