Interestingly this looks like an upstream bug as well. If for some
reason we are unable to get a zvols statistics, because perhaps the
zpool is hopelessly corrupt, we would trigger the VERIFY. This
commit adds the proper error handling just to propagate the error
back to user space. Now the user space tools still must handle this
properly but in the worst case the tool will crash or perhaps have
some missing output. That's far far better than crashing the host.
Closes#45
Several folks have now remarked that when the regression tests
fail they leave a mess behind. This was done intentionally at
the time to facilitate debugging the wreckage.
However, this also means that you may need to do some manual
cleanup such as removing the loopback devices before re-running
the tests. To simplify this proceedure I've added the '-c'
option to zconfig.sh which will attempt to cleanup the mess
from a previous test before starting.
This is somewhat dangerous because it must guess as to which
loopback devices you were using. But this risk is fairly minimal
because devices which are currently still is use can not be
cleaned up. And because only devices with 'zpool' in the name
are considered for removal. That said if your running parallel
copies of say zconfig.sh this may cause you some trouble.
Update the zconfig.sh test script to verify not only that volumes,
snapshots, and clones are created and removed properly. But also
verify that the partition information for each of these types of
devices is properly enumerated by the kernel.
Tests 4 and 5 now also create two partitions on the original volume
and these partitions are expected to also exist on the snapshot and
the clone. Correctness is verified after import/export, module
load/unload, dataset creation, and pool destruction.
Additionally, the code to create a partition table was refactored
in to a small helper function to simplify the test cases. And
finally all of the function variables were flagged 'local' to ensure
their scope is limited. This should have been done a while ago.
