Tested failing because of missing loop devices

[Dan Kenigsberg]

On Wed, Dec 23, 2015 at 03:21:31AM +0200, Nir Soffer wrote:
> Hi all,
> 
> We see too many failures of tests using loop devices. Is it possible
> that we run tests
> concurrently on the same slave, using all the available loop devices, or maybe
> creating races between different tests?
> 
> It seems that we need new decorator for disabling tests on the CI
> slaves, since this
> environment is too fragile.
> 
> Here are some failures:
> 
> 01:10:33 ======================================================================
> 01:10:33 ERROR: testLoopMount (mountTests.MountTests)
> 01:10:33 ----------------------------------------------------------------------
> 01:10:33 Traceback (most recent call last):
> 01:10:33   File
> "/home/jenkins/workspace/vdsm_master_check-patch-fc23-x86_64/vdsm/tests/mountTests.py",
> line 128, in testLoopMount
> 01:10:33     m.mount(mntOpts="loop")
> 01:10:33   File
> "/home/jenkins/workspace/vdsm_master_check-patch-fc23-x86_64/vdsm/vdsm/storage/mount.py",
> line 225, in mount
> 01:10:33     return self._runcmd(cmd, timeout)
> 01:10:33   File
> "/home/jenkins/workspace/vdsm_master_check-patch-fc23-x86_64/vdsm/vdsm/storage/mount.py",
> line 241, in _runcmd
> 01:10:33     raise MountError(rc, ";".join((out, err)))
> 01:10:33 MountError: (32, ';mount: /tmp/tmpZuJRNk: failed to setup
> loop device: No such file or directory\n')
> 01:10:33 -------------------- >> begin captured logging << --------------------
> 01:10:33 Storage.Misc.excCmd: DEBUG: /usr/bin/taskset --cpu-list 0-1
> /sbin/mkfs.ext2 -F /tmp/tmpZuJRNk (cwd None)
> 01:10:33 Storage.Misc.excCmd: DEBUG: SUCCESS: <err> = 'mke2fs 1.42.13
> (17-May-2015)\n'; <rc> = 0
> 01:10:33 Storage.Misc.excCmd: DEBUG: /usr/bin/taskset --cpu-list 0-1
> /usr/bin/mount -o loop /tmp/tmpZuJRNk /var/tmp/tmpJO52Xj (cwd None)
> 01:10:33 --------------------- >> end captured logging << ---------------------
> 01:10:33
> 01:10:33 ======================================================================
> 01:10:33 ERROR: testSymlinkMount (mountTests.MountTests)
> 01:10:33 ----------------------------------------------------------------------
> 01:10:33 Traceback (most recent call last):
> 01:10:33   File
> "/home/jenkins/workspace/vdsm_master_check-patch-fc23-x86_64/vdsm/tests/mountTests.py",
> line 150, in testSymlinkMount
> 01:10:33     m.mount(mntOpts="loop")
> 01:10:33   File
> "/home/jenkins/workspace/vdsm_master_check-patch-fc23-x86_64/vdsm/vdsm/storage/mount.py",
> line 225, in mount
> 01:10:33     return self._runcmd(cmd, timeout)
> 01:10:33   File
> "/home/jenkins/workspace/vdsm_master_check-patch-fc23-x86_64/vdsm/vdsm/storage/mount.py",
> line 241, in _runcmd
> 01:10:33     raise MountError(rc, ";".join((out, err)))
> 01:10:33 MountError: (32, ';mount: /var/tmp/tmp1UQFPz/backing.img:
> failed to setup loop device: No such file or directory\n')
> 01:10:33 -------------------- >> begin captured logging << --------------------
> 01:10:33 Storage.Misc.excCmd: DEBUG: /usr/bin/taskset --cpu-list 0-1
> /sbin/mkfs.ext2 -F /var/tmp/tmp1UQFPz/backing.img (cwd None)
> 01:10:33 Storage.Misc.excCmd: DEBUG: SUCCESS: <err> = 'mke2fs 1.42.13
> (17-May-2015)\n'; <rc> = 0
> 01:10:33 Storage.Misc.excCmd: DEBUG: /usr/bin/taskset --cpu-list 0-1
> /usr/bin/mount -o loop /var/tmp/tmp1UQFPz/link_to_image
> /var/tmp/tmp1UQFPz/mountpoint (cwd None)
> 01:10:33 --------------------- >> end captured logging << ---------------------
> 01:10:33
> 01:10:33 ======================================================================
> 01:10:33 ERROR: test_getDevicePartedInfo (parted_utils_tests.PartedUtilsTests)
> 01:10:33 ----------------------------------------------------------------------
> 01:10:33 Traceback (most recent call last):
> 01:10:33   File
> "/home/jenkins/workspace/vdsm_master_check-patch-fc23-x86_64/vdsm/tests/testValidation.py",
> line 97, in wrapper
> 01:10:33     return f(*args, **kwargs)
> 01:10:33   File
> "/home/jenkins/workspace/vdsm_master_check-patch-fc23-x86_64/vdsm/tests/parted_utils_tests.py",
> line 61, in setUp
> 01:10:33     self.assertEquals(rc, 0)
> 01:10:33 AssertionError: 1 != 0
> 01:10:33 -------------------- >> begin captured logging << --------------------
> 01:10:33 root: DEBUG: /usr/bin/taskset --cpu-list 0-1 dd if=/dev/zero
> of=/tmp/tmpasV8TD bs=100M count=1 (cwd None)
> 01:10:33 root: DEBUG: SUCCESS: <err> = '1+0 records in\n1+0 records
> out\n104857600 bytes (105 MB) copied, 0.368498 s, 285 MB/s\n'; <rc> =
> 0
> 01:10:33 root: DEBUG: /usr/bin/taskset --cpu-list 0-1 losetup -f
> --show /tmp/tmpasV8TD (cwd None)
> 01:10:33 root: DEBUG: FAILED: <err> = 'losetup: /tmp/tmpasV8TD: failed
> to set up loop device: No such file or directory\n'; <rc> = 1
> 01:10:33 --------------------- >> end captured logging << ---------------------
> 

I've reluctantly marked another test as broken in https://gerrit.ovirt.org/50484
due to a similar problem.
Your idea of @brokentest_ci decorator is slightly less bad - at least we
do not ignore errors in this test when run on non-ci platforms.

Regards,
Dan.