Commit 8b9775912cbc added support for an NFSv4 mounted
root file system, but only if the NFSv4 configuration
used id numbers in the strings.

This patch adds support for the case where the NFSv4
configuration uses name<-->id mappings via nfsuserd(8)
by priming the mapping cache with just enough entries
so that it works until the nfsuserd(8) is running.
They are listed in nfs_prime_userd[] in
sys/fs/nfs/nfs_commonsubs.c.

The entries in nfs_prime_userd[] are also wired into
the kernel's cache for name<-->id mappings when nfsuserd(8)
starts up.  This is necessary, since an upcall to the
nfsuserd(8) daemon for a mapping when looking up the
path to the passwd/group database files (/etc) will
hang the system, due to a vnode lock being held on
the entry in the path which blocks nfsuserd(8) from
accessing files.

To enable this case, the following must be put in the
NFS root file system's /boot/loader.conf:
boot.nfsroot.options="nfsv4"
boot.nfsroot.user_domain="<user.domain>"
where <user.domain> must be the same as nfsuserd
uses (usually set via the -domain flag).
If boot.nfsroot.user_domain does not exist or is
the empty string, ids is strings is configured.

MFC after:	1 week
Requested by:	Dan Shelton <dan.f.shelton@gmail.com>
Fixes:	8b9775912cbc ("nfs_diskless: Add support for an NFSv4 root fs")

This patch moves the definition of the nfsd_idargs
structure out of nfs.h and into a new file called
nfsid.h.

This is being done so that it can be included in
nfs_diskless.c in a future commit.

There should be no semantics change from this
commit.

MFC after:	1 week
Fixes:	8b9775912cbc ("nfs_diskless: Add support for an NFSv4 root fs")

Without this patch, diskless root NFS file systems
could only be mounted via NFSv3 (or NFSv2).
This patch adds the basic support needed to mount
a root fs via NFSv4.

At this time, the NFSv4 mount will only work if
the following is done on the NFS server configuration:
- The root directory specified in the "V4:" line in
  /etc/exports must be "/".  This is needed since the
  path to mount must be the same for NFSv3 and NFSv4.
- The NFS server must be configured to do both NFSv3
  and NFSv4, since the bootstrap code still uses NFSv3.
- The NFSv4 server must be configured with:
  vfs.nfs.enable_uidtostring=1
  vfs.nfsd.enable_stringtouid=1
  since the NFSv4 root fs cannot be running nfsuserd(8)
  when it is booting.  (This limitation may be removed
  in a future commit by hard-wiring enough id<-->name
  mapping entries to handle things until the nfsuserd(8)
  is running.)

To enable the root fs to be mounted via NFSv4, it needs:
- in the root file system's /boot/loader.conf
  boot.nfsroot.options="nfsv4"
  (Additional options like rsize=65536,wsize=65536 can
   also be specified.)
- in the root file system's /etc/sysctl.conf
  vfs.nfs.enable_uidtostring=1

Requested by:	Dan Shelton <dan.f.dhelton@gmail.com>
MFC after:	1 week

Name caching must be handled somewhat differently
for case insensitive file systems.  Negative name
caching does not work and, for rename, all names
associated with the rename'd vnode must be disabled.

For a case insensitive ZFS file system that is exported,
the unpatched code did work, since the change in mtime
or ctime of the directory when other case names were
created or rename'd would disable the false name cache
hit.  However, an export of an msdosfs file system
breaks the NFS client, because it only works if ctime/mtime
is changed whenever a name is added/removed.  Depending
on what the server file system is, this may not happen,
due to clock resolution or lack of support for these
attributes.

This patch checks to see if the server file system is
case insensitive and modifies the name caching to handle
this.

There is still a problem if a case insensitive file system
is a subtree of a non-case insensitive is exported by the
NFSv4 server.  This can be fixed someday, when the NFSv4
client gets support for submounts within the mount.

Suggested by:	kib
MFC after:	2 weeks

When an NFSv4.n client specifies settings for attributes other
mode during a Open/Create/Exclusive_41, these other attributes
were not being set.

This patch resolves the problem by calling nfsrv_fixsattr()
after the VOP_CREATE() call in nfsvno_open() for this case.

There is no extant NFSv4.n client that currently does this,
as far as I know.

MFC after:	2 weeks

An internet draft (expected to become an RFC someday)
https://datatracker.ietf.org/doc/draft-ietf-nfsv4-posix-acls
describes an extension to NFSv4.2 to handle POSIX draft ACLs.

This is the final patch in the series that enables
the extension of NFSv4.2 to support POSIX draft ACLs.
At this time, only UFS mounted with the "acls" option
will work, and only for FreeBSD built with these patches.
Patches for client and server for the Linux kernel are
in the works.  (I'll admit my next little project is
cleaning the Linux patches up for submission for upstream.)

To make these changes really useful, the FreeBSD port
of OpenZFS needs to be patched to add POSIX draft ACL
support.  (Support for POSIX draft ACLs is already in
the Linux port of OpenZFS.)

Interopeability with NFSv4.2 clients and servers that
do not support this extension should not be a problem.

Fixes:	a35bbd5d9f5f ("nfscommon: Add some support for POSIX draft ACLs")

An internet draft (expected to become an RFC someday)
https://datatracker.ietf.org/doc/draft-ietf-nfsv4-posix-acls
describes an extension to NFSv4.2 to handle POSIX draft ACLs.

This is the fifth of several patches that implement the
above draft.

This one mostly adds an extra argument to two functions
in nfscommon.ko.  Unfortunately, these functions are
called in many places, so the changes are numerous, but
straightforward.

Since the internal KAPI between the NFS modules is changed
by this commit, all of nfscommon.ko, nfscl.ko and nfsd.ko
must be rebuilt from sources.

There should be no semantics change for the series at
this point.

Fixes:	a35bbd5d9f5f ("nfscommon: Add some support for POSIX draft ACLs")

An internet draft (expected to become an RFC someday)
https://datatracker.ietf.org/doc/draft-ietf-nfsv4-posix-acls
describes an extension to NFSv4.2 to handle POSIX draft ACLs.

This is the fourth of several patches that implement the
above draft.

There should be no semantics change for the series at
this point.

Fixes:	a35bbd5d9f5f ("nfscommon: Add some support for POSIX draft ACLs")

An internet draft (expected to become an RFC someday)
https://datatracker.ietf.org/doc/draft-ietf-nfsv4-posix-acls
describes an extension to NFSv4.2 to handle POSIX draft ACLs.

This is the third of several patches that implement the
above draft.

There should be no semantics change for the series at
this point.

Fixes:	a35bbd5d9f5f ("nfscommon: Add some support for POSIX draft ACLs")

An internet draft (expected to become an RFC someday)
https://datatracker.ietf.org/doc/draft-ietf-nfsv4-posix-acls
describes an extension to NFSv4.2 to handle POSIX draft ACLs.

This is the second of several patches that implement the
above draft.

The only semantics change would be if you have exported
a UFS file system mounted with the "acl" option.
In that case, you would see the acl attribute supported.
This is bogus, but will be handled in the next commit.

Fixes:	a35bbd5d9f5f ("nfscommon: Add some support for POSIX draft ACLs")