Commit Graph

263 Commits

Author SHA1 Message Date
наб 5cdca5b1da autoconf: use include directives instead of recursing down cmd
No installation diff, dist lost
  -zfs-2.1.99/cmd/fsck_zfs/fsck.zfs
which was distributed erroneously, since it's generated

Also clean gitrev on clean

Also add -e 'any possible bashisms' to default checkbashisms flags,
and fully parallelise it and shellcheck, and it works out-of-tree, too

Also align the Release in the dist META file correctly

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13316
2022-05-10 10:18:38 -07:00
наб c8970f52ed autoconf: use include directives instead of recursing down lib
As a bonus, this also adds zfs-mount-generator (previously undescended
down) and libzstd (not included) to CppCheck

As a bonus bonus, abigail rules work out-of-tree, too

Against current trunk:
  $ diff -U0 ./destdir.listing ~/store/code/zfs/destdir.listing
  -destdir/usr/local/include/libspl/sscanf.h

  $ diff --color -U0 ./zfs-2.1.99.tar.gz.listing ../oot/zfs-2.1.99.tar.gz.listing | grep -v @@ | grep -v /Makefile
  -zfs-2.1.99/config/Abigail.am
  -zfs-2.1.99/lib/libspl/include/util/
  -zfs-2.1.99/lib/libspl/include/util/sscanf.h

  $ diff --color -U0 ./zfs-2.1.99.tar.gz.listing ../oot/zfs-2.1.99.tar.gz.listing | grep -v @@ | grep /Makefile
  -zfs-2.1.99/lib/libavl/Makefile.in
  -zfs-2.1.99/lib/libefi/Makefile.in
  -zfs-2.1.99/lib/libicp/Makefile.in
  -zfs-2.1.99/lib/libnvpair/Makefile.in
  -zfs-2.1.99/lib/libshare/Makefile.in
  -zfs-2.1.99/lib/libspl/include/Makefile.in
  -zfs-2.1.99/lib/libspl/include/os/freebsd/Makefile.am
  -zfs-2.1.99/lib/libspl/include/os/freebsd/Makefile.in
  -zfs-2.1.99/lib/libspl/include/os/freebsd/sys/Makefile.am
  -zfs-2.1.99/lib/libspl/include/os/freebsd/sys/Makefile.in
  -zfs-2.1.99/lib/libspl/include/os/linux/Makefile.am
  -zfs-2.1.99/lib/libspl/include/os/linux/Makefile.in
  -zfs-2.1.99/lib/libspl/include/os/linux/sys/Makefile.am
  -zfs-2.1.99/lib/libspl/include/os/linux/sys/Makefile.in
  -zfs-2.1.99/lib/libspl/include/os/Makefile.am
  -zfs-2.1.99/lib/libspl/include/os/Makefile.in
  -zfs-2.1.99/lib/libspl/include/rpc/Makefile.am
  -zfs-2.1.99/lib/libspl/include/rpc/Makefile.in
  -zfs-2.1.99/lib/libspl/include/sys/dktp/Makefile.am
  -zfs-2.1.99/lib/libspl/include/sys/dktp/Makefile.in
  -zfs-2.1.99/lib/libspl/include/sys/Makefile.am
  -zfs-2.1.99/lib/libspl/include/sys/Makefile.in
  -zfs-2.1.99/lib/libspl/include/util/Makefile.am
  -zfs-2.1.99/lib/libspl/include/util/Makefile.in
  -zfs-2.1.99/lib/libspl/Makefile.in
  -zfs-2.1.99/lib/libtpool/Makefile.in
  -zfs-2.1.99/lib/libunicode/Makefile.in
  -zfs-2.1.99/lib/libuutil/Makefile.in
  -zfs-2.1.99/lib/libzfsbootenv/Makefile.in
  -zfs-2.1.99/lib/libzfs_core/Makefile.in
  -zfs-2.1.99/lib/libzfs/Makefile.in
  -zfs-2.1.99/lib/libzpool/Makefile.in
  -zfs-2.1.99/lib/libzstd/Makefile.in
  -zfs-2.1.99/lib/libzutil/Makefile.in
  -zfs-2.1.99/lib/Makefile.in

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13316
2022-05-10 10:18:11 -07:00
Brian Behlendorf 460748d4ae
Switch from _Noreturn to __attribute__((noreturn))
Parts of the Linux kernel build system struggle with _Noreturn.  This
results in the following warnings when building on RHEL 8.5, and likely
other environments.  Switch to using the __attribute__((noreturn)).

  warning: objtool: dbuf_free_range()+0x2b8:
    return with modified stack frame
  warning: objtool: dbuf_free_range()+0x0:
    stack state mismatch: cfa1=7+40 cfa2=7+8
  ...
  WARNING: EXPORT symbol "arc_buf_size" [zfs.ko] version generation
    failed, symbol will not be versioned.
  WARNING: EXPORT symbol "spa_open" [zfs.ko] version generation
    failed, symbol will not be versioned.
  ...

Additionally, __thread_exit() has been renamed spl_thread_exit() and
made a static inline function.  This was needed because the kernel
will generate a warning for symbols which are __attribute__((noreturn))
and then exported with EXPORT_SYMBOL.

While we could continue to use _Noreturn in user space I've also
switched it to __attribute__((noreturn)) purely for consistency
throughout the code base.

Reviewed-by: Ryan Moeller <freqlabs@FreeBSD.org>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #13238
2022-03-23 08:51:00 -07:00
наб 861166b027 Remove bcopy(), bzero(), bcmp()
bcopy() has a confusing argument order and is actually a move, not a
copy; they're all deprecated since POSIX.1-2001 and removed in -2008,
and we shim them out to mem*() on Linux anyway

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #12996
2022-03-15 15:13:42 -07:00
Alejandro Colomar db7f1a91de
Use _Noreturn (C11; GNU89) properly
A function that returns with no value is a different thing from a
function that doesn't return at all.  Those are two orthogonal
concepts, commonly confused.

pthread_create(3) expects a pointer to a start routine that has a
very precise prototype:

    void *(*start_routine)(void *);

However, other thread functions, such as kernel ones, expect:

    void (*start_routine)(void *);

Providing a different one is incorrect, and has only been working
because the ABIs happen to produce a compatible function.

We should use '_Noreturn void', since it's the natural type, and
then provide a '_Noreturn void *' wrapper for pthread functions.

For consistency, replace most cases of __NORETURN or
__attribute__((noreturn)) by _Noreturn.  _Noreturn is understood
by -std=gnu89, so it should be safe to use everywhere.

Ref: https://github.com/openzfs/zfs/pull/13110#discussion_r808450136
Ref: https://software.codidact.com/posts/285972
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Closes #13120
2022-03-04 16:25:22 -08:00
Brian Behlendorf ce91f973ec
ztest: Fix ASSERT in ztest_objset_destroy_cb()
The dsl_destroy_snapshot() call in ztest_objset_destroy_cb() may
encounter a runtime error when the pool is out of space.  This is
similar to the error handling for the dsl_destroy_head() case,
but since dsl_destroy_snapshot() is implemented as a channel
program ECHRNG is returned instead of ENOSPC.  ECHRNG may also
be returned instead of EBUSY if there is a hold on the snapshot.

Reviewed by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #13155
2022-02-26 11:20:32 -08:00
Jitendra Patidar 361a7e8211
log xattr=sa create/remove/update to ZIL
As such, there are no specific synchronous semantics defined for
the xattrs. But for xattr=on, it does log to ZIL and zil_commit() is
done, if sync=always is set on dataset. This provides sync semantics
for xattr=on with sync=always set on dataset.

For the xattr=sa implementation, it doesn't log to ZIL, so, even with
sync=always, xattrs are not guaranteed to be synced before xattr call
returns to caller. So, xattr can be lost if system crash happens, before
txg carrying xattr transaction is synced.

This change adds xattr=sa logging to ZIL on xattr create/remove/update
and xattrs are synced to ZIL (zil_commit() done) for sync=always.
This makes xattr=sa behavior similar to xattr=on.

Implementation notes:
The actual logging is fairly straight-forward and does not warrant
additional explanation.
However, it has been 14 years since we last added new TX types
to the ZIL [1], hence this is the first time we do it after the
introduction of zpool features. Therefore, here is an overview of the
feature activation and deactivation workflow:

1. The feature must be enabled. Otherwise, we don't log the new
    record type. This ensures compatibility with older software.
2. The feature is activated per-dataset, since the ZIL is per-dataset.
3. If the feature is enabled and dataset is not for zvol, any append to
    the ZIL chain will activate the feature for the dataset. Likewise
    for starting a new ZIL chain.
4. A dataset that doesn't have a ZIL chain has the feature deactivated.

We ensure (3) by activating on the first zil_commit() after the feature
was enabled. Since activating the features requires waiting for txg
sync, the first zil_commit() after enabling the feature will be slower
than usual. The downside is that this is really a conservative
approximation: even if we never append a 'TX_SETSAXATTR' to the ZIL
chain, we pay the penalty for feature activation. The upside is that the
user is in control of when we pay the penalty, i.e., upon enabling the
feature.

We ensure (4) by hooking into zil_sync(), where ZIL destroy actually
happens.

One more piece on feature activation, since it's spread across
multiple functions:

zil_commit()
  zil_process_commit_list()
    if lwb == NULL // first zil_commit since zil_open
      zil_create()
        if no log block pointer in ZIL header:
          if feature enabled and not active:
	    // CASE 1
            enable, COALESCE txg wait with dmu_tx that allocated the
	    log block
         else // log block was allocated earlier than this zil_open
          if feature enabled and not active:
	    // CASE 2
            enable, EXPLICIT txg wait
    else // already have an in-DRAM LWB
      if feature enabled and not active:
        // this happens when we enable the feature after zil_create
	// CASE 3
        enable, EXPLICIT txg wait

[1] da6c28aaf6

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Christian Schwarz <christian.schwarz@nutanix.com>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Ryan Moeller <freqlabs@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jitendra Patidar <jitendra.patidar@nutanix.com>
Closes #8768 
Closes #9078
2022-02-22 13:06:43 -08:00
Damian Szuberski 63652e1546
Add `--enable-asan` and `--enable-ubsan` switches
`configure` now accepts `--enable-asan` and `--enable-ubsan` switches
which results in passing `-fsanitize=address`
and `-fsanitize=undefined`, respectively, to the compiler. Those
flags are enabled in GitHub workflows for ZTS and zloop. Errors
reported by both instrumentations are corrected, except for:

- Memory leak reporting is (temporarily) suppressed. The cost of
  fixing them is relatively high compared to the gains.

- Checksum computing functions in `module/zcommon/zfs_fletcher*`
  have UBSan errors suppressed. It is completely impractical
  to enforce 64-byte payload alignment there due to performance
  impact.

- There's no ASan heap poisoning in `module/zstd/lib/zstd.c`. A custom
  memory allocator is used there rendering that measure
  unfeasible.

- Memory leaks detection has to be suppressed for `cmd/zvol_id`.
  `zvol_id` is run by udev with the help of `ptrace(2)`. Tracing is
  incompatible with memory leaks detection.

Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: szubersk <szuberskidamian@gmail.com>
Closes #12928
2022-02-03 14:35:38 -08:00
наб 18168da727
module/*.ko: prune .data, global .rodata
Evaluated every variable that lives in .data (and globals in .rodata)
in the kernel modules, and constified/eliminated/localised them
appropriately. This means that all read-only data is now actually
read-only data, and, if possible, at file scope. A lot of previously-
global-symbols became inlinable (and inlined!) constants. Probably
not in a big Wowee Performance Moment, but hey.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #12899
2022-01-14 15:37:55 -08:00
наб d8f32c0eb7 ztest: fix unused, remove argsused
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #12835
2021-12-21 12:05:12 -08:00
Paul Dagnelie 795075e638
Add `const` to nvlist functions to properly expose their real behavior
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes #12728
2021-12-06 18:19:13 -07:00
наб 90f1c3c946 Prune /*NOTREACHED*/
This includes a simplification of mkbusy and format correctness in zhack
and ztest

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Issue #12201
2021-07-26 12:07:26 -07:00
Rich Ercolani 8e739b2c9f
Annotated dprintf as printf-like
ZFS loves using %llu for uint64_t, but that requires a cast to not 
be noisy - which is even done in many, though not all, places.
Also a couple places used %u for uint64_t, which were promoted
to %llu. 

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes #12233
2021-06-22 21:53:45 -07:00
Manoj Joseph 45516b4a0a
long options for ztest
This change introduces long options for ztest. It builds the usage
message as well as the long_options array from a single table. It also
adds #defines for the default values.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Signed-off-by: Manoj Joseph <manoj.joseph@delphix.com>
Closes #12117
2021-05-28 16:06:07 -06:00
Andrea Gelmini bf169e9f15 Fix various typos
Correct an assortment of typos throughout the code base.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Closes #11774
2021-04-02 18:52:15 -07:00
Chunwei Chen 296a4a369b
Fix zfs_get_data access to files with wrong generation
If TX_WRITE is create on a file, and the file is later deleted and a new
directory is created on the same object id, it is possible that when
zil_commit happens, zfs_get_data will be called on the new directory.
This may result in panic as it tries to do range lock.

This patch fixes this issue by record the generation number during
zfs_log_write, so zfs_get_data can check if the object is valid.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@nutanix.com>
Closes #10593
Closes #11682
2021-03-19 22:53:31 -07:00
Martin Matuška 03ef8f09e1
Add missing checks for unsupported features
After 35ec517 it has become possible to import ZFS pools witn an
active org.illumos:edonr feature on FreeBSD, leading to a panic.

In addition, "zpool status" reported all pools without edonr
as upgradable and "zpool upgrade -v" reported edonr in the list
of upgradable features.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Martin Matuska <mm@FreeBSD.org>
Closes #11653
2021-02-27 17:16:02 -08:00
Christian Schwarz 52cb284f7b ztest: propagate -o to the zdb child process
I think this is the behavior that most users expect.

Future work: have a separate flag, e.g., -O, to specify separate
set_global_vars for the zdb child than for the ztest children.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Signed-off-by: Christian Schwarz <me@cschwarz.com>
Closes #11602
2021-02-19 22:45:16 -08:00
Christian Schwarz 2801e68d1b ztest: fix -o by calling set_global_var in child processes
Without set_global_var() in the child processes the -o option provides
little use.

Before this change set_global_var() was called as a side-effect of
getopt processing which only happens for the parent ztest process.

This change limits the set of options that can be set and makes them
available to the child through ztest_shared_opts_t.

Future work: support arbitrary option count and length.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Signed-off-by: Christian Schwarz <me@cschwarz.com>
Closes #11602
2021-02-19 22:45:10 -08:00
José Luis Salvador Rufo aef1830f93
Support uClibc for the tests compilations
There are two issues that don't allow ZFS to be compiled using uClibc.
`backtrace()`, and `program_invocation_short_name` as a `const`.
This patch adds uClibc to the conditionals in the same way there are
already for Glibc for `backtrace()`; and removes the external param
`program_invocation_short_name` because its only used here for the
whole project.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: José Luis Salvador Rufo <salvador.joseluis@gmail.com>
Closes #11600
2021-02-16 21:51:46 -08:00
Brian Behlendorf 0e6c493fec cppcheck: integrete cppcheck
In order for cppcheck to perform a proper analysis it needs to be
aware of how the sources are compiled (source files, include
paths/files, extra defines, etc).  All the needed information is
available from the Makefiles and can be leveraged with a generic
cppcheck Makefile target.  So let's add one.

Additional minor changes:

* Removing the cppcheck-suppressions.txt file.  With cppcheck 2.3
  and these changes it appears to no longer be needed.  Some inline
  suppressions were also removed since they appear not to be
  needed.  We can add them back if it turns out they're needed
  for older versions of cppcheck.

* Added the ax_count_cpus m4 macro to detect at configure time how
  many processors are available in order to run multiple cppcheck
  jobs.  This value is also now used as a replacement for nproc
  when executing the kernel interface checks.

* "PHONY =" line moved in to the Rules.am file which is included
  at the top of all Makefile.am's.  This is just convenient becase
  it allows us to use the += syntax to add phony targets.

* One upside of this integration worth mentioning is it now allows
  `make cppcheck` to be run in any directory to check that subtree.

* For the moment, cppcheck is not run against the FreeBSD specific
  kernel sources.  The cppcheck-FreeBSD target will need to be
  implemented and testing on FreeBSD to support this.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #11508
2021-01-26 16:12:26 -08:00
Ryan Moeller a9eaae065b
ztest: Clean up use of ASSERT and VERIFY
Try to use more appropriate ASSERT and VERIFY variants in ztest.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #11454
2021-01-12 17:21:01 -08:00
Ryan Moeller bea3fc71ae
ztest: Use fnvlist_* instead of VERIFYing nvlist_*
Simplify ztest by using fnvlist functions to verify success.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #11441
2021-01-11 09:30:33 -08:00
Matthew Ahrens f014700a37 Memory leak in ztest_dmu_objset_own()
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #11396
2020-12-28 10:05:44 -08:00
Matthew Ahrens a0316ad268 Memory leak in ztest_vdev_attach_detach()
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #11396
2020-12-28 10:05:32 -08:00
Matthew Ahrens b6722b871b nvlist leaked in zpool_find_config()
In `zpool_find_config()`, the `pools` nvlist is leaked.  Part of it (a
sub-nvlist) is returned in `*configp`, but the callers also leak that.

Additionally, in `zdb.c:main()`, the `searchdirs` is leaked.

The leaks were detected by ASAN (`configure --enable-asan`).

This commit resolves the leaks.

Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #11396
2020-12-28 10:05:31 -08:00
Alexander Motin f8020c9363
Make metaslab class rotor and aliquot per-allocator.
Metaslab rotor and aliquot are used to distribute workload between
vdevs while keeping some locality for logically adjacent blocks.  Once
multiple allocators were introduced to separate allocation of different
objects it does not make much sense for different allocators to write
into different metaslabs of the same metaslab group (vdev) same time,
competing for its resources.  This change makes each allocator choose
metaslab group independently, colliding with others only sporadically.

Test including simultaneous write into 4 files with recordsize of 4KB
on a striped pool of 30 disks on a system with 40 logical cores show
reduction of vdev queue lock contention from 54 to 27% due to better
load distribution.  Unfortunately it won't help much ZVOLs yet since
only one dataset/ZVOL is synced at a time, and so for the most part
only one allocator is used, but it may improve later.

While there, to reduce the number of pointer dereferences change
per-allocator storage for metaslab classes and groups from several
separate malloc()'s to variable length arrays at the ends of the
original class and group structures.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes #11288
2020-12-15 10:55:44 -08:00
Brian Behlendorf b2255edcc0
Distributed Spare (dRAID) Feature
This patch adds a new top-level vdev type called dRAID, which stands
for Distributed parity RAID.  This pool configuration allows all dRAID
vdevs to participate when rebuilding to a distributed hot spare device.
This can substantially reduce the total time required to restore full
parity to pool with a failed device.

A dRAID pool can be created using the new top-level `draid` type.
Like `raidz`, the desired redundancy is specified after the type:
`draid[1,2,3]`.  No additional information is required to create the
pool and reasonable default values will be chosen based on the number
of child vdevs in the dRAID vdev.

    zpool create <pool> draid[1,2,3] <vdevs...>

Unlike raidz, additional optional dRAID configuration values can be
provided as part of the draid type as colon separated values. This
allows administrators to fully specify a layout for either performance
or capacity reasons.  The supported options include:

    zpool create <pool> \
        draid[<parity>][:<data>d][:<children>c][:<spares>s] \
        <vdevs...>

    - draid[parity]       - Parity level (default 1)
    - draid[:<data>d]     - Data devices per group (default 8)
    - draid[:<children>c] - Expected number of child vdevs
    - draid[:<spares>s]   - Distributed hot spares (default 0)

Abbreviated example `zpool status` output for a 68 disk dRAID pool
with two distributed spares using special allocation classes.

```
  pool: tank
 state: ONLINE
config:

    NAME                  STATE     READ WRITE CKSUM
    slag7                 ONLINE       0     0     0
      draid2:8d:68c:2s-0  ONLINE       0     0     0
        L0                ONLINE       0     0     0
        L1                ONLINE       0     0     0
        ...
        U25               ONLINE       0     0     0
        U26               ONLINE       0     0     0
        spare-53          ONLINE       0     0     0
          U27             ONLINE       0     0     0
          draid2-0-0      ONLINE       0     0     0
        U28               ONLINE       0     0     0
        U29               ONLINE       0     0     0
        ...
        U42               ONLINE       0     0     0
        U43               ONLINE       0     0     0
    special
      mirror-1            ONLINE       0     0     0
        L5                ONLINE       0     0     0
        U5                ONLINE       0     0     0
      mirror-2            ONLINE       0     0     0
        L6                ONLINE       0     0     0
        U6                ONLINE       0     0     0
    spares
      draid2-0-0          INUSE     currently in use
      draid2-0-1          AVAIL
```

When adding test coverage for the new dRAID vdev type the following
options were added to the ztest command.  These options are leverages
by zloop.sh to test a wide range of dRAID configurations.

    -K draid|raidz|random - kind of RAID to test
    -D <value>            - dRAID data drives per group
    -S <value>            - dRAID distributed hot spares
    -R <value>            - RAID parity (raidz or dRAID)

The zpool_create, zpool_import, redundancy, replacement and fault
test groups have all been updated provide test coverage for the
dRAID feature.

Co-authored-by: Isaac Huang <he.huang@intel.com>
Co-authored-by: Mark Maybee <mmaybee@cray.com>
Co-authored-by: Don Brady <don.brady@delphix.com>
Co-authored-by: Matthew Ahrens <mahrens@delphix.com>
Co-authored-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Mark Maybee <mmaybee@cray.com>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #10102
2020-11-13 13:51:51 -08:00
Matthew Macy 27d96d2254
Rename refcount.h to zfs_refcount.h
Renamed to avoid conflicting with refcount.h when a different
implementation is already provided by the platform.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10620
2020-07-29 16:35:33 -07:00
Matthew Ahrens 6774931dfa
Extend zdb to print inconsistencies in livelists and metaslabs
Livelists and spacemaps are data structures that are logs of allocations
and frees.  Livelists entries are block pointers (blkptr_t). Spacemaps
entries are ranges of numbers, most often used as to track
allocated/freed regions of metaslabs/vdevs.

These data structures can become self-inconsistent, for example if a
block or range can be "double allocated" (two allocation records without
an intervening free) or "double freed" (two free records without an
intervening allocation).

ZDB (as well as zfs running in the kernel) can detect these
inconsistencies when loading livelists and metaslab.  However, it
generally halts processing when the error is detected.

When analyzing an on-disk problem, we often want to know the entire set
of inconsistencies, which is not possible with the current behavior.
This commit adds a new flag, `zdb -y`, which analyzes the livelist and
metaslab data structures and displays all of their inconsistencies.
Note that this is different from the leak detection performed by
`zdb -b`, which checks for inconsistencies between the spacemaps and the
tree of block pointers, but assumes the spacemaps are self-consistent.

The specific checks added are:

Verify livelists by iterating through each sublivelists and:
- report leftover FREEs
- report double ALLOCs and double FREEs
- record leftover ALLOCs together with their TXG [see Cross Check]

Verify spacemaps by iterating over each metaslab and:
- iterate over spacemap and then the metaslab's entries in the
  spacemap log, then report any double FREEs and double ALLOCs

Verify that livelists are consistenet with spacemaps.  The space
referenced by livelists (after using the FREE's to cancel out
corresponding ALLOCs) should be allocated, according to the spacemaps.

Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Sara Hartse <sara.hartse@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-66031
Closes #10515
2020-07-14 17:51:05 -07:00
Serapheim Dimitropoulos 6f1db5f37e
Unconditionally enable debugging for libzpool
We already enable -DDEBUG unconditionally (meaning regardless
of this is a debug build or a performance build) for zdb and
ztest as they are mostly used for development and debugging.

This patch enables -DDEBUG for libzpool extending the debugging
checks for zdb, ztest, and a couple of other test utilities.

In addition to passing -DDEBUG we also enable -DZFS_DEBUG so
all assertion checks work s expected. We do so not only in
libzpool but in every utility that links to it, even if the
utility doesn't directly use any functionality wrapped in
ZFS_DEBUG macro definitions. The reason is that these utilities
may still include headers that contain structs that have more
fields when ZFS_DEBUG is defined. This can be a problem as
enabling that flag for libzpool but not for zdb can lead into
random problems (e.g. segmentation faults) as zdb may be have
an incorrect view of a struct passed to it by libzpool.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes #10549
2020-07-10 15:30:31 -07:00
Arvind Sankar 3e597dee11 Use abs_top_builddir when referencing libraries
libtool stores absolute paths in the dependency_libs component of the
.la files. If the Makefile for a dependent library refers to the
libraries by relative path, some libraries end up duplicated on the link
command line.

As an example, libzfs specifies libzfs_core, libnvpair and libuutil as
dependencies to be linked in. The .la file for libzfs_core also
specifies libnvpair, but using an absolute path, with the result that
libnvpair is present twice in the linker command line for producing
libzfs.

While the only thing this causes is to slightly slow down the linking,
we can avoid it by using absolute paths everywhere, including for
convenience libraries just for consistency.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes #10538
2020-07-10 14:26:32 -07:00
Arvind Sankar 4d61ade1a3 Clean up lib dependencies
libzutil is currently statically linked into libzfs, libzfs_core and
libzpool. Avoid the unnecessary duplication by removing it from libzfs
and libzpool, and adding libzfs_core to libzpool.

Remove a few unnecessary dependencies:
- libuutil from libzfs_core
- libtirpc from libspl
- keep only libcrypto in libzfs, as we don't use any functions from
  libssl
- librt is only used for clock_gettime, however on modern systems that's
  in libc rather than librt. Add a configure check to see if we actually
  need librt
- libdl from raidz_test

Add a few missing dependencies:
- zlib to libefi and libzfs
- libuuid to zpool, and libuuid and libudev to zed
- libnvpair uses assertions, so add assert.c to provide aok and
  libspl_assertf

Sort the LDADD for programs so that libraries that satisfy dependencies
come at the end rather than the beginning of the linker command line.

Revamp the configure tests for libaries to use FIND_SYSTEM_LIBRARY
instead. This can take advantage of pkg-config, and it also avoids
polluting LIBS.

List all the required dependencies in the pkgconfig files, and move the
one for libzfs_core into the latter's directory. Install pkgconfig files
in $(libdir)/pkgconfig on linux and $(prefix)/libdata/pkgconfig on
FreeBSD, instead of /usr/share/pkgconfig, as the more correct location
for library .pc files.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes #10538
2020-07-10 14:26:00 -07:00
Brian Behlendorf 9a49d3f3d3
Add device rebuild feature
The device_rebuild feature enables sequential reconstruction when
resilvering.  Mirror vdevs can be rebuilt in LBA order which may
more quickly restore redundancy depending on the pools average block
size, overall fragmentation and the performance characteristics
of the devices.  However, block checksums cannot be verified
as part of the rebuild thus a scrub is automatically started after
the sequential resilver completes.

The new '-s' option has been added to the `zpool attach` and
`zpool replace` command to request sequential reconstruction
instead of healing reconstruction when resilvering.

    zpool attach -s <pool> <existing vdev> <new vdev>
    zpool replace -s <pool> <old vdev> <new vdev>

The `zpool status` output has been updated to report the progress
of sequential resilvering in the same way as healing resilvering.
The one notable difference is that multiple sequential resilvers
may be in progress as long as they're operating on different
top-level vdevs.

The `zpool wait -t resilver` command was extended to wait on
sequential resilvers.  From this perspective they are no different
than healing resilvers.

Sequential resilvers cannot be supported for RAIDZ, but are
compatible with the dRAID feature being developed.

As part of this change the resilver_restart_* tests were moved
in to the functional/replacement directory.  Additionally, the
replacement tests were renamed and extended to verify both
resilvering and rebuilding.

Original-patch-by: Isaac Huang <he.huang@intel.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: John Poduska <jpoduska@datto.com>
Co-authored-by: Mark Maybee <mmaybee@cray.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #10349
2020-07-03 11:05:50 -07:00
Serapheim Dimitropoulos 42d8d1d66a
Remove unnecessary terminology from error-injection in ztest
Rephrase error-injection comment in ztest to be more clear.

Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Sara Hartse <sara.hartse@delphix.com>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes #10482
2020-06-22 09:48:36 -07:00
Arvind Sankar 65c7cc49bf Mark functions as static
Mark functions used only in the same translation unit as static. This
only includes functions that do not have a prototype in a header file
either.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes #10470
2020-06-18 12:20:38 -07:00
Brian Behlendorf c1f3de18a4
ztest: Fix spa_open() ENOENT failures
The pool may not be imported when the previous pass is terminated.
In which case, spa_open() will return ENOENT to indicate the pool
is not currently imported.  Refactor to code slightly to handle
this case by importing the pool and then retrying the spa_open().

The ztest_import() function was moved before ztest_run() and the
import logic split in to a small internal helper function.  The
ztest_freeze() function was also moved but no changes were made.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #10407
2020-06-06 12:51:35 -07:00
Brian Behlendorf 3d93161b01
ztest: Fix ztest_run_zdb() failure
It's possible for ztest to be killed while the pool is exported
which results in an empty cache file.  This is a valid state to
test, but the validation check performed by ztest_run_zdb()
depends on the pool being in the cache file.  If it's not the
following error is printed.

    zdb -bccsv -G -d -Y -U /tmp/zloop-run/zpool.cache ztest
    zdb: can't open '/tmp/zloop-run': No such file or directory

Resolve these failures by removing the dependency on the cache
file.  Functionally, we only care that the pool can be imported
and that the zdb verification passes.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #10385
2020-05-29 21:14:10 -07:00
Ryan Moeller 4d32abaa87
libzfs: Fix bounds checks for float parsing
UINT64_MAX is not exactly representable as a double.

The closest representation is UINT64_MAX + 1, so we can use a >=
comparison instead of > for the bounds check.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10127
2020-03-16 11:56:29 -07:00
Matthew Macy 2a8ba608d3 Replace ASSERTV macro with compiler annotation
Remove the ASSERTV macro and handle suppressing unused 
compiler warnings for variables only in ASSERTs using the 
__attribute__((unused)) compiler annotation.  The annotation
is understood by both gcc and clang.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9671
2019-12-05 12:37:00 -08:00
Matthew Macy da92d5cbb3 Add zfs_file_* interface, remove vnodes
Provide a common zfs_file_* interface which can be implemented on all 
platforms to perform normal file access from either the kernel module
or the libzpool library.

This allows all non-portable vnode_t usage in the common code to be 
replaced by the new portable zfs_file_t.  The associated vnode and
kobj compatibility functions, types, and macros have been removed
from the SPL.  Moving forward, vnodes should only be used in platform
specific code when provided by the native operating system.

Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9556
2019-11-21 09:32:57 -08:00
Matthew Macy bd4dde8ef7 Prefix struct rangelock
A struct rangelock already exists on FreeBSD.  Add a zfs_ prefix as
per our convention to prevent any conflict with existing symbols.
This change is a follow up to 2cc479d0.

Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9534
2019-11-01 10:37:33 -07:00
Matthew Macy 8b2d097c17 Remove gratuitous Linux only include in ztest & zdb
We don't need to include stdio_ext.h

Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9483
2019-10-19 17:08:19 -07:00
Matthew Macy e4f5fa1229 Fix strdup conflict on other platforms
In the FreeBSD kernel the strdup signature is:

```
char	*strdup(const char *__restrict, struct malloc_type *);
```

It's unfortunate that the developers have chosen to change
the signature of libc functions - but it's what I have to
deal with.

Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9433
2019-10-10 09:47:06 -07:00
Matthew Macy d31277abb1 OpenZFS restructuring - libspl
Factor Linux specific pieces out of libspl.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9336
2019-10-02 10:39:48 -07:00
Andrea Gelmini ad0b23b14a Fix typos in cmd/
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Closes #9234
2019-08-30 09:43:30 -07:00
Serapheim Dimitropoulos 43a8536260 Race condition between spa async threads and export
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 #9015 
Closes #9044
2019-07-18 13:02:33 -07:00
Serapheim Dimitropoulos 93e28d661e Log Spacemap Project
= 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
2019-07-16 10:11:49 -07:00
Brian Behlendorf e5db313494
Linux 5.0 compat: SIMD compatibility
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 #8754 
Closes #8793 
Closes #8965
2019-07-12 09:31:20 -07:00
Matthew Ahrens 050d720c43 Remove dedupditto functionality
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 #8270 
Closes #8310
2019-06-19 14:54:02 -07:00