Re: [PATCH 2/2] iotests: Add loop-accept-ro-dev test

[Kevin Wolf <kwolf@redhat.com>]

Am 28.10.2026 um 19:10 hat Eric Blake geschrieben:
> On Wed, Oct 28, 2026 at 06:10:57PM +0100, Kevin Wolf wrote:
> > Add a test for the accept-read-only-device option of host_device.
> > 
> > Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> > ---
> >  tests/qemu-iotests/tests/loop-accept-ro-dev   | 87 +++++++++++++++++++
> >  .../qemu-iotests/tests/loop-accept-ro-dev.out | 19 ++++
> >  2 files changed, 106 insertions(+)
> >  create mode 100755 tests/qemu-iotests/tests/loop-accept-ro-dev
> >  create mode 100644 tests/qemu-iotests/tests/loop-accept-ro-dev.out
> > 
> 
> > +
> > +run_qemu()
> > +{
> > +    echo -e '{"execute":"qmp_capabilities"}\n{"execute":"quit"}' |
> 
> 'printf %s' is slightly more portable than 'echo -e'; even though this
> script uses /bin/bash, you can use 'shopt -s xpg_echo' to break the
> latter. On the other hand, this is copy-paste from other tests, so not
> a showstopper.

Given that I have to fix the test anyway, I'll change it.

> > +    do_run_qemu "$@" 2>&1 | _filter_testdir | _filter_qemu | _filter_qmp |
> > +        _filter_generated_node_ids | _filter_imgfmt |
> > +        _filter_actual_image_size | _filter_img_info
> > +}
> > +
> > +if ! sudo -n losetup &>/dev/null; then
> > +    _notrun "sudo losetup not available"
> > +fi
> 
> Huh - we seem to have several outstanding patches related to probing
> whether losetup is usable:
> 
> https://lists.nongnu.org/archive/html/qemu-devel/2026-10/msg02963.html
> https://lists.nongnu.org/archive/html/qemu-devel/2026-10/msg01918.html
> 
> Is this a common enough pattern in our qemu-iotests that we should
> factor it out?

Maybe. There seem to be four tests (including this one) that use
losetup. This can be done in a separate patch, though.

> > +++ b/tests/qemu-iotests/tests/loop-accept-ro-dev.out
> > @@ -0,0 +1,19 @@
> > +QA output created by loop-accept-ro-dev
> > +
> > +=== Start QEMU on a loop device after blockdev --setro ===
> > +
> > +Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576
> > +Testing: -blockdev host_device,node-name=disk,filename=/dev/loop1 -device virtio-blk,drive=disk
> > +QEMU_PROG: -blockdev host_device,node-name=disk,filename=/dev/loop1: The device is not writable: Permission denied
> > +
> > +Testing: -blockdev host_device,node-name=disk,filename=/dev/loop1,accept-read-only-device=off -device virtio-blk,drive=disk
> 
> /dev/loop1 might already be busy, at which point losetup will pick
> /dev/loop2 or similar. This output needs to be filtered.

Oops, I'm too used to qemu-iotests filtering out all the filenames, but
obviously that doesn't work for something outside the scratch directory.
Thanks!

Kevin