History log of /freebsd-current/sys/fs/nfsclient/nfs_clcomsubs.c
Revision Date Author Comments
# 6fa843f6 11-Dec-2023 Mark Johnston <markj@FreeBSD.org>

nfsclient: Propagate copyin() errors from nfsm_uiombuf()

Approved by: so
Security: SA-23:18.nfsclient
Reviewed by: rmacklem
Sponsored by: The FreeBSD Foundation


# 685dc743 16-Aug-2023 Warner Losh <imp@FreeBSD.org>

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

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


# ba8cc6d7 12-Mar-2023 Mateusz Guzik <mjg@FreeBSD.org>

vfs: use __enum_uint8 for vtype and vstate

This whacks hackery around only reading v_type once.

Bump __FreeBSD_version to 1400093


# c1ad8a39 27-Mar-2022 Gordon Bergling <gbe@FreeBSD.org>

nfsclient: Fix a typos in source code comments

- s/ony/only/

Obtained from: NetBSD
MFC after: 3 days


# 98c78873 27-Jan-2022 Rick Macklem <rmacklem@FreeBSD.org>

nfsclient: Delete unused function nfscl_getcookie()

The function nfscl_getcookie(), which is essentially the
same as ncl_getcookie(), is never called, so delete it.
This is probably cruft left over from the port of the
NFSv4 code to FreeBSD several years ago.

Found while modifying the code to better use the
directory offset cookies.

MFC after: 2 weeks


# 90d60ca8 26-Sep-2021 Gordon Bergling <gbe@FreeBSD.org>

nfsclient: Fix a typo in a comment

- s/derefernce/dereference/

MFC after: 3 days


# dd02d9d6 07-May-2021 Rick Macklem <rmacklem@FreeBSD.org>

nfscl: Add support for va_birthtime to NFSv4

There is a NFSv4 file attribute called TimeCreate
that can be used for va_birthtime.
r362175 added some support for use of TimeCreate.
This patch completes support of va_birthtime by adding
support for setting this attribute to the server.
It also eanbles the client to
acquire and set the attribute for a NFSv4
server that supports the attribute.

Reviewed by: markj
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D30156


# 8bde6d15 04-May-2021 Mark Johnston <markj@FreeBSD.org>

nfsclient: Copy only initialized fields in nfs_getattr()

When loading attributes from the cache, the NFS client is careful to
copy only the fields that it initialized. After fetching attributes
from the server, however, it would copy the entire vattr structure
initialized from the RPC response, so uninitialized stack bytes would
end up being copied to userspace. In particular, va_birthtime (v2 and
v3) and va_gen (v3) had this problem.

Use a common subroutine to copy fields provided by the NFS client, and
ensure that we provide a dummy va_gen for the v3 case.

Reviewed by: rmacklem
Reported by: KMSAN
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D30090


# 586ee69f 01-Sep-2020 Mateusz Guzik <mjg@FreeBSD.org>

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


# 90cf38f2 11-Aug-2020 Rick Macklem <rmacklem@FreeBSD.org>

Fix a bug introduced by r363001 for the ext_pgs case.

r363001 added support for ext_pgs mbufs to nfsm_uiombuf().
By inspection, I noticed that "mlen" was not set non-zero and, as such, there
would be an iteration of the loop that did nothing.
This patch sets it.
This bug would have no effect on the system, since the ext_pgs mbuf code
is not yet enabled.


# cfaafa79 24-Jul-2020 Rick Macklem <rmacklem@FreeBSD.org>

Add support for ext_pgs mbufs to nfsm_uiombuflist() and nfsm_split().

This patch uses a slightly different algorithm for nfsm_uiombuflist() for
the non-ext_pgs case, where a variable called "mcp" is maintained, pointing to
the current location that mbuf data can be filled into. This avoids use of
mtod(mp, char *) + mp->m_len to calculate the location, since this does
not work for ext_pgs mbufs and I think it makes the algorithm more readable.
This change should not result in semantic changes for the non-ext_pgs case.
The patch also deletes come unneeded code.

It also adds support for anonymous page ext_pgs mbufs to nfsm_split().

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.
At this time for this case, use of ext_pgs mbufs cannot be enabled, since
ktls_encrypt() replaces the unencrypted data with encrypted data in place.

Until such time as this can be enabled, there should be no semantic change.
Also, note that this code is only used by the NFS client for a mirrored pNFS
server.


# 9516bcdf 22-Jul-2020 Rick Macklem <rmacklem@FreeBSD.org>

Modify writing to mirrored pNFS DSs to prepare for use of ext_pgs mbufs.

This patch modifies writing to mirrored pNFS DSs slightly so that there is
only one m_copym() call for a mirrored pair instead of two of them.
This call replaces the custom nfsm_copym() call, which is no longer needed
and deleted by this patch. The patch does introduce a new nfsm_split()
function that only calls m_split() for the non-ext_pgs case.
The semantics of nfsm_uiombuflist() is changed to include code that nul
pads the generated mbuf list. This was done by nfsm_copym() prior to this patch.

The main reason for this change is that it allows the data to be a list
of ext_pgs mbufs, since the m_copym() is for the entire mbuf list.
This support will be added in a future commit.

This patch only affects writing to mirrored flexible file layout pNFS servers.


# 6722f6e5 12-Jul-2020 Rick Macklem <rmacklem@FreeBSD.org>

Minor code cleanup that removes "nd->nd_bpos = mcp;" in both if and else.

The statement "nd->nd_bpos = mcp;" was in both the if and else. Correct,
but potentially confusing. This patch fixes this.

There should be no semantics change caused by this commit.


# 3eaf0376 07-Jul-2020 Rick Macklem <rmacklem@FreeBSD.org>

Add support for ext_pgs mbufs to nfsm_uiombuf().

This patch uses a slightly different algorithm for the non-ext_pgs case,
where a variable called "mcp" is maintained, pointing to the current
location that mbuf data can be filled into. This avoids use of
mtod(mp, char *) + mp->m_len to calculate the location, since this does
not work for ext_pgs mbufs and I think it makes the algorithm more readable.
This change should not result in semantic changes for the non-ext_pgs case.

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.

Since ND_EXTPG is never set yet, there is no semantic change at this time.


# b9cc3262 12-May-2020 Ryan Moeller <freqlabs@FreeBSD.org>

nfs: Remove APPLESTATIC macro

It is no longer useful.

Reviewed by: rmacklem
Approved by: mav (mentor)
MFC after: 1 week
Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D24811


# 32033b3d 08-May-2020 Ryan Moeller <freqlabs@FreeBSD.org>

Remove APPLEKEXT ifndefs

They are no longer useful.

Reviewed by: rmacklem
Approved by: mav (mentor)
MFC after: 1 week
Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D24752


# e4a458bb 24-Apr-2020 Rick Macklem <rmacklem@FreeBSD.org>

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.


# 3133bbf7 10-Apr-2020 Rick Macklem <rmacklem@FreeBSD.org>

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.
This conversion will be committed one file at a time.


# a95cd06e 08-Dec-2019 Rick Macklem <rmacklem@FreeBSD.org>

Delete an unused external declaration.

Since nfsv4_opflag is no longer used in nfs_clcomsubs.c, delete the
external declaration of it. Found during NFSv4.2 code merge.

MFC after: 2 weeks


# c338c94d 14-Jun-2018 Rick Macklem <rmacklem@FreeBSD.org>

Move four functions in nfscl.ko to nfscommon.ko.

Four functions nfscl_reqstart(), nfscl_fillsattr(), nfsm_stateidtom()
and nfsmnt_mdssession() are now called from within the nfsd.
As such, they needed to be moved from nfscl.ko to nfscommon.ko so that
nfsd.ko would load when nfscl.ko wasn't loaded.

Reported by: herbert@gojira.at


# ab35e1c7 12-Jun-2018 Bruce Evans <bde@FreeBSD.org>

Fix the encoding of major and minor numbers in 64-bit dev_t by restoring
the old encodings for the lower 16 and 32 bits and only using the
higher 32 bits for unusually large major and minor numbers. This
change breaks compatibility with the previous encoding (which was only
used in -current).

Fix truncation to (essentially) 16-bit dev_t in newnfs v3.

Any encoding of device numbers gives an ABI, so it can't be changed
without translations for compatibility. Extra bits give the much
larger complication that the translations need to compress into fewer
bits. Fortunately, more than 32 bits are rarely needed, so
compression is rarely needed except for 16-bit linux dev_t where it
was always needed but never done.

The previous encoding moved the major number into the top 32 bits.
Almost no translation code handled this, so the major number was blindly
truncated away in most 32-bit encodings. E.g., for ffs, mknod(8) with
major = 1 and minor = 2 gave dev_t = 0x10000002; ffs cannot represent
this and blindly truncated it to 2. But if this mknod was run on any
released version of FreeBSD, it gives dev_t = 0x102. ffs can represent
this, but in the previous encoding it was not decoded, giving major = 0,
minor = 0x102.

The presence of bugs was most obvious for exporting dev_t's from an
old system to -current, since bugs in newnfs augment them. I fixed
oldnfs to support 32-bit dev_t in 1996 (r16634), but this regressed
to 16-bit dev_t in newnfs, first to the old 16-bit encoding and then
further in -current. E.g., old ad0 with major = 234, minor = 0x10002
had the correct (major, minor) number on the wire, but newnfs truncated
this to (234, 2) and then the previous encoding shifted the major
number into oblivion as seen by ffs or old applications.

I first tried to fix this by translating on every ABI/API boundary, but
there are too many boundaries and too many sloppy translations by blind
truncation. So use the old encoding for the low 32 bits so that sloppy
translations work no worse than before provided the high 32 bits are
not set. Add some error checking for when bits are lost. Keep not
doing any error checking for translations for almost everything in
compat/linux.

compat/freebsd32/freebsd32_misc.c:
Optionally check for losing bits after possibly-truncating assignments as
before.

compat/linux/linux_stats.c:
Depend on the representation being compatible with Linux's (or just with
itself for local use) and spell some of the translations as assignments in
a macro that hides the details.

fs/nfsclient/nfs_clcomsubs.c:
Essentially the same fix as in 1996, except there is now no possible
truncation in makedev() itself. Also fix nearby style bugs.

kern/vfs_syscalls.c:
As for freebsd32. Also update the sysctl description to include file
numbers, and change it to describe device ids as device numbers.

sys/types.h:
Use inline functions (wrapped by macros) since the expressions are now
a bit too complicated for plain macros. Describe the encoding and
some of the reasons for it. 16-bit compatibility didn't leave many
reasonable choices for the 32-bit encoding, and 32-bit compatibility
doesn't leave many reasonable choices for the 64-bit encoding. My
choice is to put the 8 new minor bits in the low 8 bits of the top 32
bits. This minimizes discontiguities.

Reviewed by: kib (except for rewrite of the comment in linux_stats.c)


# b7faa59d 20-May-2018 Matt Macy <mmacy@FreeBSD.org>

nfsclient: warnings cleanups


# 222daa42 25-Jan-2018 Conrad Meyer <cem@FreeBSD.org>

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


# a0a073b1 19-Dec-2017 John Baldwin <jhb@FreeBSD.org>

Update NFS to handle larger link counts post ino64.

- Define a NFS_LINK_MAX as UINT32_MAX to match the wire protocol.
- Use NFS_LINK_MAX instead of LINK_MAX as the fallback value reported
for a PATHCONF RPC by the NFS server.
- Use NFS_LINK_MAX instead of LINK_MAX as the default value reported
by the NFS client pathconf() if not overridden by the NFS server.
- When reading the link count out of an RPC reply, read the full 32
bits instead of the lower 16 bits.

Reviewed by: rmacklem (earlier version)
Sponsored by: Chelsio Communications


# 51369649 20-Nov-2017 Pedro F. Giffuni <pfg@FreeBSD.org>

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.


# a8462c58 26-Sep-2017 Rick Macklem <rmacklem@FreeBSD.org>

Add major and minor version arguments to nfscl_reqstart().

This patch adds "vers" and "minorvers" arguments to nfscl_reqstart().
The patch always passes them in as "0" and that implies no change
in semantics. These arguments will be used by a future commit that
adds support for the Flexible File Layout.


# c36e0870 24-Sep-2017 Rick Macklem <rmacklem@FreeBSD.org>

Remove 0 filling from nfsm_uiombuflist().

nfsm_uiombuflist() zero filled the mbuf list to a multiple of 4bytes
as required for XDR. Unfortunately that modified an mbuf list after
it was m_copym()'d and was broken. This patch removes the zero filling code.
Since nfsm_uiombuflist() is not yet used in head/current, this has no
effect on users.
The function will be used by a future commit of code that adds Flex
File Layout support.


# 2742a210 19-Sep-2017 Rick Macklem <rmacklem@FreeBSD.org>

Add a new function called nfsm_uiombuflist(), similar to nfsm_uiombuf().

This patch adds a new function called nfsm_uiombuflist(), which is
similar to nfsm_uiombuf(), but doesn't not use the fields in
struct nfsrv_descript. This new function will be used by the pNFS client
for writing to mirrors using Flex Files layout.
The function is not yet called anywhere.
Also, get rid of #ifndef APPLE, which is ancient cruft left over from
the Mac OSX port of the NFSv4 client.


# a351e99c 24-Jun-2017 Rick Macklem <rmacklem@FreeBSD.org>

Add two new compound RPCs to the NFSv4.1/pNFS client.

When the NFSv4.1 client is doing pNFS, it needs to get an Open and
a Layout for every file it will be doing I/O on. The current code
does two separate RPCs to get these. This patch adds two new compounds
that do the both the Open and LayoutGet in the same RPC, reducing the
RPC count.
It also factors out the code that sets up and parses the LayoutGet operation
into separate functions, so that the code doesn't get duplicated for
these new RPCs.
This patch is fairly large, but should only affect the NFSv4.1 client
when the "pnfs" option is specified.

PR: 219550
MFC after: 2 weeks


# 46adb5dc 15-May-2017 Rick Macklem <rmacklem@FreeBSD.org>

Make nfscl_mtofh() return ENXIO when *nfhpp == NULL.

r317272 introduced a case where nfscl_mtofh() could return 0 when
*nfhpp is NULL. This patch makes it return ENXIO for this case.

MFC after: 1 week


# e96af294 21-Apr-2017 Rick Macklem <rmacklem@FreeBSD.org>

Add checks for failed operations to the NFSv4 client function nfscl_mtofh().

The nfscl_mtofh() function didn't check for failed operations and, as such,
would have returned EBADRPC for these cases, due to parsing failure.
This patch adds checks, so that it returns with ND_NOMOREDATA set.
This is needed for future use in the pNFS server and acts as a safety
belt in the meantime.

MFC after: 2 weeks


# fbbd9655 28-Feb-2017 Warner Losh <imp@FreeBSD.org>

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


# b2fc0141 23-Dec-2016 Rick Macklem <rmacklem@FreeBSD.org>

Fix NFSv4.1 client recovery from NFS4ERR_BAD_SESSION errors.

For most NFSv4.1 servers, a NFS4ERR_BAD_SESSION error is a rare failure
that indicates that the server has lost session/open/lock state.
However, recent testing by cperciva@ against the AmazonEFS server found
several problems with client recovery from this due to it generating this
failure frequently.
Briefly, the problems fixed are:
- If all session slots were in use at the time of the failure, some processes
would continue to loop waiting for a slot on the old session forever.
- If an RPC that doesn't use open/lock state failed with NFS4ERR_BAD_SESSION,
it would fail the RPC/syscall instead of initiating recovery and then
looping to retry the RPC.
- If a successful reply to an RPC for an old session wasn't processed
until after a new session was created for a NFS4ERR_BAD_SESSION error,
it would erroneously update the new session and corrupt it.
- The use of the first element of the session list in the nfs mount
structure (which is always the current metadata session) was slightly
racey. With changes for the above problems it became more racey, so all
uses of this head pointer was wrapped with a NFSLOCKMNT()/NFSUNLOCKMNT().
- Although the kernel malloc() usually allocates more bytes than requested
and, as such, this wouldn't have caused problems, the allocation of a
session structure was 1 byte smaller than it should have been.
(Null termination byte for the string not included in byte count.)

There are probably still problems with a pNFS data server that fails
with NFS4ERR_BAD_SESSION, but I have no server that does this to test
against (the AmazonEFS server doesn't do pNFS), so I can't fix these yet.

Although this patch is fairly large, it should only affect the handling
of NFS4ERR_BAD_SESSION error replies from an NFSv4.1 server.
Thanks go to cperciva@ for the extension testing he did to help isolate/fix
these problems.

Reported by: cperciva
Tested by: cperciva
MFC after: 3 months
Differential Revision: https://reviews.freebsd.org/D8745


# 1b819cf2 12-Aug-2016 Rick Macklem <rmacklem@FreeBSD.org>

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


# c3e4a726 20-Apr-2014 Rick Macklem <rmacklem@FreeBSD.org>

Modify the NFSv4 client create/mkdir RPC so that it acquires
post-create/mkdir directory attributes. This allows the RPC to
name cache the newly created directory and reduces the lookup RPC
count for applications creating a lot of directories.

MFC after: 2 weeks


# de1a42bd 19-Apr-2014 Rick Macklem <rmacklem@FreeBSD.org>

Modify the NFSv4 client open/create RPC so that it acquires
post-open/create directory attributes. This allows the RPC to
name cache the newly created file and reduces the lookup RPC
count by about 10% for software builds.

MFC after: 2 weeks


# a6f8e64e 18-Apr-2014 Rick Macklem <rmacklem@FreeBSD.org>

Modify the Lookup RPC for NFSv4 so that it acquires directory
attributes. This allows the client to cache directory names
when they are looked up, reducing the Lookup RPC count by
about 40% for software builds.

MFC after: 2 weeks


# 42b6336a 09-Nov-2013 Rick Macklem <rmacklem@FreeBSD.org>

Fix an NFSv4.1 client specific case where a forced dismount would hang.
The hang occurred in nfsv4_setsequence() when it couldn't find an
available session slot and is fixed by checking for a forced dismount
in progress and just returning for this case.

MFC after: 1 month


# 1f60bfd8 08-Dec-2012 Rick Macklem <rmacklem@FreeBSD.org>

Move the NFSv4.1 client patches over from projects/nfsv4.1-client
to head. I don't think the NFS client behaviour will change unless
the new "minorversion=1" mount option is used. It includes basic
NFSv4.1 support plus support for pNFS using the Files Layout only.
All problems detecting during an NFSv4.1 Bakeathon testing event
in June 2012 have been resolved in this code and it has been tested
against the NFSv4.1 server available to me.
Although not reviewed, I believe that kib@ has looked at it.


# eb1b1807 05-Dec-2012 Gleb Smirnoff <glebius@FreeBSD.org>

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

Exceptions:

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


# c52005a3 19-Sep-2012 Rick Macklem <rmacklem@FreeBSD.org>

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


# ff29f3b2 27-May-2011 Rick Macklem <rmacklem@FreeBSD.org>

Fix the new NFS client so that it handles NFSv4 state
correctly during a forced dismount. This required that
the exclusive and shared (refcnt) sleep lock functions check
for MNTK_UMOUNTF before sleeping, so that they won't block
while nfscl_umount() is getting rid of the state. As
such, a "struct mount *" argument was added to the locking
functions. I believe the only remaining case where a forced
dismount can get hung in the kernel is when a thread is
already attempting to do a TCP connect to a dead server
when the krpc client structure called nr_client is NULL.
This will only happen just after a "mount -u" with options
that force a new TCP connection is done, so it shouldn't
be a problem in practice.

MFC after: 2 weeks


# 418802a9 29-Mar-2011 Zack Kirsch <zack@FreeBSD.org>

This patch fixes the Experimental NFS client to properly deal with 32 bit or 64
bit fileid's in NFSv2 and NFSv3. Without this fix, invalid casting (and sign
extension) was creating problems for any fileid greater than 2^31.

We discovered this because we have test clusters with more than 2 billion
allocated files and 64-bit ino_t's (and friend structures).

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


# a7d5f7eb 19-Oct-2010 Jamie Gritton <jamie@FreeBSD.org>

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


# b38f7723 12-Jun-2010 Konstantin Belousov <kib@FreeBSD.org>

In NFS clients, instead of inconsistently using #ifdef
DIAGNOSTIC and #ifndef DIAGNOSTIC for debug assertions, prefer
KASSERT(). Also change one #ifdef DIAGNOSTIC in the new nfs server.

Submitted by: Mikolaj Golub <to.my.trociny gmail com>
MFC after: 2 weeks


# 9ec7b004 04-May-2009 Rick Macklem <rmacklem@FreeBSD.org>

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)