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
The rwlock implementation on linux does not perform as well as mutexes.
We can realize a performance benefit by replacing the zf_rwlock with a
mutex. Local microbenchmarks show ~50% improvement, and over NFS we see
~5% improvement on several of the ZFS Performance Tests cases,
especially randwrite and seq_write.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#9062
In the past we've seen multiple race conditions that have
to do with open-context threads async threads and concurrent
calls to spa_export()/spa_destroy() (including the one
referenced in issue #9015).
This patch ensures that only one thread can execute the
main body of spa_export_common() at a time, with subsequent
threads returning with a new error code created just for
this situation, eliminating this way any race condition
bugs introduced by concurrent calls to this function.
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#9015Closes#9044
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
= Motivation
At Delphix we've seen a lot of customer systems where fragmentation
is over 75% and random writes take a performance hit because a lot
of time is spend on I/Os that update on-disk space accounting metadata.
Specifically, we seen cases where 20% to 40% of sync time is spend
after sync pass 1 and ~30% of the I/Os on the system is spent updating
spacemaps.
The problem is that these pools have existed long enough that we've
touched almost every metaslab at least once, and random writes
scatter frees across all metaslabs every TXG, thus appending to
their spacemaps and resulting in many I/Os. To give an example,
assuming that every VDEV has 200 metaslabs and our writes fit within
a single spacemap block (generally 4K) we have 200 I/Os. Then if we
assume 2 levels of indirection, we need 400 additional I/Os and
since we are talking about metadata for which we keep 2 extra copies
for redundancy we need to triple that number, leading to a total of
1800 I/Os per VDEV every TXG.
We could try and decrease the number of metaslabs so we have less
I/Os per TXG but then each metaslab would cover a wider range on
disk and thus would take more time to be loaded in memory from disk.
In addition, after it's loaded, it's range tree would consume more
memory.
Another idea would be to just increase the spacemap block size
which would allow us to fit more entries within an I/O block
resulting in fewer I/Os per metaslab and a speedup in loading time.
The problem is still that we don't deal with the number of I/Os
going up as the number of metaslabs is increasing and the fact
is that we generally write a lot to a few metaslabs and a little
to the rest of them. Thus, just increasing the block size would
actually waste bandwidth because we won't be utilizing our bigger
block size.
= About this patch
This patch introduces the Log Spacemap project which provides the
solution to the above problem while taking into account all the
aforementioned tradeoffs. The details on how it achieves that can
be found in the references sections below and in the code (see
Big Theory Statement in spa_log_spacemap.c).
Even though the change is fairly constraint within the metaslab
and lower-level SPA codepaths, there is a side-change that is
user-facing. The change is that VDEV IDs from VDEV holes will no
longer be reused. To give some background and reasoning for this,
when a log device is removed and its VDEV structure was replaced
with a hole (or was compacted; if at the end of the vdev array),
its vdev_id could be reused by devices added after that. Now
with the pool-wide space maps recording the vdev ID, this behavior
can cause problems (e.g. is this entry referring to a segment in
the new vdev or the removed log?). Thus, to simplify things the
ID reuse behavior is gone and now vdev IDs for top-level vdevs
are truly unique within a pool.
= Testing
The illumos implementation of this feature has been used internally
for a year and has been in production for ~6 months. For this patch
specifically there don't seem to be any regressions introduced to
ZTS and I have been running zloop for a week without any related
problems.
= Performance Analysis (Linux Specific)
All performance results and analysis for illumos can be found in
the links of the references. Redoing the same experiments in Linux
gave similar results. Below are the specifics of the Linux run.
After the pool reached stable state the percentage of the time
spent in pass 1 per TXG was 64% on average for the stock bits
while the log spacemap bits stayed at 95% during the experiment
(graph: sdimitro.github.io/img/linux-lsm/PercOfSyncInPassOne.png).
Sync times per TXG were 37.6 seconds on average for the stock
bits and 22.7 seconds for the log spacemap bits (related graph:
sdimitro.github.io/img/linux-lsm/SyncTimePerTXG.png). As a result
the log spacemap bits were able to push more TXGs, which is also
the reason why all graphs quantified per TXG have more entries for
the log spacemap bits.
Another interesting aspect in terms of txg syncs is that the stock
bits had 22% of their TXGs reach sync pass 7, 55% reach sync pass 8,
and 20% reach 9. The log space map bits reached sync pass 4 in 79%
of their TXGs, sync pass 7 in 19%, and sync pass 8 at 1%. This
emphasizes the fact that not only we spend less time on metadata
but we also iterate less times to convergence in spa_sync() dirtying
objects.
[related graphs:
stock- sdimitro.github.io/img/linux-lsm/NumberOfPassesPerTXGStock.png
lsm- sdimitro.github.io/img/linux-lsm/NumberOfPassesPerTXGLSM.png]
Finally, the improvement in IOPs that the userland gains from the
change is approximately 40%. There is a consistent win in IOPS as
you can see from the graphs below but the absolute amount of
improvement that the log spacemap gives varies within each minute
interval.
sdimitro.github.io/img/linux-lsm/StockVsLog3Days.png
sdimitro.github.io/img/linux-lsm/StockVsLog10Hours.png
= Porting to Other Platforms
For people that want to port this commit to other platforms below
is a list of ZoL commits that this patch depends on:
Make zdb results for checkpoint tests consistent
db587941c5
Update vdev_is_spacemap_addressable() for new spacemap encoding
419ba59145
Simplify spa_sync by breaking it up to smaller functions
8dc2197b7b
Factor metaslab_load_wait() in metaslab_load()
b194fab0fb
Rename range_tree_verify to range_tree_verify_not_present
df72b8bebe
Change target size of metaslabs from 256GB to 16GB
c853f382db
zdb -L should skip leak detection altogether
21e7cf5da8
vs_alloc can underflow in L2ARC vdevs
7558997d2f
Simplify log vdev removal code
6c926f426a
Get rid of space_map_update() for ms_synced_length
425d3237ee
Introduce auxiliary metaslab histograms
928e8ad47d
Error path in metaslab_load_impl() forgets to drop ms_sync_lock
8eef997679
= References
Background, Motivation, and Internals of the Feature
- OpenZFS 2017 Presentation:
youtu.be/jj2IxRkl5bQ
- Slides:
slideshare.net/SerapheimNikolaosDim/zfs-log-spacemaps-project
Flushing Algorithm Internals & Performance Results
(Illumos Specific)
- Blogpost:
sdimitro.github.io/post/zfs-lsm-flushing/
- OpenZFS 2018 Presentation:
youtu.be/x6D2dHRjkxw
- Slides:
slideshare.net/SerapheimNikolaosDim/zfs-log-spacemap-flushing-algorithm
Upstream Delphix Issues:
DLPX-51539, DLPX-59659, DLPX-57783, DLPX-61438, DLPX-41227, DLPX-59320
DLPX-63385
Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#8442
struct pathname is originally from Solaris VFS, and it has been used
in ZoL to merely call VOP from Linux VFS interface without API change,
therefore pathname::pn_path* are unused and unneeded. Technically,
struct pathname is a wrapper for C string in ZoL.
Saves stack a bit on lookup and unlink.
(#if0'd members instead of removing since comments refer to them.)
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Closes#9025
Restore the SIMD optimization for 4.19.38 LTS, 4.14.120 LTS,
and 5.0 and newer kernels. This is accomplished by leveraging
the fact that by definition dedicated kernel threads never need
to concern themselves with saving and restoring the user FPU state.
Therefore, they may use the FPU as long as we can guarantee user
tasks always restore their FPU state before context switching back
to user space.
For the 5.0 and 5.1 kernels disabling preemption and local
interrupts is sufficient to allow the FPU to be used. All non-kernel
threads will restore the preserved user FPU state.
For 5.2 and latter kernels the user FPU state restoration will be
skipped if the kernel determines the registers have not changed.
Therefore, for these kernels we need to perform the additional
step of saving and restoring the FPU registers. Invalidating the
per-cpu global tracking the FPU state would force a restore but
that functionality is private to the core x86 FPU implementation
and unavailable.
In practice, restricting SIMD to kernel threads is not a major
restriction for ZFS. The vast majority of SIMD operations are
already performed by the IO pipeline. The remaining cases are
relatively infrequent and can be handled by the generic code
without significant impact. The two most noteworthy cases are:
1) Decrypting the wrapping key for an encrypted dataset,
i.e. `zfs load-key`. All other encryption and decryption
operations will use the SIMD optimized implementations.
2) Generating the payload checksums for a `zfs send` stream.
In order to avoid making any changes to the higher layers of ZFS
all of the `*_get_ops()` functions were updated to take in to
consideration the calling context. This allows for the fastest
implementation to be used as appropriate (see kfpu_allowed()).
The only other notable instance of SIMD operations being used
outside a kernel thread was at module load time. This code
was moved in to a taskq in order to accommodate the new kernel
thread restriction.
Finally, a few other modifications were made in order to further
harden this code and facilitate testing. They include updating
each implementations operations structure to be declared as a
constant. And allowing "cycle" to be set when selecting the
preferred ops in the kernel as well as user space.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#8754Closes#8793Closes#8965
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
ZFS tracing efforts are hampered by the inability to access zfs static
probes(probes using DTRACE_PROBE macros). The probes are available via
tracepoints for GPL modules only. The build could be modified to
generate a function for each unique DTRACE_PROBE invocation. These could
be then accessed via kprobes.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Signed-off-by: Brad Lewis <brad.lewis@delphix.com>
Closes#8659Closes#8663
* zfs redact error messages do not end with newline character
* 30af21b0 inadvertently removed some ZFS_PROP comments
* man/zfs: zfs redact <redaction_snapshot> is not optional
Reviewed-by: Giuseppe Di Natale <guss80@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes#8988
DMU sync code calls taskq_dispatch() for each sublist of os_dirty_dnodes
and os_synced_dnodes. Since the number of sublists by default is equal
to number of CPUs, it will dispatch equal, potentially large, number of
tasks, waking up many CPUs to handle them, even if only one or few of
sublists actually have any work to do.
This change adds check for empty sublists to avoid this.
Reviewed by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes#8909
With the addition of BP_EMBEDDED_TYPE_REDACTED in 30af21b0 a couple of
codepaths make wrong assumptions and could potentially result in errors.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Chris Dunlop <chris@onthe.net.au>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes#8951
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
Problem Statement
=================
ZFS Channel program scripts currently require a timeout, so that hung or
long-running scripts return a timeout error instead of causing ZFS to get
wedged. This limit can currently be set up to 100 million Lua instructions.
Even with a limit in place, it would be desirable to have a sys admin
(support engineer) be able to cancel a script that is taking a long time.
Proposed Solution
=================
Make it possible to abort a channel program by sending an interrupt signal.In
the underlying txg_wait_sync function, switch the cv_wait to a cv_wait_sig to
catch the signal. Once a signal is encountered, the dsl_sync_task function can
install a Lua hook that will get called before the Lua interpreter executes a
new line of code. The dsl_sync_task can resume with a standard txg_wait_sync
call and wait for the txg to complete. Meanwhile, the hook will abort the
script and indicate that the channel program was canceled. The kernel returns
a EINTR to indicate that the channel program run was canceled.
Porting notes: Added missing return value from cv_wait_sig()
Authored by: Don Brady <don.brady@delphix.com>
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Sara Hartse <sara.hartse@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported-by: Don Brady <don.brady@delphix.com>
Signed-off-by: Don Brady <don.brady@delphix.com>
OpenZFS-issue: https://www.illumos.org/issues/9425
OpenZFS-commit: https://github.com/illumos/illumos-gate/commit/d0cb1fb926Closes#8904
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#8945
When encryption was first added to ZFS, we made a decision to
prevent users from creating unencrypted children of encrypted
datasets. The idea was to prevent users from inadvertently
leaving some of their data unencrypted. However, since the
release of 0.8.0, some legitimate reasons have been brought up
for this behavior to be allowed. This patch simply removes this
limitation from all code paths that had checks for it and updates
the tests accordingly.
Reviewed-by: Jason King <jason.king@joyent.com>
Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#8737Closes#8870
If dedup is in use, the `dedupditto` property can be set, causing ZFS to
keep an extra copy of data that is referenced many times (>100x). The
idea was that this data is more important than other data and thus we
want to be really sure that it is not lost if the disk experiences a
small amount of random corruption.
ZFS (and system administrators) rely on the pool-level redundancy to
protect their data (e.g. mirroring or RAIDZ). Since the user/sysadmin
doesn't have control over what data will be offered extra redundancy by
dedupditto, this extra redundancy is not very useful. The bulk of the
data is still vulnerable to loss based on the pool-level redundancy.
For example, if particle strikes corrupt 0.1% of blocks, you will either
be saved by mirror/raidz, or you will be sad. This is true even if
dedupditto saved another 0.01% of blocks from being corrupted.
Therefore, the dedupditto functionality is rarely enabled (i.e. the
property is rarely set), and it fulfills its promise of increased
redundancy even more rarely.
Additionally, this feature does not work as advertised (on existing
releases), because scrub/resilver did not repair the extra (dedupditto)
copy (see https://github.com/zfsonlinux/zfs/pull/8270).
In summary, this seldom-used feature doesn't work, and even if it did it
wouldn't provide useful data protection. It has a non-trivial
maintenance burden (again see https://github.com/zfsonlinux/zfs/pull/8270).
We should remove the dedupditto functionality. For backwards
compatibility with the existing CLI, "zpool set dedupditto" will still
"succeed" (exit code zero), but won't have any effect. For backwards
compatibility with existing pools that had dedupditto enabled at some
point, the code will still be able to understand dedupditto blocks and
free them when appropriate. However, ZFS won't write any new dedupditto
blocks.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Alek Pinchuk <apinchuk@datto.com>
Issue #8270Closes#8310
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
`lz4_decompress_abd` is declared in zio_compress.h but it is not defined
anywhere. The declaration should be removed.
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed-by: Allan Jude <allanjude@freebsd.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-47477
Closes#8894
If the zfs_remove_max_segment tunable is changed to be not a multiple of
the sector size, then the device removal code will malfunction and try
to create mappings that are smaller than one sector, leading to a panic.
On debug bits this assertion will fail in spa_vdev_copy_segment():
ASSERT3U(DVA_GET_ASIZE(&dst), ==, size);
On nondebug, the system panics with a stack like:
metaslab_free_concrete()
metaslab_free_impl()
metaslab_free_impl_cb()
vdev_indirect_remap()
free_from_removing_vdev()
metaslab_free_impl()
metaslab_free_dva()
metaslab_free()
Fortunately, the default for zfs_remove_max_segment is 1MB, so this
can't occur by default. We hit it during this test because
removal_remap.ksh changes zfs_remove_max_segment to 1KB. When testing on
4KB-sector disks, we hit the bug.
This change makes the zfs_remove_max_segment tunable more robust,
automatically rounding it up to a multiple of the sector size. We also
turn some key assertions into VERIFY's so that similar bugs would be
caught before they are encoded on disk (and thus avoid a
panic-reboot-loop).
Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-61342
Closes#8893
When iterating over a ZAP object, we're almost always certain to iterate
over the entire object. If there are multiple leaf blocks, we can
realize a performance win by issuing reads for all the leaf blocks in
parallel when the iteration begins.
For example, if we have 10,000 snapshots, "zfs destroy -nv
pool/fs@1%9999" can take 30 minutes when the cache is cold. This change
provides a >3x performance improvement, by issuing the reads for all ~64
blocks of each ZAP object in parallel.
Reviewed-by: Andreas Dilger <andreas.dilger@whamcloud.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-58347
Closes#8862
Scatter ABD's are allocated from a number of pages. In contrast to
linear ABD's, these pages are disjoint in the kernel's virtual address
space, so they can't be accessed as a contiguous buffer. Therefore
routines that need a linear buffer (e.g. abd_borrow_buf() and friends)
must allocate a separate linear buffer (with zio_buf_alloc()), and copy
the contents of the pages to/from the linear buffer. This can have a
measurable performance overhead on some workloads.
https://github.com/zfsonlinux/zfs/commit/87c25d567fb7969b44c7d8af63990e
("abd_alloc should use scatter for >1K allocations") increased the use
of scatter ABD's, specifically switching 1.5K through 4K (inclusive)
buffers from linear to scatter. For workloads that access blocks whose
compressed sizes are in this range, that commit introduced an additional
copy into the read code path. For example, the
sequential_reads_arc_cached tests in the test suite were reduced by
around 5% (this is doing reads of 8K-logical blocks, compressed to 3K,
which are cached in the ARC).
This commit treats single-chunk scattered buffers as linear buffers,
because they are contiguous in the kernel's virtual address space.
All single-page (4K) ABD's can be represented this way. Some multi-page
ABD's can also be represented this way, if we were able to allocate a
single "chunk" (higher-order "page" which represents a power-of-2 series
of physically-contiguous pages). This is often the case for 2-page (8K)
ABD's.
Representing a single-entry scatter ABD as a linear ABD has the
performance advantage of avoiding the copy (and allocation) in
abd_borrow_buf_copy / abd_return_buf_copy. A performance increase of
around 5% has been observed for ARC-cached reads (of small blocks which
can take advantage of this), fixing the regression introduced by
87c25d567.
Note that this optimization is only possible because all physical memory
is always mapped into the kernel's address space. This is not the case
for HIGHMEM pages, so the optimization can not be made on 32-bit
systems.
Reviewed-by: Chunwei Chen <tuxoko@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#8580
We've observed that on some highly fragmented pools, most metaslab
allocations are small (~2-8KB), but there are some large, 128K
allocations. The large allocations are for ZIL blocks. If there is a
lot of fragmentation, the large allocations can be hard to satisfy.
The most common impact of this is that we need to check (and thus load)
lots of metaslabs from the ZIL allocation code path, causing sync writes
to wait for metaslabs to load, which can take a second or more. In the
worst case, we may not be able to satisfy the allocation, in which case
the ZIL will resort to txg_wait_synced() to ensure the change is on
disk.
To provide a workaround for this, this change adds a tunable that can
reduce the size of ZIL blocks.
External-issue: DLPX-61719
Reviewed-by: George Wilson <george.wilson@delphix.com>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#8865
On large systems, the memory used by loaded metaslabs can become
a concern. While range trees are a fairly efficient data structure,
on heavily fragmented pools they can still consume a significant
amount of memory. This problem is amplified when we fail to unload
metaslabs that we aren't using. Currently, we only unload a metaslab
during metaslab_sync_done; in order for that function to be called
on a given metaslab in a given txg, we have to have dirtied that
metaslab in that txg. If the dirtying was the result of an allocation,
we wouldn't be unloading it (since it wouldn't be 8 txgs since it
was selected), so in effect we only unload a metaslab during txgs
where it's being freed from.
We move the unload logic from sync_done to a new function, and
call that function on all metaslabs in a given vdev during
vdev_sync_done().
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#8837
When an import requires a long MMP activity check, or when the user
requests pool recovery, the import make take a long time. The user may
not know why, or be able to tell whether the import is progressing or is
hung.
Add a kstat which lists all imports currently being processed by the
kernel (currently only one at a time is possible, but the kstat allows
for more than one). The kstat is /proc/spl/kstat/zfs/import_progress.
The kstat contents are as follows:
pool_guid load_state multihost_secs max_txg pool_name
16667015954387398 3 15 0 tank3
load_state: the value of spa_load_state
multihost_secs: seconds until the end of the multihost activity
check; if over, or none required, this is 0
max_txg: current spa_load_max_txg, if rewind is occurring
This could be used by outside tools, such as a pacemaker resource agent,
to report import progress, or as a part of manual troubleshooting. The
zpool import subcommand could also be modified to report this
information.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes#8696
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
`zfs set atime|relatime=off|on` doesn't disable or enable the property
on read for datasets whose property was inherited from parent, until
a dataset is once unmounted and mounted again.
(The properties start to work properly if a dataset is once unmounted
and mounted again. The difference comes from regular mount process,
e.g. via zpool import, uses mount options based on properties read
from ondisk layout for each dataset, whereas
`zfs set atime|relatime=off|on` just remounts a specified dataset.)
--
# zpool create p1 <device>
# zfs create p1/f1
# zfs set atime=off p1
# echo test > /p1/f1/test
# sync
# zfs list
NAME USED AVAIL REFER MOUNTPOINT
p1 176K 18.9G 25.5K /p1
p1/f1 26K 18.9G 26K /p1/f1
# zfs get atime
NAME PROPERTY VALUE SOURCE
p1 atime off local
p1/f1 atime off inherited from p1
# stat /p1/f1/test | grep Access | tail -1
Access: 2019-04-26 23:32:33.741205192 +0900
# cat /p1/f1/test
test
# stat /p1/f1/test | grep Access | tail -1
Access: 2019-04-26 23:32:50.173231861 +0900
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ changed by read(2)
--
The problem is that zfsvfs::z_atime which was probably intended to keep
incore atime state just gets updated by a callback function of "atime"
property change, atime_changed_cb(), and never used for anything else.
Since now that all file read and atime update use a common function
zpl_iter_read_common() -> file_accessed(), and whether to update atime
via ->dirty_inode() is determined by atime_needs_update(),
atime_needs_update() needs to return false once atime is turned off.
It currently continues to return true on `zfs set atime=off`.
Fix atime_changed_cb() by setting or dropping SB_NOATIME in VFS super
block depending on a new atime value, so that atime_needs_update() works
as expected after property change.
The same problem applies to "relatime" except that a self contained
relatime test is needed. This is because relatime_need_update() is based
on a mount option flag MNT_RELATIME, which doesn't exist in datasets
with inherited "relatime" property via `zfs set relatime=...`, hence it
needs its own relatime test zfs_relatime_need_update().
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Closes#8674Closes#8675
This comment seems to misunderstand the ## preprocessor token, which
does token concatenation. It is not needed here, since we are
concatenating string literals, which is performed by putting the
literals next to each other.
Additionally, the comment uses offensive language.
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#8698Closes#8699
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Closes#8626
Nobody is going to be bumping SPA_VERSION again, as OpenZFS has moved on
to feature flags. Also, there is no requirement to keep GRUB
up-to-date, nor has that been happening.
The ZPL_VERSION could be bumped, but that would likely be handled in a
similar way, by adding filesystem feature flags. In any event, we do
not need this comment, and we certainly don't need a reference to the
GRUB 0.97 source code in a Solaris tree.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Closes#8626
There are several places where we use zfs_dbgmsg and %p to
print pointers. In the Linux kernel, these values obfuscated
to prevent information leaks which means the pointers aren't
very useful for debugging crash dumps. We decided to restrict
the permissions of dbgmsg (and some other kstats while we were
at it) and print pointers with %px in zfs_dbgmsg as well as
spl_dumpstack
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Gallagher <john.gallagher@delphix.com>
Signed-off-by: sara hartse <sara.hartse@delphix.com>
Closes#8467Closes#8476
UNMAP/TRIM support is a frequently-requested feature to help
prevent performance from degrading on SSDs and on various other
SAN-like storage back-ends. By issuing UNMAP/TRIM commands for
sectors which are no longer allocated the underlying device can
often more efficiently manage itself.
This TRIM implementation is modeled on the `zpool initialize`
feature which writes a pattern to all unallocated space in the
pool. The new `zpool trim` command uses the same vdev_xlate()
code to calculate what sectors are unallocated, the same per-
vdev TRIM thread model and locking, and the same basic CLI for
a consistent user experience. The core difference is that
instead of writing a pattern it will issue UNMAP/TRIM commands
for those extents.
The zio pipeline was updated to accommodate this by adding a new
ZIO_TYPE_TRIM type and associated spa taskq. This new type makes
is straight forward to add the platform specific TRIM/UNMAP calls
to vdev_disk.c and vdev_file.c. These new ZIO_TYPE_TRIM zios are
handled largely the same way as ZIO_TYPE_READs or ZIO_TYPE_WRITEs.
This makes it possible to largely avoid changing the pipieline,
one exception is that TRIM zio's may exceed the 16M block size
limit since they contain no data.
In addition to the manual `zpool trim` command, a background
automatic TRIM was added and is controlled by the 'autotrim'
property. It relies on the exact same infrastructure as the
manual TRIM. However, instead of relying on the extents in a
metaslab's ms_allocatable range tree, a ms_trim tree is kept
per metaslab. When 'autotrim=on', ranges added back to the
ms_allocatable tree are also added to the ms_free tree. The
ms_free tree is then periodically consumed by an autotrim
thread which systematically walks a top level vdev's metaslabs.
Since the automatic TRIM will skip ranges it considers too small
there is value in occasionally running a full `zpool trim`. This
may occur when the freed blocks are small and not enough time
was allowed to aggregate them. An automatic TRIM and a manual
`zpool trim` may be run concurrently, in which case the automatic
TRIM will yield to the manual TRIM.
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Contributions-by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Contributions-by: Tim Chase <tim@chase2k.com>
Contributions-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#8419Closes#598
When Multihost is enabled, and a pool is imported, uberblock writes
include ub_mmp_delay to allow an importing node to calculate the
duration of an activity test. This value, is not enough information.
If zfs_multihost_fail_intervals > 0 on the node with the pool imported,
the safe minimum duration of the activity test is well defined, but does
not depend on ub_mmp_delay:
zfs_multihost_fail_intervals * zfs_multihost_interval
and if zfs_multihost_fail_intervals == 0 on that node, there is no such
well defined safe duration, but the importing host cannot tell whether
mmp_delay is high due to I/O delays, or due to a very large
zfs_multihost_interval setting on the host which last imported the pool.
As a result, it may use a far longer period for the activity test than
is necessary.
This patch renames ub_mmp_sequence to ub_mmp_config and uses it to
record the zfs_multihost_interval and zfs_multihost_fail_intervals
values, as well as the mmp sequence. This allows a shorter activity
test duration to be calculated by the importing host in most situations.
These values are also added to the multihost_history kstat records.
It calculates the activity test duration differently depending on
whether the new fields are present or not; for importing pools with
only ub_mmp_delay, it uses
(zfs_multihost_interval + ub_mmp_delay) * zfs_multihost_import_intervals
Which results in an activity test duration less sensitive to the leaf
count.
In addition, it makes a few other improvements:
* It updates the "sequence" part of ub_mmp_config when MMP writes
in between syncs occur. This allows an importing host to detect MMP
on the remote host sooner, when the pool is idle, as it is not limited
to the granularity of ub_timestamp (1 second).
* It issues writes immediately when zfs_multihost_interval is changed
so remote hosts see the updated value as soon as possible.
* It fixes a bug where setting zfs_multihost_fail_intervals = 1 results
in immediate pool suspension.
* Update tests to verify activity check duration is based on recorded
tunable values, not tunable values on importing host.
* Update tests to verify the expected number of uberblocks have valid
MMP fields - fail_intervals, mmp_interval, mmp_seq (sequence number),
that sequence number is incrementing, and that uberblock values match
tunable settings.
Reviewed-by: Andreas Dilger <andreas.dilger@whamcloud.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes#7842
Currently, there is an issue in the sequential scrub code which
prevents self healing from working in some cases. The scrub code
will split up all DVA copies of a bp and issue each of them
separately. The problem is that, since each of the DVAs is no
longer associated with the others, the self healing code doesn't
have the opportunity to repair problems that show up in one of the
DVAs with the data from the others.
This patch fixes this issue by ensuring that all IOs issued by the
sequential scrub code include all DVAs. Initially, only the first
DVA of each is attempted. If an issue arises, the IO is retried
with all available copies, giving the self healing code a chance
to correct the issue.
To test this change, this patch also adds the ability for zinject
to specify individual DVAs to inject read errors into. We then
add a new test case that utilizes this functionality to ensure
scrubs and self-healing reads can handle and transparently fix
issues with individual copies of blocks.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#8453
Currently, there is an issue in the raw receive code where
raw receives are allowed to happen on top of previously
non-raw received datasets. This is a problem because the
source-side dataset doesn't know about how the blocks on
the destination were encrypted. As a result, any MAC in
the objset's checksum-of-MACs tree that is a parent of both
blocks encrypted on the source and blocks encrypted by the
destination will be incorrect. This will result in
authentication errors when we decrypt the dataset.
This patch fixes this issue by adding a new check to the
raw receive code. The code now maintains an "IVset guid",
which acts as an identifier for the set of IVs used to
encrypt a given snapshot. When a snapshot is raw received,
the destination snapshot will take this value from the
DRR_BEGIN payload. Non-raw receives and normal "zfs snap"
operations will cause ZFS to generate a new IVset guid.
When a raw incremental stream is received, ZFS will check
that the "from" IVset guid in the stream matches that of
the "from" destination snapshot. If they do not match, the
code will error out the receive, preventing the problem.
This patch requires an on-disk format change to add the
IVset guids to snapshots and bookmarks. As a result, this
patch has errata handling and a tunable to help affected
users resolve the issue with as little interruption as
possible.
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#8308
This patch adds the bookmark v2 feature to the on-disk format. This
feature will be needed for the upcoming redacted sends and for an
upcoming fix that for raw receives. The feature is not currently
used by any code and thus this change is a no-op, aside from the
fact that the user can now enable the feature.
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>
Issue #8308
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
By default, when multihost is enabled for a pool, the pool is
suspended if (zfs_multihost_fail_intervals*zfs_multihost_interval) ms
pass without a successful MMP write. This is the recommended
configuration.
The default value for zfs_multihost_fail_intervals has been 5, and the
default value for zfs_multihost_interval has been 1000, so pool
suspension occurred at 5 seconds.
There have been multiple cases where a single misbehaving device in a
pool triggered a SCSI reset, and all I/O paused for 5-6 seconds. This
in turn caused MMP to suspend the pool.
In the cases observed, the rest of the devices were healthy and the
pool was otherwise correctly performing I/O. The reset was handled
correctly by ZFS, and by suspending the pool MMP made replacing the
device more difficult as well as forcing the host to be rebooted.
Increase the default value of zfs_multihost_fail_intervals to 10, so
that MMP tolerates up to 10 seconds of failed MMP writes before
suspending the pool.
Increase the default value of zfs_multihost_import_intervals to 20, to
maintain the 2:1 safety factor. This results in a force import taking
approximately 20 seconds when MMP is enabled, with default values.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Andreas Dilger <andreas.dilger@whamcloud.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes#7709Closes#8495
This patch modifies the zfs_ioc_snapshot_list_next() ioctl to enable it
to take input parameters that alter the way looping through the list of
snapshots is performed. The idea here is to restrict functions that
throw away some of the snapshots returned by the ioctl to a range of
snapshots that these functions actually use. This improves efficiency
and execution speed for some rollback and send operations.
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Signed-off-by: Alek Pinchuk <apinchuk@datto.com>
Closes#8077
Instead of choosing a leaf vdev quasi-randomly, by starting at the root
vdev and randomly choosing children, rotate over leaves to issue MMP
writes. This fixes an issue in a pool whose top-level vdevs have
different numbers of leaves.
The issue is that the frequency at which individual leaves are chosen
for MMP writes is based not on the total number of leaves but based on
how many siblings the leaves have.
For example, in a pool like this:
root-vdev
+------+---------------+
vdev1 vdev2
| |
| +------+-----+-----+----+
disk1 disk2 disk3 disk4 disk5 disk6
vdev1 and vdev2 will each be chosen 50% of the time. Every time vdev1
is chosen, disk1 will be chosen. However, every time vdev2 is chosen,
disk2 is chosen 20% of the time. As a result, disk1 will be sent 5x as
many MMP writes as disk2.
This may create wear issues in the case of SSDs. It also reduces the
effectiveness of MMP as it depends on the writes being evenly
distributed for the case where some devices fail or are partitioned.
The new code maintains a list of leaf vdevs in the pool. MMP records
the last leaf used for an MMP write in mmp->mmp_last_leaf. To choose
the next leaf, MMP starts at mmp->mmp_last_leaf and traverses the list,
continuing from the head if the tail is reached. It stops when a
suitable leaf is found or all leaves have been examined.
Added a test to verify MMP write distribution is even.
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: Kash Pande <kash@tripleback.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes#7953
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
Soft lockups could happen when multiple threads trying
to get zrl on the same dnode handle in order to allocate
and initialize the dnode marked as DN_SLOT_ALLOCATED.
Don't loop from beginning when we can't get zrl, otherwise
we would increase the zrl refcount and nobody can actually
lock it.
Reviewed by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Li Dongyang <dongyangli@ddn.com>
Closes#8433
This patch introduces 3 new histograms per metaslab. These
histograms track segments that have made it to the metaslab's
space map histogram (and are part of the spacemap) but have
not yet reached the ms_allocatable tree on loaded metaslab's
because these metaslab's are currently syncing and haven't
gone through metaslab_sync_done() yet.
The histograms help when we decide whether to load an unloaded
metaslab in-order to allocate from it. When calculating the
weight of an unloaded metaslab traditionally, we look at the
highest bucket of its spacemap's histogram. The problem is
that we are not guaranteed to be able to allocated that
segment when we load the metaslab because it may still be at
the freeing, freed, or defer trees. The new histograms are
used when we try to calculate an unloaded metaslab's weight
to deal with this issue by removing segments that have would
not be in the allocatable tree at runtime. Note, that this
method of dealing with this is not completely accurate as
adjacent segments are not always consolidated in the space
map histogram of a metaslab.
In addition and to make things deterministic, we always reset
the weight of unloaded metaslabs based on their space map
weight (instead of doing that on a need basis). Thus, every
time a metaslab is loaded and its weight is reset again (from
the weight based on its space map to the one based on its
allocatable range tree) we expect (and assert) that this
change in weight can only get better if it doesn't stay the
same.
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#8358
Add -h switch to zfs send command to send dataset holds. If
holds are present in the stream, zfs receive will create them
on the target dataset, unless the zfs receive -h option is used
to skip receive of holds.
Reviewed-by: Alek Pinchuk <apinchuk@datto.com>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Signed-off-by: Paul Zuchowski <pzuchowski@datto.com>
Closes#7513
This patch is an async implementation of the existing sync
zfs_unlinked_drain() function. This function is called at mount time and
is responsible for freeing znodes that we didn't get to freeing before.
We don't have to hold mounting of the dataset until the unlinked list is
fully drained as is done now. Since we can process the unlinked set
asynchronously this results in a better user experience when mounting a
dataset with entries in the unlinked set.
Reviewed by: Jorgen Lundman <lundman@lundman.net>
Reviewed by: Tom Caputi <tcaputi@datto.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Signed-off-by: Alek Pinchuk <apinchuk@datto.com>
Closes#8142
Initially, metaslabs and space maps used to be the same thing
in ZFS. Later, we started differentiating them by referring
to the space map as the on-disk state of the metaslab, making
the metaslab a higher-level concept that is metadata that deals
with space accounting. Today we've managed to split that code
furthermore, with the space map being its own on-disk data
structure used in areas of ZFS besides metaslabs (e.g. the
vdev-wide space maps used for zpool checkpoint or vdev removal
features).
This patch refactors the space map code to further split the
space map code from the metaslab code. It does so by getting
rid of the idea that the space map can have a different in-core
and on-disk length (sm_length vs smp_length) which is something
that is only used for the metaslab code, and other consumers
of space maps just have to deal with. Instead, this patch
introduces changes that move the old in-core length of the
metaslab's space map to the metaslab structure itself (see
ms_synced_length field) while making the space map code only
care about the actual space map's length on-disk.
The result of this is that space map consumers no longer have
to deal with syncing two different lengths for the same
structure (e.g. space_map_update() goes away) while metaslab
specific behavior stays within the metaslab code. Specifically,
the ms_synced_length field keeps track of the amount of data
metaslab_load() can read from the metaslab's space map while
working concurrently with metaslab_sync() that may be
appending to that same space map.
As a side note, the patch also adds a few comments around
the metaslab code documenting some assumptions and expected
behavior.
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#8328
zfs create, receive and rename can bypass this hierarchy rule. Update
both userland and kernel module to prevent this issue and use pyzfs
unit tests to exercise the ioctls directly.
Note: this commit slightly changes zfs_ioc_create() ABI. This allow to
differentiate a generic error (EINVAL) from the specific case where we
tried to create a dataset below a ZVOL (ZFS_ERR_WRONG_PARENT).
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
The range_tree_verify function looks for a segment in a
range tree and panics if the segment is present on the
tree. This patch gives the function a more descriptive
name.
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#8327
