Recent UMA changes repurposed the use of UMA_MD_SMALL_ALLOC in a way
that breaks arc_available_memory on -CURRENT. This change
ensures that arc_available_memory uses the new symbol
while maintaining compatibility with older FreeBSD releases.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Bojan Novković <bnovkov@FreeBSD.org>
Closes#16230
With seq x -1 z and x is less than z FreeBSD seq will print the error:
$ seq 1 -1 2
seq: needs positive increment
Hide this error. Alternatively $COMP_CWORD could be checked for < 2.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Derek Schrock <dereks@lifeofadishwasher.com>
Closes#16234
This fixes FreeBSD build failure with clang-18 after 23a489a got merged.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Rob Norris <rob.norris@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#16252
If a pool is created with the cache file located in a non-default
path /etc/default/zpool.cache, removed, or the cachefile property
is set to none, zdb fails to show the pool unless we specify the
cache file or use the -e option. This PR automates this process.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Akash B <akash-b@hpe.com>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#16071
We don't build illumos-crypto for FreeBSD.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16209
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16209
Nothing calls it through the KCF interface, so this is all unused.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16209
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16209
sha2_mech_type_t serves double-duty, as the list of MAC providers and
also the algo type for direct callers to SHA2Init. Until we disentangle
that, reorganise it to make the separation more clear. While we're
there, remove the digest mechs we don't use.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16209
For whatever reason, we call digest mechanisms directly, not through the
KCF digest provider. So we can remove those entry points entirely.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16209
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16209
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16209
Still retaining the struture, for now.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16209
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16209
We're seeing failures for redacted_deleted and redacted_mount
on FreeBSD 13-15:
09:58:34.74 diff: /dev/fd/3: No such file or directory
09:58:34.74 ERROR: diff /dev/fd/3 /dev/fd/4 exited 2
The test was trying to diff the file listings between two directories to
see if they are the same. The workaround is to do a string comparison
of the directory listings instead of using `diff`.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes#16224
These members have directly references to the global variables
exposed by the kernel. They are not going to be changed by this
kernel module.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Zhenlei Huang <zlei@FreeBSD.org>
Closes#16210
The 'zpool status' output assumes that the longest prefix is six
character long plus colon plus space, eg. 'status: ', 'action: '
or 'config: ' (so eight in total). This works well even when we have
messages that requires more than one line, as '\t' is exactly eight
characters, just like the longest prefix.
The 'zpool import' output is a bit different, as it may display the
comment pool property, then the longest prefix is 'comment: ', which is
nine characters long, not eight.
All the prefixes were given an extra space in front, but:
- 'status: ' did not get an extra space.
- Messages that require more than one line should use nine spaces of
indentation, not eight.
- The extra space in front looks redundant if there is no comment
property set on the given pool.
Fix it by adding an extra space to all prefixes, but only if the comment
property is defined. Also, when we need to continue the message in a new
line, use '\t ' for indentation.
While here, apply small corrections to a couple messages.
Before:
pool: tank
id: 7412636063178848859
state: ONLINE
status: Some supported features are not enabled on the pool.
(Note that they may be intentionally disabled if the
'compatibility' property is set.)
action: The pool can be imported using its name or numeric identif[...]
some features will not be available without an explicit 'zp[...]
comment: Example comment.
config:
bclone ONLINE
ada0 ONLINE
After:
pool: tank
id: 10180960571062436759
state: ONLINE
status: Some supported features are not enabled on the pool.
(Note that they may be intentionally disabled if the
'compatibility' property is set.)
action: The pool can be imported using its name or numeric identifi[...]
some features will not be available without an explicit 'zp[...]
config:
tank ONLINE
ada3 ONLINE
pool: dozer
id: 11028319538368222579
state: ONLINE
status: Some supported features are not enabled on the pool.
(Note that they may be intentionally disabled if the
'compatibility' property is set.)
action: The pool can be imported using its name or numeric identif[...]
some features will not be available without an explicit 'z[...]
comment: Example comment.
config:
dozer ONLINE
ada1 ONLINE
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pawel Dawidek <pawel@dawidek.net>
Closes#16128
The __maybe_unused macro is defined in spl/sys/debug.h
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Martin Matuska <mm@FreeBSD.org>
Closes#16229
We always call it twice with JUSTLOOKING and then FORREAL.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pawel Jakub Dawidek <pawel@dawidek.net>
Closes#16225
Optionally turn off disk's enclosure slot if an I/O is hung
triggering the deadman.
It's possible for outstanding I/O to a misbehaving SCSI disk to
neither promptly complete or return an error. This can occur due
to retry and recovery actions taken by the SCSI layer, driver, or
disk. When it occurs the pool will be unresponsive even though
there may be sufficient redundancy configured to proceeded without
this single disk.
When a hung I/O is detected by the kmods it will be posted as a
deadman event. By default an I/O is considered to be hung after
5 minutes. This value can be changed with the zfs_deadman_ziotime_ms
module parameter. If ZED_POWER_OFF_ENCLOSURE_SLOT_ON_DEADMAN is set
the disk's enclosure slot will be powered off causing the outstanding
I/O to fail. The ZED will then handle this like a normal disk failure.
By default ZED_POWER_OFF_ENCLOSURE_SLOT_ON_DEADMAN is not set.
As part of this change `zfs_deadman_events_per_second` is added
to control the ratelimitting of deadman events independantly of
delay events. In practice, a single deadman event is sufficient
and more aren't particularly useful.
Alphabetize the zfs_deadman_* entries in zfs.4.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#16226
- Add old eviction for special and dedup metaslab classes. Those
vdevs may be potentially big and fragmented with large metaslabs,
while their asynchronous write pattern is not really different
from normal class. It seems an omission to not evict old metaslabs
from them.
- If we have metaslab preload enabled, which means we are not too
low on memory, do not evict active metaslabs even if they are not
used for some time. Eviction of active metaslabs means we won't
be able to write anything until we load them, that may take some
time, that is straight opposite to metaslab preload goals. For
small systems the memory saving should be less important after
recent reduction in number of allocators and so open metaslabs.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#16214
In case of error dmu_buf_fill_done() returns the buffer back into
DB_UNCACHED state. Since during transition from DB_UNCACHED into
DB_FILL state dbuf_noread() allocates an ARC buffer, we must free
it here, otherwise it will be leaked.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#15665Closes#15802Closes#16216
At the end of l2arc_evict() fix an assertion in the case that l2ad_hand
+ distance == l2ad_end.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#16202Closes#16207
C99 6.7.8.17 says that when an undesignated initialiser is used, only
the first element of a union is initialised. If the first element is not
the largest within the union, how the remaining space is initialised is
up to the compiler.
GCC extends the initialiser to the entire union, while Clang treats the
remainder as padding, and so initialises according to whatever
automatic/implicit initialisation rules are currently active.
When Linux is compiled with CONFIG_INIT_STACK_ALL_PATTERN,
-ftrivial-auto-var-init=pattern is added to the kernel CFLAGS. This flag
sets the policy for automatic/implicit initialisation of variables on
the stack.
Taken together, this means that when compiling under
CONFIG_INIT_STACK_ALL_PATTERN on Clang, the "zero" initialiser will only
zero the first element in a union, and the rest will be filled with a
pattern. This is significant for aes_ctx_t, which in
aes_encrypt_atomic() and aes_decrypt_atomic() is initialised to zero,
but then used as a gcm_ctx_t, which is the fifth element in the union,
and thus gets pattern initialisation. Later, it's assumed to be zero,
resulting in a hang.
As confusing and undiscoverable as it is, by the spec, we are at fault
when we initialise a structure containing a union with the zero
initializer. As such, this commit replaces these uses with an explicit
memset(0).
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16135Closes#16206
If a shrink or truncate had recently freed a portion of the ZAP, the
dbuf could still be sitting on the dbuf cache waiting for eviction. If
it is then allocated for a new leaf before it can be evicted, the
zap_leaf_t is still attached as userdata, tripping the VERIFY.
Instead, just check for the userdata, and if we find it, reuse it.
Sponsored-by: Klara, Inc.
Sponsored-by: iXsystems, Inc.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16157.
Closes#16204
Since Linux 6.7 the kernel has defined intptr_t. Clang has
-Wtypedef-redefinition by default, which causes the build to fail
because we also have a typedef for intptr_t.
Since its better to use the kernel's if it exists, detect it and skip
our own.
Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#16201
On 32-bit platforms long long is generally 64-bits. Sufficiently modern
versions of gcc (13 in my testing) complains when casting a pointer to
an integer of a different width so cast to uintptr_t first to avoid the
warning.
Fixes: c183d164aa Parallel pool import
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Don Brady <don.brady@klarasystems.com>
Signed-off-by: Brooks Davis <brooks.davis@sri.com>
Closes#16203
Even though block cloning is much faster than regular copying,
it is not instantaneous - the file might be large and the recordsize
small. It would be nice to be able to interrupt it with a signal
(e.g., SIGINFO on FreeBSD to see the progress).
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pawel Jakub Dawidek <pawel@dawidek.net>
Closes#16208
Originally Solaris didn't expect errors there, but they may happen
if we fail to add entry into ZAP. Linux fixed it in #7421, but it
was never fully ported to FreeBSD.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#13215Closes#16138
sscanf returns number of items parsed on success and EOF on failure.
Reviewed-by: Adam Moss <c@yotes.com>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Rob Norris <robn@despairlabs.com>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#16198
In 92dc4ad83 I updated the dbuf_cache accounting to track the size of
userdata associated with dbufs. This adds the size of the dbuf+userdata
together in a single call to zfs_refcount_add_many(), but sometime
removes them in separate calls to zfs_refcount_remove_many(), if dbuf
and userdata are evicted separately.
What I didn't realise is that when refcount tracking is on,
zfs_refcount_add_many() and zfs_refcount_remove_many() are expected to
be paired, with their second & third args (count & holder) the same on
both sides. Splitting the remove part into two calls means the counts
don't match up, tripping a panic.
This commit fixes that, by always adding and removing the dbuf and
userdata counts separately.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reported-by: Mark Johnston <markj@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16191
And, make the output fd an arg to zfs_dbgmsg_print(). This is a change
in behaviour, but keeps it consistent with where crash traces go, and
it's easy to argue this is what we want anyway; this is information
about the task, not the actual output of the task.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16181
FreeBSD was using fprintf(), which might not be signal-safe. Meanwhile,
Linux's locking did not cover the header output. This two quirks are
unrelated, but both have the same response: be like the other one. So
with this commit, both functions are the same except for the names of
their lock and list variables.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16181
Mostly, try a lot harder to not allocate anything.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16181
If it's going to be used directly by zdb/ztest, then it sort of doesn't
make sense to carry it with the assert code.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16181
We can show much nicer backtraces these days, lets use them.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16181
ztest has a very nice ability to show a backtrace when there's an
unexpected crash. zdb is used often enough on corrupted data and can
blow up too, so nice output is useful there too.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16181
This renames it to spa_taskq_dispatch(), and reduces and simplifies its
arguments based on these observations from its two call sites:
- arg is always the zio, so it can be typed that way, and we don't need
to provide it twice;
- ent is always &zio->io_tqent, and zio is always provided, so we can
use it directly;
- the only flag used is TQ_FRONT, which can just be a bool;
- zio != NULL was part of the "use allocator" test, but it never would
have got that far, because that arg was only set to NULL in the
reexecute path, which is forced to type CLAIM, so the condition would
fail at t == WRITE anyway.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16151
It is the only user of spa_taskq_dispatch_select(), so might as well
just carry it directly.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16151
It has no callers anymore.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16151
When stack space is tight, the stream is written to its target on a
separate taskq thread to make sure there's enough stack space to
complete it.
This has always used an IO taskq, but that doesn't really make sense for
it, and moving it onto a regular taskq lets us get rid of
spa_taskq_dispatch_sync(), which is not used anywhere else.
Stream writes may block for a long time depending on what the target is,
and we have no way of discovering this, so we can't risk using the
system taskq, as there may be many tens of sends in progress. Instead,
we create a dedicated taskq thread for each send writer to run on, and
clean it up when it's done.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16151
Ever since a10d50f999, ZFS has mounted file systems in parallel when
importing a pool. It uses a fixed size of 512 for the thread pool. But
since c183d164aa, it has also imported pools in parallel. So the total
number of threads at one time is 513 * npools + 1. That can easily
exceed the system's limit on the number of threads per process, which
will cause one or more pools to be unable to allocate any worker
threads, forcing them to fallback to slow serial mounting . To
forestall that, manage the threadpool size in /sbin/zpool, not libzfs.
Use the same size (512), but divided by the number of pools.
This is a backwards-incompatible change to the libzfs abi.
Sponsored by: Axcient
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <gwilson@delphix.com>
Signed-off-by: Alan Somers <asomers@FreeBSD.org>
Closes#16178
During parallel zpool import, /sbin/zpool will create a separate thread
pool for each pool, used to mount that pool's datasets. If the total
thread count exceed's the system's limit on threads per process, then
tpool_dispatch may fail. If it does, directly execute the mount
operation instead.
Sponsored by: Axcient
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <gwilson@delphix.com>
Signed-off-by: Alan Somers <asomers@FreeBSD.org>
Closes#16178Fixes#16172
Sponsored by: Axcient
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <gwilson@delphix.com>
Signed-off-by: Alan Somers <asomers@FreeBSD.org>
Closes#16178
If we wait until after we check for no spa references to drop the
namespace lock, then we know that spa consumers will need to call
spa_lookup() and end up waiting on the spa_namespace_cv until we
finish. This narrows the external checks to spa_lookup and we no
longer need to worry about the spa_vdev_enter case.
Sponsored-By: Klara Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <gwilson@delphix.com>
Signed-off-by: Don Brady <don.brady@klarasystems.com>
Closes#16153
Changed spa_export_common() such that it no longer holds the
spa_namespace_lock for the entire duration and instead sets
spa_export_thread to indicate an import is in progress on the
spa. This allows for an export to a diffent pool to proceed
in parallel while an export is still processing potentially
long operations like spa_unload_log_sm_flush_all().
Calls like spa_lookup() and spa_vdev_enter() that rely on
the spa_namespace_lock to serialize them against a concurrent
export, now wait for any in-progress export thread to complete
before proceeding.
The 'zpool import -a' sub-command also provides multi-threaded
support, using a thread pool to submit the exports in parallel.
Sponsored-By: Klara Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <gwilson@delphix.com>
Signed-off-by: Don Brady <don.brady@klarasystems.com>
Closes#16153
When running a debug kernel with lockdep enabled there
are several locks which report false positives. Set
MUTEX_NOLOCKDEP/RW_NOLOCKDEP to disable these warnings.
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#16188
Depending on kind of error zap_expand_leaf() may return with or
without valid leaf reference held. Make sure it returns NULL if
due to error it has no leaf to return. Make its callers to check
the returned leaf pointer, and release the leaf if it is not NULL.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#12366Closes#16159
bnovkov