over various major releases. Superblock check hashes were added for
the 12 release and cylinder-group and inode check hashes will appear
in the 13 release.

When a disk with a UFS filesystem is writably mounted, the kernel
clears the feature flags for anything that it does not support. For
example, if a UFS disk from a 12-stable kernel is mounted on an
11-stable system, the 11-stable kernel will clear the flag in the
filesystem superblock that indicates that superblock check-hashs
are being maintained. Thus if the disk is later moved back to a
12-stable system, the 12-stable system will know to ignore its
incorrect check-hash.

If the only filesystem modification done on the earlier kernel is
to run a utility such as growfs(8) that modifies the superblock but
neither updates the check-hash nor clears the feature flag indicating
that it does not support the check-hash, the disk will fail to mount
if it is moved back to its original newer kernel.

This patch moves the code that clears the filesystem feature flags
from the mount code (ffs_mountfs()) to the code that reads the
superblock (ffs_sbget()). As ffs_sbget() is used by the kernel mount
code and is imported into libufs(3), all the filesystem utilities
will now also clear these flags when they make modifications to the
filesystem.

As suggested by John Baldwin, fsck_ffs(8) has been changed to accept
and repair bad superblock check-hashes rather than refusing to run.
This change allows fsck to recover filesystems that have been impacted
by utilities older than those created after this change and is a
sensible thing to do in any event.

Reported by:  John Baldwin (jhb@)
MFC after:    2 weeks
Sponsored by: Netflix

DTrace also relies on these definitions.

Reported by:	jenkins

The  age  of   the  intel  compiler  support  is  so   old  as  to  be
uninteresting. No recent recports of  intel compiler support have been
received.  Remove  all the  special  case  workarounds for  the  Intel
compiler. Should there be interest in supporting the compiler, contact
me and I'll work with people to make it happen, though I suspect these
instances are more likely to be in the way than to be helpful.

Reviewed by: cem, emaste, vangyzen, dim
Differential Revision: https://reviews.freebsd.org/D26817

We no longer support building the kernel with the old intel
compiler. Remove support for it from in_cksum. Should there be
interest in reviving it, this is as likely to get in the way as to
help anyway.

The intel compiler support has badly decayed over the years. Stop
pretending that we support it. Note, I've stopped short of requiring
gcc builtin support with this commit since other compilers may be used
to build non-base software and we need to support those so more
investigation is needed before simplifying further.

We don't support building the kernel from such old compilers, nor with
the Intel Compiler specifically. Remove support for this old construct
that was copied from stdbool.h and not relevant here.

We no longer support old versions of GCC. Remove this check by
assuming it's false. That will make the entire expression false.  Also
remove support for Intel compiler, it's badly bitrotted.  Technically,
this removes support for C89 and K&R from compilers that don't define
_Bool in those compilation environments as well. I'm unaware of any
working compiler today for which that would be relevant (pcc has it
and tcc sadly isn't working for other reasons), though if one
pops up in ports, I'll work to resolve the issue.

This is a content change.

Reviewed by:	bcr
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D26746

rpcbind is now considered a security risk for some sites.
Since an NFSv4 only NFS server does not need rpcbind,
it makes sense to have an option that implements this.

This patch adds a "-R" option that disables the Mount
protocol (not used by NFSv4) and does not register
with rpcbind.

Changes are required to /etc/rc.d/mountd and /etc/rc.d/nfsd.
Those will be in a separate commit.

Reviewed by:	freqlabs, asomers
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D26746

jail_errmsg is for libjail, jail_attach() is a system call.

Mak the Ethernet PCP codepoint configurable
for L2 local traffic, to allow lower latency for
iSCSI block IO. This addresses the target
side only.

Reviewed by:	mav, trasz, bcr
Sponsored by:	NetApp, Inc.
Differential Revision:	https://reviews.freebsd.org/D26740

Make the Ethernet PCP codepoint configurable
for L2 local traffic, to allow lower latency for
iSCSI block IO. This addresses the initiator
side only.

Reviewed by:	mav, trasz, bcr
Sponsored by:	NetApp, Inc.
Differential Revision:	https://reviews.freebsd.org/D26739

Before this GEOM passed bio pointer to transaction start, but not end.
It was irrelevant until devstat(9) got DTrace hooks, that appeared to
provide bio pointer on I/O completion, but not on submission.

MFC after:	2 weeks
Sponsored by:	iXsystems, Inc.

In order to validate the proper marking and use of a different
ethernet priority class, add the new session-specific PCP
feature to the ping/ping6 utilities.

Reviewed by:	mav, bcr
Sponsored by:	NetApp, Inc.
Differential Revision:	https://reviews.freebsd.org/D26627

The existing names were inherited from arm64, but we should prefer
RISC-V terminology. Change the prefix to SCAUSE, and further change the
names to better match the RISC-V spec and be more consistent with one
another. Also, remove two codes that are not defined for S-mode (machine
and hypervisor ecall).

While here, apply style(9) to some condition checks.

Reviewed by:	kp
Discussed with: jrtc27
Differential Revision:	https://reviews.freebsd.org/D26918

o Add iommu_unmap_msi() to release the msi GAS entry.
o Provide default implementations for iommu init/deinit methods.

Reviewed by:	kib
Sponsored by:	Innovate DSbD
Differential Revision:	https://reviews.freebsd.org/D26906

libjail is pretty small, so it makes for a good proof of concept demonstrating
how a system library can be wrapped to create a loadable Lua module for flua.

* Introduce 3lua section for man pages
* Add libjail module

Reviewed by:	kevans, manpages
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D26080

Small EXAMPLES section.

Add reference to realpath(1) due to similarity.

Approved by:	manpages (gbe@)
Differential Revision:		https://reviews.freebsd.org/D26862

Add 3 small examples to the EXAMPLES section.

Approved by:	manpages (gbe@)
Differential Revision:		https://reviews.freebsd.org/D26866

hese kstats are often expensive to compute so we want to avoid them
unless specifically requested.

The following kstats are affected by this change:

kstat.zfs.${pool}.multihost
kstat.zfs.${pool}.misc.state
kstat.zfs.${pool}.txgs
kstat.zfs.misc.fletcher_4_bench
kstat.zfs.misc.vdev_raidz_bench
kstat.zfs.misc.dbufs
kstat.zfs.misc.dbgmsg

PR:		249258
Reported by:	mjg
Reviewed by:	mjg, allanjude
Obtained from:	https://github.com/openzfs/zfs/pull/11099
Sponsored by:	iXsystems, Inc.

Ensure we also skip descendants of SKIP nodes when iterating through children
of an explicitly specified node.

Reported by:	np
Reviewed by:	np
MFC after:	1 week
Sponsored by:	iXsystems, Inc.
Differential Revision:	https://reviews.freebsd.org/D26833

1. fix compliancy issue of CUBIC RTO handling according to RFC8312 section 4.7
2. add CUBIC CC_RTO_ERR handling

Submitted by:	chengc_netapp.com
Reviewed by:	rrs, tuexen, rscheff
MFC after:	2 weeks
Sponsored by:	NetApp, Inc.
Differential Revision:	https://reviews.freebsd.org/D26808

This will pave the way of setting ssthresh differently in TCP CUBIC, according
to RFC8312 section 4.7.

No functional change, only code movement.

Submitted by:	chengc_netapp.com
Reviewed by:	rrs, tuexen, rscheff
MFC after:	2 weeks
Sponsored by:	NetApp, Inc.
Differential Revision:	https://reviews.freebsd.org/D26807

* Use defined SYS_SYSCTL names
* Use memcmp instead of explicit loop
* Use NULL instead of 0 for pointer value
* Use __FBSDID
* Reformat, improve comments in parse()

No functional changes.

Reviewed by:	imp
MFC after:	1 week
Sponsored by:	iXsystems, Inc.
Differential Revision:	https://reviews.freebsd.org/D26832

MFC after:	2 weeks
Relnotes:	yes

This would be more accurately expressed as COMPAT_LINUXKPI implying or
requiring backlight, but config(8) doesn't really have a way to express
that. This fixes the build with COMPAT_LINUXKPI specified in one's kernel
config.

Remove unused oidpp parameter from sysctl_sysctl_next_ls and
add high level comments to describe how it works.

No functional change.

Reviewed by:	imp
MFC after:	1 week
Sponsored by:	iXsystems, Inc.
Differential Revision:	https://reviews.freebsd.org/D26854

r326145 corrected do_execve() to return EJUSTRETURN upon success so that
important registers are not clobbered. This had the side effect of tapping
out 'failures' for all *execve(2) audit records, which is less than useful
for auditing purposes.

Audit exec returns earlier, where we can know for sure that EJUSTRETURN
translates to success. Note that this unsets TDP_AUDITREC as we commit the
audit record, so the usual audit in the syscall return path will do nothing.

PR:		249179
Reported by:	Eirik Oeverby <ltning-freebsd anduin net>
Reviewed by:	csjp, kib
MFC after:	1 week
Sponsored by:	Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D26922

MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D26900

MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D26916

They are de facto ignored.

Reported by:	pho
Tested by:	pho (previous version)
Fixes:	r366974 ("vfs: stop taking the interlock in vnode reclaim")

MFC after:		1 week
Sponsored by:		Mellanox Technologies // NVIDIA Networking

Suggested by:		danfe@
Differential Revision:	https://reviews.freebsd.org/D26254
MFC after:		1 week
Sponsored by:		Mellanox Technologies // NVIDIA Networking

sys/systm.h should come right after sys/param.h

Suggested by:		kib@
Differential Revision:	https://reviews.freebsd.org/D26254
MFC after:		1 week
Sponsored by:		Mellanox Technologies // NVIDIA Networking

No functional change.

Suggested by:		kib@ and emaste@
Differential Revision:	https://reviews.freebsd.org/D26254
MFC after:		1 week
Sponsored by:		Mellanox Technologies // NVIDIA Networking

Ever since r192762 nfsstat has included a few fields whose values were
always 0. They were copied from OpenBSD, but have never been used on
FreeBSD. Don't display them.

Reviewed by:	rmacklem
Sponsored by:	Axcient
Differential Revision:	https://reviews.freebsd.org/D26920

Remove code that supported pre-2011 kernels. CTLTYPE_S64 was defined
in rev 217616. All supported branches have it, so remove its compat
definition as OBE.