Re: [PATCH v2 1/3] iotests: Fix 173

[Eric Blake]

On 10/17/19 7:17 AM, Max Reitz wrote:

> > > Why haven't we noticed the failure? Because the test rarely gets run:
> > > './check -qcow2 173' is insufficient (that defaults to using file protocol)
> > > './check -nfs 173' is insufficient (that defaults to using raw format)
> > > so the test is only run with:
> > > ./check -qcow2 -nfs 173
> > >
> > > Note that we already have a number of other problems with -nfs:
> > > ./check -nfs (fails 18/30)
> > > ./check -qcow2 -nfs (fails 45/76 after this patch)
> > > and it's not on my priority list to fix those.  Rather, I found this
> > > because of my next patch's work on tests using _send_qemu_cmd.
> > >
> > > Fixes: 655ae6b
> > > Signed-off-by: Eric Blake <address@hidden>
> > > ---
> > >   tests/qemu-iotests/173     | 4 ++--
> > >   tests/qemu-iotests/173.out | 6 +++++-
> > >   2 files changed, 7 insertions(+), 3 deletions(-)
> >
> > On second thought, I wonder whether this test actually does anything
> > with NFS.  It doesn’t look like it to me.
> >
> > I wonder because for some reason I can’t get NFS to work with qemu at
> > all.  I don’t think the iotests are at fault why so many tests fail,
> > actually.
>
> OK, I was just missing an “insecure” in my exports.  I hate debugging NFS.

Hmm, that probably explains some of my failures as well.  It is not 
obvious what has to be done to a system prior to being able to even run 
'./check -nfs'; and it would be nice if ./check could give better 
heads-up warnings about an insufficient setup.

You may indeed have a point that the test may work with other non-local 
setups.  But with this a quick hack:

diff --git i/tests/qemu-iotests/173 w/tests/qemu-iotests/173
index 29dcaa1960df..c01d0186c6ba 100755
--- i/tests/qemu-iotests/173
+++ w/tests/qemu-iotests/173
@@ -40,7 +40,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.qemu

 _supported_fmt qcow2
-_supported_proto nfs
+_supported_proto nbd nfs

 size=100M

./check -qcow2 -nfs 173   # still passes
./check -qcow2 -nbd 173   # fails:

+{"error": {"class": "GenericError", "desc": "Failed to get "write" lock"}}
+Timeout waiting for return on handle 0

there may be more I can do to let this test work with nbd as well, but 
for the sake of getting this email sent, that's as far as I've gotten 
for now.

> Now I’m down to 16/76 for qcow2, and most of those look benign.  (As in,
> they simply don’t support nfs.)
>
> Max

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org