When dRAID performs a normal read operation only the data columns
in the raid map are read from disk. This is enough information to
calculate the checksum, verify it, and return the needed data to the
application. It's only in the event of a checksum failure that the
additional parity and any empty columns must be read since they are
required for parity reconstruction.
Reading these additional columns is handled by vdev_raidz_read_all()
which calls vdev_draid_map_alloc_empty() to expand the raid_map_t
and submit IOs for the missing columns. This all works correctly,
but it fails to account for any "short" columns. These are data
columns which are padded with a empty skip sector at the end.
Since that empty sector is not needed for a normal read it's not
read when columns is first read from disk. However, like the parity
and empty columns the skip sector is needed to perform reconstruction.
The fix is to mark any "short" columns as never being read by clearing
the rc_tried flag when expanding the raid_map_t. This will cause
the entire column to re-read from disk in the event of a checksum
failure allowing the self-healing functionality to repair the block.
Note that this only effects the self-healing feature because when
scrubbing a pool the parity, data, and empty columns are all read
initially to verify their contents. Furthermore, only blocks which
contain "short" columns would be effected, and only when the memory
backing the skip sector wasn't already zeroed out.
This change extends the existing redundancy_raidz.ksh test case to
verify self-healing (as well as resilver and scrub). Then applies
the same test case to dRAID with a slightly modified version of
the test script called redundancy_draid.ksh. The unused variable
combrec was also removed from both test cases.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12010
Afterward, git grep ZoL matches:
* README.md: * [ZoL Site](https://zfsonlinux.org)
- Correct
* etc/default/zfs.in:# ZoL userland configuration.
- Changing this would induce a needless upgrade-check,
if the user has modified the configuration;
this can be updated the next time the defaults change
* module/zfs/dmu_send.c: * ZoL < 0.7 does not handle [...]
- Before 0.7 is ZoL, so fair enough
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Issue #11956
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11970
Both the zpool_initialize_import_export and checkpoint_discard_busy
test cases a known to occasionally fail. Add them to the list of
known possible failures and reference the appropriate issue on the
tracker.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11949
Receiving datasets while blanket inheriting properties like zfs
receive -x mountpoint can generally be desirable, e.g. to avoid
unexpected mounts on backup hosts.
Currently this will fail to receive zvols due to the mountpoint
property being applicable to filesystems only. This limitation
currently requires operators to special-case their minds and tools
for zvols.
This change gets rid of this limitation for inherit (-x) by
Spiting up the dataset type handling: Warnings for inheriting (-x),
errors for overriding (-o).
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: InsanePrawn <insane.prawny@gmail.com>
Closes#11416Closes#11840Closes#11864
- Add additional logging to provide more information about why the
test failed. This including logging more of the individual commands
and the contents and differences of the record files on failure.
- Updated get_vdevs() to properly exclude all top-level vdevs
including raidz3 and draid[1-3].
- Replaced gnudd with dd. This is the only remaining place in the
test suite gnudd is used and it shouldn't be needed.
- The refill_test_env function expects the pool as the first argument
but never sets the pool variable.
- Only fill the test pools to 50% of capacity instead of 75% to help
speed up the tests.
- Fix replace_missing_devs() calculation, MINDEVSIZE should be
MINVDEVSIZE.
- Fix damage_devs() so it overwrites almost all of the device so
we're guaranteed to damage filesystem blocks.
- redundancy_stripe.ksh should not use log_mustnot to check if the
pool is healthy since the return value may be misinterpreted.
Just perform a normal conditional check and log the failure.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11906
It's been observed in the CI that the required 25% of obsolete bytes
in the mapping can be to high a threshold for this test resulting in
condensing never being triggered and a test failure. To prevent these
failures make the existing zfs_condense_indirect_obsolete_pct tuning
available so the obsolete percentage can be reduced from 25% to 5%
during this test.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11869
The fault/auto_spare_shared, l2arc/persist_l2arc_007_pos, and
alloc_class/alloc_class_013_pos test cases are not entirely reliable
and may occasionally fail resulting in a false positive in the CI.
Add these tests to known list of possible failures until they can
be made 100% reliable.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11890
A tentative implementation and discussion was done in #5285.
According to it a send --skip-missing|-s flag has been added.
In a replication stream, when there are snapshots missing in
the hierarchy, if -s is provided print a warning and ignore
dataset (and its children) instead of throwing an error
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pablo Correa Gómez <ablocorrea@hotmail.com>
Closes#11710
Kill the removal operation on every platform, not just Linux.
The test has been fixed and is now stable on FreeBSD.
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11856
As described in #11854, zhack is occasionally segfaulting on FreeBSD.
Debugging this is proving to be tricky. To avoid false positives in
the CI add entries for the tests that use zhack in zts-report to
accept that they may occasionally fail on FreeBSD.
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Issue #11854Closes#11855
Just as delay zevents can flood the zevent pipe when a vdev becomes
unresponsive, so do the deadman zevents.
Ratelimit deadman zevents according to the same tunable as for delay
zevents.
Enable deadman tests on FreeBSD and add a test for deadman event
ratelimiting.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Don Brady <don.brady@delphix.com>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11786
get_clones_string currently returns an empty string for filesystem
snapshots which have no clones. This breaks parsable `zfs get` output as
only three columns are output, instead of 4.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Fiddaman <github@m.fiddaman.uk>
Co-authored-by: matt <matt@fiddaman.net>
Closes#11837
The pool_checkpoint tests may incorrectly fail because several of
them invoke zdb for an imported pool. In this scenario it's not
unexpected for zdb to fail if the pool is modified. To resolve
this these zdb checks are now done after the pool has been exported.
Additionally, the default cleanup functions assumed the pool would
be imported when they were run. If this was not the case they're
exit early and fail to cleanup all of the test state causing
subsequent tests to fail. Add a check to only destroy the pool
when it is imported.
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11832
Correct an assortment of typos throughout the code base.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Closes#11774
200ms time-out is relatively long, but if we already hit the cap,
then we'll likely be able to spawn multiple new jobs when we wake up
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#11807
Add inheritance/inherit_001_pos to the maybe fails on FreeBSD list.
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11830
Nothing bad happens if a prefix of your pool name matches a disk name.
This is a bit of a silly restriction at this point.
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Ryan Moeller <freqlabs@FreeBSD.org>
Closes#11781Closes#11813
Commit 235a85657 introduced a regression in evaluation of POSIX modes
that require group DENY entries in the internal ZFS ACL. An example
of such a POSX mode is 007. When write_implies_delete_child is set,
then ACE_WRITE_DATA is added to `wanted_dirperms` in prior to calling
zfs_zaccess_common(). This occurs is zfs_zaccess_delete().
Unfortunately, when zfs_zaccess_aces_check hits this particular DENY
ACE, zfs_groupmember() is checked to determine whether access should be
denied, and since zfs_groupmember() always returns B_TRUE on Linux and
so this check is failed, resulting ultimately in EPERM being returned.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Andrew Walker <awalker@ixsystems.com>
Closes#11760
This change adds a new test that covers a bug fix in the binary search
in the redacted send resume logic that causes a kernel panic.
The bug was fixed in https://github.com/openzfs/zfs/pull/11297.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: John Kennedy <john.kennedy@delphix.com>
Signed-off-by: Palash Gandhi <palash.gandhi@delphix.com>
Closes#11764
Create a new section of tests to run with acltype=off.
For now the only test we have is for the DOS mode READONLY attribute on
FreeBSD.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11734
You can't use user_run to eval ksh functions defined in libtest unless
you include libtest in the user shell.
Fix xattr_003_neg by:
* include libtest in the user shell
* *then* run get_xattr
* assert this fails
* use variables for filenames so they don't change in the user's shell
* don't log the contents of /etc/passwd
* cleanup all byproducts
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11185
The current user_run often does not work as expected. Commands are run
in a different shell, with a different environment, and all output is
discarded.
Simplify user_run to retain the current environment, eliminate eval,
and feed the command string into ksh. Enhance the logging for
user_run so we can see out and err.
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11185
Importing a pool using the cachefile is ideal to reduce the time
required to import a pool. However, if the devices associated with
a pool in the cachefile have changed, then the import would fail.
This can easily be corrected by doing a normal import which would
then read the pool configuration from the labels.
The goal of this change is make importing using a cachefile more
resilient and auto-correcting. This is accomplished by having
the cachefile import logic automatically fallback to reading the
labels of the devices similar to a normal import. The main difference
between the fallback logic and a normal import is that the cachefile
import logic will only look at the device directories that were
originally used when the cachefile was populated. Additionally,
the fallback logic will always import by guid to ensure that only
the pools in the cachefile would be imported.
External-issue: DLPX-71980
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Wilson <gwilson@delphix.com>
Closes#11716
A few deadman tunables ended up in the wrong sysctl node.
Move them to vfs.zfs.deadman.*
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11715
events_002 exercises the ZED, ensuring that it neither misses events,
nor reporting events twice.
On slow test hardware, some of the timeouts are insufficient to allow
the ZED to properly settle. Conversely, on fast hardware these same
timeouts are too long, unnecessarily slowing the test run.
Instead of using a fixed timeout, wait for the expected final event
before returning. Additionally, wait with a timeout for unexpected
events to avoid missing them if they show up late.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Antonio Russo <aerusso@aerusso.net>
Closes#11703
* Restore original kern.corefile value after the test.
* Don't leave behind a frozen pool.
* Clean up leftover vdev files.
* Make zpool_002_pos and zpool_003_pos consistent in their handling of
core files while here.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11694
When a device which is actively trimming or initializing becomes
FAULTED, and therefore no longer writable, cancel the active
TRIM or initialization. When the device is merely taken offline
with `zpool offline` then stop the operation but do not cancel it.
When the device is brought back online the operation will be
resumed if possible.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Vipin Kumar Verma <vipin.verma@hpe.com>
Signed-off-by: Srikanth N S <srikanth.nagasubbaraoseetharaman@hpe.com>
Closes#11588
Several of the TRIM tests were based of the initialize tests and
then adapted for TRIM. The zpool_trim_start_and_cancel_pos.ksh
test was intended to be one such test but it was overlooked and
actually never adapted. Update it accordingly.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11649
The behavior of a NULL fromsnap was inadvertently changed for a doall
send when the send/recv logic in libzfs was updated. Restore the
previous behavior by correcting send_iterate_snap() to include all
the snapshots in the nvlist for this case.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Cedric Maunoury <cedric.maunoury@gmail.com>
Closes#11608
Fix regression seen in issue #11545 where checksum errors
where not being counted or showing up in a zpool event.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Don Brady <don.brady@delphix.com>
Closes#11609
Property to allow sets of features to be specified; for compatibility
with specific versions / releases / external systems. Influences
the behavior of 'zpool upgrade' and 'zpool create'. Initial man
page changes and test cases included.
Brief synopsis:
zpool create -o compatibility=off|legacy|file[,file...] pool vdev...
compatibility = off : disable compatibility mode (enable all features)
compatibility = legacy : request that no features be enabled
compatibility = file[,file...] : read features from specified files.
Only features present in *all* files will be enabled on the
resulting pool. Filenames may be absolute, or relative to
/etc/zfs/compatibility.d or /usr/share/zfs/compatibility.d (/etc
checked first).
Only affects zpool create, zpool upgrade and zpool status.
ABI changes in libzfs:
* New function "zpool_load_compat" to load and parse compat sets.
* Add "zpool_compat_status_t" typedef for compatibility parse status.
* Add ZPOOL_PROP_COMPATIBILITY to the pool properties enum
* Add ZPOOL_STATUS_COMPATIBILITY_ERR to the pool status enum
An initial set of base compatibility sets are included in
cmd/zpool/compatibility.d, and the Makefile for cmd/zpool is
modified to install these in $pkgdatadir/compatibility.d and to
create symbolic links to a reasonable set of aliases.
Reviewed-by: ericloewe
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Colm Buckley <colm@tuatha.org>
Closes#11468
There are two issues that don't allow ZFS to be compiled using uClibc.
`backtrace()`, and `program_invocation_short_name` as a `const`.
This patch adds uClibc to the conditionals in the same way there are
already for Glibc for `backtrace()`; and removes the external param
`program_invocation_short_name` because its only used here for the
whole project.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: José Luis Salvador Rufo <salvador.joseluis@gmail.com>
Closes#11600
All tests need to be included in the Makefiles.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Melikov <mail@gmelikov.ru>
Closes#11541
While you can use zdb -R poolname vdev:offset:[<lsize>/]<psize>[:flags]
to extract individual DVAs from a vdev, it would be handy for be able
copy an entire file out of the pool.
Given a file or object number, add support to copy the contents to a
file. Useful for debugging and recovery.
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Closes#11027
If there is no scsi_debug module, then this test
must be skipped, in this case cleanup routine should
be prepared for absent pool.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Melikov <mail@gmelikov.ru>
Closes#11534
When scrubbing, (non-sequential) resilvering, or correcting a checksum
error using RAIDZ parity, ZFS should heal any incorrect RAIDZ parity by
overwriting it. For example, if P disks are silently corrupted (P being
the number of failures tolerated; e.g. RAIDZ2 has P=2), `zpool scrub`
should detect and heal all the bad state on these disks, including
parity. This way if there is a subsequent failure we are fully
protected.
With RAIDZ2 or RAIDZ3, a block can have silent damage to a parity
sector, and also damage (silent or known) to a data sector. In this
case the parity should be healed but it is not.
The problem can be noticed by scrubbing the pool twice. Assuming there
was no damage concurrent with the scrubs, the first scrub should fix all
silent damage, and the second scrub should be "clean" (`zpool status`
should not report checksum errors on any disks). If the bug is
encountered, then the second scrub will repair the silently-damaged
parity that the first scrub failed to repair, and these checksum errors
will be reported after the second scrub. Since the first scrub repaired
all the damaged data, the bug can not be encountered during the second
scrub, so subsequent scrubs (more than two) are not necessary.
The root cause of the problem is some code that was inadvertently added
to `raidz_parity_verify()` by the DRAID changes. The incorrect code
causes the parity healing to be aborted if there is damaged data
(`rc_error != 0`) or the data disk is not present (`!rc_tried`). These
checks are not necessary, because we only call `raidz_parity_verify()`
if we have the correct data (which may have been reconstructed using
parity, and which was verified by the checksum).
This commit fixes the problem by removing the incorrect checks in
`raidz_parity_verify()`.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#11489Closes#11510
- refactor cleanup routines into common kshlib zpool_export_cleanup func
- don't require physical disks to test, just use files
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Will Andrews <will@firepipe.net>
Closes#11518
Instead of just failing, indicate the expected and actual value and
source as a NOTE. Tests using this failed in an earlier version of
the changeset and this information helped find the cause.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Will Andrews <will@firepipe.net>
Closes#11517
There is an identical definition in zfs_set_common.kshlib already.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Will Andrews <will@firepipe.net>
Closes#11516
This avoids globbing together multiple lines in the log, if you happen
to specify LOGAPI_DEBUG because you want to see it.
Signed-off-by: Will Andrews <will@firepipe.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11515
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11503
Provide a basic test coverage for io_uring I/O.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#11497
In FreeBSD the struct uio was just a typedef to uio_t. In order to
extend this struct, outside of the definition for the struct uio, the
struct uio has been embedded inside of a uio_t struct.
Also renamed all the uio_* interfaces to be zfs_uio_* to make it clear
this is a ZFS interface.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes#11438
Prior to util-linux 2.36.2, if a file or directory in the
current working directory was named 'dataset' then mount(8)
would prepend the current working directory to the dataset.
Eventually, we should be able to drop this workaround.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Sterling Jensen <sterlingjensen@users.noreply.github.com>
Closes#11295Closes#11462
As described in #11445, the kernel interface kernel_{read,write} no
longer act on special devices. In the ZTS, zfs send and receive are
tested by piping to these devices, leading to spurious failures (for
positive tests) and may mask errors (for negative tests).
Until a more permanent mechanism to address this deficiency is
developed, clean up the output from the ZTS by avoiding directly piping
to or from /dev/null and /dev/zero.
For /dev/zero input, simply use a pipe: `cat </dev/zero |` .
However, for /dev/null output, the shell semantics for pipe failures
means that zfs send error codes will be masked by the successful
`| cat >/dev/null` command execution. In that case, use a temporary
file under $TEST_BASE_DIR for output in favor.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Attila Fülöp <attila@fueloep.org>
Signed-off-by: Antonio Russo <aerusso@aerusso.net>
Closes#11478
The zfs_rollback_001 test modifies files in a temporary, test dataset
repeatedly. Before each iteration, any preexisting dataset is removed,
after unmounted with umount -f, if necessary.
Add a short delay after the forced unmount, avoiding a race that can
prevent zfs destroy from succeeding, leading to a test failure.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Antonio Russo <aerusso@aerusso.net>
Closes#11451
