Re: virtio-9p-test.c:300:v9fs_req_recv: assertion failed (hdr.id == id): (7 == 73)

[Christian Schoenebeck]

On Montag, 23. November 2020 14:17:34 CET Greg Kurz wrote:
> Fixed maintainer's address: s/oss@crudebyte.com/qemu_oss@crudebyte.com
> 
> On Sat, 21 Nov 2020 17:03:14 -0500
> 
> Cole Robinson <crobinso@redhat.com> wrote:
> > Hi, I'm consistently seeing this assertion running the qemu-5.2.0  test
> > suite. rc0, rc1, rc2 have been consistently affected, it reproduces
> > consistently in parts of Fedora's build system. Here's an example build
> > log for rc2 x86 against Fedora 32
> > 
> > https://download.copr.fedorainfracloud.org/results/@kubevirt/qemu-5.2.0-0.
> > 6.rc2/fedora-32-x86_64/01781514-qemu/builder-live.log.gz
> > 
> > The full test error:
> > 
> > ...
> > PASS 26 qtest-arm/qos-test
> > /arm/virt/virtio-mmio/virtio-bus/virtio-9p-device/virtio-9p/virtio-9p-test
> > s/synth/readdir/split_128 PASS 27 qtest-arm/qos-test
> > /arm/virt/virtio-mmio/virtio-bus/virtio-9p-device/virtio-9p/virtio-9p-test
> > s/local/config
> Ok so the next test is supposed to be:
> 
> /arm/virt/virtio-mmio/virtio-bus/virtio-9p-device/virtio-9p/virtio-9p-tests/
> local/create_dir
> 
> This was added recently. This configures the virtio-9p device in QEMU
> to serve a real test directory from the host. This test directory is
> created under the current directory of the test process. The purpose
> of the test is then to ask the 9p server to create a directory within
> the test directory.
> 
> > Received response 7 (RLERROR) instead of 73 (RMKDIR)
> > ERROR qtest-arm/qos-test - Bail out!
> > ERROR:../tests/qtest/virtio-9p-test.c:300:v9fs_req_recv: assertion
> > failed (hdr.id == id): (7 == 73)
> > Rlerror has errno 95 (Operation not supported)
> 
> So this basically means that QEMU got ENOTSUP/EOPNOTSUPP when calling
> mkdir() into the test directory... not sure what could cause that. I'd
> need more details on the filesystem setup for the build.
> 
> Anyway, we already experienced some breakage in upstream CI because of
> the same family of tests that do real access to the host filesystem.
> Since they're being introduced in QEMU 5.2, I'll try to see if I can
> disable them to be run by default for RC3.
> 
> Cheers,
> 
> --
> Greg
> 
> > **
> > ERROR:../tests/qtest/virtio-9p-test.c:300:v9fs_req_recv: assertion
> > failed (hdr.id == id): (7 == 73)
> > make: *** [Makefile.mtest:1257: run-test-155] Error 1
> > error: Bad exit status from /var/tmp/rpm-tmp.EG4Dav (%check)
> > 
> > 
> > Thanks,
> > Cole

Yeah, looks like the mkdir() call which is supposed to create the 9p test 
directory, is failing there for some reason. The question is how to find that 
out (effectively) without having access to an affected system.

It's now too late for 5.2, but I think for 6.0 it would make sense introducing 
a dedicated 9p option loglevel=..., so we can tell people to enable this to 
capture the precise source location where an error ocurred. That would mean 
spreading a huge bunch of macros all over the 9p code base, but it would 
definitely help a lot understanding the root cause of reported issues in an 
efficient way.

Best regards,
Christian Schoenebeck