Re: [PATCH 1/5] populate: export the metadump description name

[Zorro Lang <zlang@redhat.com>]

On Thu, Oct 13, 2022 at 12:12:19PM -0700, Darrick J. Wong wrote:
> On Fri, Oct 14, 2022 at 12:28:26AM +0800, Zorro Lang wrote:
> > On Thu, Oct 13, 2022 at 08:54:35AM -0700, Darrick J. Wong wrote:
> > > On Thu, Oct 13, 2022 at 10:55:15PM +0800, Zorro Lang wrote:
> > > > On Tue, Oct 11, 2022 at 06:45:27PM -0700, Darrick J. Wong wrote:
> > > > > From: Darrick J. Wong <djwong@kernel.org>
> > > > > 
> > > > > Not sure why this hasn't been broken all along, but we should be
> > > > > exporting this variable so that it shows up in subshells....
> > > > 
> > > > May I ask where's the subshell which uses $POPULATE_METADUMP?
> > > 
> > > _scratch_xfs_fuzz_metadata does this:
> > > 
> > > 	echo "${fields}" | while read field; do
> > > 		echo "${verbs}" | while read fuzzverb; do
> > > 			__scratch_xfs_fuzz_mdrestore
> > > 				_xfs_mdrestore "${POPULATE_METADUMP}"
> > > 
> > > The (nested) echo piped to while starts subshells.
> > 
> > I'm not so familar with this part, so I didn't a simple test[1], and looks like
> > the PARAM can be seen, even it's not exported. Do I misunderstand something?
> > 
> > Thanks,
> > Zorro
> > 
> > [1]
> > $ echo "$list"
> > a
> > b
> > cc
> > $ PARAM="This's a test"
> > $ echo "$list"|while read c1;do echo "$list"|while read c2;do echo $PARAM;done; done
> > This's a test
> > This's a test
> > This's a test
> > This's a test
> > This's a test
> > This's a test
> > This's a test
> > This's a test
> > This's a test
> 
> Hmm.  I can't figure out why I needed the export here.  It was late one
> night, something was broken, and exporting the variable made it work.
> Now I can't recall exactly what that was and it seems fine without
> it...?
> 
> I guess I'll put it back and rerun the entire fuzz suite to see what
> pops out...

Sure, I don't have objection on this patch, so you can have the RVB when
you change "local POPULATE_METADUMP_DESCR" to lower-case, and show at least
one example about why POPULATE_METADUMP need to be exported in next version.
No push:)

Reviewed-by: Zorro Lang <zlang@redhat.com>

Thanks,
Zorro

> 
> --D
> 
> > > 
> > > > > 
> > > > > Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> > > > > ---
> > > > >  common/populate |    6 +++---
> > > > >  1 file changed, 3 insertions(+), 3 deletions(-)
> > > > > 
> > > > > 
> > > > > diff --git a/common/populate b/common/populate
> > > > > index cfdaf766f0..b501c2fe45 100644
> > > > > --- a/common/populate
> > > > > +++ b/common/populate
> > > > > @@ -868,9 +868,9 @@ _scratch_populate_cached() {
> > > > >  	local meta_tag="$(echo "${meta_descr}" | md5sum - | cut -d ' ' -f 1)"
> > > > >  	local metadump_stem="${TEST_DIR}/__populate.${FSTYP}.${meta_tag}"
> > > > >  
> > > > > -	# These variables are shared outside this function
> > > > > -	POPULATE_METADUMP="${metadump_stem}.metadump"
> > > > > -	POPULATE_METADUMP_DESCR="${metadump_stem}.txt"
> > > > > +	# This variable is shared outside this function
> > > > > +	export POPULATE_METADUMP="${metadump_stem}.metadump"
> > > > > +	local POPULATE_METADUMP_DESCR="${metadump_stem}.txt"
> > > > 
> > > > If the POPULATE_METADUMP_DESCR is not shared outside anymore, how about change
> > > > it to lower-case?
> > > 
> > > Ok.
> > > 
> > > --D
> > > 
> > > > >  
> > > > >  	# Don't keep metadata images cached for more 48 hours...
> > > > >  	rm -rf "$(find "${POPULATE_METADUMP}" -mtime +2 2>/dev/null)"
> > > > > 
> > > > 
> > > 
> > 
>