[Qemu-devel] [PATCH 0/2] iotests: Fix 226 on _my_ system

[Qemu-devel] [PATCH 0/2] iotests: Fix 226 on _my_ system

[Fam Zheng]

Something has locked /dev/null on my system (I still don't know what to do with
the annoying incapability of lslocks, or more precisely /proc/locks, on
inspecting OFD lock information), and as a result 226 cannot pass due to the
unexpected image locking error.

Fix the test case by disabling locking, and add a doc text about using test
images.

Fam Zheng (2):
  docs: Describe using images in writing iotests
  iotests: Don't lock /dev/null in 226

 docs/devel/testing.rst | 11 +++++++++++
 tests/qemu-iotests/226 |  4 ++--
 2 files changed, 13 insertions(+), 2 deletions(-)

-- 
2.17.1

[Qemu-devel] [PATCH 1/2] docs: Describe using images in writing iotests

[Fam Zheng]

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 docs/devel/testing.rst | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/docs/devel/testing.rst b/docs/devel/testing.rst
index 5e19cd50da..8e1fa3a66e 100644
--- a/docs/devel/testing.rst
+++ b/docs/devel/testing.rst
@@ -255,6 +255,17 @@ comparable library support for invoking and interacting with QEMU programs. If
 you opt for Python, it is strongly recommended to write Python 3 compatible
 code.
 
+Both Python and Bash frameworks in iotests provide helpers to manage test
+images. They can be used to create and clean up images under the test
+directory. If no I/O or any protocol specific feature is needed, it is often
+more convenient to use the pseudo block driver, ``null-co://``, as the test
+image, which doesn't require image creation or cleaning up. Avoid system-wide
+devices or files whenever possible, such as ``/dev/null`` or ``/dev/zero``.
+Otherwise, image locking implications have to be considered.  For example,
+another application on the host may have locked the file, possibly leading to a
+test failure.  If using such devices are explicitly desired, consider adding
+``locking=off`` option to disable image locking.
+
 Docker based tests
 ==================
 
-- 
2.17.1

[Qemu-devel] [PATCH 2/2] iotests: Don't lock /dev/null in 226

[Fam Zheng]

On my system (Fedora 28), this script reports a 'failed to get
"consistent read" lock' error. Following docs/devel/testing.rst, it's
better to add locking=off here.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 tests/qemu-iotests/226 | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/qemu-iotests/226 b/tests/qemu-iotests/226
index 211ea9888a..8ec3e612dd 100755
--- a/tests/qemu-iotests/226
+++ b/tests/qemu-iotests/226
@@ -56,10 +56,10 @@ for PROTO in "file" "host_device" "host_cdrom"; do
     echo
     echo "== Testing RO =="
     $QEMU_IO -c "open -r -o driver=$PROTO,filename=$TEST_IMG" 2>&1 | _filter_testdir | _filter_imgfmt
-    $QEMU_IO -c "open -r -o driver=$PROTO,filename=/dev/null" 2>&1 | _filter_imgfmt
+    $QEMU_IO -c "open -r -o driver=$PROTO,filename=/dev/null,locking=off" 2>&1 | _filter_imgfmt
     echo "== Testing RW =="
     $QEMU_IO -c "open -o driver=$PROTO,filename=$TEST_IMG" 2>&1 | _filter_testdir | _filter_imgfmt
-    $QEMU_IO -c "open -o driver=$PROTO,filename=/dev/null" 2>&1 | _filter_imgfmt
+    $QEMU_IO -c "open -o driver=$PROTO,filename=/dev/null,locking=off" 2>&1 | _filter_imgfmt
 done
 
 # success, all done
-- 
2.17.1

Re: [Qemu-devel] [PATCH 0/2] iotests: Fix 226 on _my_ system

[Eric Blake]

On 07/24/2018 03:47 AM, Fam Zheng wrote:
> Something has locked /dev/null on my system (I still don't know what to do with
> the annoying incapability of lslocks, or more precisely /proc/locks, on
> inspecting OFD lock information), and as a result 226 cannot pass due to the
> unexpected image locking error.
> 
> Fix the test case by disabling locking, and add a doc text about using test
> images.
> 
> Fam Zheng (2):
>    docs: Describe using images in writing iotests
>    iotests: Don't lock /dev/null in 226
> 

Reviewed-by: Eric Blake <eblake@redhat.com>

>   docs/devel/testing.rst | 11 +++++++++++
>   tests/qemu-iotests/226 |  4 ++--
>   2 files changed, 13 insertions(+), 2 deletions(-)
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

Re: [Qemu-devel] [PATCH 0/2] iotests: Fix 226 on _my_ system

[John Snow]

On 07/24/2018 04:47 AM, Fam Zheng wrote:
> Something has locked /dev/null on my system (I still don't know what to do with
> the annoying incapability of lslocks, or more precisely /proc/locks, on
> inspecting OFD lock information), and as a result 226 cannot pass due to the
> unexpected image locking error.
> 
> Fix the test case by disabling locking, and add a doc text about using test
> images.
> 
> Fam Zheng (2):
>   docs: Describe using images in writing iotests
>   iotests: Don't lock /dev/null in 226
> 
>  docs/devel/testing.rst | 11 +++++++++++
>  tests/qemu-iotests/226 |  4 ++--
>  2 files changed, 13 insertions(+), 2 deletions(-)
> 

I think this is the better approach for now, yeah. Sorry my test caused
so many problems... :[

Reviewed-by: John Snow <jsnow@redhat.com>

Re: [Qemu-devel] [PATCH 0/2] iotests: Fix 226 on _my_ system

[Fam Zheng]

On Tue, 07/24 16:47, Fam Zheng wrote:
> Something has locked /dev/null on my system (I still don't know what to do with
> the annoying incapability of lslocks, or more precisely /proc/locks, on
> inspecting OFD lock information), and as a result 226 cannot pass due to the
> unexpected image locking error.
> 
> Fix the test case by disabling locking, and add a doc text about using test
> images.
> 
> Fam Zheng (2):
>   docs: Describe using images in writing iotests
>   iotests: Don't lock /dev/null in 226
> 
>  docs/devel/testing.rst | 11 +++++++++++
>  tests/qemu-iotests/226 |  4 ++--
>  2 files changed, 13 insertions(+), 2 deletions(-)

Kevin, could you apply this for 3.0 too?

Fam

Re: [Qemu-devel] [PATCH 0/2] iotests: Fix 226 on _my_ system

[Kevin Wolf]

Am 27.07.2018 um 11:24 hat Fam Zheng geschrieben:
> On Tue, 07/24 16:47, Fam Zheng wrote:
> > Something has locked /dev/null on my system (I still don't know what to do with
> > the annoying incapability of lslocks, or more precisely /proc/locks, on
> > inspecting OFD lock information), and as a result 226 cannot pass due to the
> > unexpected image locking error.
> > 
> > Fix the test case by disabling locking, and add a doc text about using test
> > images.
> > 
> > Fam Zheng (2):
> >   docs: Describe using images in writing iotests
> >   iotests: Don't lock /dev/null in 226
> > 
> >  docs/devel/testing.rst | 11 +++++++++++
> >  tests/qemu-iotests/226 |  4 ++--
> >  2 files changed, 13 insertions(+), 2 deletions(-)
> 
> Kevin, could you apply this for 3.0 too?

Sure, applied to the block branch.

Out of curiosity, did you find out what had locked the devices?

Kevin

Re: [Qemu-devel] [PATCH 0/2] iotests: Fix 226 on _my_ system

[Fam Zheng]

On Fri, Jul 27, 2018 at 6:04 PM Kevin Wolf <kwolf@redhat.com> wrote:
>
> Am 27.07.2018 um 11:24 hat Fam Zheng geschrieben:
> > On Tue, 07/24 16:47, Fam Zheng wrote:
> > > Something has locked /dev/null on my system (I still don't know what to do with
> > > the annoying incapability of lslocks, or more precisely /proc/locks, on
> > > inspecting OFD lock information), and as a result 226 cannot pass due to the
> > > unexpected image locking error.
> > >
> > > Fix the test case by disabling locking, and add a doc text about using test
> > > images.
> > >
> > > Fam Zheng (2):
> > >   docs: Describe using images in writing iotests
> > >   iotests: Don't lock /dev/null in 226
> > >
> > >  docs/devel/testing.rst | 11 +++++++++++
> > >  tests/qemu-iotests/226 |  4 ++--
> > >  2 files changed, 13 insertions(+), 2 deletions(-)
> >
> > Kevin, could you apply this for 3.0 too?
>
> Sure, applied to the block branch.
>
> Out of curiosity, did you find out what had locked the devices?

No, but I'll for sure allocate some time to understand kernel's OFD
internals, find the holder application, then hopefully, propose
something that can fix lslocks.

Thanks,
Fam

>
> Kevin