nfsd: Fix Link conformance with RFC8881 for delegations

RFC8881 specifies that, when a Link operation occurs on an
NFSv4, that file delegations issued to other clients must
be recalled. Discovered during a recent discussion on nfsv4@ietf.org.

Although I have not observed a problem caused by not doing
the required delegation recall, it is definitely required
by the RFC, so this patch makes the server do the recall.

Tested during a recent NFSv4 IETF Bakeathon event.

MFC after: 1 week

Add vnode_pager_clean_{a,}sync(9)

Bump __FreeBSD_version for ZFS use.

Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D43356

sys: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

nfsd: Avoid acquiring a vnode for some NFSv4 Readdir operations

Without this patch, a NFSv4 Readdir operation acquires the vnode for
each entry in the directory. If only the Type, Fileid, Mounted_on_fileid
and ReaddirError attributes are requested by a client, acquiring the vnode
is not necessary for non-directories. Directory vnodes must be acquired
to check for server file system mount points.

This patch avoids acquiring the vnode, as above, resulting in a 3-8%
improvement in Readdir RPC RTT for some simple tests I did.

Note that only non-rdirplus NFSv4 mounts will benefit from this change.

Tested during a recent IETF NFSv4 Bakeathon testing event.

MFC after: 1 month

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

vfs: use __enum_uint8 for vtype and vstate

This whacks hackery around only reading v_type once.

Bump __FreeBSD_version to 1400093

nfsd: Fix NFSv3 Readdir/ReaddirPlus reply for large i-node numbers

If the i-node number (d_fileno) for a file on the server did
not fit in 32bits, it would be truncated to the low order 32bits
for the NFSv3 Readdir and ReaddirPlus RPC replies.
This is no longer correct, given that ino_t is now 64bits.

This patch fixes this by sending the full 64bits of d_fileno
on the wire in the NFSv3 Readdir/ReaddirPlus RPC reply.

PR: 271174
Reported by: bmueller@panasas.com
Tested by: bmueller@panasas.com
MFC after: 2 weeks

nfscl: Add a new NFSv4.1/4.2 mount option for Kerberized mounts

Without this patch, a Kerberized NFSv4.1/4.2 mount must provide
a Kerberos credential for the client at mount time. This credential
is typically referred to as a "machine credential". It can be
created one of two ways:
- The user (usually root) has a valid TGT at the time the mount
is done and this becomes the machine credential.
There are two problems with this.
1 - The user doing the mount must have a valid TGT for a user
principal at mount time. As such, the mount cannot be put
in fstab(5) or similar.
2 - When the TGT expires, the mount breaks.
- The client machine has a service principal in its default keytab
file and this service principal (typically called a host-based
initiator credential) is used as the machine credential.
There are problems with this approach as well:
1 - There is a certain amount of administrative overhead creating
the service principal for the NFS client, creating a keytab
entry for this principal and then copying the keytab entry
into the client's default keytab file via some secure means.
2 - The NFS client must have a fixed, well known, DNS name, since
that FQDN is in the service principal name as the instance.

This patch uses a feature of NFSv4.1/4.2 called SP4_NONE, which
allows the state maintenance operations to be performed by any
authentication mechanism, to do these operations via AUTH_SYS
instead of RPCSEC_GSS (Kerberos). As such, neither of the above
mechanisms is needed.

It is hoped that this option will encourage adoption of Kerberized
NFS mounts using TLS, to provide a more secure NFS mount.

This new NFSv4.1/4.2 mount option, called "syskrb5" must be used
with "sec=krb5[ip]" to avoid the need for either of the above
Kerberos setups to be done by the client.

Note that all file access/modification operations still require
users on the NFS client to have a valid TGT recognized by the
NFSv4.1/4.2 server. As such, this option allows, at most, a
malicious client to do some sort of DOS attack.

Although not required, use of "tls" with this new option is
encouraged, since it provides on-the-wire encryption plus,
optionally, client identity verification via a X.509
certificate provided to the server during TLS handshake.
Alternately, "sec=krb5p" does provide on-the-wire
encryption of file data.

A mount_nfs(8) man page update will be done in a separate commit.

Discussed on: freebsd-current@
MFC after: 3 months

nfsd: Return ENXIO instead of EPERM when nfsd(8) already running

The nfsd(8) daemon generates an error message that does not
indicate that the nfsd daemon is already running when the nfssvc(2)
syscall fails for the NFSSVC_STABLERESTART. Also, the check for
running nfsd(8) in a vnet prison will return EPERM when it fails.

This patch replaces EPERM with ENXIO so that the nfsd(8) daemon
can generate more reasonable failure messages. The nfsd(8) daemon
will be patched in a future commit.

MFC after: 3 months

vfs_export: Add mnt_exjail to control exports done in prisons

If there are multiple instances of mountd(8) (in different
prisons), there will be confusion if they manipulate the
exports of the same file system. This patch adds mnt_exjail
to "struct mount" so that the credentials (and, therefore,
the prison) that did the exports for that file system can
be recorded. If another prison has already exported the
file system, vfs_export() will fail with an error.
If mnt_exjail == NULL, the file system has not been exported.
mnt_exjail is checked by the NFS server, so that exports done
from within a different prison will not be used.

The patch also implements vfs_exjail_destroy(), which is
called from prison_cleanup() to release all the mnt_exjail
credential references, so that the prison can be removed.
Mainly to avoid doing a scan of the mountlist for the case
where there were no exports done from within the prison,
a count of how many file systems have been exported from
within the prison is kept in pr_exportcnt.

Reviewed by: markj
Discussed with: jamie
Differential Revision: https://reviews.freebsd.org/D38371
MFC after: 3 months

nfsd: Add VNET_SYSUNINIT() macros for vnet cleanup

Commit ed03776ca7f4 enabled the vnet front end macros.
As such, for kernels built with the VIMAGE option will malloc
data and initialize locks on a per-vnet basis, typically
via a VNET_SYSINIT().

This patch adds VNET_SYSUNINIT() macros to do the frees
of the per-vnet malloc'd data and destroys of per-vnet
locks. It also removes the mtx_lock/mtx_unlock calls
from nfsrvd_cleancache(), since they are not needed.

Discussed with: bz, jamie
MFC after: 3 months

nfsd: Enable the NFSD_VNET vnet front end macros

Several commits have added front end macros for the vnet
macros to the NFS server, krpc and kgssapi. These macros
are now null, but this patch changes them to front end
the vnet macros.

With this commit, many global variables in the code become
vnet'd, so that nfsd(8), nfsuserd(8), rpc.tlsservd(8) and
gssd(8) can run in a vnet prison, once enabled.
To run the NFS server in a vnet prison still requires a
couple of patches (in D37741 and D38371) that allow mountd(8)
to export file systems from within a vnet prison. Once
these are committed to main, a small patch to kern_jail.c
allowing "allow.nfsd" without VNET_NFSD defined will allow
the NFS server to run in a vnet prison.

One area that still needs to be settled is cleanup when a
prison is removed. Without this, everything should work
except there will be a leak of malloc'd data and mutex locks
when a vnet prison is removed.

MFC after: 3 months

nfsd: Wrap nfsstatsv1_p in the NFSD_VNET() macro

Commit 7344856e3a6d added a lot of macros that will front end
vnet macros so that nfsd(8) can run in vnet prison.
The nfsstatsv1_p variable got missed. This patch wraps all
uses of nfsstatsv1_p with the NFSD_VNET() macro.
The NFSD_VNET() macro is still a null macro.

MFC after: 3 months

nfsd: Continue adding macros so nfsd can run in a vnet prison

Commit 7344856e3a6d added a lot of macros that will front end
vnet macros so that nfsd(8) can run in vnet prison.
This patch adds some more of them and also a lot of uses of
nfsstatsv1_p instead of nfsstatsv1. nfsstatsv1_p points to
nfsstatsv1 for prison0, but will point to a malloc'd structure
for other prisons.

It also puts nfsstatsv1_p in nfscommon.ko instead of nfsd.ko.

MFC after: 3 months

nfsd: Fix initialization broken by 7344856e3a6d

Oops, although the vneting macros do not do anything yet,
commit 7344856e3a6d did change where things are initialized
and one of the initialization functions was not being called
early enough. This patch moves nfsrvd_init(0) to the
function called via (VNET_)SYSINIT() to fix this.

Reported by: olivier
MFC after: 3 months

nfsd: Delete nfsrv_prison_cleanup() until vneting enabled

Oops, although the vneting macros do not do anything yet,
commit 7344856e3a6d enabled the prison cleanup function, that
would get called and crash the system when a jail was terminated.

This patch gets rid of nfsrv_prison_cleanup() for now.
It can go in when the vnet macros are enabled as
front ends to the vnet macros.

MFC after: 3 months

nfsd: Prepare the NFS server code to run in a vnet prison

This patch defines null macros that can be used to apply
the vnet macros for global variables and SYSCTL flags.
It also applies these macros to many of the global variables
and some of the SYSCTLs. Since the macros do nothing, these
changes should not result in semantics changes, although the
changes are large in number.

The patch does change several global variables that were
arrays or structures to pointers to same. For these variables,
modified initialization and cleanup code malloc's and free's
the arrays/structures. This was done so that the vnet footprint
would be about 300bytes when the macros are defined as vnet macros,
allowing nfsd.ko to load dynamically.

I believe the comments in D37519 have been addressed, although
it has never been reviewed, due in part to the large size of the patch.
This is the first of a series of patches that will put D37519 in main.

Once everything is in main, the macros will be defined as front
end macros to the vnet ones.

MFC after: 3 months
Differential Revision: https://reviews.freebsd.org/D37519

nfsd: Add a KASSERT in nfsvno_open

Commit ded5f2954e1a defined done_namei to indicate that
nd_repstat was set after a successful nfsvno_namei(),
so that a cleanup needs to be done in nfsvno_open().
This only happens when nfsvno_namei() is done with CREATE.

This patch adds a KASSERT() to check for that.

PR: 268971

nfsd: Fix handling of the error case for nfsvno_open some more

Commit ded5f2954e1a defined done_namei to indicate that
nd_repstat was set after a successful nfsvno_namei(),
so that a cleanup needs to be done in nfsvno_open().
However, it missed the case where a call to
nfsrv_opencheck() in nfsvno_open() sets nd_repstat non-zero.

This would cause panics due to a dangling locked vnode
when nfsrv_opencheck() set nd_repstat, such as during grace
just after a server boot.

This patch fixes the problem.

PR: 268971

nfsd: Fix handling of the error case for nfsvno_open

Using done_namei instead of ni_startdir did not
fix the crashes reported in the PR. Upon looking
more closely at the code, the only case where the
code near the end of nfsvno_open() needs to be
executed is when nfsvno_namei() has succeeded,
but a subsequent error was detected.

This patch uses done_namei to indicate this case.

Also, nfsvno_relpathbuf() should only be called for
this case and not whenever nfsvno_open() is called
with nd_repstat != 0. A bug was introduced here when
the HASBUF flag was deleted.

Reviewed by: mjg
PR: 268971
Tested by: ish@amail.plala.or.jp
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D38430

nfsserver: Fix vrele() panic in nfsvno_open()

Commit 65127e982b94 removed a check for ni_startdir != NULL.
This allowed the vrele(ndp->ni_dvp) to be called with
a NULL argument.

This patch adds a new boolean argument to nfsvno_open()
that can be checked instead of ni_startdir, since mjg@ requested
that ni_startdir not be used. (Discussed in PR#268828.)

PR: 268828
Reviewed by: mjg
Differential Revision: https://reviews.freebsd.org/D38032

nfsd: Handle file systems without a VOP_VPTOFH()

Unlike NFSv3, the NFSv4 server follows mount points
within the file system tree below the NFSv4 root directory.
If there is a file system mounted within this subtree
that returns EOPNOTSUPP for VOP_VPTOFH(), the NFSv4 server
would return an error for the mount point entry.
This resulted in an "I/O error" report from the Linux NFSv4
client. It also put an error code in the Readdir reply
that is not defined in the NFSv4 RFCs.

For the FreeBSD NFSv4 client, the entry with the error would
be ignored, which I think is reasonable behaviour for a
mounted file system that can never be exported.

This patch changes the NFSv4 server behaviour to ignore the
mount point entry and not send it in the Readdir reply.
It also changes the behaviour of Lookup for the entry so
that it replies ENOENT for the mount point directory, so
that it is consistent with no entry in the Readdir reply.

With these two changes, the Linux client behaviour is the
same as the FreeBSD client behaviour. It also avoids
putting an unknown error on the wire to the client.

MFC after: 1 week

nfs: stop using SAVESTART

Only the name is wanted which is already always provided.

Reviewed by: rmacklem
Tested by: pho, rmacklem
Differential Revision: https://reviews.freebsd.org/D34470

nfsd: Make the pNFS server update Change for Setxattr/Rmxattr

When the NFS server does the Setxattr or Rmxattr operation,
the Change attribute (va_filerev) needs to be updated.

Without this patch, that was not happening for the
pNFS server configuration. This patch does a Setattr
against the DS file to make the Change attribute
change.

This bug was discovered during a recent IETF NFSv4 testing
event, where the Change attribute wasn't changed in the
operation reply.

MFC after: 1 month

Revert "unbound: Vendor import 1.17.0"

This reverts commit 64d318ea98b7c59f5567d47a9a8474887d8b5cb8, reversing
changes made to 8063dc03202fad7d6bdf34976bc8556fa3f23fa1.

Revert a mismerge which reversed 8063dc03202fad7d6bdf34976bc8556fa3f23fa1.

nfsd: Make Setxattr/Removexattr NFSv4.2 ops IO_SYNC

When the NFS server does Setxattr or Removexattr, the
operations must be done IO_SYNC. If a server
crashes/reboots immediately after replying it must
have the extended attribute changes.

Since UFS does extended attributes asynchronously
by default and there is no "ioflag" argument in
the VOP calls, follow the VOP calls with VOP_FSYNC(),
to ensure the operation has been done synchronously.

This was found by inspection while investigating a
bug discovered during a recent IETF NFSv4 testing
event, where the Change attribute wasn't changed
in the operation reply.

This bug will take further work for ZFS and the
pNFS server configuration, but is now fixed for
a non-pNFS UFS exported file system.

MFC after: 1 month

vfs: always retain path buffer after lookup

This removes some of the complexity needed to maintain HASBUF and
allows for removing injecting SAVENAME by filesystems.

Reviewed by: kib (previous version)
Differential Revision: https://reviews.freebsd.org/D36542

nfscl: Change the cred argument to non-NULL for pNFS proxies

Commit 326bcf9394c7 added a "cred" argument to nfscl_reqstart().
For the pNFS proxy calls on the server, the argument
should be "cred" instead of NULL.
This patch fixes this.

Since the argument is not yet used, this patch
should not result in a semantics change.

PR: 260011
MFC after: 2 weeks

nfscl: Add a cred argument to nfscl_reqstart()

To deal with broken session slots caused by the use of the
"soft" and/or "intr" mount options, nfsv4_sequencelookup()
will be modified to track the potentially broken session
slots. Then, when all session slots are potentially
broken, do a DeleteSession operation, so that the NFSv4
server will reply NFSERR_BADSESSION to uses of the session.
These changes will be done in future commits. However,
to do the DeleteSession RPC, a "cred" argument is needed
for nfscl_reqstart(). This patch adds this argument,
which is unused at this time. If the argument is NULL,
it indicates that DeleteSession should not be done
(usually because the RPC does not use sessions).

This patch should not cause any semantics change.

PR: 260011
MFC after: 2 weeks

nfsd: Fix handling of Open/Create for the pNFS server

When the MDS of a pNFS service receives an Open/Create
and the file already exists, it must do a Setattr of
size == 0. Without this patch, this was eroneously
done via a VOP_SETAATR() call, which would set the
length of the MDS file to 0 (which is already is,
since all data lives on the DSs).

This patch fixes the problem by doing a nfsvno_setattr()
instead of VOP_SETATTR(), which knows to do a proxied
Setattr on the DSs.

For a non-pNFS server, the change has no effect, since
nfsvno_setattr() only does a VOP_SETATTR() for that case.

This was found during a recent IETF NFSv4 testing event.

MFC after: 2 weeks

vfs: prefix lookup and relookup with vfs_

Reviewed by: imp, mckusick
Differential Revision: https://reviews.freebsd.org/D34530

nfsd: Do not exempt NFSv3 Fsinfo from the TLS check

The Fsinfo RPC is exempt from the check for
Kerberized NFS being required, as recommended
by RFC2623. However, there is no reason to
exempt Fsinfo from the requirement to use TLS.

This patch fixes the code so that the exemption
only applies to Kerberized NFS and not
NFS-over-TLS.

This only affects NFS-over-TLS for an NFSv3
mount when it is required, but the client does
not do so.

MFC after: 1 month

nfsd: Do not accept audit/alarm ACEs for the NFSv4 server

The UFS and ZFS file systems only support Allow/Deny ACEs
in the NFSv4 ACLs. This patch does not allow the server
to parse Audit/Alarm ACEs. The NFSv4 client is still
allowed to pase Audit/Alarm ACEs, since non-FreeBSD NFSv4
servers may use them.

This patch should not have a significant effect, since the
UFS and ZFS file systems will not handle these ACEs anyhow.
It simply serves as an additional "safety belt" for the
NFSv4 server.

MFC after: 2 weeks

Revert "nfscommon: Add arguments for support of the dacl attribute"

This reverts commit 0fa074b53e7c22157dcb41aaa25a33abc8118f26.

I now see that the implementation of the "dacl" operation
requires that the NFSv4 server to "automatic inheritance"
and I do not plan on doing this. As such, this patch is
harmless, but unneeded.

nfsd: Reduce callouts rate.

Before this callouts were scheduled twice a seconds even if nfsd was
never used. This reduces the rate to ~1Hz and only after nfsd first
started.

MFC after: 2 weeks

nfscommon: Add arguments for support of the dacl attribute

NFSv4.1/4.2 has an alternative to the acl attribute, called
dacl, that includes support for the ACL_ENTRY_INHERITED flag,
called NFSV4ACE_INHERITED in NFSv4.

This patch adds a dacl argument to nfsrv_buildacl(),
nfsrv_dissectacl() and nfsrv_dissectace(), so that they
will handle NFSV4ACE_INHERITED when dacl == true.

Since these functions are always called with dacl == false
for this patch, semantics should not have changed.
A future patch will add support for dacl.

MFC after: 2 weeks

rpc: Delete AUTH_NEEDS_TLS(_MUTUAL_HOST) auth_stat values

I thought that these new auth_stat values had been agreed
upon by the IETF NFSv4 working group, but that no longer
is the case. As such, delete them and use AUTH_TOOWEAK
instead. Leave the code that uses these new auth_stat
values in the sources #ifdef notnow, in case they are
defined in the future.

MFC after: 1 week

Change VOP_READDIR's cookies argument to a **uint64_t

The cookies argument is only used by the NFS server. NFSv2 defines the
cookie as 32 bits on the wire, but NFSv3 increased it to 64 bits. Our
VOP_READDIR, however, has always defined it as u_long, which is 32 bits
on some architectures. Change it to 64 bits on all architectures. This
doesn't matter for any in-tree file systems, but it matters for some
FUSE file systems that use 64-bit directory cookies.

PR: 260375
Reviewed by: rmacklem
Differential Revision: https://reviews.freebsd.org/D33404

nfs: don't truncate directory cookies to 32-bits in the NFS server

In NFSv2, the directory cookie was 32-bits. NFSv3 widened it to
64-bits and SVN r22521 widened the corresponding argument in
VOP_READDIR, but FreeBSD's NFS server continued to treat the cookies as
32-bits, and 0-extended to fill the field on the wire. Nobody ever
noticed, because every in-tree file system generates cookies that fit
comfortably within 32-bits.

Also, have better type safety for txdr_hyper. Turn it into an inline
function that type-checks its arguments. Prevents warnings about
shift-count-overflow.

PR: 260375
MFC after: 2 weeks
Reviewed by: rmacklem
Differential Revision: https://reviews.freebsd.org/D33404

nfs: Quiet a few "unused" warnings

For most of these warnings, the variable is loaded
with data parsed out of an RPC messages. In case
the data is useful in the future, I just marked
these with __unused.

vfs: remove the unused thread argument from NDINIT*

See b4a58fbf640409a1 ("vfs: remove cn_thread")

Bump __FreeBSD_version to 1400043.

nfsd: Fix the NFSv4.2 pNFS MDS server for NFSERR_NOSPC via LayoutError

If a pNFS server's DS runs out of disk space, it replies
NFSERR_NOSPC to the client doing writing. For the Linux
client, it then sends a LayoutError RPC to the MDS server to
tell it about the error and keeps retrying, doing repeated
LayoutGets to the MDS and Write RPCs to the DS. The Linux client is
"stuck" until disk space on the DS is free'd up unless
a subsequent LayoutGet request is sent a NFSERR_NOSPC
reply.
The looping problem still occurs for NFSv4.1 mounts, but no
fix for this is known at this time.

This patch changes the pNFS MDS server to reply to LayoutGet
operations with NFSERR_NOSPC once a LayoutError reports the
problem, until the DS has available space. This keeps the Linux
NFSv4.2 from looping.

Found during recent testing because of issues w.r.t. a DS
being out of space found during a recent IEFT NFSv4 working
group testing event.

MFC after: 2 weeks

vfs: Add "ioflag" and "cred" arguments to VOP_ALLOCATE

When the NFSv4.2 server does a VOP_ALLOCATE(), it needs
the operation to be done for the RPC's credential and not
td_ucred. It also needs the writing to be done synchronously.

This patch adds "ioflag" and "cred" arguments to VOP_ALLOCATE()
and modifies vop_stdallocate() to use these arguments.

The VOP_ALLOCATE.9 man page will be patched separately.

Reviewed by: khng, kib
Differential Revision: https://reviews.freebsd.org/D32865

vfs: remove cn_thread

It is always curthread.

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D32453

nfsd: Fix pNFS handling of Deallocate

For a pNFS server configuration, an NFSv4.2 Deallocate operation
is proxied to the DS(s). The code that parsed the reply for the
proxy RPC is broken and did not process the pre-operation attributes.

This patch fixes this problem.

This bug would only affect pNFS servers built from recent main/FreeBSD14
sources.

nfs: eliminate thread argument from nfsvno_namei

This is a step towards retiring struct componentname cn_thread

Reviewed by: rmacklem
Differential Revision: https://reviews.freebsd.org/D32267

nfsd: Make loop calling VOP_ALLOCATE() iterate until done

The NFSv4.2 Deallocate operation loops on VOP_DEALLOCATE()
while progress is being made (remaining length decreasing).
This patch changes the loop on VOP_ALLOCATE() for the NFSv4.2
Allocate operation do the same, instead of stopping after
an arbitrary 20 iterations.

MFC after: 2 weeks

nfsd: Add support for the NFSv4.2 Deallocate operation

The recently added VOP_DEALLOCATE(9) VOP call allows
implementation of the Deallocate NFSv4.2 operation.

Since the Deallocate operation is a single succeed/fail
operation, the call to VOP_DEALLOCATE(9) loops so long
as progress is being made. It calls maybe_yield()
between loop iterations to allow other processes
to preempt it.

Where RFC 7862 underspecifies behaviour, the code
is written to be Linux NFSv4.2 server compatible.

Reviewed by: khng
Differential Revision: https://reviews.freebsd.org/D31624

nfsd: Add sysctl to set maximum I/O size up to 1Mbyte

Since MAXPHYS now allows the FreeBSD NFS client
to do 1Mbyte I/O operations, add a sysctl called vfs.nfsd.srvmaxio
so that the maximum NFS server I/O size can be set up to 1Mbyte.
The Linux NFS client can also do 1Mbyte I/O operations.

The default of 128Kbytes for the maximum I/O size has
not been changed for two reasons:
- kern.ipc.maxsockbuf must be increased to support 1Mbyte I/O
- The limited benchmarking I can do actually shows a drop in I/O rate
when the I/O size is above 256Kbytes.
However, daveb@spectralogic.com reports seeing an increase
in I/O rate for the 1Mbyte I/O size vs 128Kbytes using a Linux client.

Reviewed by: asomers
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D30826

nfsd: Fix when NFSERR_WRONGSEC may be replied to NFSv4 clients

Commit d224f05fcfc1 pre-parsed the next operation number for
the put file handle operations. This patch uses this next
operation number, plus the type of the file handle being set by
the put file handle operation, to implement the rules in RFC5661
Sec. 2.6 with respect to replying NFSERR_WRONGSEC.

This patch also adds a check to see if NFSERR_WRONGSEC should be
replied when about to perform Lookup, Lookupp or Open with a file
name component, so that the NFSERR_WRONGSEC reply is done for
these operations, as required by RFC5661 Sec. 2.6.

This patch does not have any practical effect for the FreeBSD NFSv4
client and I believe that the same is true for the Linux client,
since NFSERR_WRONGSEC is considered a fatal error at this time.

MFC after: 2 weeks

nfsserver: use VOP_VPUT_PAIR().

Apply VOP_VPUT_PAIR() to the end of vnode operations after the
VOP_MKNOD(), VOP_MKDIR(), VOP_LINK(), VOP_SYMLINK(), VOP_CREATE().

Reviewed by: chs, mckusick
Tested by: pho
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation

Convert remaining cap_rights_init users to cap_rights_init_one

semantic patch:

@@

expression rights, r;

@@

- cap_rights_init(&rights, r)
+ cap_rights_init_one(&rights, r)

nfsd: add KASSERTs to nfsm_trimtrailing() for M_EXTPG mbufs

Add KASSERTS to nfsm_trimtrailing() to confirm the sanity of
the arguments for the M_EXTPG case.

Suggested by: kib
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D28053

nfs server: improve use of the VFS KPI

In particular, do not assume that vn_start_write() returns the same mp
as it was passed in, or never returns error.

Also be more accurate to return NULL vp and mp when error occured, to
catch wrong control flow easier.

Stop checking for NULL mp before calling vn_finished_write(), NULL mp
is handled transparently by the function.

Reviewed by: rmacklem
Tested by: pho
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D27881

nfsd: fix NFS server for ERELOOKUP

r367672 modified UFS such that certain VOPs, such as
VOP_CREATE() will intermittently return ERELOOKUP.
When this happens, the entire system call, or NFS
operation in the case of the NFS server, must be redone.

This patch adds that support to the NFS server by rolling
back the state of the NFS request arguments and NFS
reply arguments mbuf lists to the condition they were
in before the operation and then redoing the operation.

Tested by: pho
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D27875

fs: clean up empty lines in .c and .h files

Add flags to enable NFS over TLS to the NFS client and server.

An Internet Draft titled "Towards Remote Procedure Call Encryption By Default"
(soon to be an RFC I think) describes how Sun RPC is to use TLS with NFS
as a specific application case.
Various commits prepared the NFS code to use KERN_TLS, mainly enabling use
of ext_pgs mbufs for large RPC messages.
r364475 added TLS support to the kernel RPC.

This commit (which is the final one for kernel changes required to do
NFS over TLS) adds support for three export flags:
MNT_EXTLS - Requires a TLS connection.
MNT_EXTLSCERT - Requires a TLS connection where the client presents a valid
X.509 certificate during TLS handshake.
MNT_EXTLSCERTUSER - Requires a TLS connection where the client presents a
valid X.509 certificate with "user@domain" in the otherName
field of the SubjectAltName during TLS handshake.
Without these export options, clients are permitted, but not required, to
use TLS.

For the client, a new nmount(2) option called "tls" makes the client do
a STARTTLS Null RPC and TLS handshake for all TCP connections used for the
mount. The CLSET_TLS client control option is used to indicate to the kernel RPC
that this should be done.

Unless the above export flags or "tls" option is used, semantics should
not change for the NFS client nor server.

For NFS over TLS to work, the userspace daemons rpctlscd(8) { for client }
or rpctlssd(8) daemon { for server } must be running.

Delete the unused "use_ext" argument to nfscl_reqstart().

This is a partial revert of r363210, since the "use_ext" argument added
by that commit is not actually useful.

This patch should not result in any semantics change.

Add optional support for ext_pgs mbufs to the NFS server's read, readlink
and getxattr operations.

This patch optionally enables generation of read, readlink and getxattr replies
in ext_pgs mbufs. Since neither of ND_EXTPG or ND_TLS are currently ever set,
there is no change in semantics at this time.
It also corrects the message in a couple of panic()s that should never occur.

This is another in the series of commits that add support to the NFS client
and server for building RPC messages in ext_pgs mbufs with anonymous pages.
This is useful so that the entire mbuf list does not need to be
copied before calling sosend() when NFS over TLS is enabled.

Use of ext_pgs mbufs will not be enabled until the kernel RPC is updated
to handle TLS.

Add support for ext_pgs mbufs to nfsrvd_readdir() and nfsrvd_readdirplus().

This patch code that optionally (based on ND_TLS, never set yet) generates
readdir replies in ext_pgs mbufs.
To trim the list back, a new function that is ext_pgs aware called
nfsm_trimtrailing() replaces newnfs_trimtrailing().
newnfs_trimtrailing() is no longer used, but will be removed in a future
commit, since its removal does modify the internal kpi between the NFS
modules.

This is another in the series of commits that add support to the NFS client
and server for building RPC messages in ext_pgs mbufs with anonymous pages.
This is useful so that the entire mbuf list does not need to be
copied before calling sosend() when NFS over TLS is enabled.

Use of ext_pgs mbufs will not be enabled until the kernel RPC is updated
to handle TLS.

Fix the NFS server so that it sets va_birthtime.

r362490 marked that the NFSv4 attribute TimeCreate (va_birthtime) is supported,
but it did not change the NFS server code to actually do it.
As such, errors could occur when unrolling a tarball onto an NFSv4 mounted
volume, since setting TimeCreate would fail with a NFSERR_ATTRNOTSUPP reply.

This patch fixes the server so that it does TimeCreate and also makes
sure that TimeCreate will not be set for a DS file for a pNFS server.

A separate commit will add a check to the NFSv4 client for support of
the TimeCreate attribute before attempting to set it, to avoid a problem
when mounting a server that does not support the attribute.
The failures will still occur for r362490 or later kernels that do not
have this patch, since they indicate support for the attribute, but do not
actually support the attribute.

Add support for ext_pgs mbufs to nfsrv_adj().

This patch uses a slightly different algorithm for nfsrv_adj()
since ext_pgs mbuf lists are not permitted to have m_len == 0 mbufs.
As such, the code now frees mbufs after the adjustment in the list instead
of setting their m_len field to 0.
Since mbuf(s) may be trimmed off the tail of the list, the function now
returns a pointer to the last mbuf in the list. This saves the caller
from needing to use m_last() to find the last mbuf.
It also implies that it might return a nul list, which required a check for
that in nfsrvd_readlink().

This is another in the series of commits that add support to the NFS client
and server for building RPC messages in ext_pgs mbufs with anonymous pages.
This is useful so that the entire mbuf list does not need to be
copied before calling sosend() when NFS over TLS is enabled.

Use of ext_pgs mbufs will not be enabled until the kernel RPC is updated
to handle TLS.

Add a boolean argument to nfscl_reqstart() to indicate that ext_pgs mbufs
should be used.

For KERN_TLS (and possibly some other future network interface) the mbuf
list passed into sosend() must be ext_pgs mbufs. The krpc could simply
copy all the mbuf data into ext_pgs mbufs before calling sosend(), but
that would be inefficient for large RPC messages.
This patch adds an argument to nfscl_reqstart() to indicate that it should
fill the RPC message into ext_pgs mbufs.
It also adds fields to "struct nfsrv_descript" needed for building NFS RPC
messages in ext_pgs mbufs, along with new flags for this.

Since the argument is always "false", this commit should not result in any
semantic change. However, this commit prepares the code
for future commits that will add support for building of NFS RPC messages
in ext_pgs mbufs.

Fix export_args ex_flags field so that is 64bits, the same as mnt_flags.

Since mnt_flags was upgraded to 64bits there has been a quirk in
"struct export_args", since it hold a copy of mnt_flags
in ex_flags, which is an "int" (32bits).
This happens to currently work, since all the flag bits used in ex_flags are
defined in the low order 32bits. However, new export flags cannot be defined.
Also, ex_anon is a "struct xucred", which limits it to 16 additional groups.
This patch revises "struct export_args" to make ex_flags 64bits and replaces
ex_anon with ex_uid, ex_ngroups and ex_groups (which points to a
groups list, so it can be malloc'd up to NGROUPS in size.
This requires that the VFS_CHECKEXP() arguments change, so I also modified the
last "secflavors" argument to be an array pointer, so that the
secflavors could be copied in VFS_CHECKEXP() while the export entry is locked.
(Without this patch VFS_CHECKEXP() returns a pointer to the secflavors
array and then it is used after being unlocked, which is potentially
a problem if the exports entry is changed.
In practice this does not occur when mountd is run with "-S",
but I think it is worth fixing.)

This patch also deleted the vfs_oexport_conv() function, since
do_mount_update() does the conversion, as required by the old vfs_cmount()
calls.

Reviewed by: kib, freqlabs
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D25088

Deduplicate fsid comparisons

Comparing fsid_t objects requires internal knowledge of the fsid structure
and yet this is duplicated across a number of places in the code.

Simplify by creating a fsidcmp function (macro).

Reviewed by: mjg, rmacklem
Approved by: mav (mentor)
MFC after: 1 week
Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D24749

Add a function nfsm_set() to initialize "struct nfsrv_descript" for building
mbuf lists.

This function is currently trivial, but will that will change when
support for building NFS messages in ext_pgs mbufs is added.
Adding support for ext_pgs mbufs is needed for KERN_TLS, which will
be used to implement nfs-over-tls.

Remove Mac OS/X macros that did nothing for FreeBSD.

The macros CAST_USER_ADDR_T() and CAST_DOWN() were used for the Mac OS/X
port. The first of these macros was a no-op for FreeBSD and the second
is no longer used.
This patch gets rid of them. It also deletes the "mbuf_t" typedef which
is no longer used in the FreeBSD code from nfskpiport.h

This patch should not change semantics.

Add a sanity check for nes_numsecflavor to the NFS server.

Ryan Moeller reported crashes in the NFS server that appear to be
caused by stack corruption in nfsrv_compound(). It appears that
the stack got corrupted just after a NFSv4.1 Lookup that crosses
a server mount point.
Although it is just a "theory" at this point, the most obvious way
the stack could get corrupted would be if nfsvno_checkexp() somehow
acquires an export with a bogus nes_numsecflavor value. This would
cause the copying of the secflavors to run off the end of the array,
which is allocated on the stack below where the corruption occurs.

This sanity check is simple to do and would stop the stack corruption
if the theory is correct. Otherwise, doing the sanity check seems to
be a reasonable safety belt to add to the code.

Reported by: freqlabs
MFC after: 2 weeks

Fix the NFSv2 extended attribute support to handle 0 length attributes.

I did not realize that zero length attributes are allowed, but they are.
This patch fixes the NFSv4.2 client and server to handle zero length
extended attributes correctly.

Submitted by: Frank van der Linden <fllinden@amazon.com> (earlier version)
Reported by: Frank van der Linden <fllinder@amazon.com>

Replace mbuf macros with the code they would generate in the NFS code.

When the code was ported to Mac OS/X, mbuf handling functions were
converted to using the Mac OS/X accessor functions. For FreeBSD, they
are a simple set of macros in sys/fs/nfs/nfskpiport.h.
Since porting to Mac OS/X is no longer a consideration, replacement of
these macros with the code generated by them makes the code more
readable.
When support for external page mbufs is added as needed by the KERN_TLS,
the patch becomes simpler if done without the macros.

This patch should not result in any semantic change.

Remove the old NFS lock device driver that uses Giant.

This NFS lock device driver was replaced by the kernel NLM around FreeBSD7 and
has not normally been used since then.
To use it, the kernel had to be built without "options NFSLOCKD" and
the nfslockd.ko had to be deleted as well.
Since it uses Giant and is no longer used, this patch removes it.

With this device driver removed, there is now a lot of unused code
in the userland rpc.lockd. That will be removed on a future commit.

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D22933

Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many)

r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.

This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.

Mark all obvious cases as MPSAFE. All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT

Approved by: kib (mentor, blanket)
Commented by: kib, gallatin, melifaro
Differential Revision: https://reviews.freebsd.org/D23718

nfs: add missing CLTFLAG_MPSAFE annotations

vfs: rework vnode list management

The current notion of an active vnode is eliminated.

Vnodes transition between 0<->1 hold counts all the time and the
associated traversal between different lists induces significant
scalability problems in certain workloads.

Introduce a global list containing all allocated vnodes. They get
unlinked only when UMA reclaims memory and are only requeued when
hold count reaches 0.

Sample result from an incremental make -s -j 104 bzImage on tmpfs:
stock: 118.55s user 3649.73s system 7479% cpu 50.382 total
patched: 122.38s user 1780.45s system 6242% cpu 30.480 total

Reviewed by: jeff
Tested by: pho (in a larger patch, previous version)
Differential Revision: https://reviews.freebsd.org/D22997

vfs: add per-mount vnode lazy list and use it for deferred inactive + msync

This obviates the need to scan the entire active list looking for vnodes
of interest.

msync is handled by adding all vnodes with write count to the lazy list.

deferred inactive directly adds vnodes as it sets the VI_DEFINACT flag.

Vnodes get dequeued from the list when their hold count reaches 0.

Newly added MNT_VNODE_FOREACH_LAZY* macros support filtering so that
spurious locking is avoided in the common case.

Reviewed by: jeff
Tested by: pho (in a larger patch, previous version)
Differential Revision: https://reviews.freebsd.org/D22995

vfs: drop the mostly unused flags argument from VOP_UNLOCK

Filesystems which want to use it in limited capacity can employ the
VOP_UNLOCK_FLAGS macro.

Reviewed by: kib (previous version)
Differential Revision: https://reviews.freebsd.org/D21427

Silence some "might not be initialized" warnings for riscv64.

None of these case were actually using the variable(s) uninitialized, but
I figured that silencing the warnings via initializing them made sense.

Some of these predated r355677.

Add some more initializations to quiet riscv build.

The one case in nfs_copy_file_range() was a legitimate case, although
it would probably never occur in practice.

Fix the build for MAC not defined and a couple of might not be initialized.

r355677 broke the build for the not MAC defined case and a couple of
might not be initialized warnings were generated for riscv. Others seem
to be erroneous.

Hopefully there won't be too many more build errors.

Pointy hat goes on me.

Add support for NFSv4.2 to the NFS client and server.

This patch adds support for NFSv4.2 (RFC-7862) and Extended Attributes
(RFC-8276) to the NFS client and server.
NFSv4.2 is comprised of several optional features that can be supported
in addition to NFSv4.1. This patch adds the following optional features:
- posix_fadvise(POSIX_FADV_WILLNEED/POSIX_FADV_DONTNEED)
- posix_fallocate()
- intra server file range copying via the copy_file_range(2) syscall
--> Avoiding data tranfer over the wire to/from the NFS client.
- lseek(SEEK_DATA/SEEK_HOLE)
- Extended attribute syscalls for "user" namespace attributes as defined
by RFC-8276.

Although this patch is fairly large, it should not affect support for
the other versions of NFS. However it does add two new sysctls that allow
a sysadmin to limit which minor versions of NFSv4 a server supports, allowing
a sysadmin to disable NFSv4.2.

Unfortunately, when the NFS stats structure was last revised, it was assumed
that there would be no additional operations added beyond what was
specified in RFC-7862. However RFC-8276 did add additional operations,
forcing the NFS stats structure to revised again. It now has extra unused
entries in all arrays, so that future extensions to NFSv4.2 can be
accomodated without revising this structure again.

A future commit will update nfsstat(1) to report counts for the new NFSv4.2
specific operations/procedures.

This patch affects the internal interface between the nfscommon, nfscl and
nfsd modules and, as such, they all must be upgraded simultaneously.
I will do a version bump (although arguably not needed), due to this.

This code has survived a "make universe" but has not been built with a
recent GCC. If you encounter build problems, please email me.

Relnotes: yes

vfs: introduce v_irflag and make v_type smaller

The current vnode layout is not smp-friendly by having frequently read data
avoidably sharing cachelines with very frequently modified fields. In
particular v_iflag inspected for VI_DOOMED can be found in the same line with
v_usecount. Instead make it available in the same cacheline as the v_op, v_data
and v_type which all get read all the time.

v_type is avoidably 4 bytes while the necessary data will easily fit in 1.
Shrinking it frees up 3 bytes, 2 of which get used here to introduce a new
flag field with a new value: VIRF_DOOMED.

Reviewed by: kib, jeff
Differential Revision: https://reviews.freebsd.org/D22715

Fix the pNFS server's reporting of SpaceUsed (va_bytes).

The pNFS server currently reports SpaceUsed (va_bytes) for the metadata
file. This in not correct, since the metadata file is always empty and,
as such, va_bytes is just the allocation for the empty file.
This patch adds va_bytes to the list of attributes acquired from the
DS for a file, so that it includes the allocated data size and is updated
when the file is written.
For files created on a pNFS server before this patch is applied, the
va_bytes value is estimated by rounding va_size up to a multiple of
BLKDEV_IOSIZE. Once the file is written after this patch has been
applied to the metadata server, the va_bytes returned for the file
will be correct.

This patch only affects a pNFS metadata server.

Found during testing of the NFSv4.2 pNFS server for the Allocate operation.
(Not yet in head/current.)

MFC after: 2 weeks

Replace OBJ_MIGHTBEDIRTY with a system using atomics. Remove the TMPFS_DIRTY
flag and use the same system.

This enables further fault locking improvements by allowing more faults to
proceed with a shared lock.

Reviewed by: kib
Tested by: pho
Differential Revision: https://reviews.freebsd.org/D22116

Delete the unused "nd" argument for nfsrv_proxyds().

The "nd" argument for nfsrv_proxyds() is no longer used by the function.
This patch deletes it. This allows a subsequent patch to delete the "nd"
argument from nfsvno_getattr(), since it's only use of "nd" was to pass it
to nfsrv_proxyds().
Getting rid of the "nd" argument from nfsvno_getattr() avoids confusion
over why it might need "nd".

This patch is trivial and does not have any semantic effect.

Delete the unused "nd" argument for nfsrv_checkdsattr().

The "nd" argument for nfsrv_checkdsattr() is no longer used by the function.
This patch deletes it. This allows subsequent patches to delete the "nd"
argument from nfsrv_proxyds(), since it's only use of "nd" was to pass it
to nfsrv_checkdsattr(). The same will then be true for nfsvno_getattr(),
which passes "nd" to nfsrv_proxyds().
Getting rid of the "nd" argument from nfsvno_getattr() avoids confusion
over why it might need "nd".

This patch is trivial and does not have any semantic effect.
Found by inspection while working on the NFSv4.2 server.

Add support for the ModeSetMasked attribute to the NFSv4.1 server.

I do not know of an extant NFSv4.1 client that currently does a Setattr
operation for the ModeSetMasked, but it has been discussed on the linux-nfs
mailing list.
This patch adds support for doing a Setattr of ModeSetMasked, so that it
will work for any future NFSv4.1 client that chooses to do so.
Tested via a hacked FreeBSD NFSv4.1 client.

MFC after: 2 weeks

Fix the NFSv4.0 server so that it does not support NFSv4.1 attributes.

During inspection of a packet trace, I noticed that an NFSv4.0 mount
reported that it supported attributes that are only defined for NFSv4.1.
In practice, this bug appears to be benign, since NFSv4.0 clients will
not use attributes that were added for NFSv4.1.
However, this was not correct and this patch fixes the NFSv4.0 server
so that it only supports attributes defined for NFSv4.0.
It also adds a definition for NFSv4.1 attributes that can only be set,
although it is only defined as 0 for now.
This is anticipation of the addition of support for the NFSv4.1 mode+mask
attribute soon.

MFC after: 2 weeks

Drop unused 'p' argument to nfsv4_strtogid().

MFC after: 2 weeks
Sponsored by: DARPA, AFRL

Drop unused 'p' argument to nfsv4_strtouid().

MFC after: 2 weeks
Sponsored by: DARPA, AFRL

Don't pass td to nfsvno_open().

MFC after: 2 weeks
Sponsored by: DARPA, AFRL

Don't pass td to nfsvno_createsub().

MFC after: 2 weeks
Sponsored by: DARPA, AFRL

Don't pass td to nfsd_fhtovp(), it's unused.

Reviewed by: rmacklem (earlier version)
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D19421

Push down the thread argument in NFS server code, using curthread
instead of passing it explicitly. No functional changes

Reviewed by: rmacklem (earlier version)
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D19419

nfs: Zero the buffers exported by NFSSVC_DUMPCLIENTS and DUMPLOCKS.

Note that these interfaces are available only to root.

admbugs: 765
Reported by: Vlad Tsyrklevich <vlad@tsyrklevich.net>
Reviewed by: rmacklem
MFC after: 1 day
Security: Kernel memory disclosure
Sponsored by: The FreeBSD Foundation

Remove unused argument to priv_check_cred.

Patch mostly generated with cocinnelle:

@@
expression E1,E2;
@@

- priv_check_cred(E1,E2,0)
+ priv_check_cred(E1,E2)

Sponsored by: The FreeBSD Foundation

Improve sanity checking for the dircount hint argument to
NFSv3's ReaddirPlus and NFSv4's Readdir operations. The code
checked for a zero argument, but did not check for a very large value.
This patch clips dircount at the server's maximum data size.

MFC after: 1 week

nfsrvd_readdirplus: for some errors, do not fail the entire request

Instead, a failing entry is skipped.
This change consist of two logical changes.

A failure to vget or lookup an entry is considered to be a result of a
concurrent removal, which is the only reasonable explanation given that
the filesystem is busied. So, the entry would be silently skipped.

In the case of a failure to get attributes of an entry for an NFSv3
request, the entry would be silently skipped. There can be legitimate
reasons for the failure, but NFSv3 does not provide any means to report
the error, so we have two options: either fail the whole request or
ignore the failed entry. Traditionally, the old NFS server used the
latter option, so the code is reverted to it. Making the whole
directory unreadable because of a single entry seems to be unpractical.

Additionally, some bits of code are slightly re-arranged to account for
the new control flow and to honor style(9).

Reviewed by: rmacklem
Sponsored by: Panzura
Differential Revision: https://reviews.freebsd.org/D15424

Fix the pNFS server's reporting of disk space usage for the "#<path>" case.

The pNFS server would report the total disk space used and free for all
of the DSs, even when certain DSs are assigned to the file system via
the "#<path>" suffix used in the "nfsd -p" option argument.
This patch fixes this case. It only reports usage for the file system
that the argument vnode resides on. This is consistent with the non-pNFS
NFSv4 server. In NFSv4 it is possible to have subtrees on other file
systems, but these are not included in the usage information for NFSv4.

Approved by: re (gjb)

Fix LORs between vn_start_write() and vn_lock() in the pNFS server.

When coding the pNFS server, I added several vn_start_write() calls done
while the vnode was locked, not realizing I had introduced LORs and
possible deadlock when an exported file system on the MDS is suspended.
This patch fixes this by removing the added vn_start_write() calls and
modifying the code so that the extant vn_start_write() call before the
NFS RPC/operation is done when needed by the pNFS server.
Flags are changed so that LayoutCommit and LayoutReturn now get a
vn_start_write() done for them.
When the pNFS server is enabled, the code now also changes the flags for
Getattr, so that the vn_start_write() is done for Getattr, since it may
need to do a vn_set_extattr(). The nfs_writerpc flag array was made global
to the NFS server and renamed nfsrv_writerpc, which is consistent naming
for globals in the NFS server.
Thanks go to kib@ for reporting that doing vn_start_write() while the vnode is
locked results in a LOR.
This patch only affects the behaviour of the pNFS server.

Don't set a file's size for the MDS file of a pNFS service.

When a pNFS service is running, the size of the files created on the MDS
are normally 0, since the data is written to the data files on the DS(s).
However, without this patch, if a Setattr with a non-zero size was done by
a client, the MDS file was set to that size. This was thought to be benign,
but it turns out that files with a non-zero size plus extended attributes
can cause a "ffs_truncate3" panic in UFS. Although the exact cause of this
panic() has not been isolated, this patch avoids the panic() and leaves
the MDS files in a consistent state of always having a size == 0.
Note that these MDS files never store data. The patch also includes an
unnecessary initialization of savsize in case some compiler or static
analyser complains it might not be initialized.
This patch only affects the NFS server when pNFS is enabled via the "-p"
command line option on nfsd.

Copy all bits of a file handle in case there is padding in the structure.

At least on x86, fhandle_t is a packed structure, so I believe an
assignment will copy all the bits. However, for some current/future
architectures, there might be padding in the structure that doesn't get
copied via an assignment.
Since NFS assumes a file handle is an opaque blob of bits that can be
compared via memcmp()/bcmp(), all the bits including any padding must be
copied.
This patch replaces the assignments with a call to a byte copy function.
Spotted during code inspection.

Silence newer gcc warnings.

Newer versions of gcc generate "set, but not used" warnings in the NFS server.
Add __unused macros to silence these warnings.

Requested by: mmacy

Ignore the cookie verifier for NFSv4.1 when the cookie is 0.

RFC5661 states that the cookie verifier should be 0 when the cookie is 0.
However, the wording is somewhat unclear and a recent discussion on the
nfsv4@ietf.org mailing list indicated that the NFSv4 server should ignore
the cookie verifier's value when the dirctory offset cookie is 0.
This patch deletes the check for this that would return NFSERR_BAD_COOKIE
when the verifier was not 0.
This was found during testing of the ESXi client against the NFSv4.1 server.

Reported by: daniel@ftml.net (via packet trace)
MFC after: 2 weeks

Add support for a "forced" pnfsdskill to the pNFS server kernel code.

The pnfsdskill(8) command will normally fail if there is no valid mirror
for the DS to be disabled. However, a system administrator may need to
disable a DS which does not have a valid mirror so that the nfsd threads
can be terminated. This patch adds the kernel code needed by pnfsdskill(8)
to implement this "forced" case of disabling a DS.
This patch only affects the pNFS server.

Fix handling of the hybrid DS case for a pNFS server.

After the addition of the "#mds_path" suffix for a DS specification on the
"-p" nfsd option, it is possible to have a mix of DSs assigned to an MDS
file system and DSs that store files for all DSs. This is what I referred
to as "hybrid" above.
At first, I didn't think this hybrid case would be useful, but I now believe
that some system administrators may fine it useful.
This patch modifies the file storage assignment algorithm so that it
makes the "#mds_path" DSs take priority and the all file systems DSs
are now only used for MDS file systems with no "#mds_path" DS servers.
This only affects the pNFS server for this "hybrid" case.

Add an optional feature to the pNFS server.

Without this patch, the pNFS server distributes the data storage files across
all of the specified DSs.
A tester noted that it would be nice if a system administrator could control
which DSs are used to store the file data for a given exported MDS file system.
This patch adds the kernel support to do this. It also makes a slight semantic
change to nfsv4_findmirror(), since some uses of it no longer require that
the DS being searched for have a current mirror.
A patch that will be committed in a few minutes will modify the nfsd daemon
to support this feature.
The patch should only affect sites using the pNFS server (specified via the
"-p" command line option for nfsd.

Suggested by: james.rose@framestore.com

Fix the pNFS server for a case where mirror level equals number of DSs.

If a pNFS service was set up where the number of DSs equals the mirror level
and then a DS was disabled, the service would create files with duplicate
entries for the same DS. This bug occurred because I didn't realize that
TAILQ_FOREACH_FROM() would start at the beginning of the list when the
inital value of the variable was NULL.
This patch also changes the pNFS server DS file creation code so that it
creates entrie(s) with 0.0.0.0 IP address when it cannot create mirror level
files due to lack of DSs.
The patch only affects the pNFS service and only when it was created with
a number of DSs equal to the mirror level and mirroring is enabled.

Merge the pNFS server code from projects/pnfs-planb-server into head.

This code merge adds a pNFS service to the NFSv4.1 server. Although it is
a large commit it should not affect behaviour for a non-pNFS NFS server.
Some documentation on how this works can be found at:
http://people.freebsd.org/~rmacklem/pnfs-planb-setup.txt
and will hopefully be turned into a proper document soon.
This is a merge of the kernel code. Userland and man page changes will
come soon, once the dust settles on this merge.
It has passed a "make universe", so I hope it will not cause build problems.
It also adds NFSv4.1 server support for the "current stateid".

Here is a brief overview of the pNFS service:
A pNFS service separates the Read/Write oeprations from all the other NFSv4.1
Metadata operations. It is hoped that this separation allows a pNFS service
to be configured that exceeds the limits of a single NFS server for either
storage capacity and/or I/O bandwidth.
It is possible to configure mirroring within the data servers (DSs) so that
the data storage file for an MDS file will be mirrored on two or more of
the DSs.
When this is used, failure of a DS will not stop the pNFS service and a
failed DS can be recovered once repaired while the pNFS service continues
to operate. Although two way mirroring would be the norm, it is possible
to set a mirroring level of up to four or the number of DSs, whichever is
less.
The Metadata server will always be a single point of failure,
just as a single NFS server is.

A Plan B pNFS service consists of a single MetaData Server (MDS) and K
Data Servers (DS), all of which are recent FreeBSD systems.
Clients will mount the MDS as they would a single NFS server.
When files are created, the MDS creates a file tree identical to what a
single NFS server creates, except that all the regular (VREG) files will
be empty. As such, if you look at the exported tree on the MDS directly
on the MDS server (not via an NFS mount), the files will all be of size 0.
Each of these files will also have two extended attributes in the system
attribute name space:
pnfsd.dsfile - This extended attrbute stores the information that
the MDS needs to find the data storage file(s) on DS(s) for this file.
pnfsd.dsattr - This extended attribute stores the Size, AccessTime, ModifyTime
and Change attributes for the file, so that the MDS doesn't need to
acquire the attributes from the DS for every Getattr operation.
For each regular (VREG) file, the MDS creates a data storage file on one
(or more if mirroring is enabled) of the DSs in one of the "dsNN"
subdirectories. The name of this file is the file handle
of the file on the MDS in hexadecimal so that the name is unique.
The DSs use subdirectories named "ds0" to "dsN" so that no one directory
gets too large. The value of "N" is set via the sysctl vfs.nfsd.dsdirsize
on the MDS, with the default being 20.
For production servers that will store a lot of files, this value should
probably be much larger.
It can be increased when the "nfsd" daemon is not running on the MDS,
once the "dsK" directories are created.

For pNFS aware NFSv4.1 clients, the FreeBSD server will return two pieces
of information to the client that allows it to do I/O directly to the DS.
DeviceInfo - This is relatively static information that defines what a DS
is. The critical bits of information returned by the FreeBSD
server is the IP address of the DS and, for the Flexible
File layout, that NFSv4.1 is to be used and that it is
"tightly coupled".
There is a "deviceid" which identifies the DeviceInfo.
Layout - This is per file and can be recalled by the server when it
is no longer valid. For the FreeBSD server, there is support
for two types of layout, call File and Flexible File layout.
Both allow the client to do I/O on the DS via NFSv4.1 I/O
operations. The Flexible File layout is a more recent variant
that allows specification of mirrors, where the client is
expected to do writes to all mirrors to maintain them in a
consistent state. The Flexible File layout also allows the
client to report I/O errors for a DS back to the MDS.
The Flexible File layout supports two variants referred to as
"tightly coupled" vs "loosely coupled". The FreeBSD server always
uses the "tightly coupled" variant where the client uses the
same credentials to do I/O on the DS as it would on the MDS.
For the "loosely coupled" variant, the layout specifies a
synthetic user/group that the client uses to do I/O on the DS.
The FreeBSD server does not do striping and always returns
layouts for the entire file. The critical information in a layout
is Read vs Read/Writea and DeviceID(s) that identify which
DS(s) the data is stored on.

At this time, the MDS generates File Layout layouts to NFSv4.1 clients
that know how to do pNFS for the non-mirrored DS case unless the sysctl
vfs.nfsd.default_flexfile is set non-zero, in which case Flexible File
layouts are generated.
The mirrored DS configuration always generates Flexible File layouts.
For NFS clients that do not support NFSv4.1 pNFS, all I/O operations
are done against the MDS which acts as a proxy for the appropriate DS(s).
When the MDS receives an I/O RPC, it will do the RPC on the DS as a proxy.
If the DS is on the same machine, the MDS/DS will do the RPC on the DS as
a proxy and so on, until the machine runs out of some resource, such as
session slots or mbufs.
As such, DSs must be separate systems from the MDS.

Tested by: james.rose@framestore.com
Relnotes: yes

Revert r334586 since I now think __unused is the better way to handle this.

Fix a gcc8 warning about a write only variable.

gcc8 warns that "verf" was set but not used. This was because the code
that uses it is disabled via a "#if 0".
This patch adds a "#if 0" to the variable's declaration and assignment
to get rid of the warning.
This way the code could be re-enabled without difficulty.

Requested by: mmacy
MFC after: 2 weeks

style: Remove remaining deprecated MALLOC/FREE macros

Mechanically replace uses of MALLOC/FREE with appropriate invocations of
malloc(9) / free(9) (a series of sed expressions). Something like:

* MALLOC(a, b, ... -> a = malloc(...
* FREE( -> free(
* free((caddr_t) -> free(

No functional change.

For now, punt on modifying contrib ipfilter code, leaving a definition of
the macro in its KMALLOC().

Reported by: jhb
Reviewed by: cy, imp, markj, rmacklem
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D14035

Do pass removing some write-only variables from the kernel.

This reduces noise when kernel is compiled by newer GCC versions,
such as one used by external toolchain ports.

Reviewed by: kib, andrew(sys/arm and sys/arm64), emaste(partial), erj(partial)
Reviewed by: jhb (sys/dev/pci/* sys/kern/vfs_aio.c and sys/kern/kern_synch.c)
Differential Revision: https://reviews.freebsd.org/D10385

sys: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Rename vfs.nfsd.enable_uidtostring to vfs.nfs.enable_uidtostring.
It applies to both NFS client and NFS server, and is useful for both.
This is different from vfs.nfsd.enable_stringtouid, which is specific
to server side.

Reviewed by: rmacklem@
MFC after: 2 weeks
Sponsored by: DARPA, AFRL

Add vfs.nfsd.nfsd_enable_uidtostring, which works just like
vfs.nfsd.nfsd_enable_stringtouid, but in reverse - when set to 1,
it forces the NFSv4 server to return numeric UIDs and GIDs instead
of "user@domain" strings. This helps with clients that can't
translate returned identifiers, eg when rerooting.

The same can be achieved by just never running nfsuserd(8),
but the sysctl is useful to toggle the behaviour back and forth
without rebooting.

Reviewed by: rmacklem (earlier version)
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D11326

Commit the 64-bit inode project.

Extend the ino_t, dev_t, nlink_t types to 64-bit ints. Modify
struct dirent layout to add d_off, increase the size of d_fileno
to 64-bits, increase the size of d_namlen to 16-bits, and change
the required alignment. Increase struct statfs f_mntfromname[] and
f_mntonname[] array length MNAMELEN to 1024.

ABI breakage is mitigated by providing compatibility using versioned
symbols, ingenious use of the existing padding in structures, and
by employing other tricks. Unfortunately, not everything can be
fixed, especially outside the base system. For instance, third-party
APIs which pass struct stat around are broken in backward and
forward incompatible ways.

Kinfo sysctl MIBs ABI is changed in backward-compatible way, but
there is no general mechanism to handle other sysctl MIBS which
return structures where the layout has changed. It was considered
that the breakage is either in the management interfaces, where we
usually allow ABI slip, or is not important.

Struct xvnode changed layout, no compat shims are provided.

For struct xtty, dev_t tty device member was reduced to uint32_t.
It was decided that keeping ABI compat in this case is more useful
than reporting 64-bit dev_t, for the sake of pstat.

Update note: strictly follow the instructions in UPDATING. Build
and install the new kernel with COMPAT_FREEBSD11 option enabled,
then reboot, and only then install new world.

Credits: The 64-bit inode project, also known as ino64, started life
many years ago as a project by Gleb Kurtsou (gleb). Kirk McKusick
(mckusick) then picked up and updated the patch, and acted as a
flag-waver. Feedback, suggestions, and discussions were carried
by Ed Maste (emaste), John Baldwin (jhb), Jilles Tjoelker (jilles),
and Rick Macklem (rmacklem). Kris Moore (kris) performed an initial
ports investigation followed by an exp-run by Antoine Brodin (antoine).
Essential and all-embracing testing was done by Peter Holm (pho).
The heavy lifting of coordinating all these efforts and bringing the
project to completion were done by Konstantin Belousov (kib).

Sponsored by: The FreeBSD Foundation (emaste, kib)
Differential revision: https://reviews.freebsd.org/D10439

Fix the setting of atime for Linux client NFSv4 mounts.

The FreeBSD NFSv4 server did not set the attribute bit for TimeAccess in
the reply to an Open with exclusive_create, as required by the RFCs.
(This is required since the FreeBSD NFS server stores the create_verifier
in the va_atime attribute.)
As such, the Linux NFSv4 client did not set the TimeAccess (atime) in
the Setattr done in an RPC after the one with the Open/exclusive_create.
This patch fixes the server to set the TimeAccess bit in the reply.

I believe that storing the create_verifier in an extended attribute for
file systems that support extended attributes might be a good idea,
but I will wait for a discussion of this on the freebsd-fs@ email list
before considering committing a patch to do this.

Reported by: jim@ks.uiuc.edu
Suggested by: dfr
MFC after: 2 weeks

Renumber copyright clause 4

Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96

Workaround NFS bug with readdirplus when there are greater than 1 billion files in a filesystem.

Reviewed by kib
MFC after: 2 weeks
Sponsored by: iXsystems
Differential Revision: D9009

Allow some dotdot lookups in capability mode.

If dotdot lookup does not escape from the file descriptor passed as
the lookup root, we can allow the component traversal. Track the
directories traversed, and check the result of dotdot lookup against
the recorded list of the directory vnodes.

Dotdot lookups are enabled by sysctl vfs.lookup_cap_dotdot, currently
disabled by default until more verification of the approach is done.

Disallow non-local filesystems for dotdot, since remote server might
conspire with the local process to allow it to escape the namespace.
This might be too cautious, provide the knob
vfs.lookup_cap_dotdot_nonlocal to override as well.

Idea by: rwatson
Discussed with: emaste, jonathan, rwatson
Reviewed by: mjg (previous version)
Tested by: pho (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 2 week
Differential revision: https://reviews.freebsd.org/D8110

Update the nfsstats structure to include the changes needed by
the patch in D1626 plus changes so that it includes counts for
NFSv4.1 (and the draft of NFSv4.2).
Also, make all the counts uint64_t and add a vers field at the
beginning, so that future revisions can easily be implemented.
There is code in place to handle the old vesion of the nfsstats
structure for backwards binary compatibility.

Subsequent commits will update nfsstat(8) to use the new fields.

Submitted by: will (earlier version)
Reviewed by: ken
MFC after: 1 month
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D1626

NFS: spelling fixes on comments.

No funcional change.

If the VOP_SETATTR() call that saves the exclusive create verifier failed,
the NFS server would leave the newly created vnode locked. This could
result in a file system that would not unmount and processes wedged,
waiting for the file to be unlocked.
Since this VOP_SETATTR() never fails for most file systems, this bug
doesn't normally manifest itself. I found it during testing of an
exported GlusterFS file system, which can fail.
This patch adds the vput() and changes the error to the correct NFS one.

MFC after: 2 weeks

Cleanup unnecessary semicolons from the kernel.

Found with devel/coccinelle.

Add kernel support to the NFS server for the "-manage-gids"
option that will be added to the nfsuserd daemon in a future
commit. It modifies the cache used by NFSv4 for name<-->id
translation (both username/uid and group/gid) to support this.
When "-manage-gids" is set, the server looks up each uid
for the RPC and uses the list of groups cached in the server
instead of the list of groups provided in the RPC request.
The cached group list is acquired for the cache by the nfsuserd
daemon via getgrouplist(3).
This avoids the 16 groups limit for the list in the RPC request.
Since the cache is now used for every RPC when "-manage-gids"
is enabled, the code also modifies the cache to use a separate
mutex for each hash list instead of a single global mutex.

Suggested by: jpaetzel
Tested by: jpaetzel
MFC after: 2 weeks

Make the size of the hash tables used by the NFSv4 server tunable.
No appreciable change in performance was observed after increasing
the sizes of these tables and then testing with a single client.
However, there was an email that indicated high CPU overheads for
a heavily loaded NFSv4 and it is hoped that increasing the sizes
of the hash tables via these tunables might help.
The tables remain the same size by default.

Differential Revision: https://reviews.freebsd.org/D2596
MFC after: 2 weeks

Replace "new NFS" with just "NFS" in some sysctl description strings.

Sponsored by: The FreeBSD Foundation

File systems that do not use the buffer cache (such as ZFS) must
use VOP_FSYNC() to perform the NFS server's Commit operation.
This patch adds a mnt_kern_flag called MNTK_USES_BCACHE which
is set by file systems that use the buffer cache. If this flag
is not set, the NFS server always does a VOP_FSYNC().
This should be ok for old file system modules that do not set
MNTK_USES_BCACHE, since calling VOP_FSYNC() is correct, although
it might not be optimal for file systems that use the buffer cache.

Reviewed by: kib
MFC after: 2 weeks

Use M_SIZE() instead of hand-crafted (and mostly correct) NFSMSIZ() macro
in the NFS server; garbage collect now-unused NFSMSIZ() and M_HASCL()
macros. Also garbage collect now-unused versions in headers for the
removed previous NFS client and server.

Reviewed by: rmacklem
Sponsored by: EMC / Isilon Storage Division

A deadlock in the NFSv4 server with vfs.nfsd.enable_locallocks=1
was reported via email. This was caused by a LOR between the
sleep lock used to serialize the local locking (nfsrv_locklf())
and locking the vnode. I believe this patch fixes the problem
by delaying relocking of the vnode until the sleep lock is
unlocked (nfsrv_unlocklf()). To avoid nfsvno_advlock() having the side
effect of unlocking the vnode, unlocking the vnode was moved to before
the functions that call nfsvno_advlock().
It shouldn't affect the execution of the default case where
vfs.nfsd.enable_locallocks=0.

Reported by: loic.blot@unix-experience.fr
Discussed with: kib
MFC after: 1 week

Fix failures and warnings reported by newpynfs20090424 test tool.
This fix addresses only issues with the pynfs reports, none of these
issues are know to create problems for extant real clients.

Submitted by: Bart Hsiao <bart.hsiao@gmail.com>
Reworked by: myself
Reviewed by: rmacklem
Approved by: rmacklem
Sponsored by: QNAP Systems Inc.

Do not generate 1000 unique lock names for nfsrc hash chain locks.
It overflows witness.

Shorten the names of some nfs mutexes.

Reported and tested by: pho
No objections from: rmacklem, mav
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

The new NFSv3 server did not generate directory postop attributes for
the reply to ReaddirPlus when the server failed within the loop
that calls VFS_VGET(). This failure is most likely an error
return from VFS_VGET() caused by a bogus d_fileno that was
truncated to 32bits.
This patch fixes the server so that it will return directory postop
attributes for the failure. It does not fix the underlying issue caused
by d_fileno being uint32_t when a file system like ZFS generates
a fileno that is greater than 32bits.

Reported by: jpaetzel
Reviewed by: jpaetzel
MFC after: 1 month

Merge the NFSv4.1 server code in projects/nfsv4.1-server over
into head. The code is not believed to have any effect
on the semantics of non-NFSv4.1 server behaviour.
It is a rather large merge, but I am hoping that there will
not be any regressions for the NFS server.

MFC after: 1 month

Change NFS readdir() to only ignore cookies preceding the given offset for
UFS rather than for all but ZFS. This code was assuming that offsets were
monotonically increasing for all file systems except ZFS and that the
cookies from a previous call may have been rewound to a block boundary.
According to mckusick@ only UFS is known to do this, so only requests against
UFS file systems should remove cookies smaller than the given offset. This
fixes serving TMPFS over NFS as it too does not have monotonically increasing
offsets. The comment around the code also indicated it was specific to UFS.

Some of the code using 'not_zfs' is specific to ZFS snapshot handling, so
add a 'is_zfs' variable for those cases.

It's possible that 'is_zfs' check for VFS_VGET() support may not be
specific to ZFS. This needs more research and testing.

After this fix TMPFS and other file systems can be served over NFS.

To test I compared the results of syncing a /usr/src tree into a tmpfs and
serving that over NFS. Before the fix 3589 files were missing on the remote
view. After the fix all files were successfully found.

Reviewed by: rmacklem
Discussed with: mckusick, rmacklem via fs@
Discussed at: http://lists.freebsd.org/pipermail/freebsd-fs/2014-April/019264.html
MFC after: 2 weeks
Sponsored by: EMC / Isilon Storage Division

The new draft specification for NFSv4.0 specifies that a server
should either accept owner and owner_group strings that are just
the digits of the uid/gid or return NFS4ERR_BADOWNER.
This patch adds a sysctl vfs.nfsd.enable_stringtouid, which can
be set to enable the server w.r.t. accepting numeric string. It
also ensures that NFS4ERR_BADOWNER is returned if numeric uid/gid
strings are not enabled. This fixes the server for recent Linux
nfs4 clients that use numeric uid/gid strings by default.

Reported and tested by: craigyk@gmail.com
MFC after: 2 weeks

The PR reported that the old NFS server did not set uio_td == NULL
for the VOP_READ() call. This patch fixes both the old and new
server for this case.

PR: 185232
Submitted by: PR had patch for old server
Reviewed by: kib
MFC after: 2 weeks

Update kernel inclusions of capability.h to use capsicum.h instead; some
further refinement is required as some device drivers intended to be
portable over FreeBSD versions rely on __FreeBSD_version to decide whether
to include capability.h.

MFC after: 3 weeks

Rework NFS Duplicate Request Cache cleanup logic.

- Introduce additional hash to group requests by hash of sockref. This
allows to process TCP acknowledgements without looping though all the cache,
and as result allows to do it every time.
- Indroduce additional callbacks to notify application layer about sockets
disconnection. Without this last few requests processed just before socket
disconnection never processed their ACKs and stuck in cache for many hours.
- Implement transport-specific method for tracking reply acknowledgements.
New implementation does not cross multiple stack layers to get the data and
does not have race conditions that previously made some requests stuck
in cache. This could be done more efficiently at sockbuf layer, but that
would broke some KBIs, while I don't know other consumers for it aside NFS.
- Instead of traversing all DRC twice per request, run cleaning only once
per request, and except in some conditions traverse only single hash slot
at a time.

Together this limits NFS DRC growth only to situations of real connectivity
problems. If network is working well, and so all replies are acknowledged,
cache remains almost empty even after hours of heavy load. Without this
change on the same test cache was growing to many thousand requests even
with perfectly working local network.

As another result this reduces CPU time spent on the DRC handling during
SPEC NFS benchmark from about 10% to 0.5%.

Sponsored by: iXsystems, Inc.

The NFSv4 server would call VOP_SETATTR() with a shared locked vnode
when a Getattr for a file is done by a client other than the one that
holds the file's delegation. This would only happen when delegations
are enabled and the problem is fixed by this patch.

MFC after: 1 week

An intermittent problem with NFSv4 exporting of ZFS snapshots was
reported to the freebsd-fs mailing list. I believe the problem was
caused by the Readdir operation using VFS_VGET() for a snapshot file entry
instead of VOP_LOOKUP(). This would not occur for NFSv3, since it
will do a VFS_VGET() of "." which fails with ENOTSUPP at the beginning
of the directory, whereas NFSv4 does not check "." or "..". This
patch adds a call to VFS_VGET() for the directory being read to check
for ENOTSUPP.
I also observed that the mount_on_fileid and fsid attributes were
not correct at the snapshot's auto mountpoints when looking at packet
traces for the Readdir. This patch fixes the attributes by doing a check
for different v_mount structure, even if the vnode v_mountedhere is not
set.

Reported by: jas@cse.yorku.ca
Tested by: jas@cse.yorku.ca
Reviewed by: asomers
MFC after: 1 week

Change the cap_rights_t type from uint64_t to a structure that we can extend
in the future in a backward compatible (API and ABI) way.

The cap_rights_t represents capability rights. We used to use one bit to
represent one right, but we are running out of spare bits. Currently the new
structure provides place for 114 rights (so 50 more than the previous
cap_rights_t), but it is possible to grow the structure to hold at least 285
rights, although we can make it even larger if 285 rights won't be enough.

The structure definition looks like this:

struct cap_rights {
uint64_t cr_rights[CAP_RIGHTS_VERSION + 2];
};

The initial CAP_RIGHTS_VERSION is 0.

The top two bits in the first element of the cr_rights[] array contain total
number of elements in the array - 2. This means if those two bits are equal to
0, we have 2 array elements.

The top two bits in all remaining array elements should be 0.
The next five bits in all array elements contain array index. Only one bit is
used and bit position in this five-bits range defines array index. This means
there can be at most five array elements in the future.

To define new right the CAPRIGHT() macro must be used. The macro takes two
arguments - an array index and a bit to set, eg.

#define CAP_PDKILL CAPRIGHT(1, 0x0000000000000800ULL)

We still support aliases that combine few rights, but the rights have to belong
to the same array element, eg:

#define CAP_LOOKUP CAPRIGHT(0, 0x0000000000000400ULL)
#define CAP_FCHMOD CAPRIGHT(0, 0x0000000000002000ULL)

#define CAP_FCHMODAT (CAP_FCHMOD | CAP_LOOKUP)

There is new API to manage the new cap_rights_t structure:

cap_rights_t *cap_rights_init(cap_rights_t *rights, ...);
void cap_rights_set(cap_rights_t *rights, ...);
void cap_rights_clear(cap_rights_t *rights, ...);
bool cap_rights_is_set(const cap_rights_t *rights, ...);

bool cap_rights_is_valid(const cap_rights_t *rights);
void cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src);
void cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src);
bool cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little);

Capability rights to the cap_rights_init(), cap_rights_set(),
cap_rights_clear() and cap_rights_is_set() functions are provided by
separating them with commas, eg:

cap_rights_t rights;

cap_rights_init(&rights, CAP_READ, CAP_WRITE, CAP_FSTAT);

There is no need to terminate the list of rights, as those functions are
actually macros that take care of the termination, eg:

#define cap_rights_set(rights, ...) \
__cap_rights_set((rights), __VA_ARGS__, 0ULL)
void __cap_rights_set(cap_rights_t *rights, ...);

Thanks to using one bit as an array index we can assert in those functions that
there are no two rights belonging to different array elements provided
together. For example this is illegal and will be detected, because CAP_LOOKUP
belongs to element 0 and CAP_PDKILL to element 1:

cap_rights_init(&rights, CAP_LOOKUP | CAP_PDKILL);

Providing several rights that belongs to the same array's element this way is
correct, but is not advised. It should only be used for aliases definition.

This commit also breaks compatibility with some existing Capsicum system calls,
but I see no other way to do that. This should be fine as Capsicum is still
experimental and this change is not going to 9.x.

Sponsored by: The FreeBSD Foundation

Fix several performance related issues in the new NFS server's
DRC for NFS over TCP.
- Increase the size of the hash tables.
- Create a separate mutex for each hash list of the TCP hash table.
- Single thread the code that deletes stale cache entries.
- Add a tunable called vfs.nfsd.tcphighwater, which can be increased
to allow the cache to grow larger, avoiding the overhead of frequent
scans to delete stale cache entries.
(The default value will result in frequent scans to delete stale cache
entries, analagous to what the pre-patched code does.)
- Add a tunable called vfs.nfsd.cachetcp that can be used to disable
DRC caching for NFS over TCP, since the old NFS server didn't DRC cache TCP.
It also adjusts the size of nfsrc_floodlevel dynamically, so that it is
always greater than vfs.nfsd.tcphighwater.

For UDP the algorithm remains the same as the pre-patched code, but the
tunable vfs.nfsd.udphighwater can be used to allow the cache to grow
larger and reduce the overhead caused by frequent scans for stale entries.
UDP also uses a larger hash table size than the pre-patched code.

Reported by: wollman
Tested by: wollman (earlier version of patch)
Submitted by: ivoras (earlier patch)
Reviewed by: jhb (earlier version of patch)
MFC after: 1 month

- Convert the bufobj lock to rwlock.
- Use a shared bufobj lock in getblk() and inmem().
- Convert softdep's lk to rwlock to match the bufobj lock.
- Move INFREECNT to b_flags and protect it with the buf lock.
- Remove unnecessary locking around bremfree() and BKGRDINPROG.

Sponsored by: EMC / Isilon Storage Division
Discussed with: mckusick, kib, mdf

Fix typo in comment.

Submitted by: Alex Weber <alexwebr@gmail.com>
MFC after: 1 week

Fix a bug that allows NFS clients to issue READDIR on files.

PR: kern/178016
Security: CVE-2013-3266
Security: FreeBSD-SA-13:05.nfsserver

Revamp the old NFS server's File Handle Affinity (FHA) code so that
it will work with either the old or new server.

The FHA code keeps a cache of currently active file handles for
NFSv2 and v3 requests, so that read and write requests for the same
file are directed to the same group of threads (reads) or thread
(writes). It does not currently work for NFSv4 requests. They are
more complex, and will take more work to support.

This improves read-ahead performance, especially with ZFS, if the
FHA tuning parameters are configured appropriately. Without the
FHA code, concurrent reads that are part of a sequential read from
a file will be directed to separate NFS threads. This has the
effect of confusing the ZFS zfetch (prefetch) code and makes
sequential reads significantly slower with clients like Linux that
do a lot of prefetching.

The FHA code has also been updated to direct write requests to nearby
file offsets to the same thread in the same way it batches reads,
and the FHA code will now also send writes to multiple threads when
needed.

This improves sequential write performance in ZFS, because writes
to a file are now more ordered. Since NFS writes (generally
less than 64K) are smaller than the typical ZFS record size
(usually 128K), out of order NFS writes to the same block can
trigger a read in ZFS. Sending them down the same thread increases
the odds of their being in order.

In order for multiple write threads per file in the FHA code to be
useful, writes in the NFS server have been changed to use a LK_SHARED
vnode lock, and upgrade that to LK_EXCLUSIVE if the filesystem
doesn't allow multiple writers to a file at once. ZFS is currently
the only filesystem that allows multiple writers to a file, because
it has internal file range locking. This change does not affect the
NFSv4 code.

This improves random write performance to a single file in ZFS, since
we can now have multiple writers inside ZFS at one time.

I have changed the default tuning parameters to a 22 bit (4MB)
window size (from 256K) and unlimited commands per thread as a
result of my benchmarking with ZFS.

The FHA code has been updated to allow configuring the tuning
parameters from loader tunable variables in addition to sysctl
variables. The read offset window calculation has been slightly
modified as well. Instead of having separate bins, each file
handle has a rolling window of bin_shift size. This minimizes
glitches in throughput when shifting from one bin to another.

sys/conf/files:
Add nfs_fha_new.c and nfs_fha_old.c. Compile nfs_fha.c
when either the old or the new NFS server is built.

sys/fs/nfs/nfsport.h,
sys/fs/nfs/nfs_commonport.c:
Bring in changes from Rick Macklem to newnfs_realign that
allow it to operate in blocking (M_WAITOK) or non-blocking
(M_NOWAIT) mode.

sys/fs/nfs/nfs_commonsubs.c,
sys/fs/nfs/nfs_var.h:
Bring in a change from Rick Macklem to allow telling
nfsm_dissect() whether or not to wait for mallocs.

sys/fs/nfs/nfsm_subs.h:
Bring in changes from Rick Macklem to create a new
nfsm_dissect_nonblock() inline function and
NFSM_DISSECT_NONBLOCK() macro.

sys/fs/nfs/nfs_commonkrpc.c,
sys/fs/nfsclient/nfs_clkrpc.c:
Add the malloc wait flag to a newnfs_realign() call.

sys/fs/nfsserver/nfs_nfsdkrpc.c:
Setup the new NFS server's RPC thread pool so that it will
call the FHA code.

Add the malloc flag argument to newnfs_realign().

Unstaticize newnfs_nfsv3_procid[] so that we can use it in
the FHA code.

sys/fs/nfsserver/nfs_nfsdsocket.c:
In nfsrvd_dorpc(), add NFSPROC_WRITE to the list of RPC types
that use the LK_SHARED lock type.

sys/fs/nfsserver/nfs_nfsdport.c:
In nfsd_fhtovp(), if we're starting a write, check to see
whether the underlying filesystem supports shared writes.
If not, upgrade the lock type from LK_SHARED to LK_EXCLUSIVE.

sys/nfsserver/nfs_fha.c:
Remove all code that is specific to the NFS server
implementation. Anything that is server-specific is now
accessed through a callback supplied by that server's FHA
shim in the new softc.

There are now separate sysctls and tunables for the FHA
implementations for the old and new NFS servers. The new
NFS server has its tunables under vfs.nfsd.fha, the old
NFS server's tunables are under vfs.nfsrv.fha as before.

In fha_extract_info(), use callouts for all server-specific
code. Getting file handles and offsets is now done in the
individual server's shim module.

In fha_hash_entry_choose_thread(), change the way we decide
whether two reads are in proximity to each other.
Previously, the calculation was a simple shift operation to
see whether the offsets were in the same power of 2 bucket.
The issue was that there would be a bucket (and therefore
thread) transition, even if the reads were in close
proximity. When there is a thread transition, reads wind
up going somewhat out of order, and ZFS gets confused.

The new calculation simply tries to see whether the offsets
are within 1 << bin_shift of each other. If they are, the
reads will be sent to the same thread.

The effect of this change is that for sequential reads, if
the client doesn't exceed the max_reqs_per_nfsd parameter
and the bin_shift is set to a reasonable value (22, or
4MB works well in my tests), the reads in any sequential
stream will largely be confined to a single thread.

Change fha_assign() so that it takes a softc argument. It
is now called from the individual server's shim code, which
will pass in the softc.

Change fhe_stats_sysctl() so that it takes a softc
parameter. It is now called from the individual server's
shim code. Add the current offset to the list of things
printed out about each active thread.

Change the num_reads and num_writes counters in the
fha_hash_entry structure to 32-bit values, and rename them
num_rw and num_exclusive, respectively, to reflect their
changed usage.

Add an enable sysctl and tunable that allows the user to
disable the FHA code (when vfs.XXX.fha.enable = 0). This
is useful for before/after performance comparisons.

nfs_fha.h:
Move most structure definitions out of nfs_fha.c and into
the header file, so that the individual server shims can
see them.

Change the default bin_shift to 22 (4MB) instead of 18
(256K). Allow unlimited commands per thread.

sys/nfsserver/nfs_fha_old.c,
sys/nfsserver/nfs_fha_old.h,
sys/fs/nfsserver/nfs_fha_new.c,
sys/fs/nfsserver/nfs_fha_new.h:
Add shims for the old and new NFS servers to interface with
the FHA code, and callbacks for the

The shims contain all of the code and definitions that are
specific to the NFS servers.

They setup the server-specific callbacks and set the server
name for the sysctl and loader tunable variables.

sys/nfsserver/nfs_srvkrpc.c:
Configure the RPC code to call fhaold_assign() instead of
fha_assign().

sys/modules/nfsd/Makefile:
Add nfs_fha.c and nfs_fha_new.c.

sys/modules/nfsserver/Makefile:
Add nfs_fha_old.c.

Reviewed by: rmacklem
Sponsored by: Spectra Logic
MFC after: 2 weeks

Switch the vm_object mutex to be a rwlock. This will enable in the
future further optimizations where the vm_object lock will be held
in read mode most of the time the page cache resident pool of pages
are accessed for reading purposes.

The change is mostly mechanical but few notes are reported:
* The KPI changes as follow:
- VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK()
- VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK()
- VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK()
- VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED()
(in order to avoid visibility of implementation details)
- The read-mode operations are added:
VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(),
VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED()
* The vm/vm_pager.h namespace pollution avoidance (forcing requiring
sys/mutex.h in consumers directly to cater its inlining functions
using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h
consumers now must include also sys/rwlock.h.
* zfs requires a quite convoluted fix to include FreeBSD rwlocks into
the compat layer because the name clash between FreeBSD and solaris
versions must be avoided.
At this purpose zfs redefines the vm_object locking functions
directly, isolating the FreeBSD components in specific compat stubs.

The KPI results heavilly broken by this commit. Thirdy part ports must
be updated accordingly (I can think off-hand of VirtualBox, for example).

Sponsored by: EMC / Isilon storage division
Reviewed by: jeff
Reviewed by: pjd (ZFS specific review)
Discussed with: alc
Tested by: pho

Merge Capsicum overhaul:

- Capability is no longer separate descriptor type. Now every descriptor
has set of its own capability rights.

- The cap_new(2) system call is left, but it is no longer documented and
should not be used in new code.

- The new syscall cap_rights_limit(2) should be used instead of
cap_new(2), which limits capability rights of the given descriptor
without creating a new one.

- The cap_getrights(2) syscall is renamed to cap_rights_get(2).

- If CAP_IOCTL capability right is present we can further reduce allowed
ioctls list with the new cap_ioctls_limit(2) syscall. List of allowed
ioctls can be retrived with cap_ioctls_get(2) syscall.

- If CAP_FCNTL capability right is present we can further reduce fcntls
that can be used with the new cap_fcntls_limit(2) syscall and retrive
them with cap_fcntls_get(2).

- To support ioctl and fcntl white-listing the filedesc structure was
heavly modified.

- The audit subsystem, kdump and procstat tools were updated to
recognize new syscalls.

- Capability rights were revised and eventhough I tried hard to provide
backward API and ABI compatibility there are some incompatible changes
that are described in detail below:

CAP_CREATE old behaviour:
- Allow for openat(2)+O_CREAT.
- Allow for linkat(2).
- Allow for symlinkat(2).
CAP_CREATE new behaviour:
- Allow for openat(2)+O_CREAT.

Added CAP_LINKAT:
- Allow for linkat(2). ABI: Reuses CAP_RMDIR bit.
- Allow to be target for renameat(2).

Added CAP_SYMLINKAT:
- Allow for symlinkat(2).

Removed CAP_DELETE. Old behaviour:
- Allow for unlinkat(2) when removing non-directory object.
- Allow to be source for renameat(2).

Removed CAP_RMDIR. Old behaviour:
- Allow for unlinkat(2) when removing directory.

Added CAP_RENAMEAT:
- Required for source directory for the renameat(2) syscall.

Added CAP_UNLINKAT (effectively it replaces CAP_DELETE and CAP_RMDIR):
- Allow for unlinkat(2) on any object.
- Required if target of renameat(2) exists and will be removed by this
call.

Removed CAP_MAPEXEC.

CAP_MMAP old behaviour:
- Allow for mmap(2) with any combination of PROT_NONE, PROT_READ and
PROT_WRITE.
CAP_MMAP new behaviour:
- Allow for mmap(2)+PROT_NONE.

Added CAP_MMAP_R:
- Allow for mmap(PROT_READ).
Added CAP_MMAP_W:
- Allow for mmap(PROT_WRITE).
Added CAP_MMAP_X:
- Allow for mmap(PROT_EXEC).
Added CAP_MMAP_RW:
- Allow for mmap(PROT_READ | PROT_WRITE).
Added CAP_MMAP_RX:
- Allow for mmap(PROT_READ | PROT_EXEC).
Added CAP_MMAP_WX:
- Allow for mmap(PROT_WRITE | PROT_EXEC).
Added CAP_MMAP_RWX:
- Allow for mmap(PROT_READ | PROT_WRITE | PROT_EXEC).

Renamed CAP_MKDIR to CAP_MKDIRAT.
Renamed CAP_MKFIFO to CAP_MKFIFOAT.
Renamed CAP_MKNODE to CAP_MKNODEAT.

CAP_READ old behaviour:
- Allow pread(2).
- Disallow read(2), readv(2) (if there is no CAP_SEEK).
CAP_READ new behaviour:
- Allow read(2), readv(2).
- Disallow pread(2) (CAP_SEEK was also required).

CAP_WRITE old behaviour:
- Allow pwrite(2).
- Disallow write(2), writev(2) (if there is no CAP_SEEK).
CAP_WRITE new behaviour:
- Allow write(2), writev(2).
- Disallow pwrite(2) (CAP_SEEK was also required).

Added convinient defines:

#define CAP_PREAD (CAP_SEEK | CAP_READ)
#define CAP_PWRITE (CAP_SEEK | CAP_WRITE)
#define CAP_MMAP_R (CAP_MMAP | CAP_SEEK | CAP_READ)
#define CAP_MMAP_W (CAP_MMAP | CAP_SEEK | CAP_WRITE)
#define CAP_MMAP_X (CAP_MMAP | CAP_SEEK | 0x0000000000000008ULL)
#define CAP_MMAP_RW (CAP_MMAP_R | CAP_MMAP_W)
#define CAP_MMAP_RX (CAP_MMAP_R | CAP_MMAP_X)
#define CAP_MMAP_WX (CAP_MMAP_W | CAP_MMAP_X)
#define CAP_MMAP_RWX (CAP_MMAP_R | CAP_MMAP_W | CAP_MMAP_X)
#define CAP_RECV CAP_READ
#define CAP_SEND CAP_WRITE

#define CAP_SOCK_CLIENT \
(CAP_CONNECT | CAP_GETPEERNAME | CAP_GETSOCKNAME | CAP_GETSOCKOPT | \
CAP_PEELOFF | CAP_RECV | CAP_SEND | CAP_SETSOCKOPT | CAP_SHUTDOWN)
#define CAP_SOCK_SERVER \
(CAP_ACCEPT | CAP_BIND | CAP_GETPEERNAME | CAP_GETSOCKNAME | \
CAP_GETSOCKOPT | CAP_LISTEN | CAP_PEELOFF | CAP_RECV | CAP_SEND | \
CAP_SETSOCKOPT | CAP_SHUTDOWN)

Added defines for backward API compatibility:

#define CAP_MAPEXEC CAP_MMAP_X
#define CAP_DELETE CAP_UNLINKAT
#define CAP_MKDIR CAP_MKDIRAT
#define CAP_RMDIR CAP_UNLINKAT
#define CAP_MKFIFO CAP_MKFIFOAT
#define CAP_MKNOD CAP_MKNODAT
#define CAP_SOCK_ALL (CAP_SOCK_CLIENT | CAP_SOCK_SERVER)

Sponsored by: The FreeBSD Foundation
Reviewed by: Christoph Mallon <christoph.mallon@gmx.de>
Many aspects discussed with: rwatson, benl, jonathan
ABI compatibility discussed with: kib

Use vfs_timestamp() to set file timestamps rather than invoking
getmicrotime() or getnanotime() directly in NFS.

Reviewed by: rmacklem, bde
MFC after: 1 week

Mechanically substitute flags from historic mbuf allocator with
malloc(9) flags within sys.

Exceptions:

- sys/contrib not touched
- sys/mbuf.h edited manually

Remove the support for using non-mpsafe filesystem modules.

In particular, do not lock Giant conditionally when calling into the
filesystem module, remove the VFS_LOCK_GIANT() and related
macros. Stop handling buffers belonging to non-mpsafe filesystems.

The VFS_VERSION is bumped to indicate the interface change which does
not result in the interface signatures changes.

Conducted and reviewed by: attilio
Tested by: pho

Add two new options to the nfssvc(2) syscall that allow
processes running as root to suspend/resume execution
of the kernel nfsd threads. An earlier version of this
patch was tested by Vincent Hoffman (vince at unsane.co.uk)
and John Hickey (jh at deterlab.net).

Reviewed by: kib
MFC after: 2 weeks

Fix the mis-handling of the VV_TEXT on the nullfs vnodes.

If you have a binary on a filesystem which is also mounted over by
nullfs, you could execute the binary from the lower filesystem, or
from the nullfs mount. When executed from lower filesystem, the lower
vnode gets VV_TEXT flag set, and the file cannot be modified while the
binary is active. But, if executed as the nullfs alias, only the
nullfs vnode gets VV_TEXT set, and you still can open the lower vnode
for write.

Add a set of VOPs for the VV_TEXT query, set and clear operations,
which are correctly bypassed to lower vnode.

Tested by: pho (previous version)
MFC after: 2 weeks

Modify the NFSv4 client so that it can handle owner
and owner_group strings that consist entirely of
digits, interpreting them as the uid/gid number.
This change was needed since new (>= 3.3) Linux
servers reply with these strings by default.
This change is mandated by the rfc3530bis draft.
Reported on freebsd-stable@ under the Subject
heading "Problem with Linux >= 3.3 as NFSv4 server"
by Norbert Aschendorff on Aug. 20, 2012.

Tested by: norbert.aschendorff at yahoo.de
Reviewed by: jhb
MFC after: 2 weeks

Use the common api helper routine instead of freeing the namei
buffer directly.

Approved by: rmacklem (mentor)
MFC after: 1 month

Fix a leak of namei lookup path buffers that occurs when a
ZFS volume is exported via the new NFS server. The leak occurred
because the new NFS server code didn't handle the case where
a file system sets the SAVENAME flag in its VOP_LOOKUP() and
ZFS does this for the DELETE case.

Tested by: Oliver Brandmueller (ob at gruft.de), hrs
PR: kern/167266
MFC after: 1 month

This change creates a new list of active vnodes associated with
a mount point. Active vnodes are those with a non-zero use or hold
count, e.g., those vnodes that are not on the free list. Note that
this list is in addition to the list of all the vnodes associated
with a mount point.

To avoid adding another set of linkage pointers to the vnode
structure, the active list uses the existing linkage pointers
used by the free list (previously named v_freelist, now renamed
v_actfreelist).

This update adds the MNT_VNODE_FOREACH_ACTIVE interface that loops
over just the active vnodes associated with a mount point (typically
less than 1% of the vnodes associated with the mount point).

Reviewed by: kib
Tested by: Peter Holm
MFC after: 2 weeks

The name caching changes of r230394 exposed an intermittent bug
in the new NFS server for NFSv4, where it would report ENOENT
when the file actually existed on the server. This turned out
to be caused by not initializing ni_topdir before calling lookup()
and there was a rare case where the value on the stack location
assigned to ni_topdir happened to be a pointer to a ".." entry,
such that "dp == ndp->ni_topdir" succeeded in lookup().
This patch initializes ni_topdir to fix the problem.

MFC after: 5 days

Delete a couple of out of date comments that are no longer true in
the new NFS client.

Requested by: bde
MFC after: 1 week

Patch the new NFS server in a manner analagous to r228520 for the
old NFS server, so that it correctly handles a count == 0 argument
for Commit.

PR: kern/118126
MFC after: 2 weeks

Enhance the sequential access heuristic used to perform readahead in the
NFS server and reuse it for writes as well to allow writes to the backing
store to be clustered.
- Use a prime number for the size of the heuristic table (1017 is not
prime).
- Move the logic to locate a heuristic entry from the table and compute
the sequential count out of VOP_READ() and into a separate routine.
- Use the logic from sequential_heuristic() in vfs_vnops.c to update the
seqcount when a sequential access is performed rather than just
increasing seqcount by 1. This lets the clustering count ramp up
faster.
- Allow for some reordering of RPCs and if it is detected leave the current
seqcount as-is rather than dropping back to a seqcount of 1. Also,
when out of order access is encountered, cut seqcount in half rather than
dropping it all the way back to 1 to further aid with reordering.
- Fix the new NFS server to properly update the next offset after a
successful VOP_READ() so that the readahead actually works.

Some of these changes came from an earlier patch by Bjorn Gronwall that was
forwarded to me by bde@.

Discussed with: bde, rmacklem, fs@
Submitted by: Bjorn Gronwall (1, 4)
MFC after: 2 weeks

This patch enables the new/default NFS server's use of shared
vnode locking for read, readdir, readlink, getattr and access.
It is hoped that this will improve server performance for these
operations, since they will no longer be serialized for a given
file/vnode.

In order to maximize the re-usability of kernel code in user space this
patch modifies makesyscalls.sh to prefix all of the non-compatibility
calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel
entry points and all places in the code that use them. It also
fixes an additional name space collision between the kernel function
psignal and the libc function of the same name by renaming the kernel
psignal kern_psignal(). By introducing this change now we will ease future
MFCs that change syscalls.

Reviewed by: rwatson
Approved by: re (bz)

Fix the NFS servers so that they can do a Lookup of "..",
which requires that ni_strictrelative be set to 0, post-r224810.

Tested by: swills (earlier version), geo dot liaskos at gmail.com
Approved by: re (kib)

Fix a merge conflict.

r224086 added "goto out"-style error handling to nfssvc_nfsd(), in order
to reliably call NFSEXITCODE() before returning. Our Capsicum changes,
based on the old "return (error)" model, did not merge nicely.

Approved by: re (kib), mentor (rwatson)
Sponsored by: Google Inc

Second-to-last commit implementing Capsicum capabilities in the FreeBSD
kernel for FreeBSD 9.0:

Add a new capability mask argument to fget(9) and friends, allowing system
call code to declare what capabilities are required when an integer file
descriptor is converted into an in-kernel struct file *. With options
CAPABILITIES compiled into the kernel, this enforces capability
protection; without, this change is effectively a no-op.

Some cases require special handling, such as mmap(2), which must preserve
information about the maximum rights at the time of mapping in the memory
map so that they can later be enforced in mprotect(2) -- this is done by
narrowing the rights in the existing max_protection field used for similar
purposes with file permissions.

In namei(9), we assert that the code is not reached from within capability
mode, as we're not yet ready to enforce namespace capabilities there.
This will follow in a later commit.

Update two capability names: CAP_EVENT and CAP_KEVENT become
CAP_POST_KEVENT and CAP_POLL_KEVENT to more accurately indicate what they
represent.

Approved by: re (bz)
Submitted by: jonathan
Sponsored by: Google Inc

Add DEXITCODE plumbing to NFS.

Isilon has the concept of an in-memory exit-code ring that saves the last exit
code of a function and allows for stack tracing. This is very helpful when
debugging tough issues.

This patch is essentially a no-op for BSD at this point, until we upstream
the dexitcode logic itself. The patch adds DEXITCODE calls to every NFS
function that returns an errno error code. A number of code paths were also
reorganized to have single exit paths, to reduce code duplication.

Submitted by: David Kwan <dkwan@isilon.com>
Reviewed by: rmacklem
Approved by: zml (mentor)
MFC after: 2 weeks

Simple find/replace of VOP_ISLOCKED -> NFSVOPISLOCKED. This is done so that NFSVOPISLOCKED can be modified later to add enhanced logging and assertions.

Reviewed by: rmacklem
Approved by: zml (mentor)
MFC after: 2 weeks

Simple find/replace of VOP_UNLOCK -> NFSVOPUNLOCK. This is done so that NFSVOPUNLOCK can be modified later to add enhanced logging and assertions.

Reviewed by: rmacklem
Approved by: zml (mentor)
MFC after: 2 weeks

Simple find/replace of vn_lock -> NFSVOPLOCK. This is done so that NFSVOPLOCK can be modified later to add enhanced logging and assertions.

Reviewed by: rmacklem
Approved by: zml (mentor)
MFC after: 2 weeks

Remove unnecessary thread pointer from VOPLOCK macros and current users.

Reviewed by: rmacklem
Approved by: zml (mentor)
MFC after: 2 weeks

Move nfsvno_pathconf to be accessible to sys/fs/nfs; no functionality change.

Reviewed by: rmacklem
Approved by: zml (mentor)
MFC after: 2 weeks

Small acl patch to return the aclerror that comes back from nfsrv_dissectacl(). This fixes a problem where ATTRNOTSUPP was being returned instead of BADOWNER.

Reviewed by: rmacklem
Approved by: zml (mentor)
MFC after: 2 weeks

Modify the new NFS server so that the NFSv3 Pathconf RPC
doesn't return an error when the underlying file system
lacks support for any of the four _PC_xxx values used, by
falling back to default values.

Tested by: avg
MFC after: 2 weeks

Add a lock flags argument to the VFS_FHTOVP() file system
method, so that callers can indicate the minimum vnode
locking requirement. This will allow some file systems to choose
to return a LK_SHARED locked vnode when LK_SHARED is specified
for the flags argument. This patch only adds the flag. It
does not change any file system to use it and all callers
specify LK_EXCLUSIVE, so file system semantics are not changed.

Reviewed by: kib

Change the new NFS server so that it uses vfs.nfsd naming
for its sysctls instead of vfs.newnfs. This separates the
names from the ones used by the client.

Change the new NFS server so that it returns 0 when the f_bavail
or f_ffree fields of "struct statfs" are negative, since the
values that go on the wire are unsigned and will appear to be
very large positive values otherwise. This makes the handling
of a negative f_bavail compatible with the old/regular NFS server.

MFC after: 2 weeks

Fix the experimental NFSv4 server so that it uses VOP_PATHCONF()
to determine if a file system supports NFSv4 ACLs. Since
VOP_PATHCONF() must be called with a locked vnode, the function
is called before nfsvno_fillattr() and the result is passed in
as an extra argument.

MFC after: 2 weeks

Modify the experimental NFSv4 server so that it handles
crossing of server mount points properly. The functions
nfsvno_fillattr() and nfsv4_fillattr() were modified to
take the extra arguments that are the mount point, a flag
to indicate that it is a file system root and the mounted
on fileno. The mount point argument needs to be busy when
nfsvno_fillattr() is called, since the vp argument is not
locked.

Reviewed by: kib
MFC after: 2 weeks

Vrele ni_startdir in the experimental NFS server for the case
of NFSv2 getting an error return from VOP_MKNOD(). Without this
patch, the server file system remains busy after an NFSv2
VOP_MKNOD() fails.

MFC after: 2 weeks

Add some cleanup code to the module unload operation for
the experimental NFS server, so that it doesn't leak memory
when unloaded. However, unloading the NFSv4 server is not
recommended, since all NFSv4 state will be lost by the unload
and clients will have to recover the state after a server
reload/restart as if the server crashed/rebooted.

MFC after: 2 weeks

Add a VOP_UNLOCK() for the directory, when that is not what
VOP_LOOKUP() returned. This fixes a bug in the experimental
NFS server for the case where VFS_VGET() fails returning EOPNOTSUPP
in the ReaddirPlus RPC, forcing the use of VOP_LOOKUP() instead.

MFC after: 2 weeks

Add some FEATURE macros for various features (AUDIT/CAM/IPC/KTR/MAC/NFS/NTP/
PMC/SYSV/...).

No FreeBSD version bump, the userland application to query the features will
be committed last and can serve as an indication of the availablility if
needed.

Sponsored by: Google Summer of Code 2010
Submitted by: kibab
Reviewed by: arch@ (parts by rwatson, trasz, jhb)
X-MFC after: to be determined in last commit with code from this project

Unless "cnt" exceeds MAX_COMMIT_COUNT, nfsrv_commit() and nfsvno_fsync() are
incorrectly calling vm_object_page_clean(). They are passing the length of
the range rather than the ending offset of the range.

Perform the OFF_TO_IDX() conversion in vm_object_page_clean() rather than the
callers.

Reviewed by: kib
MFC after: 3 weeks

Modify the experimental NFSv4 server so that it posts a SIGUSR2
signal to the master nfsd daemon whenever the stable restart
file has been modified. This will allow the master nfsd daemon
to maintain an up to date backup copy of the file. This is
enabled via the nfssvc() syscall, so that older nfsd daemons
will not be signaled.

Reviewed by: jhb
MFC after: 1 week

Clean up the experimental NFS server replay cache when the module is unloaded.

Reviewed by: rmacklem
Approved by: zml (mentor)

Modify readdirplus in the experimental NFS server in a
manner analogous to r216633 for the regular server. This
change busies the file system so that VFS_VGET() is
guaranteed to be using the correct mount point even
during a forced dismount attempt. Since nfsd_fhtovp() is
not called immediately before readdirplus, the patch is
actually a clone of pjd@'s nfs_serv.c.4.patch instead of
the one committed in r216633.

Reviewed by: kib
MFC after: 10 days

Since the VFS_LOCK_GIANT() code in the experimental NFS
server is broken and the major file systems are now all
mpsafe, modify the server so that it will only export
mpsafe file systems. This was discussed on freebsd-fs@
and removes a fair bit of crufty code.

MFC after: 12 days

Fix the experimental NFS server to use vfs_busyfs() instead
of vfs_getvfs() so that the mount point is busied for the
VFS_FHTOVP() call. This is analagous to r185432 for the
regular NFS server.

Reviewed by: kib
MFC after: 12 days

Fix the nlm so that it no longer depends on the regular
nfs client and, as such, can be loaded for the experimental
nfs client without the regular client.

Reviewed by: jhb
MFC after: 2 weeks

Fix the experimental NFS server so that it doesn't leak
a reference count on the directory when creating device
special files.

MFC after: 2 weeks

Delete some cruft from the experimental NFS server that was
only used by the OpenBSD port for its pseudo-fs.

MFC after: 2 weeks

Add checks for VI_DOOMED and vn_lock() failures to the
experimental NFS server, to handle the case where an
exported file system is forced dismounted while an RPC
is in progress. Further commits will fix the cases where
a mount point is used when the associated vnode isn't locked.

Reviewed by: kib
MFC after: 2 weeks

Delete the nfsvno_localconflict() function in the experimental
NFS server since it is no longer used and is broken.

MFC after: 2 weeks

Modify the experimental NFS server so that it uses LK_SHARED
for RPC operations when it can. Since VFS_FHTOVP() currently
always gets an exclusively locked vnode and is usually called
at the beginning of each RPC, the RPCs for a given vnode will
still be serialized. As such, passing a lock type argument to
VFS_FHTOVP() would be preferable to doing the vn_lock() with
LK_DOWNGRADE after the VFS_FHTOVP() call.

Reviewed by: kib
MFC after: 2 weeks

Add an argument to nfsvno_getattr() in the experimental
NFS server, so that it can avoid calling VOP_ISLOCKED()
when the vnode is known to be locked. This will allow
LK_SHARED to be used for these cases, which happen to
be all the cases that can use LK_SHARED. This does not
fix any bug, but it reduces the number of calls to
VOP_ISLOCKED() and prepares the code so that it can be
switched to using LK_SHARED in a future patch.

Reviewed by: kib
MFC after: 2 weeks

Simplify vnode locking in the expeimental NFS server's
readdir functions. In particular, get rid of two bogus
VOP_ISLOCKED() calls. Removing the VOP_ISLOCKED() calls
is the only actual bug fixed by this patch.

Reviewed by: kib
MFC after: 2 weeks

Since VOP_READDIR() for ZFS does not return monotonically
increasing directory offset cookies, disable the UFS related
loop that skips over directory entries at the beginning of
the block for the experimental NFS server. This loop is
required for UFS since it always returns directory entries
starting at the beginning of the block that
the requested directory offset is in. In discussion with pjd@
and mckusick@ it seems that this behaviour of UFS should maybe
change, with this fix being an interim patch until then.
This patch only fixes the experimental server, since pjd@ is
working on a patch for the regular server.

Discussed with: pjd, mckusick
MFC after: 5 days

Modify the experimental NFSv4 server's file handle hash function
to use the generic hash32_buf() function. Although adding the
bytes seemed sufficient for UFS and ZFS, since most of the bytes
are the same for file handles on the same volume, this might not
be sufficient for other file systems. Use of a generic function
also seems preferable to one specific to NFSv4.

Suggested by: gleb.kurtsou at gmail.com
MFC after: 10 days

Modify the file handle hash function in the experimental NFS
server so that it will work better for non-UFS file systems.
The new function simply sums the bytes of the fh_fid field
of fhandle_t.

MFC after: 10 days

Modify the experimental NFS server in a manner analagous to
r214049 for the regular NFS server, so that it will not do
a VOP_LOOKUP() of ".." when at the root of a file system
when performing a ReaddirPlus RPC.

MFC after: 10 days

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Fix the experimental NFSv4 server so that it performs local VOP_ADVLOCK()
unlock operations correctly. It was passing in F_SETLK instead of
F_UNLCK as the operation for the unlock case. This only affected
operation when local locking (vfs.newnfs.enable_locallocks=1) was enabled.

MFC after: 1 week

Add MODULE_DEPEND() macros to the experimental NFS client and
server so that the modules will load when kernels are built with
none of the NFS* configuration options specified. I believe this
resolves the problems reported by PR kern/144458 and the email on
freebsd-stable@ posted by Dmitry Pryanishnikov on June 13.

Tested by: kib
PR: kern/144458
Reviewed by: kib
MFC after: 1 week

Merge r205010 from head to stable/8:

Update nfsrv_getsocksndseq() for changes in TCP internals since FreeBSD 6.x:

- so_pcb is now guaranteed to be non-NULL and valid if a valid socket
reference is held.

- Need to check INP_TIMEWAIT and INP_DROPPED before assuming inp_ppcb is a
tcpcb, as it might be a tcptw or NULL otherwise.

- tp can never be NULL by the end of the function, so only check
TCPS_ESTABLISHED before extracting tcpcb fields.

The NFS server arguably incorporates too many assumptions about TCP
internals, but fixing that is left for another day.

Reviewed by: bz
Reviewed and tested by: rmacklem
Sponsored by: Juniper Networks

Approved by: re (kib)

MFC: r206170
Harden the experimental NFS server a little, by adding extra checks
in the readdir functions for non-positive byte count arguments.
For the negative case, set it to the maximum allowable, since it
was actually a large positive value (unsigned) on the wire.
Also, fix up the readdir function comment a bit.

MFC: r206063
For the experimental NFS server, add a call to free the lookup
path buffer for one case where it was missing when doing mkdir.
This could have conceivably resulted in a leak of a buffer, but
a leak was never observed during testing, so I suspect it would
have occurred rarely, if ever, in practice.

MFC: r205663
Patch the experimental NFS server in a manner analagous to r205661
for the regular NFS server, to ensure that ESTALE is
returned to the client for all errors returned by VFS_FHTOVP().

Harden the experimental NFS server a little, by adding extra checks
in the readdir functions for non-positive byte count arguments.
For the negative case, set it to the maximum allowable, since it
was actually a large positive value (unsigned) on the wire.
Also, fix up the readdir function comment a bit.

Suggested by: dillon AT apollo.backplane.com
MFC after: 2 weeks

For the experimental NFS server, add a call to free the lookup
path buffer for one case where it was missing when doing mkdir.
This could have conceivably resulted in a leak of a buffer, but
a leak was never observed during testing, so I suspect it would
have occurred rarely, if ever, in practice.

MFC after: 2 weeks

Patch the experimental NFS server in a manner analagous to r205661
for the regular NFS server, to ensure that ESTALE is
returned to the client for all errors returned by VFS_FHTOVP().

MFC after: 2 weeks

Update nfsrv_getsocksndseq() for changes in TCP internals since FreeBSD 6.x:

- so_pcb is now guaranteed to be non-NULL and valid if a valid socket
reference is held.

- Need to check INP_TIMEWAIT and INP_DROPPED before assuming inp_ppcb is a
tcpcb, as it might be a tcptw or NULL otherwise.

- tp can never be NULL by the end of the function, so only check
TCPS_ESTABLISHED before extracting tcpcb fields.

The NFS server arguably incorporates too many assumptions about TCP
internals, but fixing that is left for nother day.

MFC after: 1 week
Reviewed by: bz
Reviewed and tested by: rmacklem
Sponsored by: Juniper Networks

MFC: r200999
Modify the experimental server so that it uses VOP_ACCESSX().
This is necessary in order to enable NFSv4 ACL support. The
argument to nfsvno_accchk() was changed to an accmode_t and
the function nfsrv_aclaccess() was no longer needed and,
therefore, deleted.

Reviewed by: trasz

Modify the experimental server so that it uses VOP_ACCESSX().
This is necessary in order to enable NFSv4 ACL support. The
argument to nfsvno_accchk() was changed to an accmode_t and
the function nfsrv_aclaccess() was no longer needed and,
therefore, deleted.

Reviewed by: trasz
MFC after: 2 weeks

MFC: r199715
Modify the experimental nfs server so that it falls back to
using VOP_LOOKUP() when VFS_VGET() returns EOPNOTSUPP in the
ReaddirPlus RPC. This patch is based upon one by pjd@ for the
regular nfs server which has not yet been committed. It is needed
when a ZFS volume is exported and ReaddirPlus (which almost
always happens for NFSv4) is performed by a client. The patch
also simplifies vnode lock handling somewhat.

Tested by: gerrit at pmp.uni-hannover.de

MFC: r199616
Patch the experimental NFS server is a manner analagous to
r197525, so that the creation verifier is handled correctly
in va_atime for 64bit architectures. There were two problems.
One was that the code incorrectly assumed that
sizeof (struct timespec) == 8 and the other was that the tv_sec
field needs to be assigned from a signed 32bit integer, so that
sign extension occurs on 64bit architectures. This is required
for correct operation when exporting ZFS volumes.

Tested by: gerrit at pmp.uni-hannover.de
Reviewed by: pjd

Modify the experimental nfs server so that it falls back to
using VOP_LOOKUP() when VFS_VGET() returns EOPNOTSUPP in the
ReaddirPlus RPC. This patch is based upon one by pjd@ for the
regular nfs server which has not yet been committed. It is needed
when a ZFS volume is exported and ReaddirPlus (which almost
always happens for NFSv4) is performed by a client. The patch
also simplifies vnode lock handling somewhat.

MFC after: 2 weeks

Patch the experimental NFS server is a manner analagous to
r197525, so that the creation verifier is handled correctly
in va_atime for 64bit architectures. There were two problems.
One was that the code incorrectly assumed that
sizeof (struct timespec) == 8 and the other was that the tv_sec
field needs to be assigned from a signed 32bit integer, so that
sign extension occurs on 64bit architectures. This is required
for correct operation when exporting ZFS volumes.

Reviewed by: pjd
MFC after: 2 weeks

Build on Jeff Roberson's linker-set based dynamic per-CPU allocator
(DPCPU), as suggested by Peter Wemm, and implement a new per-virtual
network stack memory allocator. Modify vnet to use the allocator
instead of monolithic global container structures (vinet, ...). This
change solves many binary compatibility problems associated with
VIMAGE, and restores ELF symbols for virtualized global variables.

Each virtualized global variable exists as a "reference copy", and also
once per virtual network stack. Virtualized global variables are
tagged at compile-time, placing the in a special linker set, which is
loaded into a contiguous region of kernel memory. Virtualized global
variables in the base kernel are linked as normal, but those in modules
are copied and relocated to a reserved portion of the kernel's vnet
region with the help of a the kernel linker.

Virtualized global variables exist in per-vnet memory set up when the
network stack instance is created, and are initialized statically from
the reference copy. Run-time access occurs via an accessor macro, which
converts from the current vnet and requested symbol to a per-vnet
address. When "options VIMAGE" is not compiled into the kernel, normal
global ELF symbols will be used instead and indirection is avoided.

This change restores static initialization for network stack global
variables, restores support for non-global symbols and types, eliminates
the need for many subsystem constructors, eliminates large per-subsystem
structures that caused many binary compatibility issues both for
monitoring applications (netstat) and kernel modules, removes the
per-function INIT_VNET_*() macros throughout the stack, eliminates the
need for vnet_symmap ksym(2) munging, and eliminates duplicate
definitions of virtualized globals under VIMAGE_GLOBALS.

Bump __FreeBSD_version and update UPDATING.

Portions submitted by: bz
Reviewed by: bz, zec
Discussed with: gnn, jamie, jeff, jhb, julian, sam
Suggested by: peter
Approved by: re (kensmith)

Rework the credential code to support larger values of NGROUPS and
NGROUPS_MAX, eliminate ABI dependencies on them, and raise the to 1024
and 1023 respectively. (Previously they were equal, but under a close
reading of POSIX, NGROUPS_MAX was defined to be too large by 1 since it
is the number of supplemental groups, not total number of groups.)

The bulk of the change consists of converting the struct ucred member
cr_groups from a static array to a pointer. Do the equivalent in
kinfo_proc.

Introduce new interfaces crcopysafe() and crsetgroups() for duplicating
a process credential before modifying it and for setting group lists
respectively. Both interfaces take care for the details of allocating
groups array. crsetgroups() takes care of truncating the group list
to the current maximum (NGROUPS) if necessary. In the future,
crsetgroups() may be responsible for insuring invariants such as sorting
the supplemental groups to allow groupmember() to be implemented as a
binary search.

Because we can not change struct xucred without breaking application
ABIs, we leave it alone and introduce a new XU_NGROUPS value which is
always 16 and is to be used or NGRPS as appropriate for things such as
NFS which need to use no more than 16 groups. When feasible, truncate
the group list rather than generating an error.

Minor changes:
- Reduce the number of hand rolled versions of groupmember().
- Do not assign to both cr_gid and cr_groups[0].
- Modify ipfw to cache ucreds instead of part of their contents since
they are immutable once referenced by more than one entity.

Submitted by: Isilon Systems (initial implementation)
X-MFC after: never
PR: bin/113398 kern/133867

Unbreak options VIMAGE kernel builds.

Approved by: julian (mentor)

Fix the experimental nfs subsystem so that it builds with the
current NFSv4 ACLs, as defined in sys/acl.h. It still needs a
way to test a mount point for NFSv4 ACL support before it will
work. Until then, the NFSHASNFS4ACL() macro just always returns 0.

Approved by: kib (mentor)

Fix the experimental nfs server so that it depends on the nlm,
since it now calls nlm_acquire_next_sysid().

Approved by: kib (mentor)

Modify sys/fs/nfsserver/nfs_nfsdport.c to use nlm_acquire_next_sysid()
to set the l_sysid for locks correctly.

Approved by: kib (mentor)

Fix the acquisition of local locks via VOP_ADVLOCK() by the
experimental nfsv4 server. It was setting the a_id argument
to a fixed value, but that wasn't sufficient for FreeBSD8.
Instead, set l_pid and l_sysid to 0 plus set the F_REMOTE
flag to indicate that these fields are used to check for
same lock owner. Since, for NFSv4, a lockowner is a ClientID plus
an up to 1024byte name, it can't be put in l_sysid easily.
I also renamed the p variable to td, since it's a thread ptr.

Approved by: kib (mentor)

Added a SYSCTL to sys/fs/nfsserver/nfs_nfsdport.c so that the value of
nfsrv_dolocallocks can be changed via sysctl. I also added some non-empty
descriptor strings and reformatted some overly long lines.

Approved by: kib (mentor)

Apply changes to the experimental nfs server so that it uses the security
flavors as exported in FreeBSD-CURRENT. This allows it to use a
slightly modified mountd.c instead of a different utility.

Approved by: kib (mentor)

Modify the experimental nfs server to use the new nfsd_nfsd_args
structure for nfsd. Includes a change that clarifies the use of
an empty principal name string to indicate AUTH_SYS only.

Approved by: kib (mentor)

Change the name of the nfs server addsock structure from nfsd_args
to nfsd_addsock_args, so that it is consistent with the one in
sys/nfsserver/nfs.h.

Approved by: kib (mentor)

Modify nfsvno_fhtovp() to ensure that it always sets the credp
argument. Returning without credp set could result in a caller
doing crfree() on garbage.

Reviewed by: kan
Approved by: kib (mentor)

Remove the thread argument from the FSD (File-System Dependent) parts of
the VFS. Now all the VFS_* functions and relating parts don't want the
context as long as it always refers to curthread.

In some points, in particular when dealing with VOPs and functions living
in the same namespace (eg. vflush) which still need to be converted,
pass curthread explicitly in order to retain the old behaviour.
Such loose ends will be fixed ASAP.

While here fix a bug: now, UFS_EXTATTR can be compiled alone without the
UFS_EXTATTR_AUTOSTART option.

VFS KPI is heavilly changed by this commit so thirdy parts modules needs
to be recompiled. Bump __FreeBSD_version in order to signal such
situation.

Do not embed struct ucred into larger netcred parent structures.

Credential might need to hang around longer than its parent and be used
outside of mnt_explock scope controlling netcred lifetime. Use separate
reference-counted ucred allocated separately instead.

While there, extend mnt_explock coverage in vfs_stdexpcheck and clean-up
some unused declarations in new NFS code.

Reported by: John Hickey
PR: kern/133439
Reviewed by: dfr, kib

Add the experimental nfs subtree to the kernel, that includes
support for NFSv4 as well as NFSv2 and 3.
It lives in 3 subdirs under sys/fs:
nfs - functions that are common to the client and server
nfsclient - a mutation of sys/nfsclient that call generic functions
to do RPCs and handle state. As such, it retains the
buffer cache handling characteristics and vnode semantics that
are found in sys/nfsclient, for the most part.
nfsserver - the server. It includes a DRC designed specifically for
NFSv4, that is used instead of the generic DRC in sys/rpc.
The build glue will be checked in later, so at this point, it
consists of 3 new subdirs that should not affect kernel building.

Approved by: kib (mentor)