- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Add support for host-based (Kerberos 5 service principal) initiator
credentials to the kernel rpc. Modify the NFSv4 client to add
support for the gssname and allgssname mount options to use this
capability. Requires the gssd daemon to be running with the "-h" option.

Reviewed by: jhb

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

Further refine the handling of stop signals in the NFS client. The
changes in r246417 were incomplete as they did not add explicit calls to
sigdeferstop() around all the places that previously passed SBDRY to
_sleep(). In addition, nfs_getcacheblk() could trigger a write RPC from
getblk() resulting in sigdeferstop() recursing. Rather than manually
deferring stop signals in specific places, change the VFS_*() and VOP_*()
methods to defer stop signals for filesystems which request this behavior
via a new VFCF_SBDRY flag. Note that this has to be a VFC flag rather than
a MNTK flag so that it works properly with VFS_MOUNT() when the mount is
not yet fully constructed. For now, only the NFS clients are set this new
flag in VFS_SET().

A few other related changes:
- Add an assertion to ensure that TDF_SBDRY doesn't leak to userland.
- When a lookup request uses VOP_READLINK() to follow a symlink, mark
the request as being on behalf of the thread performing the lookup
(cnp_thread) rather than using a NULL thread pointer. This causes
NFS to properly handle signals during this VOP on an interruptible
mount.

PR: kern/176179
Reported by: Russell Cattelan (sigdeferstop() recursion)
Reviewed by: kib
MFC after: 1 month

Rework the handling of stop signals in the NFS client. The changes in
195702, 195703, and 195821 prevented a thread from suspending while holding
locks inside of NFS by forcing the thread to fail sleeps with EINTR or
ERESTART but defer the thread suspension to the user boundary. However,
this had the effect that stopping a process during an NFS request could
abort the request and trigger EINTR errors that were visible to userland
processes (previously the thread would have suspended and completed the
request once it was resumed).

This change instead effectively masks stop signals while in the NFS client.
It uses the existing TDF_SBDRY flag to effect this since SIGSTOP cannot
be masked directly. Also, instead of setting PBDRY on individual sleeps,
the NFS client now sets the TDF_SBDRY flag around each NFS request and
stop signals are masked for all sleeps during that region (the previous
change missed sleeps in lockmgr locks). The end result is that stop
signals sent to threads performing an NFS request are completely
ignored until after the NFS request has finished processing and the
thread prepares to return to userland. This restores the behavior of
stop signals being transparent to userland processes while still
preventing threads from suspending while holding NFS locks.

Reviewed by: kib
MFC after: 1 month

Further cleanups to use of timestamps in NFS:
- Use NFSD_MONOSEC (which maps to time_uptime) instead of the seconds
portion of wall-time stamps to manage timeouts on events.
- Remove unused nd_starttime from the per-request structure in the new
NFS server.
- Use nanotime() for the modification time on a delegation to get as
precise a time as possible.
- Use time_second instead of extracting the second from a call to
getmicrotime().

Submitted by: bde (3)
Reviewed by: bde, rmacklem
MFC after: 2 weeks

- More properly handle interrupted NFS requests on an interruptible mount
by returning an error of EINTR rather than EACCES.
- While here, bring back some (but not all) of the NFS RPC statistics lost
when krpc was committed.

Reviewed by: rmacklem
MFC after: 1 week

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.

Martin Cracauer reported a problem to freebsd-current@ under the
subject "Data corruption over NFS in -current". During investigation
of this, I came across an ugly bogusity in the new NFS client where
it replaced the cr_uid with the one used for the mount. This was
done so that "system operations" like the NFSv4 Renew would be
performed as the user that did the mount. However, if any other
thread shares the credential with the one doing this operation,
it could do an RPC (or just about anything else) as the wrong cr_uid.
This patch fixes the above, by using the mount credentials instead of
the one provided as an argument for this case. It appears
to have fixed Martin's problem.
This patch is needed for NFSv4 mounts and NFSv3 mounts against
some non-FreeBSD servers that do not put post operation attributes
in the NFSv3 Statfs RPC reply.

Tested by: Martin Cracauer (cracauer at cons.org)
Reviewed by: jhb
MFC after: 2 weeks

opt_inet6.h was missing from some files in the new NFS subsystem.
The effect of this was, for clients mounted via inet6 addresses,
that the DRC cache would never have a hit in the server. It also
broke NFSv4 callbacks when an inet6 address was the only one available
in the client. This patch fixes the above, plus deletes opt_inet6.h
from a couple of files it is not needed for.

MFC after: 2 weeks

jwd@ reported a problem via email where the old NFS client would
get a reply of EEXIST from an NFS server when a Mkdir RPC was retried,
for an NFS over UDP mount.
Upon investigation, it was found that the client was retransmitting
the Mkdir RPC request over UDP, but with a different xid. As such,
the retransmitted message would miss the Duplicate Request Cache
in the server, causing it to reply EEXIST. The kernel client side
UDP rpc code has two timers. The first one causes a retransmit using
the same xid and socket and was set to a fixed value of 3seconds.
(The default can be overridden via CLSET_RETRY_TIMEOUT.)
The second one creates a new socket and xid and should be larger
than the first. However, both NFS clients were setting the second
timer to nm_timeo ("timeout=<value>" mount argument), which defaulted to
1second, so the first timer would never time out.
This patch fixes both NFS clients so that they set the first timer
using nm_timeo and makes the second timer larger than the first one.

Reported by: jwd
Tested by: jwd
Reviewed by: jhb
MFC after: 2 weeks

The new NFSv4 client handled NFSERR_GRACE as a fatal error
for the remove and rename operations. Some NFSv4 servers will
report NFSERR_GRACE for these operations. This patch changes
the behaviour of the client so that it handles NFSERR_GRACE
like NFSERR_DELAY for non-state related operations like
remove and rename. It also exempts the delegreturn operation
from handling within newnfs_request() for NFSERR_DELAY/NFSERR_GRACE
so that it can handle NFSERR_GRACE in the same manner as before.
This problem was resolved thanks to discussion with bfields at fieldses.org.
The problem was identified at the recent NFSv4 ineroperability
bakeathon.

MFC after: 2 weeks

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

Plug an mbuf leak in the new NFS client that occurred when a
server replied NFS3ERR_JUKEBOX/NFS4ERR_DELAY to an rpc.
This affected both NFSv3 and NFSv4. Found during testing
at the recent NFSv4 interoperability Bakeathon.

MFC after: 2 weeks

Fix the new NFSv4 client so that it uses the same uid as
was used for doing a mount when performing system operations
on AUTH_SYS mounts. This resolved an issue when mounting
a Linux server. Found during testing at the recent
NFSv4 interoperability Bakeathon.

MFC after: 2 weeks

Fix the kgssapi so that it can be loaded as a module. Currently
the NFS subsystems use five of the rpcsec_gss/kgssapi entry points,
but since it was not obvious which others might be useful, all
nineteen were included. Basically the nineteen entry points are
set in a structure called rpc_gss_entries and inline functions
defined in sys/rpc/rpcsec_gss.h check for the entry points being
non-NULL and then call them. A default value is returned otherwise.
Requested by rwatson.

Reviewed by: jhb
MFC after: 2 weeks

Add DTrace support to the new NFS client. This is essentially
cloned from the old NFS client, plus additions for NFSv4. A
review of this code is in progress, however it was felt by the
reviewer that it could go in now, before code slush. Any changes
required by the review can be committed as bug fixes later.

Change the sysctl naming for the old and new NFS clients
to vfs.oldnfs.xxx and vfs.nfs.xxx respectively. This makes
the default nfs client use vfs.nfs.xxx after r221124.

Get rid of the "nfscl: consider increasing kern.ipc.maxsockbuf"
message that was generated when doing experimental NFS client
mounts. I put that message in because the krpc would hang with
the default size for mounts that used large rsize/wsize values.
Since the bug that caused these hangs was fixed by r213756,
I think the message is no longer needed.

MFC after: 2 weeks

Patch the experimental NFS client so that it works for NFSv2
by adding the necessary mapping from NFSv3 procedure numbers
to NFSv2 procedure numbers when doing NFSv2 RPCs.

MFC after: 1 week

An NFSv4 server will reply NFSERR_GRACE for non-recovery RPCs
during the grace period after startup. This grace period must
be at least the lease duration, which is typically 1-2 minutes.
It seems prudent for the experimental NFS client to wait a few
seconds before retrying such an RPC, so that the server isn't
flooded with non-recovery RPCs during recovery. This patch adds
an argument to nfs_catnap() to implement a 5 second delay
for this case.

MFC after: 1 week

Add calls to the experimental nfs client for the case of an "intr" mount,
so that signals that aren't supposed to terminate RPCs in progress are
masked off during the RPC.

Approved by: re (kensmith), kib (mentor)

Crib the realign function out of nfs_krpc.c and add a call
to it for the client side reply. Hopefully this fixes the
problem with using the new krpc for arm for the experimental
nfs client.

Approved by: kib (mentor)

Fix the experimental nfsv4 client so that it works for the
case of a kerberized mount without a host based principal
name. This will only work for mounts being done by a user
other than root. Support for a host based principal name
will not work until proposed changes to the rpcsec_gss part
of the krpc are committed. It now builds for "options KGSSAPI".

Approved by: kib (mentor)

Fix the rpc_gss_secfind() call in nfs_commonkrpc.c so that
the code will build when "options KGSSAPI" is specified
without requiring the proposed changes that add host based
initiator principal support. It will not handle the case where
the client uses a host based initiator principal until those
changes are committed. The code that uses those changes is
#ifdef'd notyet until the krpc rpcsec_changes are committed.

Approved by: kib (mentor)

Remove the unmaintained University of Michigan NFSv4 client from 8.x
prior to 8.0-RELEASE. Rick Macklem's new and more feature-rich NFSv234
client and server are replacing it.

Discussed with: rmacklem

Fixed the Null callback RPCs so that they work with the new krpc. This
required two changes: setting the program and version numbers before
connect and fixing the handling of the Null Rpc case in newnfs_request().

Approved by: kib (mentor)

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)