Report the correct error message in libzfs when attaching/replacing a
vdev with a higher ashift.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#16449
zpool upgraded with 'feature@project_quota' needs re-layout of SA's
to fix the SA_ZPL_PROJID at SA_PROJID_OFFSET (128). Its necessary for
the correct accounting of object usage against its projid.
Old object (created before upgrade) when gets a projid assigned, its
SA gets re-layout via sa_add_projid(). If object has xattr dir, SA
of xattr dir also gets re-layout. But SA re-layout of xattr objects
inside a xattr dir is not done.
Fix zfs_setattr_dir() to re-layout SA's on xattr objects, when setting
projid on old xattr object (created before upgrade).
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jitendra Patidar <jitendra.patidar@nutanix.com>
Closes#16355Closes#16356
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: Rob Norris <robn@despairlabs.com>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#16431
Use /dev/urandom so we never have to wait on entropy.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes#16442
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/Closes#16400
Since the change to folios it has just been a wrapper anyway. Linux has
removed their wrapper, so we add one.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/Closes#16400
These fields are very old, so no detection necessary; we just move them
into the limit setup functions.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/Closes#16400
Apply them with with the rest of the settings.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/Closes#16400
Detect it, and use a macro to make sure we always match the prototype.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/Closes#16400
It's no longer available directly on the request queue, but its easy to
get from the attached disk.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/Closes#16400
In 6.11 struct queue_limits gains a 'features' field, where, among other
things, flush and write-cache are enabled. Detect it and use it.
Along the way, the blk_queue_set_write_cache() compat wrapper gets a
little cleanup. Since both flags are alway set together, its now a
single bool. Also the very very ancient version that sets q->flush_flags
directly couldn't actually turn it off, so I've fixed that. Not that we
use it, but still.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/Closes#16400
It gets hairier again in Linux 6.11, so I want some actual theory of
operation laid out for next time.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/Closes#16400
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#16432
-shared was hardcoded, so when building with --disable-shared it amounts
to trying to do shared linkage against static libs, which naturally
fails.
The fix is straightforward; just don't hardcode it. libtool will work
out what to do.
Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#16427
This applies the same change in #9115 to FreeBSD. This was actually the
old behavior in FreeBSD 12; it only regressed when FreeBSD support was
added to OpenZFS. As far as I can tell, the timeline went like this:
* Illumos's zfsvfs_teardown used an unconditional txg_wait_synced
* Illumos added the dirty data check [^4]
* FreeBSD merged in Illumos's conditional check [^3]
* OpenZFS forked from Illumos
* OpenZFS removed the dirty data check in #7795 [^5]
* @mattmacy forked the OpenZFS repo and began to add FreeBSD support
* OpenZFS PR #9115[^1] recreated the same dirty data check that Illumos
used, in slightly different form. At this point the OpenZFS repo did
not yet have multi-OS support.
* Matt Macy merged in FreeBSD support in #8987[^2] , but it was based on
slightly outdated OpenZFS code.
In my local testing, this vastly improves the reboot speed of a server
with a large pool that has 1000 datasets and is resilvering an HDD.
[^1]: https://github.com/openzfs/zfs/pull/9115
[^2]: https://github.com/openzfs/zfs/pull/8987
[^3]: 10b9d77bf1
[^4]: 5aaeed5c61
[^5]: https://github.com/openzfs/zfs/pull/7795
Sponsored by: Axcient
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Alan Somers <asomers@gmail.com>
Closes#16268
When building a static build (--disable-shared), zstream fails to link
because of the duplicate highbit64() in libzpool/kernel.c. Since they're
identical, and the libzpool one is visible to zstream, we remove
zstream's copy and just use the common one.
Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#16426
It's now the caller's responsibility do special handling for holes if
that's something it wants.
This also makes zio_compress_data() and zio_decompress_data() properly
the inverse of each other.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Jason Lee <jasonlee@lanl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16326
Commit 46ebd0a updated the build system to make symbolic link for zpool.
However, this commit did not update the automake file to also add the
symbolic link to the CLEANFILES variable. This is necessary so the link
is removed when running make clean/distclean.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes#16422
ln will fail if the target already exists, which causes make to bail
out. Adding -f makes it more "compiler-like", overwriting the target
instead.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Mateusz Piotrowski <0mp@FreeBSD.org>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16423
Previous code evicted nr_to_scan items from each NUMA node. This
not only multiplied the eviction by the number of nodes, but could
exhaust the smaller ones, evicting inodes used by acive workload
and requiring their immediate recreation. This patch spreads the
requested eviction between all NUMA nodes proportionally to their
evictable counts, which should be closer to expected LRU logic.
See kernel's super_cache_scan() as a similar logic example.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ameer Hamza <ahamza@ixsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#16397
Previous code pruned 10% of dnodes once 3/4 of metadata appeared
unevictable. On workloads with many millions of dnodes and little
other metadata it creates significant load spikes for many seconds
straight. This change instead gradually increases pruning as
unevictable metadata grow above the 3/4, which may allow it to
stabilize at some level.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#16401
- Skip config lock enter/exit for embedded blocks. They have no
DVAs, so there is nothing to check under the lock.
- Skip CHECKSUM check and properly check PSIZE for embedded blocks.
- Add static branch predictions for unlikely conditions.
- Do not verify DVAs for blocks already in ARC. ARC hit already
"verified" the first (often the only) DVA, and it does not worth to
enter/exit config lock for nothing.
Some profiles show me up to 3% of CPU saving from this change.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#16387
So far, the values of ZFS_MAXPROPLEN and ZPOOL_MAXPROPLEN were equal to
MAXPATHLEN, which is 1024 on FreeBSD and 4096 on Linux. This wasn't
ideal. Some of the surprising outcomes of this implementation are:
1. When creating a pool user property with zpool-set(8), libzfs makes
sure that the length of the property's value is less than
ZFS_MAXPROPLEN. However, the ZFS kernel module does not do that.
Instead, it checks the length against ZAP_MAXVALUELEN. As a result,
it is possible to create a property the length of which is going to
be larger than zpool(8) is ready to read.
2. A pool user property created on Linux is too big to be read on
FreeBSD.
This change sets both ZFS_MAXPROPLEN and ZPOOL_MAXPROPLEN to
ZAP_MAXVALUELEN, which is 8192 at the moment.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Mateusz Piotrowski <0mp@FreeBSD.org>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes#16248
The documentation mentioned that the property name can be 256 characters
long. This was incorrect. The last byte is reserved for NUL, so the
name provided by the operator can be only 255 characters long.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Mateusz Piotrowski <0mp@FreeBSD.org>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes#16248
Spare and l2cache vdev labels are not updated during import. Therefore,
if disk paths are updated between pool export and import, the AUX label
still shows the old paths. This patch syncs the AUX label
during import to show the correct path information.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Umer Saleem <usaleem@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#15817
Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
ZFS implements copy_file_range(2) using block cloning when possible.
This implementation must respect the RLIMIT_FSIZE limit.
zfs_clone_range() already checks the limit, so it is safe to remove this
check in zfs_freebsd_copy_file_range(). Moreover, the removed check
produces false positives: the length passed to copy_file_range(2) may be
larger than the input file size; as the man page notes, "for best
performance, call copy_file_range() with the largest len value
possible." In particular, some existing code passes SSIZE_MAX there.
The check in zfs_clone_range() clamps the length to the input file's
size before checking, but the removed check uses the caller supplied
length, so something like
$ echo a > /tmp/foo
$ limits -f 1024 cat /tmp/foo > /tmp/bar
fails because FreeBSD's cat(1) uses copy_file_range(2) in the manner
described above.
Reported-by: Philip Paeps <philip@FreeBSD.org>
Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
When importing multiple pools, the nvlist of properties given with "-o"
is shared amongst the several threads. So no thread should modify it.
Previously, in the course of validating the cachefile property, the
zpool_valid_proplist function would temporarily modify the value, and
then change it back. Now it will operate on a clone of the value.
Sponsored by: Axcient
Fixes#16405
Signed-off-by: Alan Somers <asomers@gmail.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Some libc's like uClibc lag the proper definition of SEEK_DATA
and SEEK_HOLE. Since we have only two files in ZTS which use
these definitons, let's define them by hand:
```
#ifndef SEEK_DATA
#define SEEK_DATA 3
#endif
#ifndef SEEK_HOLE
#define SEEK_HOLE 4
#endif
```
There should be no failures, because:
- FreeBSD has support for SEEK_DATA/SEEK_HOLE since FreeBSD 8
- Linux has it since Linux 3.1
- the libc will submit the parameters unchanged to the kernel
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Sponsored-by: Klara, Inc.
Signed-off-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Simplify the test, by using the variable "$PLATFORM_ID" in favor
of "$REDHAT_SUPPORT_PRODUCT_VERSION".
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
This fixes things so mirrored special vdevs report themselves as
"class=special" rather than "class=normal".
This happens due to the way the vdev nvlists are constructed:
mirrored special devices - The 'mirror' vdev has allocation bias as
"special" and it's leaf vdevs are "normal"
single or RAID0 special devices - Leaf vdevs have allocation bias as
"special".
This commit adds in code to check if a leaf's parent is a "special"
vdev to see if it should also report "special".
Reviewed-by: Ameer Hamza <ahamza@ixsystems.com>
Reviewed-by: Umer Saleem <usaleem@ixsystems.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes#16217
Run basic JSON validation tests on the new `zfs|zpool -j` output.
Reviewed-by: Ameer Hamza <ahamza@ixsystems.com>
Reviewed-by: Umer Saleem <usaleem@ixsystems.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes#16217
This commit adds support for zpool status command to displpay status
of ZFS pools in JSON format using '-j' option. Status information is
collected in nvlist which is later dumped on stdout in JSON format.
Existing options for zpool status work with '-j' flag. man page for
zpool status is updated accordingly.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Ameer Hamza <ahamza@ixsystems.com>
Signed-off-by: Umer Saleem <usaleem@ixsystems.com>
Closes#16217
This commit adds support for zpool list command to output the list of
ZFS pools in JSON format using '-j' option.. Information about available
pools is collected in nvlist which is later printed to stdout in JSON
format.
Existing options for zfs list command work with '-j' flag. man page for
zpool list is updated accordingly.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Ameer Hamza <ahamza@ixsystems.com>
Signed-off-by: Umer Saleem <usaleem@ixsystems.com>
Closes#16217
This commit adds support for zpool get command to output the list of
properties for ZFS Pools and VDEVS in JSON format using '-j' option.
Man page for zpool get is updated to include '-j' option.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Ameer Hamza <ahamza@ixsystems.com>
Signed-off-by: Umer Saleem <usaleem@ixsystems.com>
Closes#16217
This commit adds support for zpool version to output in JSON format
using '-j' option. Userland kernel module version is collected in nvlist
which is later displayed in JSON format. man page for zpool is updated.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Ameer Hamza <ahamza@ixsystems.com>
Signed-off-by: Umer Saleem <usaleem@ixsystems.com>
Closes#16217
This commit adds support for zfs mount to display mounted file systems
in JSON format using '-j' option. Data is collected in nvlist which is
printed in JSON format. man page for zfs mount is updated accordingly.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Ameer Hamza <ahamza@ixsystems.com>
Signed-off-by: Umer Saleem <usaleem@ixsystems.com>
Closes#16217
This commit adds support for JSON output for zfs list using '-j' option.
Information is collected in JSON format which is later printed in jSON
format. Existing options for zfs list also work with '-j'. man pages are
updated with relevant information.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Ameer Hamza <ahamza@ixsystems.com>
Signed-off-by: Umer Saleem <usaleem@ixsystems.com>
Closes#16217
This commit adds support for JSON output for zfs version and zfs get
commands. '-j' flag can be used to get output in JSON format.
Information is collected in nvlist objects which is later printed in
JSON format. Existing options that work for zfs get and zfs version
also work with '-j' flag.
man pages for zfs get and zfs version are updated accordingly.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Ameer Hamza <ahamza@ixsystems.com>
Signed-off-by: Umer Saleem <usaleem@ixsystems.com>
Closes#16217
Last commit should fix the underlying problem, so these should be
passing reliably again.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16364
Currently, if a minor is in use when we try to remove it, we'll skip it
and never come back to it again. Since the zvol state is hung off the
minor in the kernel, this can get us into weird situations if something
tries to use it after the removal fails. It's even worse at pool export,
as there's now a vestigial zvol state with no pool under it. It's
weirder again if the pool is subsequently reimported, as the zvol code
(reasonably) assumes the zvol state has been properly setup, when it's
actually left over from the previous import of the pool.
This commit attempts to tackle that by setting a flag on the zvol if its
minor can't be removed, and then checking that flag when a request is
made and rejecting it, thus stopping new work coming in.
The flag also causes a condvar to be signaled when the last client
finishes. For the case where a single minor is being removed (eg
changing volmode), it will wait for this signal before proceeding.
Meanwhile, when removing all minors, a background task is created for
each minor that couldn't be removed on the spot, and those tasks then
wake and clean up.
Since any new tasks are queued on to the pool's spa_zvol_taskq,
spa_export_common() will continue to wait at export until all minors are
removed.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#14872Closes#16364
SET_ERROR is our facility for tracking errors internally. The negation
is to match the what the kernel expects from us. Thus, the negation
should happen outside of the SET_ERROR.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16364
ZVOL_DUMPIFIED is a vestigial Solaris leftover, and not used anywhere.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16364
This includes the last 12.x release (now EOL) and 13.0 development
versions (<1300139).
Sponsored-by: https://despairlabs.com/sponsor/
Signed-off-by: Rob Norris <robn@despairlabs.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
This test was failing before:
- FAIL cli_root/zfs_copies/zfs_copies_006_pos (expected PASS)
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
The timezone "US/Mountain" isn't supported on newer linux versions.
Using the correct timezone "America/Denver" like it's done in FreeBSD
will fix this. Older Linux distros should behave also okay with this.
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
