Commit Graph

212 Commits

Author SHA1 Message Date
Sara Hartse
a887d653b3 Restrict kstats and print real pointers
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 #8467 
Closes #8476
2019-04-04 18:57:06 -07:00
Brian Behlendorf
1b939560be
Add TRIM support
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 #8419 
Closes #598
2019-03-29 09:13:20 -07:00
Olaf Faaland
8133679ff0 Do not resume a pool if multihost is enabled
When multihost is enabled, and a pool is suspended, return
EINVAL in response to "zpool clear <pool>".  The pool
may have been imported on another host while I/O was suspended.

Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes #6933 
Closes #8460
2019-02-28 17:56:19 -08:00
Tony Hutter
caacc6e4c4 GCC 9.0: Fix ztest "directive argument is not a nul-terminated string"
GCC 9.0 is complaining because we're trying to print strings that
are defined like this:

.zo_pool = { 'z', 't', 'e', 's', 't', '\0' },

Fix them by making them actual strings.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes #8330
2019-01-28 10:11:45 -08:00
Brian Behlendorf
ce5fb2a7c6
ztest: scrub verification
By design ztest will never inject non-repairable damage in to the
pool.  Update the ztest_scrub() test case such that it waits for
the scrub to complete and verifies the pool is always repairable.

After enabling scrub verification two scenarios were encountered
which are the result of how ztest manages failure injection.

The first case is straight forward and pertains to detaching a
mirror vdev.  In this case, the pool must always be scrubbed prior
the detach.  Failure to do so can potentially lock in previously
repairable data corruption by removing all good copies of a block
leaving only damaged ones.

The second is a little more subtle.  The child/offset selection
logic in ztest_fault_inject() depends on the calculated number of
leaves always remaining constant between injection passes.  This
is true within a single execution of ztest, but when using zloop.sh
random values are selected for each restart.  Therefore, when ztest
imports an existing pool it must be scrubbed before failure injection
can be safely enabled.  Otherwise it is possible that it will inject
non-repairable damage.

Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #8269
2019-01-18 09:47:55 -08:00
Tom Caputi
305781da4b Fix error handling incallers of dbuf_hold_level()
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
2019-01-17 15:47:08 -08:00
Brian Behlendorf
52b684236d
ztest: scrub ddt repair
The ztest_ddt_repair() test is designed inflict damage to the
ddt which can be repairable by a scrub.  Unfortunately, this
repair logic was broken at some point and it went undetected.
This issue is not specific to ztest, but thankfully this extra
redundancy is rarely enabled and even more rarely needed.

The root cause was identified to be the ddt_bp_create()
function called by dsl_scan_ddt_entry() which did not set the
dedup bit of the generated block pointer.

The consequence of this was that the ZIO_DDT_READ_PIPELINE was
never enabled for the block pointer during the scrub, and the
dedup ditto repair logic was never run.  Note that for demand
reads which don't rely on ddt_bp_create() the required pipeline
stages would be enabled and the repair performed.

This was resolved by unconditionally setting the dedup bit in
ddt_bp_create().  This way all codes paths which may need to
perform a repair from a block pointer generated from the dtt
entry will be able too.  The only exception is that the dedup
bit is cleared in ddt_phys_free() which is required to avoid
leaking space.

Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Tom Caputi <tcaputi@datto.com>
Reviewed by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #8270
2019-01-17 15:25:00 -08:00
Brian Behlendorf
64bdf63f5c
ztest: split block reconstruction
Increase the default allowed number of reconstruction attempts.
There's not an exact right number for this setting.  It needs
to be set large enough to cover any realistic failure scenarios
and small enough to avoid stalling the IO pipeline and invoking
the dead man detection.

The current value of 256 was empirically determined to be too
low based on multi-day runs of ztest.  The fault injection code
would inject more damage than could be reconstructed given the
relatively small number of attempts.  However, in all observed
cases the block could be reconstructed using a slightly higher
limit.

Based on local testing increasing the default value to 4096 was
determined to strike the best balance.  Checking all combinations
takes less than 10s in the worst case, and has so far eliminated
the vast majority of false positives detected by ztest.  This
delay is roughly on par with how long retries may be performed
to a misbehaving HDD and was deemed to be reasonable.  Better to
err on the side of a brief delay rather than fail to reconstruct
the data.

Lastly, the -Y flag has been added to zdb to make it easy to try all
possible combinations when performing split block reconstruction.
For badly damaged blocks with 18 splits, they can be fully enumerated
within a few minutes.  This has been done to ensure permanent errors
are never incorrectly reported when ztest verifies the pool with zdb.

Reviewed by: Tom Caputi <tcaputi@datto.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #8271
2019-01-16 14:10:02 -08:00
Brian Behlendorf
6e91a72fe3
Disable 'zfs remap' command
The implementation of 'zfs remap' has proven to be problematic since
it modifies the objset (but not its logical contents) by dirtying
metadata without owning it.  The consequence of which is that
dmu_objset_remap_indirects() is vulnerable to certain races.

For example, if we are in the middle of receiving into the filesystem
while it is being remapped.  Then it is possible we could evict the
objset when the receive completes (see dsl_dataset_clone_swap_sync_impl,
or dmu_recv_end_sync), but dmu_objset_remap_indirects() may be still
using the objset.  The result of which would be a panic.

Extended runs of ztest(8) have exposed other possible races which
can occur when using 'zfs remap'.  Several of these have been fixed
but there may be others which have not yet been encountered and
diagnosed.

Furthermore, the ability to manually remap a filesystem is no longer
particularly useful now that the removal code can map large chunks.
Coupled with the fact that explaining what this command does and why
it may be useful requires a detailed understanding of the internals
of device removal.  These are details users should not be bothered
with.

Therefore, the 'zfs remap' command is being disabled but not entirely
removed.  It may be removed in the future or potentially reworked
to address the issues described above.  Since 'zfs remap' has never
been part of a tagged release its removal is expected to have
minimal impact.

The ZTS tests have been updated to continue to exercise the command
to prevent atrophy, but it has been removed entirely from ztest(8).

Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #8238
2019-01-15 15:46:58 -08:00
Brian Behlendorf
d611989fdc
Minor spelling corrections
Some minor spelling mistakes and typos.  No functional changes.

Reviewed-by: Neal Gompa <ngompa@datto.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Giuseppe Di Natale <guss80@gmail.com>
Reviewed-by: bunder2015 <omfgbunder@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #8272
2019-01-13 10:11:52 -08:00
George Wilson
c10d37dd9f zfs initialize performance enhancements
PROBLEM
========

When invoking "zpool initialize" on a pool the command will
create a thread to initialize each disk. Unfortunately, it does
this serially across many transaction groups which can result
in commands taking a long time to return to the user and may
appear hung. The same thing is true when trying to suspend/cancel
the operation.

SOLUTION
=========

This change refactors the way we invoke the initialize interface
to ensure we can start or stop the intialization in just a few
transaction groups.

When stopping or cancelling a vdev initialization perform it
in two phases.  First signal each vdev initialization thread
that it should exit, then after all threads have been signaled
wait for them to exit.

On a pool with 40 leaf vdevs this reduces the vdev initialize
stop/cancel time from ~10 minutes to under a second.  The reason
for this is spa_vdev_initialize() no longer needs to wait on
multiple full TXGs per leaf vdev being stopped.

This commit additionally adds some missing checks for the passed
"initialize_vdevs" input nvlist.  The contents of the user provided
input "initialize_vdevs" nvlist must be validated to ensure all
values are uint64s.  This is done in zfs_ioc_pool_initialize() in
order to keep all of these checks in a single location.

Updated the innvl and outnvl comments to match the formatting used
for all other new sytle ioctls.

Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Reviewed-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Wilson <george.wilson@delphix.com>
Closes #8230
2019-01-07 11:03:08 -08:00
George Wilson
619f097693 OpenZFS 9102 - zfs should be able to initialize storage devices
PROBLEM
========

The first access to a block incurs a performance penalty on some platforms
(e.g. AWS's EBS, VMware VMDKs). Therefore we recommend that volumes are
"thick provisioned", where supported by the platform (VMware). This can
create a large delay in getting a new virtual machines up and running (or
adding storage to an existing Engine). If the thick provision step is
omitted, write performance will be suboptimal until all blocks on the LUN
have been written.

SOLUTION
=========

This feature introduces a way to 'initialize' the disks at install or in the
background to make sure we don't incur this first read penalty.

When an entire LUN is added to ZFS, we make all space available immediately,
and allow ZFS to find unallocated space and zero it out. This works with
concurrent writes to arbitrary offsets, ensuring that we don't zero out
something that has been (or is in the middle of being) written. This scheme
can also be applied to existing pools (affecting only free regions on the
vdev). Detailed design:
        - new subcommand:zpool initialize [-cs] <pool> [<vdev> ...]
                - start, suspend, or cancel initialization
        - Creates new open-context thread for each vdev
        - Thread iterates through all metaslabs in this vdev
        - Each metaslab:
                - select a metaslab
                - load the metaslab
                - mark the metaslab as being zeroed
                - walk all free ranges within that metaslab and translate
                  them to ranges on the leaf vdev
                - issue a "zeroing" I/O on the leaf vdev that corresponds to
                  a free range on the metaslab we're working on
                - continue until all free ranges for this metaslab have been
                  "zeroed"
                - reset/unmark the metaslab being zeroed
                - if more metaslabs exist, then repeat above tasks.
                - if no more metaslabs, then we're done.

        - progress for the initialization is stored on-disk in the vdev’s
          leaf zap object. The following information is stored:
                - the last offset that has been initialized
                - the state of the initialization process (i.e. active,
                  suspended, or canceled)
                - the start time for the initialization

        - progress is reported via the zpool status command and shows
          information for each of the vdevs that are initializing

Porting notes:
- Added zfs_initialize_value module parameter to set the pattern
  written by "zpool initialize".
- Added zfs_vdev_{initializing,removal}_{min,max}_active module options.

Authored by: George Wilson <george.wilson@delphix.com>
Reviewed by: John Wren Kennedy <john.kennedy@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: loli10K <ezomori.nozomu@gmail.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Richard Lowe <richlowe@richlowe.net>
Signed-off-by: Tim Chase <tim@chase2k.com>
Ported-by: Tim Chase <tim@chase2k.com>

OpenZFS-issue: https://www.illumos.org/issues/9102
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/c3963210eb
Closes #8230
2019-01-07 10:37:26 -08:00
Brian Behlendorf
65ca2c1eb9
Fix 'zpool remap' freeing race
The dmu_objset_remap_indirects_impl() logic depends on dnode_hold()
returning ENOENT for dnodes which will be freed and should be skipped.

This behavior can only be relied upon when taking a new hold and
while the caller has an open transaction.  This ensures that the
open txg cannot advance and that a concurrent free will end up
in the same txg (which is critical).  Relying on an existing hold
will not prevent dnode_free() from succeeding.

The solution is to take an additional dnode_hold() after assigning
the transaction.  This ensures the remap will never dirty the dnode
if it was freed while we were waiting in dmu_tx_assign(, TXG_WAIT).

Randomly set zfs_object_remap_one_indirect_delay_ms in ztest.  This
increases the likelihood of an operation racing with the remap.
Converted from ticks to milliseconds.

Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Tom Caputi <tcaputi@datto.com>
Reviewed by: Igor Kozhukhov <igor@dilos.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #8215
2019-01-02 11:46:04 -08:00
Brian Behlendorf
0dd6b6bfcb
ztest: ENOSPC in ztest_objset_destroy_cb()
While unlikely it is possible for dsl_destroy_head() to return
ENOSPC in the ztest_objset_destroy_cb().  This can occur even
when ZFS_SPACE_CHECK_DESTROY is used with the dsl_sync_task().
Both the existence of a checkpoint and pending deferred frees
can cause this.

Reviewed-by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #8206
2018-12-14 10:03:05 -08:00
Prakash Surya
900d09b285 OpenZFS 9962 - zil_commit should omit cache thrash
As a result of the changes made in 8585, it's possible for an excessive
amount of vdev flush commands to be issued under some workloads.

Specifically, when the workload consists of mostly async write activity,
interspersed with some sync write and/or fsync activity, we can end up
issuing more flush commands to the underlying storage than is actually
necessary. As a result of these flush commands, the write latency and
overall throughput of the pool can be poorly impacted (latency
increases, throughput decreases).

Currently, any time an lwb completes, the vdev(s) written to as a result
of that lwb will be issued a flush command. The intenion is so the data
written to that vdev is on stable storage, prior to communicating to any
waiting threads that their data is safe on disk.

The problem with this scheme, is that sometimes an lwb will not have any
threads waiting for it to complete. This can occur when there's async
activity that gets "converted" to sync requests, as a result of calling
the zil_async_to_sync() function via zil_commit_impl(). When this
occurs, the current code may issue many lwbs that don't have waiters
associated with them, resulting in many flush commands, potentially to
the same vdev(s).

For example, given a pool with a single vdev, and a single fsync() call
that results in 10 lwbs being written out (e.g. due to other async
writes), that will result in 10 flush commands to that single vdev (a
flush issued after each lwb write completes). Ideally, we'd only issue a
single flush command to that vdev, after all 10 lwb writes completed.

Further, and most important as it pertains to this change, since the
flush commands are often very impactful to the performance of the pool's
underlying storage, unnecessarily issuing these flush commands can
poorly impact the performance of the lwb writes themselves. Thus, we
need to avoid issuing flush commands when possible, in order to acheive
the best possible performance out of the pool's underlying storage.

This change attempts to address this problem by changing the ZIL's logic
to only issue a vdev flush command when it detects an lwb that has a
thread waiting for it to complete. When an lwb does not have threads
waiting for it, the responsibility of issuing the flush command to the
vdevs involved with that lwb's write is passed on to the "next" lwb.
It's only once a write for an lwb with waiters completes, do we issue
the vdev flush command(s). As a result, now when we issue the flush(s),
we will issue them to the vdevs involved with that specific lwb's write,
but potentially also to vdevs involved with "previous" lwb writes (i.e.
if the previous lwbs did not have waiters associated with them).

Thus, in our prior example with 10 lwbs, it's only once the last lwb
completes (which will be the lwb containing the waiter for the thread
that called fsync) will we issue the vdev flush command; all of the
other lwbs will find they have no waiters, so they'll pass the
responsibility of the flush to the "next" lwb (until reaching the last
lwb that has the waiter).

Porting Notes:
* Reconciled conflicts with the fastwrite feature.

Authored by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed by: Patrick Mooney <patrick.mooney@joyent.com>
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Approved by: Joshua M. Clulow <josh@sysmgr.org>
Ported-by: Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/9962
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/545190c6
Closes #8188
2018-12-07 11:09:42 -08:00
Tom Caputi
0b606cb33f Fix ztest deadlock in ztest_zil_remount()
This patch fixes a small race condition in ztest_zil_remount()
that could result in a deadlock. ztest_device_removal() calls
spa_vdev_remove() which may eventually call spa_reset_logs().
If ztest_zil_remount() attempts to call zil_close() while this
is happening, it may fail when it asserts !zilog_is_dirty(zilog).
This patch simply adds locking to correct the issue.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #8154
2018-12-04 09:43:31 -08:00
Tom Caputi
c40a1124e1 Fix consistency of ztest_device_removal_active
ztest currently uses the boolean flag ztest_device_removal_active
to protect some tests that may not run successfully if they occur
at the same time as ztest_device_removal(). Unfortunately, in the
event that ztest is in the middle of a device removal when it
decides to issue a SIGKILL, the device removal will be
automatically restarted (without setting the flag) when the pool
is re-imported on the next run. This patch corrects this by
ensuring that any in-progress removals are completed before running
further tests after the re-import.

This patch also makes a few small changes to prevent race conditions
involving the creation and destruction of spa->spa_vdev_removal,
since this field is not protected by any locks. Some checks that
may run concurrently with setting / unsetting this field have been
updated to check spa->spa_removing_phys.sr_state instead. The most
significant change here is that spa_removal_get_stats() no longer
accounts for in-flight work done, since that could result in a NULL
pointer dereference.

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #8105
2018-11-28 20:47:09 -08:00
Tom Caputi
a2d88f778a Fix !zilog_is_dirty() assert during ztest
ztest occasionally hits an assert that !zilog_is_dirty() during
zil_close(). This is caused by an interaction between 2 threads.
First, ztest_run() waits for each test thread to complete and
closes the associated dataset as soon as the thread joins. At
the same time, the ztest_vdev_add_remove() test may attempt to
remove the slog, which will open, dirty, and reset the logs on
every dataset in the pool (including those of other threads).
This patch simply ensures that we always join all of the test
threads before closing any datasets.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #8094
2018-11-07 15:46:50 -08:00
Tom Caputi
f44ad9297d Replay logs before starting ztest workers
This patch ensures that logs are replayed on all datasets prior
to starting ztest workers. This ensures that the call to
vdev_offline() a log device in ztest_fault_inject() will not fail
due to the log device being required for replay.

This patch also fixes a small issue found during testing where
spa_keystore_load_wkey() does not check that the dataset specified
is an encryption root. This check was present in libzfs, however.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #8084
2018-11-07 15:40:24 -08:00
Brian Behlendorf
09b85f2ded
ztest: reduce gangblock creation
In order to validate the gang block code ztest is configured to
artificially force a fraction of large blocks to be written as
gang blocks.  The default setting chosen for this was to
write 25% of all blocks 32k or larger using gang blocks.

The confluence of an unrealistically large number of gang blocks,
the aggressive fault injection done by ztest, and the split
segment reconstruction logic introduced by device removal has
resulted in the following type of failure:

  zdb -bccsv -G -d ... exit code 3

Specifically, zdb was unable to open the pool because it was
unable to reconstruct a damaged block.  Manual investigation
of multiple failures clearly showed that the block could be
reconstructed.  However, due to the large number of damaged
segments (>35) it could not be done in the allotted time.

Furthermore, the large number of gang blocks was determined
to be the reason for the unrealistically large number of
damaged segments.  In order to make this situation less
likely, this change both increases the forced gang block
size to 64k and reduces the frequency to 3% of blocks.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #8080
2018-11-05 11:53:49 -08:00
Don Brady
e89f1295d4 Add libzutil for libzfs or libzpool consumers
Adds a libzutil for utility functions that are common to libzfs and
libzpool consumers (most of what was in libzfs_import.c).  This
removes the need for utilities to link against both libzpool and
libzfs.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Don Brady <don.brady@delphix.com>
Closes #8050
2018-11-05 11:22:33 -08:00
Tom Caputi
7d658d29cf Fix waiting in ztest_device_removal()
spa->spa_vdev_removal is created in a sync task that is initiated
via dsl_sync_task_nowait(). Since the task may not run before
spa_vdev_remove() returns, we must wait at least 1 txg to ensure
that the removal struct has been created.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #8010
2018-10-24 14:37:35 -07:00
Tom Caputi
4a7eb69a5a Fix ztest deadman panic with indirect vdev damage
This patch fixes an issue where ztest's deadman thread would
trigger a panic because reconstructing artifically damaged
blocks would take too long to reconstruct. This patch simply
limits how often ztest inflicts split-block damage and how
many segments it can damage when it does.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #8010
2018-10-24 14:37:31 -07:00
Tom Caputi
ab4c009e3d Fix dbgmsg printing in ztest and zdb
This patch resolves a problem where the -G option in both zdb and
ztest would cause the code to call __dprintf() to print zfs_dbgmsg
output. This function was not properly wired to add messages to the
dbgmsg log as it is in userspace and so the messages were simply
dropped. This patch also tries to add some degree of distinction to
dprintf() (which now prints directly to stdout) and zfs_dbgmsg()
(which adds messages to an internal list that can be dumped with
zfs_dbgmsg_print()).

In addition, this patch corrects an issue where ztest used a global
variable to decide whether to dump the dbgmsg buffer on a crash.
This did not work because ztest spins up more instances of itself
using execv(), which did not copy the global variable to the new
process. The option has been moved to the ztest_shared_opts_t
which already exists for interprocess communication.

This patch also changes zfs_dbgmsg_print() to use write() calls
instead of printf() so that it will not fail when used in a signal
handler.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #8010
2018-10-24 14:36:50 -07:00
Tom Caputi
9410257800 Fix random ztest_deadman_thread failures
The zloop test has been failing in buildbot for the last few weeks
with various failures in ztest_deadman_thread(). This is due to the
fact that this thread is not stopped when performing pool import /
export tests as it should be. This patch simply corrects this.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #8010
2018-10-24 14:36:21 -07:00
Matthew Ahrens
d637db98e1 OpenZFS 9681 - ztest failure in spa_history_log_internal due to spa_rename()
Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed by: George Melikov <mail@gmelikov.ru>
Reviewed by: Tom Caputi <tcaputi@datto.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/9681
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/6aee0ad7
Closes #8041
2018-10-19 12:02:28 -07:00
Matt Ahrens
5d43cc9a59 OpenZFS 9689 - zfs range lock code should not be zpl-specific
The ZFS range locking code in zfs_rlock.c/h depends on ZPL-specific
data structures, specifically znode_t.  However, it's also used by
the ZVOL code, which uses a "dummy" znode_t to pass to the range
locking code.

We should clean this up so that the range locking code is generic
and can be used equally by ZPL and ZVOL, and also can be used by
future consumers that may need to run in userland (libzpool) as
well as the kernel.

Porting notes:
* Added missing sys/avl.h include to sys/zfs_rlock.h.
* Removed 'dbuf is within the locked range' ASSERTs from dmu_sync().
  This was needed because ztest does not yet use a locked_range_t.
* Removed "Approved by:" tag requirement from OpenZFS commit
  check to prevent needless warnings when integrating changes
  which has not been merged to illumos.
* Reverted free_list range lock changes which were originally
  needed to defer the cv_destroy() which was called immediately
  after cv_broadcast().  With d2733258 this should be safe but
  if not we may need to reintroduce this logic.
* Reverts: The following two commits were reverted and squashed in
  to this change in order to make it easier to apply OpenZFS 9689.
  - d88895a0, which removed the dummy znode from zvol_state
  - e3a07cd0, which updated ztest to use range locks
* Preserved optimized rangelock comparison function.  Preserved the
  rangelock free list.  The cv_destroy() function will block waiting
  for all processes in cv_wait() to be scheduled and drop their
  reference.  This is done to ensure it's safe to free the condition
  variable.  However, blocking while holding the rl->rl_lock mutex
  can result in a deadlock on Linux.  A free list is introduced to
  defer the cv_destroy() and kmem_free() until after the mutex is
  released.

Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://illumos.org/issues/9689
OpenZFS-commit: https://github.com/openzfs/openzfs/pull/680
External-issue: DLPX-58662
Closes #7980
2018-10-11 10:19:33 -07:00
Tom Caputi
52ce99dd61 Refcounted DSL Crypto Key Mappings
Since native ZFS encryption was merged, we have been fighting
against a series of bugs that come down to the same problem: Key
mappings (which must be present during all I/O operations) are
created and destroyed based on dataset ownership, but I/Os can
have traditionally been allowed to "leak" into the next txg after
the dataset is disowned.

In the past we have attempted to solve this problem by trying to
ensure that datasets are disowned ater all I/O is finished by
calling txg_wait_synced(), but we have repeatedly found edge cases
that need to be squashed and code paths that might incur a high
number of txg syncs. This patch attempts to resolve this issue
differently, by adding a reference to the key mapping for each txg
it is dirtied in. By doing so, we can remove many of the
unnecessary calls to txg_wait_synced() we have added in the past
and ensure we don't need to deal with this problem in the future.

Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #7949
2018-10-03 09:47:11 -07:00
Tim Schumacher
424fd7c3e0 Prefix all refcount functions with zfs_
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
2018-10-01 10:42:05 -07:00
Brian Behlendorf
1258bd778e
Refine split block reconstruction
Due to a flaw in 4589f3ae the number of unique combinations
could be calculated incorrectly.  This could result in the
random combinations reconstruction being used when it would
have been possible to check all combinations.

This change fixes the unique combinations calculation and
simplifies the reconstruction logic by maintaining a per-
segment list of unique copies.

The vdev_indirect_splits_damage() function was introduced
to validate both the enumeration and random reconstruction
logic with ztest.  It is implemented such it will never
make a known recoverable block unrecoverable.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #6900 
Closes #7934
2018-10-01 10:36:34 -07:00
Tim Schumacher
c13060e478 Linux 4.19-rc3+ compat: Remove refcount_t compat
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 #7885 
Closes #7932
2018-09-26 10:29:26 -07:00
Don Brady
cc99f275a2 Pool allocation classes
Allocation Classes add the ability to have allocation classes in a
pool that are dedicated to serving specific block categories, such
as DDT data, metadata, and small file blocks. A pool can opt-in to
this feature by adding a 'special' or 'dedup' top-level VDEV.

Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Alek Pinchuk <apinchuk@datto.com>
Reviewed-by: Håkan Johansson <f96hajo@chalmers.se>
Reviewed-by: Andreas Dilger <andreas.dilger@chamcloud.com>
Reviewed-by: DHE <git@dehacked.net>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: Gregor Kopka <gregor@kopka.net>
Reviewed-by: Kash Pande <kash@tripleback.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Don Brady <don.brady@delphix.com>
Closes #5182
2018-09-05 18:33:36 -07:00
Tom Caputi
c3bd3fb4ac OpenZFS 9403 - assertion failed in arc_buf_destroy()
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/fa98e487a9
Closes #7822
2018-08-29 11:33:33 -07:00
Olaf Faaland
5200237711 MMP should not suspend pool in ztest
When running ztest, never suspend the pool due to failed or delayed
MMP writes.

There are many sources of long delays within ztest, such as device
opens, closes, etc. which in combination, may delay MMP writes too
long and cause MMP to suspend the pool.

Some of these delays also affect real pools, and should be fixed.
That is being worked separately.

Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes #7776
2018-08-13 08:12:25 -07:00
Nathan Lewis
010d12474c Add support for selecting encryption backend
- Add two new module parameters to icp (icp_aes_impl, icp_gcm_impl)
  that control the crypto implementation.  At the moment there is a
  choice between generic and aesni (on platforms that support it).
- This enables support for AES-NI and PCLMULQDQ-NI on AMD Family
  15h (bulldozer) and newer CPUs (zen).
- Modify aes_key_t to track what implementation it was generated
  with as key schedules generated with various implementations
  are not necessarily interchangable.

Reviewed by: Gvozden Neskovic <neskovic@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Signed-off-by: Nathaniel R. Lewis <linux.robotdude@gmail.com>
Closes #7102 
Closes #7103
2018-08-02 11:59:24 -07:00
Serapheim Dimitropoulos
4d044c4c1d OpenZFS 9238 - ZFS Spacemap Encoding V2
Motivation
==========

The current space map encoding has the following disadvantages:
[1] Assuming 512 sector size each entry can represent at most 16MB for a segment.
    This makes the encoding very inefficient for large regions of space.
[2] As vdev-wide space maps have started to be used by new features (i.e.
    device removal, zpool checkpoint) we've started imposing limits in the
    vdevs that can be used with them based on the maximum addressable offset
    (currently 64PB for a top-level vdev).

New encoding
============

The layout can be found at space_map.h and it remains backwards compatible with
the old one. The introduced two-word entry format, besides extending the limits
imposed by the single-entry layout, also includes a vdev field and some extra
padding after its prefix.

The extra padding after the prefix should is reserved for future usage (e.g.
new prefixes for future encodings or new fields for flags). The new vdev field
not only makes the space maps more self-descriptive, but also opens the doors
for pool-wide space maps (expected to be used in the log spacemap project).

One final important note is that the number of bits used for vdevs is reduced
to 24 bits for blkptrs. That was decided as we don't know of any setups that
use more than 16M vdevs for the time being and we wanted to fit the vdev field
in the space map. In addition that gives us some extra bits in dva_t.

Other references:
=================

The new encoding is also discussed towards the end of the Log Space Map
presentation from 2017's OpenZFS summit.
Link: https://www.youtube.com/watch?v=jj2IxRkl5bQ

Authored by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <gwilson@zfsmail.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Gordon Ross <gwr@nexenta.com>
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Tim Chase <tim@chase2k.com>

OpenZFS-commit: https://github.com/openzfs/openzfs/commit/90a56e6d
OpenZFS-issue: https://www.illumos.org/issues/9238
Closes #7665
2018-07-05 12:02:34 -07:00
Serapheim Dimitropoulos
d2734cce68 OpenZFS 9166 - zfs storage pool checkpoint
Details about the motivation of this feature and its usage can
be found in this blogpost:

    https://sdimitro.github.io/post/zpool-checkpoint/

A lightning talk of this feature can be found here:
https://www.youtube.com/watch?v=fPQA8K40jAM

Implementation details can be found in big block comment of
spa_checkpoint.c

Side-changes that are relevant to this commit but not explained
elsewhere:

* renames members of "struct metaslab trees to be shorter without
  losing meaning

* space_map_{alloc,truncate}() accept a block size as a
  parameter. The reason is that in the current state all space
  maps that we allocate through the DMU use a global tunable
  (space_map_blksz) which defauls to 4KB. This is ok for metaslab
  space maps in terms of bandwirdth since they are scattered all
  over the disk. But for other space maps this default is probably
  not what we want. Examples are device removal's vdev_obsolete_sm
  or vdev_chedkpoint_sm from this review. Both of these have a
  1:1 relationship with each vdev and could benefit from a bigger
  block size.

Porting notes:

* The part of dsl_scan_sync() which handles async destroys has
  been moved into the new dsl_process_async_destroys() function.

* Remove "VERIFY(!(flags & FWRITE))" in "kernel.c" so zhack can write
  to block device backed pools.

* ZTS:
  * Fix get_txg() in zpool_sync_001_pos due to "checkpoint_txg".

  * Don't use large dd block sizes on /dev/urandom under Linux in
    checkpoint_capacity.

  * Adopt Delphix-OS's setting of 4 (spa_asize_inflation =
    SPA_DVAS_PER_BP + 1) for the checkpoint_capacity test to speed
    its attempts to fill the pool

  * Create the base and nested pools with sync=disabled to speed up
    the "setup" phase.

  * Clear labels in test pool between checkpoint tests to avoid
    duplicate pool issues.

  * The import_rewind_device_replaced test has been marked as "known
    to fail" for the reasons listed in its DISCLAIMER.

  * New module parameters:

      zfs_spa_discard_memory_limit,
      zfs_remove_max_bytes_pause (not documented - debugging only)
      vdev_max_ms_count (formerly metaslabs_per_vdev)
      vdev_min_ms_count

Authored by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Richard Lowe <richlowe@richlowe.net>
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Tim Chase <tim@chase2k.com>

OpenZFS-issue: https://illumos.org/issues/9166
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/7159fdb8
Closes #7570
2018-06-26 10:07:42 -07:00
Brian Behlendorf
c91cf36fc2
Fix ztest_vdev_add_remove() test case
Commit 2ffd89fc allowed two new errors to be reported by zil_reset()
in order to provide a descriptive error message regarding why a log
device could not be removed.  However, the new return values were
not handled in the ztest_vdev_add_remove() test case resulting in
ztest failures during automated testing.

Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Paul Zuchowski <pzuchowski@datto.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #7630
2018-06-14 09:41:27 -07:00
Brian Behlendorf
2d9142c9d4
Remove rwlock wrappers
The only remaining consumer of the rwlock compatibility wrappers
is ztest.  Remove the wrappers and convert the few remaining
calls to the underlying pthread functions.

    rwlock_init()    -> pthread_rwlock_init()
    rwlock_destroy() -> pthread_rwlock_destroy()
    rw_rdlock()      -> pthread_rwlock_rdlock()
    rw_wrlock()      -> pthread_rwlock_wrlock()
    rw_unlock()      -> pthread_rwlock_unlock()

Note pthread_rwlock_init() defaults to PTHREAD_PROCESS_PRIVATE
which is equivilant to the USYNC_THREAD behavior.  There is no
functional change.

Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #7591
2018-06-04 16:52:10 -07:00
Matthew Ahrens
964c2d69a9 OpenZFS 9236 - nuke spa_dbgmsg
We should use zfs_dbgmsg instead of spa_dbgmsg. Or at least,
metaslab_condense() should call zfs_dbgmsg because it's important and
rare enough to always log. It's possible that the message in
zio_dva_allocate() would be too high-frequency for zfs_dbgmsg.

Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Richard Lowe <richlowe@richlowe.net>
Ported-by: Giuseppe Di Natale <dinatale2@llnl.gov>

Patch Notes:
* Removed ZFS_DEBUG_SPA from zfs-module-parameters.5

OpenZFS-issue: https://www.illumos.org/issues/9236
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/cfaba7f668
Closes #7467
2018-04-30 10:19:48 -07:00
Matt Ahrens
d830d4795a OpenZFS 9280 - Assertion failure while running removal_with_ganging test with 4K devices
Authored by: Matt Ahrens <Matt.Ahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Approved by: Garrett D'Amore <garrett@damore.org>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/9280
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/243952c
Closes #7445
2018-04-17 10:44:50 -07:00
Brian Behlendorf
4589f3ae4c Optimize possible split block search space
Remove duplicate segment copies to minimize the possible search
space for reconstruction.  Once reduced an accurate assessment can
be made regarding the difficulty in reconstructing the block.

Also, ztest will now run zdb with
zfs_reconstruct_indirect_combinations_max set to 1000000 in an attempt
to avoid checksum errors.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #6900
2018-04-14 12:22:43 -07:00
Matthew Ahrens
9e052db462 OpenZFS 9290 - device removal reduces redundancy of mirrors
Mirrors are supposed to provide redundancy in the face of whole-disk
failure and silent damage (e.g. some data on disk is not right, but ZFS
hasn't detected the whole device as being broken). However, the current
device removal implementation bypasses some of the mirror's redundancy.
Note that in no case is incorrect data returned, but we might get a
checksum error when we should have been able to find the right data.

There are two underlying problems:

1. When we remove a mirror device, we only read one side of the mirror.
Since we can't verify the checksum, this side may be silently bad, but
the good data is on the other side of the mirror (which we didn't read).
This can cause the removal to "bake in" the busted data – all copies of
the data in the new location are the same, busted version, while we left
the good version behind.

The fix for this is to read and copy both sides of the mirror. If the
old and new vdevs are mirrors, we will read both sides of the old
mirror, and write each copy to the corresponding side of the new mirror.
(If the old and new vdevs have a different number of children, we will
do this as best as possible.) Even though we aren't verifying checksums,
this ensures that as long as there's a good copy of the data, we'll have
a good copy after the removal, even if there's silent damage to one side
of the mirror. If we're removing a mirror that has some silent damage,
we'll have exactly the same damage in the new location (assuming that
the new location is also a mirror).

2. When we read from an indirect vdev that points to a mirror vdev, we
only consider one copy of the data. This can lead to reduced effective
redundancy, because we might read a bad copy of the data from one side
of the mirror, and not retry the other, good side of the mirror.

Note that the problem is not with the removal process, but rather after
the removal has completed (having copied correct data to both sides of
the mirror), if one side of the new mirror is silently damaged, we
encounter the problem when reading the relocated data via the indirect
vdev. Also note that the problem doesn't occur when ZFS knows that one
side of the mirror is bad, e.g. when a disk entirely fails or is
offlined.

The impact is that reads (from indirect vdevs that point to mirrors) may
return a checksum error even though the good data exists on one side of
the mirror, and scrub doesn't repair all data on the mirror (if some of
it is pointed to via an indirect vdev).

The fix for this is complicated by "split blocks" - one logical block
may be split into two (or more) pieces with each piece moved to a
different new location. In this case we need to read all versions of
each split (one from each side of the mirror), and figure out which
combination of versions results in the correct checksum, and then repair
the incorrect versions.

This ensures that we supply the same redundancy whether you use device
removal or not. For example, if a mirror has small silent errors on all
of its children, we can still reconstruct the correct data, as long as
those errors are at sufficiently-separated offsets (specifically,
separated by the largest block size - default of 128KB, but up to 16MB).

Porting notes:

* A new indirect vdev check was moved from dsl_scan_needs_resilver_cb()
  to dsl_scan_needs_resilver(), which was added to ZoL as part of the
  sequential scrub work.

* Passed NULL for zfs_ereport_post_checksum()'s zbookmark_phys_t
  parameter.  The extra parameter is unique to ZoL.

* When posting indirect checksum errors the ABD can be passed directly,
  zfs_ereport_post_checksum() is not yet ABD-aware in OpenZFS.

Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Tim Chase <tim@chase2k.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: Tim Chase <tim@chase2k.com>

OpenZFS-issue: https://illumos.org/issues/9290
OpenZFS-commit: https://github.com/openzfs/openzfs/pull/591
Closes #6900
2018-04-14 12:21:39 -07:00
Matthew Ahrens
a1d477c24c OpenZFS 7614, 9064 - zfs device evacuation/removal
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/f539f1eb
Closes #6900
2018-04-14 12:16:17 -07:00
Brian Behlendorf
60b8207496
Set persistent ztest failure mode
In order to reliably detect deadlocks in the create and import
path ztest should set the failure mode property.  This ensures
that the pool is always using the correct failmode behavior.

Removed insidious use of local variable in MAXFAULTS macro.

Converted VERIFY() to VERIFY0() where appropriate.

Reviewed-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #7111
2018-02-05 12:00:26 -08:00
Tom Caputi
047116ac76 Raw sends must be able to decrease nlevels
Currently, when a raw zfs send file includes a DRR_OBJECT record
that would decrease the number of levels of an existing object,
the object is reallocated with dmu_object_reclaim() which
creates the new dnode using the old object's nlevels. For non-raw
sends this doesn't really matter, but raw sends require that
nlevels on the receive side match that of the send side so that
the checksum-of-MAC tree can be properly maintained. This patch
corrects the issue by freeing the object completely before
allocating it again in this case.

This patch also corrects several issues with dnode_hold_impl()
and related functions that prevented dnodes (particularly
multi-slot dnodes) from being reallocated properly due to
the fact that existing dnodes were not being fully cleaned up
when they were freed.

This patch adds a test to make sure that zfs recv functions
properly with incremental streams containing dnodes of different
sizes.

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #6821
Closes #6864
2018-02-02 11:43:11 -08:00
Brian Behlendorf
8fb1ede146 Extend deadman logic
The intent of this patch is extend the existing deadman code
such that it's flexible enough to be used by both ztest and
on production systems.  The proposed changes include:

* Added a new `zfs_deadman_failmode` module option which is
  used to dynamically control the behavior of the deadman.  It's
  loosely modeled after, but independant from, the pool failmode
  property.  It can be set to wait, continue, or panic.

    * wait     - Wait for the "hung" I/O (default)
    * continue - Attempt to recover from a "hung" I/O
    * panic    - Panic the system

* Added a new `zfs_deadman_ziotime_ms` module option which is
  analogous to `zfs_deadman_synctime_ms` except instead of
  applying to a pool TXG sync it applies to zio_wait().  A
  default value of 300s is used to define a "hung" zio.

* The ztest deadman thread has been re-enabled by default,
  aligned with the upstream OpenZFS code, and then extended
  to terminate the process when it takes significantly longer
  to complete than expected.

* The -G option was added to ztest to print the internal debug
  log when a fatal error is encountered.  This same option was
  previously added to zdb in commit fa603f82.  Update zloop.sh
  to unconditionally pass -G to obtain additional debugging.

* The FM_EREPORT_ZFS_DELAY event which was previously posted
  when the deadman detect a "hung" pool has been replaced by
  a new dedicated FM_EREPORT_ZFS_DEADMAN event.

* The proposed recovery logic attempts to restart a "hung"
  zio by calling zio_interrupt() on any outstanding leaf zios.
  We may want to further restrict this to zios in either the
  ZIO_STAGE_VDEV_IO_START or ZIO_STAGE_VDEV_IO_DONE stages.
  Calling zio_interrupt() is expected to only be useful for
  cases when an IO has been submitted to the physical device
  but for some reasonable the completion callback hasn't been
  called by the lower layers.  This shouldn't be possible but
  has been observed and may be caused by kernel/driver bugs.

* The 'zfs_deadman_synctime_ms' default value was reduced from
  1000s to 600s.

* Depending on how ztest fails there may be no cache file to
  move.  This should not be considered fatal, collect the logs
  which are available and carry on.

* Add deadman test cases for spa_deadman() and zio_wait().

* Increase default zfs_deadman_checktime_ms to 60s.

Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed by: Thomas Caputi <tcaputi@datto.com>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #6999
2018-01-25 13:40:38 -08:00
Brian Behlendorf
e1a0850c35
Force ztest to always use /dev/urandom
For ztest, which is solely for testing, using a pseudo random
is entirely reasonable.  Using /dev/urandom ensures the system
entropy pool doesn't get depleted thus stalling the testing.
This is a particular problem when testing in VMs.

Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed by: Thomas Caputi <tcaputi@datto.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #7017 
Closes #7036
2018-01-12 09:36:26 -08:00
Brian Behlendorf
fed90353d7
Support -fsanitize=address with --enable-asan
When --enable-asan is provided to configure then build all user
space components with fsanitize=address.  For kernel support
use the Linux KASAN feature instead.

https://github.com/google/sanitizers/wiki/AddressSanitizer

When using gcc version 4.8 any test case which intentionally
generates a core dump will fail when using --enable-asan.
The default behavior is to disable core dumps and only newer
versions allow this behavior to be controled at run time with
the ASAN_OPTIONS environment variable.

Additionally, this patch includes some build system cleanup.

* Rules.am updated to set the minimum AM_CFLAGS, AM_CPPFLAGS,
  and AM_LDFLAGS.  Any additional flags should be added on a
  per-Makefile basic.  The --enable-debug and --enable-asan
  options apply to all user space binaries and libraries.

* Compiler checks consolidated in always-compiler-options.m4
  and renamed for consistency.

* -fstack-check compiler flag was removed, this functionality
  is provided by asan when configured with --enable-asan.

* Split DEBUG_CFLAGS in to DEBUG_CFLAGS, DEBUG_CPPFLAGS, and
  DEBUG_LDFLAGS.

* Moved default kernel build flags in to module/Makefile.in and
  split in to ZFS_MODULE_CFLAGS and ZFS_MODULE_CPPFLAGS.  These
  flags are set with the standard ccflags-y kbuild mechanism.

* -Wframe-larger-than checks applied only to binaries or
  libraries which include source files which are built in
  both user space and kernel space.  This restriction is
  relaxed for user space only utilities.

* -Wno-unused-but-set-variable applied only to libzfs and
  libzpool.  The remaining warnings are the result of an
  ASSERT using a variable when is always declared.

* -D_POSIX_PTHREAD_SEMANTICS and -D__EXTENSIONS__ dropped
  because they are Solaris specific and thus not needed.

* Ensure $GDB is defined as gdb by default in zloop.sh.

Signed-off-by: DHE <git@dehacked.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #7027
2018-01-10 10:49:27 -08:00
Brian Behlendorf
06401e4222 Fix ztest_verify_dnode_bt() test case
In ztest_verify_dnode_bt the ztest_object_lock must be held in
order to safely verify the unused bonus space.

Reviewed-by: DHE <git@dehacked.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #6941
2018-01-09 12:27:12 -08:00