Since AVL already has embedded element counter, use dn_dbufs_count
only for dbufs not counted there (bonus buffers) and just add them.
This removes two atomics per dbuf life cycle.
According to profiler it reduces time spent by dbuf_destroy() inside
bottlenecked dbuf_evict_thread() from 13.36% to 9.20% of the core.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#9949
Coverity reports the variable may be NULL, but due to the
way the dirty records are handled this cannot be the case.
Add a comment and VERIFY to make this clear and silence
the warning.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#9962
As explained by the comment in dbuf_read() and above dbuf_read_impl().
Under all circumstances the parent lock specified by dblt should be
dropped when existing dbuf_read_impl(). This was not being done for
two exist paths. Additionally, ensure the mutex is unlocked before
dropping the parent lock.
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#9968
Factor the portion of dbuf_sync_leaf() responsible for handling bonus
buffers out in to its own dbuf_sync_bonus() helper function.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#9909
Move db_link into the same cache line as db_blkid and db_level.
It allows significantly reduce avl_add() time in dbuf_create() on
systems with large RAM and huge number of dbufs per dnode.
Avoid few accesses to dbuf_caches[].size, which is highly congested
under high IOPS and never stays in cache for a long time. Use local
value we are receiving from zfs_refcount_add_many() any way.
Remove cache_size_bytes_max bump from dbuf_evict_one(). I don't see
a point to do it on dbuf eviction after we done it on insertion in
dbuf_rele_and_unlock().
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#9931
Additionally pull in state machine comments about
upcoming async cow work.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#9902
It violated sequence described in kstat.h, and at least on FreeBSD
kstat_install() uses provided names to create the sysctls. If the
names are not available at the time, it ends up bad.
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#9933
Remove the ASSERTV macro and handle suppressing unused
compiler warnings for variables only in ASSERTs using the
__attribute__((unused)) compiler annotation. The annotation
is understood by both gcc and clang.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#9671
This change modifies some of the infrastructure for enabling the use of
the DTRACE_PROBE* macros, such that we can use tehm in the "spl" module.
Currently, when the DTRACE_PROBE* macros are used, they get expanded to
create new functions, and these dynamically generated functions become
part of the "zfs" module.
Since the "spl" module does not depend on the "zfs" module, the use of
DTRACE_PROBE* in the "spl" module would result in undefined symbols
being used in the "spl" module. Specifically, DTRACE_PROBE* would turn
into a function call, and the function being called would be a symbol
only contained in the "zfs" module; which results in a linker and/or
runtime error.
Thus, this change adds the necessary logic to the "spl" module, to
mirror the tracing functionality available to the "zfs" module. After
this change, we'll have a "trace_zfs.h" header file which defines the
probes available only to the "zfs" module, and a "trace_spl.h" header
file which defines the probes available only to the "spl" module.
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Prakash Surya <prakash.surya@delphix.com>
Closes#9525
Move Linux specific tracing headers and source to platform directories
and update the build system.
Reviewed-by: Allan Jude <allanjude@freebsd.org>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#9290
Adds ZFS_MODULE_PARAM to abstract module parameter
setting to operating systems other than Linux.
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@ixsystems.com>
Closes#9230
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Closes#9240
Even though the bug's writeup (Github issue #9136) is very detailed,
we still don't know exactly how we got to that state, thus I wasn't
able to reproduce the bug. That said, we can make an educated guess
combining the information on filled issue with the code.
From the fact that `dp_dirty_total` was 0 (which is less than
`zfs_dirty_data_max`) we know that there was one thread that set it to
0 and then signaled one of the waiters of `dp_spaceavail_cv` [see
`dsl_pool_dirty_delta()` which is also the only place that
`dp_dirty_total` is changed]. Thus, the only logical explaination
then for the bug being hit is that the waiter that just got awaken
didn't go through `dsl_pool_dirty_data()`. Given that this function
is only called by `dsl_pool_dirty_space()` or `dsl_pool_undirty_space()`
I can only think of two possible ways of the above scenario happening:
[1] The waiter didn't call into any of the two functions - which I
find highly unlikely (i.e. why wait on `dp_spaceavail_cv` to begin
with?).
[2] The waiter did call in one of the above function but it passed 0 as
the space/delta to be dirtied (or undirtied) and then the callee
returned immediately (e.g both `dsl_pool_dirty_space()` and
`dsl_pool_undirty_space()` return immediately when space is 0).
In any case and no matter how we got there, the easy fix would be to
just broadcast to all waiters whenever `dp_dirty_total` hits 0. That
said and given that we've never hit this before, it would make sense
to think more on why the above situation occured.
Attempting to mimic what Prakash was doing in the issue filed, I
created a dataset with `sync=always` and started doing contiguous
writes in a file within that dataset. I observed with DTrace that even
though we update the pool's dirty data accounting when we would dirty
stuff, the accounting wouldn't be decremented incrementally as we were
done with the ZIOs of those writes (the reason being that
`dbuf_write_physdone()` isn't be called as we go through the override
code paths, and thus `dsl_pool_undirty_space()` is never called). As a
result we'd have to wait until we get to `dsl_pool_sync()` where we
zero out all dirty data accounting for the pool and the current TXG's
metadata.
In addition, as Matt noted and I later verified, the same issue would
arise when using dedup.
In both cases (sync & dedup) we shouldn't have to wait until
`dsl_pool_sync()` zeros out the accounting data. According to the
comment in that part of the code, the reasons why we do the zeroing,
have nothing to do with what we observe:
````
/*
* We have written all of the accounted dirty data, so our
* dp_space_towrite should now be zero. However, some seldom-used
* code paths do not adhere to this (e.g. dbuf_undirty(), also
* rounding error in dbuf_write_physdone).
* Shore up the accounting of any dirtied space now.
*/
dsl_pool_undirty_space(dp, dp->dp_dirty_pertxg[txg & TXG_MASK], txg);
````
Ideally what we want to do is to undirty in the accounting exactly what
we dirty (I use the word ideally as we can still have rounding errors).
This would make the behavior of the system more clear and predictable.
Another interesting issue that I observed with DTrace was that we
wouldn't update any of the pool's dirty data accounting whenever we
would dirty and/or undirty MOS data. In addition, every time we would
change the size of a dbuf through `dbuf_new_size()` we wouldn't update
the accounted space dirtied in the appropriate dirty record, so when
ZIOs are done we would undirty less that we dirtied from the pool's
accounting point of view.
For the first two issues observed (sync & dedup) this patch ensures
that we still update the pool's accounting when we undirty data,
regardless of the write being physical or not.
For changes in the MOS, we first ensure to zero out the pool's dirty
data accounting in `dsl_pool_sync()` after we synced the MOS. Then we
can go ahead and enable the update of the pool's dirty data accounting
wheneve we change MOS data.
Another fix is that we now update the accounting explicitly for
counting errors in `dbuf_write_done()`.
Finally, `dbuf_new_size()` updates the accounted space of the
appropriate dirty record correctly now.
The problem is that we still don't know how the bug came up in the
issue filled. That said the issues fixed seem to be very relevant, so
instead of going with the broadcasting solution right away,
I decided to leave this patch as is.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
External-issue: DLPX-47285
Closes#9137
This patch introduces an assertion that can catch pitfalls in
development where there is a mismatch between the size of
reads and writes between a *_phys structure and its respective
in-core structure when bonus buffers are used.
This debugging-aid should be complementary to the verification
done by ztest in ztest_verify_dnode_bt().
A side to this patch is that we now clear out any extra bytes
past a bonus buffer's new size when the buffer is shrinking.
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#8348
Deleting a clone requires finding blocks are clone-only, not shared
with the snapshot. This was done by traversing the entire block tree
which results in a large performance penalty for sparsely
written clones.
This is new method keeps track of clone blocks when they are
modified in a "Livelist" so that, when it’s time to delete,
the clone-specific blocks are already at hand.
We see performance improvements because now deletion work is
proportional to the number of clone-modified blocks, not the size
of the original dataset.
Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: Sara Hartse <sara.hartse@delphix.com>
Closes#8416
lockdep reports a possible recursive lock in dbuf_destroy.
It is true that dbuf_destroy is acquiring the dn_dbufs_mtx
on one dnode while holding it on another dnode. However,
it is impossible for these to be the same dnode because,
among other things,dbuf_destroy checks MUTEX_HELD before
acquiring the mutex.
This fix defines a class NESTED_SINGLE == 1 and changes
that lock to call mutex_enter_nested with a subclass of
NESTED_SINGLE.
In order to make the userspace code compile,
include/sys/zfs_context.h now defines mutex_enter_nested and
NESTED_SINGLE.
This is the lockdep report:
[ 122.950921] ============================================
[ 122.950921] WARNING: possible recursive locking detected
[ 122.950921] 4.19.29-4.19.0-debug-d69edad5368c1166 #1 Tainted: G O
[ 122.950921] --------------------------------------------
[ 122.950921] dbu_evict/1457 is trying to acquire lock:
[ 122.950921] 0000000083e9cbcf (&dn->dn_dbufs_mtx){+.+.}, at: dbuf_destroy+0x3c0/0xdb0 [zfs]
[ 122.950921]
but task is already holding lock:
[ 122.950921] 0000000055523987 (&dn->dn_dbufs_mtx){+.+.}, at: dnode_evict_dbufs+0x90/0x740 [zfs]
[ 122.950921]
other info that might help us debug this:
[ 122.950921] Possible unsafe locking scenario:
[ 122.950921] CPU0
[ 122.950921] ----
[ 122.950921] lock(&dn->dn_dbufs_mtx);
[ 122.950921] lock(&dn->dn_dbufs_mtx);
[ 122.950921]
*** DEADLOCK ***
[ 122.950921] May be due to missing lock nesting notation
[ 122.950921] 1 lock held by dbu_evict/1457:
[ 122.950921] #0: 0000000055523987 (&dn->dn_dbufs_mtx){+.+.}, at: dnode_evict_dbufs+0x90/0x740 [zfs]
[ 122.950921]
stack backtrace:
[ 122.950921] CPU: 0 PID: 1457 Comm: dbu_evict Tainted: G O 4.19.29-4.19.0-debug-d69edad5368c1166 #1
[ 122.950921] Hardware name: Supermicro H8SSL-I2/H8SSL-I2, BIOS 080011 03/13/2009
[ 122.950921] Call Trace:
[ 122.950921] dump_stack+0x91/0xeb
[ 122.950921] __lock_acquire+0x2ca7/0x4f10
[ 122.950921] lock_acquire+0x153/0x330
[ 122.950921] dbuf_destroy+0x3c0/0xdb0 [zfs]
[ 122.950921] dbuf_evict_one+0x1cc/0x3d0 [zfs]
[ 122.950921] dbuf_rele_and_unlock+0xb84/0xd60 [zfs]
[ 122.950921] dnode_evict_dbufs+0x3a6/0x740 [zfs]
[ 122.950921] dmu_objset_evict+0x7a/0x500 [zfs]
[ 122.950921] dsl_dataset_evict_async+0x70/0x480 [zfs]
[ 122.950921] taskq_thread+0x979/0x1480 [spl]
[ 122.950921] kthread+0x2e7/0x3e0
[ 122.950921] ret_from_fork+0x27/0x50
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jeff Dike <jdike@akamai.com>
Closes#8984
Currently, sequential async write workloads spend a lot of time
contending on the dn_struct_rwlock. This lock is responsible for
protecting the entire block tree below it; this naturally results
in some serialization during heavy write workloads. This can be
resolved by having per-dbuf locking, which will allow multiple
writers in the same object at the same time.
We introduce a new rwlock, the db_rwlock. This lock is responsible
for protecting the contents of the dbuf that it is a part of; when
reading a block pointer from a dbuf, you hold the lock as a reader.
When writing data to a dbuf, you hold it as a writer. This allows
multiple threads to write to different parts of a file at the same
time.
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed by: Matt Ahrens matt@delphix.com
Reviewed by: George Wilson george.wilson@delphix.com
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
External-issue: DLPX-52564
External-issue: DLPX-53085
External-issue: DLPX-57384
Closes#8946
The "zfs remap" command was disabled by
6e91a72fe3, because it has little utility
and introduced some tricky bugs. This commit removes the code for it,
the associated ZFS_IOC_REMAP ioctl, and tests.
Note that the ioctl and property will remain, but have no functionality.
This allows older software to fail gracefully if it attempts to use
these, and avoids a backwards incompatibility that would be introduced if
we renumbered the later ioctls/props.
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#8944
Redacted send/receive allows users to send subsets of their data to
a target system. One possible use case for this feature is to not
transmit sensitive information to a data warehousing, test/dev, or
analytics environment. Another is to save space by not replicating
unimportant data within a given dataset, for example in backup tools
like zrepl.
Redacted send/receive is a three-stage process. First, a clone (or
clones) is made of the snapshot to be sent to the target. In this
clone (or clones), all unnecessary or unwanted data is removed or
modified. This clone is then snapshotted to create the "redaction
snapshot" (or snapshots). Second, the new zfs redact command is used
to create a redaction bookmark. The redaction bookmark stores the
list of blocks in a snapshot that were modified by the redaction
snapshot(s). Finally, the redaction bookmark is passed as a parameter
to zfs send. When sending to the snapshot that was redacted, the
redaction bookmark is used to filter out blocks that contain sensitive
or unwanted information, and those blocks are not included in the send
stream. When sending from the redaction bookmark, the blocks it
contains are considered as candidate blocks in addition to those
blocks in the destination snapshot that were modified since the
creation_txg of the redaction bookmark. This step is necessary to
allow the target to rehydrate data in the case where some blocks are
accidentally or unnecessarily modified in the redaction snapshot.
The changes to bookmarks to enable fast space estimation involve
adding deadlists to bookmarks. There is also logic to manage the
life cycles of these deadlists.
The new size estimation process operates in cases where previously
an accurate estimate could not be provided. In those cases, a send
is performed where no data blocks are read, reducing the runtime
significantly and providing a byte-accurate size estimate.
Reviewed-by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Prashanth Sreenivasa <pks@delphix.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Reviewed-by: Chris Williamson <chris.williamson@delphix.com>
Reviewed-by: Pavel Zhakarov <pavel.zakharov@delphix.com>
Reviewed-by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#7958
When receiving a DRR_OBJECT record the receive_object() function
needs to determine how to handle a spill block associated with the
object. It may need to be removed or kept depending on how the
object was modified at the source.
This determination is currently accomplished using a heuristic which
takes in to account the DRR_OBJECT record and the existing object
properties. This is a problem because there isn't quite enough
information available to do the right thing under all circumstances.
For example, when only the block size changes the spill block is
removed when it should be kept.
What's needed to resolve this is an additional flag in the DRR_OBJECT
which indicates if the object being received references a spill block.
The DRR_OBJECT_SPILL flag was added for this purpose. When set then
the object references a spill block and it must be kept. Either
it is update to date, or it will be replaced by a subsequent DRR_SPILL
record. Conversely, if the object being received doesn't reference
a spill block then any existing spill block should always be removed.
Since previous versions of ZFS do not understand this new flag
additional DRR_SPILL records will be inserted in to the stream.
This has the advantage of being fully backward compatible. Existing
ZFS systems receiving this stream will recreate the spill block if
it was incorrectly removed. Updated ZFS versions will correctly
ignore the additional spill blocks which can be identified by
checking for the DRR_SPILL_UNMODIFIED flag.
The small downside to this approach is that is may increase the size
of the stream and of the received snapshot on previous versions of
ZFS. Additionally, when receiving streams generated by previous
unpatched versions of ZFS spill blocks may still be lost.
OpenZFS-issue: https://www.illumos.org/issues/9952
FreeBSD-issue: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=233277
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#8668
Fix style issue for 'tx->tx_txg&TXG_MASK'. There should be white
space around the '&' character. Split the dnode_reallocate() ASSERT
to make it more readable to clearly separate the checks.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#8606
Currently, the receive code can create an unreadable dataset from
a correct raw send stream. This is because it is currently
impossible to set maxblkid to a lower value without freeing the
associated object. This means truncating files on the send side
to a non-0 size could result in corruption. This patch solves this
issue by adding a new 'force' flag to dnode_new_blkid() which will
allow the raw receive code to force the DMU to accept the provided
maxblkid even if it is a lower value than the existing one.
For testing purposes the send_encrypted_files.ksh test has been
extended to include a variety of truncated files and multiple
snapshots. It also now leverages the xattrtest command to help
ensure raw receives correctly handle xattrs.
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#8168Closes#8487
The function bpobj_iterate_impl overflows the stack when bpobjs
are deeply nested. Rewrite the function to eliminate the recursion.
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Zuchowski <pzuchowski@datto.com>
Closes#7674Closes#7675Closes#7908
Currently, the functions dbuf_prefetch_indirect_done() and
dmu_assign_arcbuf_by_dnode() assume that dbuf_hold_level() cannot
fail. In the event of an error the former will cause a NULL pointer
dereference and the later will trigger a VERIFY. This patch adds
error handling to these functions and their callers where necessary.
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#8291
Currently, dbuf_read() may decide to create a zio_root which is
used as a parent for any child zios created in dbuf_read_impl().
However, if there is an error in dbuf_read_impl(), this zio is
never executed and ends up leaked. This patch simply ensures
that we always execute the root zio, even i it has no real work
to do.
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#8267
Recent changes in the Linux kernel made it necessary to prefix
the refcount_add() function with zfs_ due to a name collision.
To bring the other functions in line with that and to avoid future
collisions, prefix the other refcount functions as well.
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Schumacher <timschumi@gmx.de>
Closes#7963
torvalds/linux@59b57717f ("blkcg: delay blkg destruction until
after writeback has finished") added a refcount_t to the blkcg
structure. Due to the refcount_t compatibility code, zfs_refcount_t
was used by mistake.
Resolve this by removing the compatibility code and replacing the
occurrences of refcount_t with zfs_refcount_t.
Reviewed-by: Franz Pletz <fpletz@fnordicwalking.de>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Schumacher <timschumi@gmx.de>
Closes#7885Closes#7932
We can simplify the dbuf_hold code by allocating dbuf_hold_arg_t's on
demand, rather than allocating a big array of them up front. While this
can occasionally increase the number of allocations, typically only one
allocation is needed since the indirect block is already cached.
The performance test suite gets the same results with this change.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#7841
Assertion failed in arc_buf_destroy() when concurrently reading
block with checksum error.
Porting notes:
* The ability to zinject decompression errors has been added, but
this only works at the zio_decompress() level, where we have all
of the info we need to match against the user's zinject options.
* The decompress_fault test has been added to test the new zinject
functionality
* We attempted to set zio_decompress_fail_fraction to (1 << 18) in
ztest for further test coverage. Although this did uncover a few
low priority issues, this unfortuantely also causes ztest to
ASSERT in many locations where the code is working correctly since
it is designed to fail on IO errors. Developers can manually set
this variable with the '-o' option to find and debug issues.
Authored by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Matt Ahrens <mahrens@delphix.com>
Ported-by: Tom Caputi <tcaputi@datto.com>
OpenZFS-issue: https://illumos.org/issues/9403
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/fa98e487a9Closes#7822
This patch fixes 2 issues with raw, deduplicated send streams. The
first is that datasets who had been completely received earlier in
the stream were not still marked as raw receives. This caused
problems when newly received datasets attempted to fetch raw data
from these datasets without this flag set.
The second problem was that the arc freeze checksum code was not
consistent about which locks needed to be held while performing
its asserts. The proper locking needed to run these asserts is
actually fairly nuanced, since the asserts touch the linked list
of buffers (requiring the header lock), the arc_state (requiring
the b_evict_lock), and the b_freeze_cksum (requiring the
b_freeze_lock). This seems like a large performance sacrifice and
a lot of unneeded complexity to verify that this relatively small
debug feature is working as intended, so this patch simply removes
these asserts instead.
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7701
Fix comment on calculating blkid at level n within dnode's blkptrs.
"(2^(level*(indblkshift - SPA_BLKPTRSHIFT)" is part of divisor
in this division.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@osnexus.com>
Closes#7768
This change reintroduces logic required by OpenZFS 9577. When
OpenZFS 9337, zfs get all is slow due to uncached metadata, was
merged in it ended up removing logic required by OpenZFS 9577,
remove zfs_dbuf_evict_key, and inadvertently reintroduced the
bug that 9577 was designed to fix.
This change re-enables the "evicting" flag to dbuf_rele_and_unlock
and dnode_rele_and_unlock and updates all callers to provide the
correct parameter.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Wilson <george.wilson@delphix.com>
Closes#7758
This project's goal is to make read-heavy channel programs and zfs(1m)
administrative commands faster by caching all the metadata that they will
need in the dbuf layer. This will prevent the data from being evicted, so
that any future call to i.e. zfs get all won't have to go to disk (very
much). There are two parts:
The dbuf_metadata_cache. We identify what to put into the cache based on
the object type of each dbuf. Caching objset properties os
{version,normalization,utf8only,casesensitivity} in the objset_t. The reason
these needed to be cached is that although they are queried frequently,
they aren't stored in a dbuf type which we can easily recognize and cache in
the dbuf layer; instead, we have to explicitly store them. There's already
existing infrastructure for maintaining cached properties in the objset
setup code, so I simply used that.
Performance Testing:
- Disabled kmem_flags
- Tuned dbuf_cache_max_bytes very low (128K)
- Tuned zfs_arc_max very low (64M)
Created test pool with 400 filesystems, and 100 snapshots per filesystem.
Later on in testing, added 600 more filesystems (with no snapshots) to make
sure scaling didn't look different between snapshots and filesystems.
Results:
| Test | Time (trunk / diff) | I/Os (trunk / diff) |
+------------------------+---------------------+---------------------+
| zpool import | 0:05 / 0:06 | 12.9k / 12.9k |
| zfs get all (uncached) | 1:36 / 0:53 | 16.7k / 5.7k |
| zfs get all (cached) | 1:36 / 0:51 | 16.0k / 6.0k |
Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Thomas Caputi <tcaputi@datto.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Richard Lowe <richlowe@richlowe.net>
Ported-by: Alek Pinchuk <apinchuk@datto.com>
Signed-off-by: Alek Pinchuk <apinchuk@datto.com>
OpenZFS-issue: https://illumos.org/issues/9337
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/7dec52fCloses#7668
CID 176037: Uninitialized scalar variable
This patch fixes an uninitialized variable defect caught by
coverity and introduced in 69830602
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7667
This patch fixes two problems with the encryption code. First, the
current code does not correctly prohibit the DMU from updating
dn_maxblkid during object truncation within a raw receive. This
usually only causes issues when the truncating DRR_FREE record is
aggregated with DRR_FREE records later in the receive, so it is
relatively hard to hit.
Second, this patch fixes a security issue where reading blocks
within an encrypted object did not guarantee that the dnode block
itself had ever been verified against its MAC. Usually the
verification happened anyway when the bonus buffer was read, but
some use cases (notably zvols) might never perform the check.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7632
This patch simply adds an ASSERT that confirms that the last
decrypting reference on a dataset waits until the dataset is
no longer dirty. This should help to debug issues where the
ZIO layer cannot find encryption keys after a dataset has been
disowned.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7637
The zfs_dbuf_evict_key TSD (thread-specific data) is not necessary -
we can instead pass a flag down in a few places to prevent recursive
dbuf eviction. Making this change has 3 benefits:
1. The code semantics are easier to understand.
2. On Linux, performance is improved, because creating/removing
TSD values (by setting to NULL vs non-NULL) is expensive, and
we do it very often.
3. According to Nexenta, the current semantics can cause a
deadlock when concurrently calling dmu_objset_evict_dbufs()
(which is rare today, but they are working on a "parallel
unmount" change that triggers this more easily):
Porting Notes:
* Minor conflict with OpenZFS 9337 which has not yet been ported.
Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
OpenZFS-issue: https://illumos.org/issues/9577
OpenZFS-commit: https://github.com/openzfs/openzfs/pull/645
External-issue: DLPX-58547
Closes#7602
In pursuit of improving performance on multi-core systems, we should
implements fanned out counters and use them to improve the performance of
some of the arc statistics. These stats are updated extremely frequently,
and can consume a significant amount of CPU time.
Authored by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: Paul Dagnelie <pcd@delphix.com>
OpenZFS-issue: https://www.illumos.org/issues/8484
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/7028a8b92b7
Issue #3752Closes#7462
Minimal changes required to integrate the SPL sources in to the
ZFS repository build infrastructure and packaging.
Build system and packaging:
* Renamed SPL_* autoconf m4 macros to ZFS_*.
* Removed redundant SPL_* autoconf m4 macros.
* Updated the RPM spec files to remove SPL package dependency.
* The zfs package obsoletes the spl package, and the zfs-kmod
package obsoletes the spl-kmod package.
* The zfs-kmod-devel* packages were updated to add compatibility
symlinks under /usr/src/spl-x.y.z until all dependent packages
can be updated. They will be removed in a future release.
* Updated copy-builtin script for in-kernel builds.
* Updated DKMS package to include the spl.ko.
* Updated stale AUTHORS file to include all contributors.
* Updated stale COPYRIGHT and included the SPL as an exception.
* Renamed README.markdown to README.md
* Renamed OPENSOLARIS.LICENSE to LICENSE.
* Renamed DISCLAIMER to NOTICE.
Required code changes:
* Removed redundant HAVE_SPL macro.
* Removed _BOOT from nvpairs since it doesn't apply for Linux.
* Initial header cleanup (removal of empty headers, refactoring).
* Remove SPL repository clone/build from zimport.sh.
* Use of DEFINE_RATELIMIT_STATE and DEFINE_SPINLOCK removed due
to build issues when forcing C99 compilation.
* Replaced legacy ACCESS_ONCE with READ_ONCE.
* Include needed headers for `current` and `EXPORT_SYMBOL`.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
TEST_ZIMPORT_SKIP="yes"
Closes#7556
In the existing code, when doing a raw (encrypted) zfs receive,
we call arc_convert_to_raw() from open context. This creates a
race condition between arc_release()/arc_change_state() and
writing out the block from syncing context (arc_write_ready/done()).
This change makes it so that when we are doing a raw (encrypted)
zfs receive, we save the crypt parameters (salt, iv, mac) of dnode
blocks in the dbuf_dirty_record_t, and call arc_convert_to_raw()
from syncing context when writing out the block of dnodes.
Additionally, we can eliminate dr_raw and associated setters, and
instead know that dnode blocks are always raw when doing a zfs
receive (see the new field os_raw_receive).
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#7424Closes#7429
OpenZFS 7614 - zfs device evacuation/removal
OpenZFS 9064 - remove_mirror should wait for device removal to complete
This project allows top-level vdevs to be removed from the storage pool
with "zpool remove", reducing the total amount of storage in the pool.
This operation copies all allocated regions of the device to be removed
onto other devices, recording the mapping from old to new location.
After the removal is complete, read and free operations to the removed
(now "indirect") vdev must be remapped and performed at the new location
on disk. The indirect mapping table is kept in memory whenever the pool
is loaded, so there is minimal performance overhead when doing operations
on the indirect vdev.
The size of the in-memory mapping table will be reduced when its entries
become "obsolete" because they are no longer used by any block pointers
in the pool. An entry becomes obsolete when all the blocks that use
it are freed. An entry can also become obsolete when all the snapshots
that reference it are deleted, and the block pointers that reference it
have been "remapped" in all filesystems/zvols (and clones). Whenever an
indirect block is written, all the block pointers in it will be "remapped"
to their new (concrete) locations if possible. This process can be
accelerated by using the "zfs remap" command to proactively rewrite all
indirect blocks that reference indirect (removed) vdevs.
Note that when a device is removed, we do not verify the checksum of
the data that is copied. This makes the process much faster, but if it
were used on redundant vdevs (i.e. mirror or raidz vdevs), it would be
possible to copy the wrong data, when we have the correct data on e.g.
the other side of the mirror.
At the moment, only mirrors and simple top-level vdevs can be removed
and no removal is allowed if any of the top-level vdevs are raidz.
Porting Notes:
* Avoid zero-sized kmem_alloc() in vdev_compact_children().
The device evacuation code adds a dependency that
vdev_compact_children() be able to properly empty the vdev_child
array by setting it to NULL and zeroing vdev_children. Under Linux,
kmem_alloc() and related functions return a sentinel pointer rather
than NULL for zero-sized allocations.
* Remove comment regarding "mpt" driver where zfs_remove_max_segment
is initialized to SPA_MAXBLOCKSIZE.
Change zfs_condense_indirect_commit_entry_delay_ticks to
zfs_condense_indirect_commit_entry_delay_ms for consistency with
most other tunables in which delays are specified in ms.
* ZTS changes:
Use set_tunable rather than mdb
Use zpool sync as appropriate
Use sync_pool instead of sync
Kill jobs during test_removal_with_operation to allow unmount/export
Don't add non-disk names such as "mirror" or "raidz" to $DISKS
Use $TEST_BASE_DIR instead of /tmp
Increase HZ from 100 to 1000 which is more common on Linux
removal_multiple_indirection.ksh
Reduce iterations in order to not time out on the code
coverage builders.
removal_resume_export:
Functionally, the test case is correct but there exists a race
where the kernel thread hasn't been fully started yet and is
not visible. Wait for up to 1 second for the removal thread
to be started before giving up on it. Also, increase the
amount of data copied in order that the removal not finish
before the export has a chance to fail.
* MMP compatibility, the concept of concrete versus non-concrete devices
has slightly changed the semantics of vdev_writeable(). Update
mmp_random_leaf_impl() accordingly.
* Updated dbuf_remap() to handle the org.zfsonlinux:large_dnode pool
feature which is not supported by OpenZFS.
* Added support for new vdev removal tracepoints.
* Test cases removal_with_zdb and removal_condense_export have been
intentionally disabled. When run manually they pass as intended,
but when running in the automated test environment they produce
unreliable results on the latest Fedora release.
They may work better once the upstream pool import refectoring is
merged into ZoL at which point they will be re-enabled.
Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Alex Reece <alex@delphix.com>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Richard Laager <rlaager@wiktel.com>
Reviewed by: Tim Chase <tim@chase2k.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Garrett D'Amore <garrett@damore.org>
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Tim Chase <tim@chase2k.com>
OpenZFS-issue: https://www.illumos.org/issues/7614
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/f539f1ebCloses#6900
Currently, dnode_check_slots_free() works by checking dn->dn_type
in the dnode to determine if the dnode is reclaimable. However,
there is a small window of time between dnode_free_sync() in the
first call to dsl_dataset_sync() and when the useraccounting code
is run when the type is set DMU_OT_NONE, but the dnode is not yet
evictable, leading to crashes. This patch adds the ability for
dnodes to track which txg they were last dirtied in and adds a
check for this before performing the reclaim.
This patch also corrects several instances when dn_dirty_link was
treated as a list_node_t when it is technically a multilist_node_t.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7147Closes#7388
Currently, the decryption and block authentication code in
the ZIO / ARC layers is a bit inconsistent with regards to
the ereports that are produces and the error codes that are
passed to calling functions. This patch ensures that all of
these errors (which begin as ECKSUM) are converted to EIO
before they leave the ZIO or ARC layer and that ereports
are correctly generated on each decryption / authentication
failure.
In addition, this patch fixes a bug in zio_decrypt() where
ECKSUM never gets written to zio->io_error.
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7372
Encrypted dnode blocks are always initially read as raw data and
converted to decrypted data when an encrypted bonus buffer is
needed. This allows the DMU to be used for things like fetching
the DMU master node without requiring keys to be loaded. However,
dbuf_issue_final_prefetch() does not currently read the data as
raw. The end result of this is that prefetched dnode blocks are
read twice from disk: once decrypted and then again as raw data.
This patch corrects the issue by adding the flag when appropriate.
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7362
With compressed ARC (bug 6950) we use up to 25% of our CPU to decompress
indirect blocks, under a workload of random cached reads. To reduce this
decompression cost, we would like to increase the size of the dbuf cache so
that more indirect blocks can be stored uncompressed.
If we are caching entire large files of recordsize=8K, the indirect blocks
use 1/64th as much memory as the data blocks (assuming they have the same
compression ratio). We suggest making the dbuf cache be 1/32nd of all memory,
so that in this scenario we should be able to keep all the indirect blocks
decompressed in the dbuf cache. (We want it to be more than the 1/64th that
the indirect blocks would use because we need to cache other stuff in the dbuf
cache as well.)
In real world workloads, this won't help as dramatically as the example above,
but we think it's still worth it because the risk of decreasing performance is
low. The potential negative performance impact is that we will be slightly
reducing the size of the ARC (by ~3%).
Porting Notes:
* Added modules options to zfs-module-parameters.5 man page.
* Preserved scaling based on target ARC size rather than max ARC size.
Authored by: George Wilson <george.wilson@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Prashanth Sreenivasa <pks@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
OpenZFS-issue: https://www.illumos.org/issues/9188
OpenZFS-commit: https://github.com/openzfs/openzfs/pull/564
Upstream bug: DLPX-46942
Closes#7273
b1d21733 made it possible for empty metadnode blocks to be
compressed to a hole, fixing a bug that would cause invalid
metadnode MACs when a send stream attempted to free objects
and allowing the blocks to be reclaimed when they were no
longer needed. However, this patch also introduced a race
condition; if a txg sync occurred after a DRR_OBJECT_RANGE
record was received but before any objects were added, the
metadnode block would be compressed to a hole and lose all
of its encryption parameters. This would cause subsequent
DRR_OBJECT records to fail when they attempted to write
their data into an unencrypted block. This patch defers the
DRR_OBJECT_RANGE handling to receive_object() so that the
encryption parameters are set with each object that is
written into that block.
Reviewed-by: Kash Pande <kash@tripleback.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7215Closes#7236
Currently, the DMU relies on ZIO layer compression to free LO
dnode blocks that no longer have objects in them. However,
raw receives disable all compression, meaning that these blocks
can never be freed. In addition to the obvious space concerns,
this could also cause incremental raw receives to fail to mount
since the MAC of a hole is different from that of a completely
zeroed block.
This patch corrects this issue by adding a special case in
zio_write_compress() which will attempt to compress these blocks
to a hole even if ZIO_FLAG_RAW_ENCRYPT is set. This patch also
removes the zfs_mdcomp_disable tunable, since tuning it could
cause these same issues.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7198
Project quota is a new ZFS system space/object usage accounting
and enforcement mechanism. Similar as user/group quota, project
quota is another dimension of system quota. It bases on the new
object attribute - project ID.
Project ID is a numerical value to indicate to which project an
object belongs. An object only can belong to one project though
you (the object owner or privileged user) can change the object
project ID via 'chattr -p' or 'zfs project [-s] -p' explicitly.
The object also can inherit the project ID from its parent when
created if the parent has the project inherit flag (that can be
set via 'chattr +P' or 'zfs project -s [-p]').
By accounting the spaces/objects belong to the same project, we
can know how many spaces/objects used by the project. And if we
set the upper limit then we can control the spaces/objects that
are consumed by such project. It is useful when multiple groups
and users cooperate for the same project, or a user/group needs
to participate in multiple projects.
Support the following commands and functionalities:
zfs set projectquota@project
zfs set projectobjquota@project
zfs get projectquota@project
zfs get projectobjquota@project
zfs get projectused@project
zfs get projectobjused@project
zfs projectspace
zfs allow projectquota
zfs allow projectobjquota
zfs allow projectused
zfs allow projectobjused
zfs unallow projectquota
zfs unallow projectobjquota
zfs unallow projectused
zfs unallow projectobjused
chattr +/-P
chattr -p project_id
lsattr -p
This patch also supports tree quota based on the project quota via
"zfs project" commands set as following:
zfs project [-d|-r] <file|directory ...>
zfs project -C [-k] [-r] <file|directory ...>
zfs project -c [-0] [-d|-r] [-p id] <file|directory ...>
zfs project [-p id] [-r] [-s] <file|directory ...>
For "df [-i] $DIR" command, if we set INHERIT (project ID) flag on
the $DIR, then the proejct [obj]quota and [obj]used values for the
$DIR's project ID will be shown as the total/free (avail) resource.
Keep the same behavior as EXT4/XFS does.
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by Ned Bass <bass6@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Fan Yong <fan.yong@intel.com>
TEST_ZIMPORT_POOLS="zol-0.6.1 zol-0.6.2 master"
Change-Id: Ib4f0544602e03fb61fd46a849d7ba51a6005693c
Closes#6290
Currently, os_next_write_raw is a single boolean used for determining
whether or not the next call to dmu_objset_sync() should write out
the objset_phys_t as a raw buffer. Since the boolean is not associated
with a txg, the work simply happens during the next txg, which is not
necessarily the correct one. In the current implementation this issue
was misdiagnosed, resulting in a small hack in dmu_objset_sync() which
seemed to resolve the problem.
This patch changes os_next_write_raw to be an array of booleans, one
for each txg in TXG_OFF and removes the hack.
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#6864
