libc: expose execvpe for Linux compat

We already implemented execvpe internally with an _ prefix in libc so
go ahead and expose it for compatibility with Linux.

This reverts c605eea952146348e5e1ad5cab6c127d7a1bd164.

Bump __FreeBSD_version for the addition and add definitions to supress
compat shims in libzfs (zfs changes were merged from upstream).

PR: 275370 (request and exp-run (thanks antoine!))
Reviewed by: kevans
Differential Revision: https://reviews.freebsd.org/D42846

Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

zfs: merge openzfs/zfs@b9d98453f

Notable upstream pull request merges:
#12321 Fix inflated quiesce time caused by lwb_tx during zil_commit()
#13244 zstd early abort
#13360 Verify BPs as part of spa_load_verify_cb()
#13452 More speculative prefetcher improvements
#13466 Expose zpool guids through kstats
#13476 Refactor Log Size Limit
#13484 FreeBSD: libspl: Add locking around statfs globals
#13498 Cancel in-progress rebuilds when we finish removal
#13499 zed: Take no action on scrub/resilver checksum errors
#13513 Remove wrong assertion in log spacemap

Obtained from: OpenZFS
OpenZFS commit: b9d98453f9387c413f91d1d9cdb0cba8e04dbd95

cddl: fix missing ZFS library dependencies

In 9fae47666 zfsd got a libspl dependency to avoid undefined references.
However that workaround did not help external consumers of libzfs_core.

Fix all missing dependencies lld 13 and the rtld complain about.

Reviewed by: freqlabs, markj
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D32521

Explicitly link zfsd with libspl to avoid undefined references

Because lld 13.0.0 is more strict about undefined references when
linking to shared libraries, it produces the following errors for zfsd:

ld: error: /home/dim/obj/home/dim/src/llvm-13-update/amd64.amd64/tmp/usr/lib/libzfs_core.so: undefined reference to libspl_assertf [--no-allow-shlib-undefined]
ld: error: /home/dim/obj/home/dim/src/llvm-13-update/amd64.amd64/tmp/usr/lib/libnvpair.so: undefined reference to libspl_assertf [--no-allow-shlib-undefined]
ld: error: /home/dim/obj/home/dim/src/llvm-13-update/amd64.amd64/tmp/usr/lib/libavl.so: undefined reference to libspl_assertf [--no-allow-shlib-undefined]
*** [zfsd.full] Error code 1

Fix this by adding libspl (where libspl_assertf lives) to zfsd's LIBADD.

MFC after: 3 days

Remove -I flag for include path that doesn't exist

Found this while trying to get macOS bootstrap to work again after OpenZFS merge.

Reviewed By: #zfs, freqlabs
Differential Revision: https://reviews.freebsd.org/D26192

Merge OpenZFS support in to HEAD.

The primary benefit is maintaining a completely shared
code base with the community allowing FreeBSD to receive
new features sooner and with less effort.

I would advise against doing 'zpool upgrade'
or creating indispensable pools using new
features until this change has had a month+
to soak.

Work on merging FreeBSD support in to what was
at the time "ZFS on Linux" began in August 2018.
I first publicly proposed transitioning FreeBSD
to (new) OpenZFS on December 18th, 2018. FreeBSD
support in OpenZFS was finally completed in December
2019. A CFT for downstreaming OpenZFS support in
to FreeBSD was first issued on July 8th. All issues
that were reported have been addressed or, for
a couple of less critical matters there are
pull requests in progress with OpenZFS. iXsystems
has tested and dogfooded extensively internally.
The TrueNAS 12 release is based on OpenZFS with
some additional features that have not yet made
it upstream.

Improvements include:
project quotas, encrypted datasets,
allocation classes, vectorized raidz,
vectorized checksums, various command line
improvements, zstd compression.

Thanks to those who have helped along the way:
Ryan Moeller, Allan Jude, Zack Welch, and many
others.

Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D25872

Drop -g from CFLAGS for zfsd(8). No idea why it was ever there.

Reviewed by: kib, ngie, asomers
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D19915

Make zfsd(8) build obey CFLAGS.

Reviewed by: imp
Obtained from: CheriBSD
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D19865

Integrate cddl/usr.sbin/zfds/tests into the FreeBSD test suite

This change integrates the unit tests for zfsd into the test suite using the
integration method described in r345203.

This change removes the `LOCALBASE` includes added for the port version of
googlemock/googletest, as well as unnecessary `LIBADD`/`DPADD` and `CXXFLAGS`
defines, which are included in the `GTEST_CXXFLAGS` variable, as part of
r345203.

Reviewed by: asomers
Approved by: emaste (mentor)
MFC after: 2 months
MFC with: r345203
Differential Revision: https://reviews.freebsd.org/D19552

Do not blindly include illumos kernel headers instead of user-space.
It is not needed now, and I doubt it much helped at all, creating more
confusions then good.

Use SRCTOP instead of a homegrown definition for it (SRCDIR)

MFC after: 1 week
Sponsored by: EMC / Isilon Storage Division

zfsd(8), the ZFS fault management daemon

Add zfsd, which deals with hard drive faults in ZFS pools. It manages
hotspares and replements in drive slots that publish physical paths.

cddl/usr.sbin/zfsd
Add zfsd(8) and its unit tests

cddl/usr.sbin/Makefile
Add zfsd to the build

lib/libdevdctl
A C++ library that helps devd clients process events

lib/Makefile
share/mk/bsd.libnames.mk
share/mk/src.libnames.mk
Add libdevdctl to the build. It's a private library, unusable by
out-of-tree software.

etc/defaults/rc.conf
By default, set zfsd_enable to NO

etc/mtree/BSD.include.dist
Add a directory for libdevdctl's include files

etc/mtree/BSD.tests.dist
Add a directory for zfsd's unit tests

etc/mtree/BSD.var.dist
Add /var/db/zfsd/cases, where zfsd stores case files while it's shut
down.

etc/rc.d/Makefile
etc/rc.d/zfsd
Add zfsd's rc script

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev.c
Fix the resource.fs.zfs.statechange message. It had a number of
problems:

It was only being emitted on a transition to the HEALTHY state.
That made it impossible for zfsd to take actions based on drives
getting sicker.

It compared the new state to vdev_prevstate, which is the state that
the vdev had the last time it was opened. That doesn't make sense,
because a vdev can change state multiple times without being
reopened.

vdev_set_state contains logic that will change the device's new
state based on various conditions. However, the statechange event
was being posted _before_ that logic took effect. Now it's being
posted after.

Submitted by: gibbs, asomers, mav, allanjude
Reviewed by: mav, delphij
Relnotes: yes
Sponsored by: Spectra Logic Corp, iX Systems
Differential Revision: https://reviews.freebsd.org/D6564

cddl: fix missing ZFS library dependencies

In 9fae47666 zfsd got a libspl dependency to avoid undefined references.
However that workaround did not help external consumers of libzfs_core.

Fix all missing dependencies lld 13 and the rtld complain about.

Reviewed by: freqlabs, markj
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D32521

Explicitly link zfsd with libspl to avoid undefined references

Because lld 13.0.0 is more strict about undefined references when
linking to shared libraries, it produces the following errors for zfsd:

ld: error: /home/dim/obj/home/dim/src/llvm-13-update/amd64.amd64/tmp/usr/lib/libzfs_core.so: undefined reference to libspl_assertf [--no-allow-shlib-undefined]
ld: error: /home/dim/obj/home/dim/src/llvm-13-update/amd64.amd64/tmp/usr/lib/libnvpair.so: undefined reference to libspl_assertf [--no-allow-shlib-undefined]
ld: error: /home/dim/obj/home/dim/src/llvm-13-update/amd64.amd64/tmp/usr/lib/libavl.so: undefined reference to libspl_assertf [--no-allow-shlib-undefined]
*** [zfsd.full] Error code 1

Fix this by adding libspl (where libspl_assertf lives) to zfsd's LIBADD.

MFC after: 3 days

Remove -I flag for include path that doesn't exist

Found this while trying to get macOS bootstrap to work again after OpenZFS merge.

Reviewed By: #zfs, freqlabs
Differential Revision: https://reviews.freebsd.org/D26192

Merge OpenZFS support in to HEAD.

The primary benefit is maintaining a completely shared
code base with the community allowing FreeBSD to receive
new features sooner and with less effort.

I would advise against doing 'zpool upgrade'
or creating indispensable pools using new
features until this change has had a month+
to soak.

Work on merging FreeBSD support in to what was
at the time "ZFS on Linux" began in August 2018.
I first publicly proposed transitioning FreeBSD
to (new) OpenZFS on December 18th, 2018. FreeBSD
support in OpenZFS was finally completed in December
2019. A CFT for downstreaming OpenZFS support in
to FreeBSD was first issued on July 8th. All issues
that were reported have been addressed or, for
a couple of less critical matters there are
pull requests in progress with OpenZFS. iXsystems
has tested and dogfooded extensively internally.
The TrueNAS 12 release is based on OpenZFS with
some additional features that have not yet made
it upstream.

Improvements include:
project quotas, encrypted datasets,
allocation classes, vectorized raidz,
vectorized checksums, various command line
improvements, zstd compression.

Thanks to those who have helped along the way:
Ryan Moeller, Allan Jude, Zack Welch, and many
others.

Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D25872

Drop -g from CFLAGS for zfsd(8). No idea why it was ever there.

Reviewed by: kib, ngie, asomers
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D19915

Make zfsd(8) build obey CFLAGS.

Reviewed by: imp
Obtained from: CheriBSD
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D19865

Integrate cddl/usr.sbin/zfds/tests into the FreeBSD test suite

This change integrates the unit tests for zfsd into the test suite using the
integration method described in r345203.

This change removes the `LOCALBASE` includes added for the port version of
googlemock/googletest, as well as unnecessary `LIBADD`/`DPADD` and `CXXFLAGS`
defines, which are included in the `GTEST_CXXFLAGS` variable, as part of
r345203.

Reviewed by: asomers
Approved by: emaste (mentor)
MFC after: 2 months
MFC with: r345203
Differential Revision: https://reviews.freebsd.org/D19552

Fix integration with zfsd_unittest

The previous code didn't nul out SRCS after setting the pre-bsd.progs.mk value,
however, when recursing down into bsd.prog.mk, it was appending the per-prog
value to the value of SRCS.

The other catch is that code did not install the zfsd headers, so some of the
headers, e.g., callout.h could not be found. So, add
`-I${SRCTOP}/cddl/usr.sbin` to CXXFLAGS.

While here, fix a typo: `LIBDADD.zfsd_unittest` should have been
`LIBADD.zfsd_unittest`, and remove the superfluous `DPADD` part which was never
required post-LIBADD integration.

Do not blindly include illumos kernel headers instead of user-space.
It is not needed now, and I doubt it much helped at all, creating more
confusions then good.

Use SRCTOP instead of a homegrown definition for it (SRCDIR)

MFC after: 1 week
Sponsored by: EMC / Isilon Storage Division

zfsd(8), the ZFS fault management daemon

Add zfsd, which deals with hard drive faults in ZFS pools. It manages
hotspares and replements in drive slots that publish physical paths.

cddl/usr.sbin/zfsd
Add zfsd(8) and its unit tests

cddl/usr.sbin/Makefile
Add zfsd to the build

lib/libdevdctl
A C++ library that helps devd clients process events

lib/Makefile
share/mk/bsd.libnames.mk
share/mk/src.libnames.mk
Add libdevdctl to the build. It's a private library, unusable by
out-of-tree software.

etc/defaults/rc.conf
By default, set zfsd_enable to NO

etc/mtree/BSD.include.dist
Add a directory for libdevdctl's include files

etc/mtree/BSD.tests.dist
Add a directory for zfsd's unit tests

etc/mtree/BSD.var.dist
Add /var/db/zfsd/cases, where zfsd stores case files while it's shut
down.

etc/rc.d/Makefile
etc/rc.d/zfsd
Add zfsd's rc script

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev.c
Fix the resource.fs.zfs.statechange message. It had a number of
problems:

It was only being emitted on a transition to the HEALTHY state.
That made it impossible for zfsd to take actions based on drives
getting sicker.

It compared the new state to vdev_prevstate, which is the state that
the vdev had the last time it was opened. That doesn't make sense,
because a vdev can change state multiple times without being
reopened.

vdev_set_state contains logic that will change the device's new
state based on various conditions. However, the statechange event
was being posted _before_ that logic took effect. Now it's being
posted after.

Submitted by: gibbs, asomers, mav, allanjude
Reviewed by: mav, delphij
Relnotes: yes
Sponsored by: Spectra Logic Corp, iX Systems
Differential Revision: https://reviews.freebsd.org/D6564