- 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

When the NFSv4.1 client is writing to a pNFS Data Server (DS), the
file's size attribute does not get updated. As such, it is necessary
to invalidate the attribute cache before clearing NMODIFIED for pNFS.

MFC after: 2 weeks

- 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

Add support for the eofflag to nfs_readdir() in the new NFS
client so that it works under a unionfs mount.

Submitted by: Jared Yanovich (slovichon@gmail.com)
Reviewed by: kib
MFC after: 2 weeks

Revert 195703 and 195821 as this special stop handling in NFS is now
implemented via VFCF_SBDRY rather than passing PBDRY to individual
sleep calls.

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

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

Reviewed by: rmacklem, bde
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.

PR# 165923 reported intermittent write failures for dirty
memory mapped pages being written back on an NFS mount.
Since any thread can call VOP_PUTPAGES() to write back a
dirty page, the credentials of that thread may not have
write access to the file on an NFS server. (Often the uid
is 0, which may be mapped to "nobody" in the NFS server.)
Although there is no completely correct fix for this
(NFS servers check access on every write RPC instead of at
open/mmap time), this patch avoids the common cases by
holding onto a credential that recently opened the file
for writing and uses that credential for the write RPCs
being done by VOP_PUTPAGES() for both NFS clients.

Tested by: Joel Ray Holveck (joelh at juniper.net)
PR: kern/165923
Reviewed by: kib
MFC after: 2 weeks

It was reported via email that some non-FreeBSD NFS servers
do not include file attributes in the reply to an NFS create RPC
under certain circumstances.
This resulted in a vnode of type VNON that was not usable.
This patch adds an NFS getattr RPC to nfs_create() for this case,
to fix the problem. It was tested by the person that reported
the problem and confirmed to fix this case for their server.

Tested by: Steven Haber (steven.haber at isilon.com)
MFC after: 2 weeks

Add sysctl vfs.nfs.nfs_keep_dirty_on_error to switch the nfs client
behaviour on error from write RPC back to behaviour of old nfs client.
When set to not zero, the pages for which write failed are kept dirty.

PR: kern/165927
Reviewed by: alc
MFC after: 2 weeks

Post r230394, the Lookup RPC counts for both NFS clients increased
significantly. Upon investigation this was caused by name cache
misses for lookups of "..". For name cache entries for non-".."
directories, the cache entry serves double duty. It maps both the
named directory plus ".." for the parent of the directory. As such,
two ctime values (one for each of the directory and its parent) need
to be saved in the name cache entry.
This patch adds an entry for ctime of the parent directory to the
name cache. It also adds an additional uma zone for large entries
with this time value, in order to minimize memory wastage.
As well, it fixes a couple of cases where the mtime of the parent
directory was being saved instead of ctime for positive name cache
entries. With this patch, Lookup RPC counts return to values similar
to pre-r230394 kernels.

Reported by: bde
Discussed with: kib
Reviewed by: jhb
MFC after: 2 weeks

Fix found places where uio_resid is truncated to int.

Add the sysctl debug.iosize_max_clamp, enabled by default. Setting the
sysctl to zero allows to perform the SSIZE_MAX-sized i/o requests from
the usermode.

Discussed with: bde, das (previous versions)
MFC after: 1 month

Rename cache_lookup_times() to cache_lookup() and retire the old API and
ABI stub for cache_lookup().

Current implementations of sync(2) and syncer vnode fsync() VOP uses
mnt_noasync counter to temporary remove MNTK_ASYNC mount option, which
is needed to guarantee a synchronous completion of the initiated i/o
before syscall or VOP return. Global removal of MNTK_ASYNC option is
harmful because not only i/o started from corresponding thread becomes
synchronous, but all i/o is synchronous on the filesystem which is
initiated during sync(2) or syncer activity.

Instead of removing MNTK_ASYNC from mnt_kern_flag, provide a local
thread flag to disable async i/o for current thread only. Use the
opportunity to move DOINGASYNC() macro into sys/vnode.h and
consistently use it through places which tested for MNTK_ASYNC.

Some testing demonstrated 60-70% improvements in run time for the
metadata-intensive operations on async-mounted UFS volumes, but still
with great deviation due to other reasons.

Reviewed by: mckusick
Tested by: scottl
MFC after: 2 weeks

Fix remaining calls to cache_enter() in both NFS clients to provide
appropriate timestamps. Restore the assertions which verify that
NCF_TS is set when timestamp is asked for.

Reviewed by: jhb (previous version)
MFC after: 2 weeks

Add a timeout on positive name cache entries in the NFS client. That is,
we will only trust a positive name cache entry for a specified amount of
time before falling back to a LOOKUP RPC, even if the ctime for the file
handle matches the cached copy in the name cache entry. The timeout is
configured via a new 'nametimeo' mount option and defaults to 60 seconds.
It may be set to zero to disable positive name caching entirely.

Reviewed by: rmacklem
MFC after: 1 week

Close a race in NFS lookup processing that could result in stale name cache
entries on one client when a directory was renamed on another client. The
root cause for the stale entry being trusted is that each per-vnode nfsnode
structure has a single 'n_ctime' timestamp used to validate positive name
cache entries. However, if there are multiple entries for a single vnode,
they all share a single timestamp. To fix this, extend the name cache
to allow filesystems to optionally store a timestamp value in each name
cache entry. The NFS clients now fetch the timestamp associated with
each name cache entry and use that to validate cache hits instead of the
timestamps previously stored in the nfsnode. Another part of the fix is
that the NFS clients now use timestamps from the post-op attributes of
RPCs when adding name cache entries rather than pulling the timestamps out
of the file's attribute cache. The latter is subject to races with other
lookups updating the attribute cache concurrently. Some more details:
- Add a variant of nfsm_postop_attr() to the old NFS client that can return
a vattr structure with a copy of the post-op attributes.
- Handle lookups of "." as a special case in the NFS clients since the name
cache does not store name cache entries for ".", so we cannot get a
useful timestamp. It didn't really make much sense to recheck the
attributes on the the directory to validate the namecache hit for "."
anyway.
- ABI compat shims for the name cache routines are present in this commit
so that it is safe to MFC.

MFC after: 2 weeks

Modify the new NFS client so that nfs_fsync() only calls ncl_flush()
for regular files. Since other file types don't write into the
buffer cache, calling ncl_flush() is almost a no-op. However, it does
clear the NMODIFIED flag and this shouldn't be done by nfs_fsync() for
directories.

MFC after: 2 weeks

Since NFSv4 byte range locking only works for regular files,
add a sanity check for the vnode type to the NFSv4 client.

MFC after: 2 weeks

The new NFS client failed to vput() the new vnode if a setattr
failed after the file was created in nfs_create(). This would
probably only happen during a forced dismount. The old NFS client
does have a vput() for this case. Detected by pho during recent
testing, where an open syscall returned with a vnode still locked.

Tested by: pho
Approved by: re (kib)
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

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.

Add support for flock(2) locks to the new NFSv4 client. I think this
should be ok, since the client now delays NFSv4 Close operations
until VOP_INACTIVE()/VOP_RECLAIM(). As such, there should be no
risk that the NFSv4 Open is closed while an associated byte range lock
still exists.

Tested by: avg
MFC after: 2 weeks

The new NFSv4 client was erroneously using "p" instead of
"p_leader" for the "id" for POSIX byte range locking. I think
this would only have affected processes created by rfork(2)
with the RFTHREAD flag specified. This patch fixes that by
passing the "id" down through the various functions from
nfs_advlock().

MFC after: 2 weeks

Fix the new NFS client so that it doesn't do an NFSv3
Pathconf RPC for cases where the reply doesn't include
the answer. This fixes a problem reported by avg@ where
the NFSv3 Pathconf RPC would fail when "ls -l" did an
lpathconf(2) for _PC_ACL_NFS4.

Tested by: avg
MFC after: 2 weeks

Add some missing mutex locking to the new NFS client.

MFC after: 2 weeks

Fix the new NFS client so that it correctly sets the "must_commit"
argument for a write RPC when it succeeds for the first one and
fails for a subsequent RPC within the same call to the function.
This makes it compatible with the old NFS client for this case.

MFC after: 2 weeks

Eliminate duplicate #include's.

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.

Implemented a mount option "nocto" that disables cache coherency
checking at open time. It may improve performance for read-only
NFS mounts. Use deliberately.

MFC after: 1 week
Reviewed by: rmacklem, jhb (earlier version)

Add a vput() to nfs_lookitup() in the experimental NFS client
for a case that will probably never happen. It can only
happen if a server were to successfully lookup a file, but not
return attributes for that file. Although technically allowed
by the NFSv3 RFC, I doubt any server would ever do this.
However, if it did, the client would have not vput()'d the
new vnode when it needed to do so.

MFC after: 2 weeks

Add vput() calls in two places in the experimental NFS client
that would be needed if, in the future, nfscl_loadattrcache()
were to return an error. Currently nfscl_loadattrcache()
never returns an error, so these cases never currently happen.

MFC after: 2 weeks

Change the mutex locking for several locations in the
experimental NFS client's vnode op functions to make
them compatible with the regular NFS client. I'll admit
I'm not sure that the mutex locks around the assignments
are needed, but the regular client has them, so I added them.
Also, add handling of the case of partial attributes in
setattr to be compatible with the regular client.

MFC after: 2 weeks

Fix up some of the sysctls for the experimental NFS client so
that they use the same names as the regular client. Also add
string descriptions for them.

MFC after: 2 weeks

Add a lktype flags argument to nfscl_nget() and ncl_nget() in the
experimental NFS client so that its nfs_lookup() function can use
cn_lkflags in a manner analagous to the regular NFS client.

MFC after: 2 weeks

Add VOP_PATHCONF() support to the experimental NFS client
so that it can, along with other things, report whether or
not NFS4 ACLs are supported.

MFC after: 2 weeks

Modify nfs_open() in the experimental NFS client to be compatible
with the regular NFS client. Also, fix a couple of mutex lock issues.

MFC after: 1 week

Modify the NFS clients and the NLM so that the NLM can be used
by both clients. Since the NLM uses various fields of the
nfsmount structure, those fields were extracted and put in a
separate nfs_mountcommon structure stored in sys/nfs/nfs_mountcommon.h.
This structure also has a function pointer for a function that
extracts the required information from the mount point and nfs vnode
for that particular client, for information stored differently by the
clients.

Reviewed by: jhb
MFC after: 2 weeks

Fix the experimental NFS client so that it doesn't panic when
NFSv2,3 byte range locking is attempted. A fix that allows the
nlm_advlock() to work with both clients is in progress, but
may take a while. As such, I am doing this commit so that
the kernel doesn't panic in the meantime.

Submitted by: jh
MFC after: 2 weeks

Store the full timestamp when caching timestamps of files and
directories for purposes of validating name cache entries. This
closes races where two updates to a file or directory within the same
second could result in stale entries in the name cache. While here,
remove the 'n_expiry' field as it is no longer used.

Reviewed by: rmacklem
MFC after: 1 week

Disable use of the NLM in the experimental NFS client, since
it will crash the kernel because it uses the nfsmount and
nfsnode structures of the regular NFS client.

MFC after: 2 weeks

Modify the return value for nfscl_mustflush() from boolean_t,
which I mistakenly thought was correct w.r.t. style(9), back
to int and add the checks for != 0. This is just a stylistic
modification.

MFC after: 1 week

Move sys/nfsclient/nfs_lock.c into sys/nfs and build it as a separate
module that can be used by both the regular and experimental nfs
clients. This fixes the problem reported by jh@ where /dev/nfslock
would be registered twice when both nfs clients were used.
I also defined the size of the lm_fh field to be the correct value,
as it should be the maximum size of an NFSv3 file handle.

Reviewed by: jh
MFC after: 2 weeks

Add a call to nfscl_mustflush() in nfs_close() of the experimental
NFSv4 client, so that attributes are not acquired from the server
when a delegation for the file is held. This can reduce the number
of Getattr Ops significantly.

MFC after: 2 weeks

Merge 208603, 209946, and 209948 to the new NFS client:
Move attribute cache flushes from VOP_OPEN() to VOP_LOOKUP() to provide
more graceful recovery for stale filehandles and eliminate the need for
conditionally clearing the attribute cache in the !NMODIFIED case in
VOP_OPEN().

Reviewed by: rmacklem
MFC after: 2 weeks

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

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

When the experimental NFS client is handling an NFSv4 server reboot
with delegations enabled, the recovery could fail if the renew
thread is trying to return a delegation, since it will not do the
recovery. This patch fixes the above by having nfscl_recalldeleg()
fail with the I/O operations returning EIO, so that they will be
attempted later. Most of the patch consists of adding an argument
to various functions to indicate the delegation recall case where
this needs to be done.

MFC after: 1 week

Patch the experimental NFS client so that there is a timeout
for negative name cache entries in a manner analogous to
r202767 for the regular NFS client. Also, make the code in
nfs_lookup() compatible with that of the regular client
and replace the sysctl variable that enabled negative name
caching with the mount point option.

MFC after: 2 weeks

When porting the experimental nfs subsystem to the FreeBSD8 krpc,
I added 3 functions that were already in the experimental client
under different names. This patch deletes the functions in the
experimental client and renames the calls to use the other set.
(This is just removal of duplicated code and does not fix any bug.)

MFC after: 2 weeks

Remove unneeded ifdefs.

Reviewed by: rmacklem

Create verifier used by FreeBSD NFS client is suboptimal because the
first part of a verifier is set to the first IP address from
V_in_ifaddrhead list. This address is typically the loopback address
making the first part of the verifier practically non-unique. The second
part of the verifier is initialized to zero making its initial value
non-unique too.

This commit changes the strategy for create verifier initialization:
just initialize it to a random value. Also move verifier handling into
its own function and use a mutex to protect the variable.

This change is a candidate for porting to sys/nfsclient.

Reviewed by: jhb, rmacklem
Approved by: trasz (mentor)

Fix NFS panics with options VIMAGE kernels by apropriately setting curvnet
context inside the RPC code.

Temporarily set td's cred to mount's cred before calling socreate() via
__rpc_nconf2socket().

Submitted by: rmacklem (in part)
Reviewed by: rmacklem, rwatson
Discussed with: dfr, bz
Approved by: re (rwatson), julian (mentor)
MFC after: 3 days

Fix the experimental nfs client so that it only calls ncl_vinvalbuf()
for NFSv2 and not NFSv4 when nfscl_mustflush() returns 0. Since
nfscl_mustflush() only returns 0 when there is a valid write delegation
issued to the client, it only affects the case of an NFSv4 mount with
callbacks/delegations enabled.

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

Add changes to the experimental nfs client to use the PBDRY flag for
msleep(9) when a vnode lock or similar may be held. The changes are
just a clone of the changes applied to the regular nfs client by
r195703.

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

Fix the experimental nfs client so that it does not cause a
"share->excl" panic when doing a lookup of dotdot at the root
of a server's file system. The patch avoids calling vn_lock()
for that case, since nfscl_nget() has already acquired a lock
for the vnode.

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

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)

Fix the handling of dotdot in lookup for the experimental nfs client
in a manner analagous to the change in r195294 for the regular nfs client.

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

Add a new global rwlock, in_ifaddr_lock, which will synchronize use of the
in_ifaddrhead and INADDR_HASH address lists.

Previously, these lists were used unsynchronized as they were effectively
never changed in steady state, but we've seen increasing reports of
writer-writer races on very busy VPN servers as core count has gone up
(and similar configurations where address lists change frequently and
concurrently).

For the time being, use rwlocks rather than rmlocks in order to take
advantage of their better lock debugging support. As a result, we don't
enable ip_input()'s read-locking of INADDR_HASH until an rmlock conversion
is complete and a performance analysis has been done. This means that one
class of reader-writer races still exists.

MFC after: 6 weeks
Reviewed by: bz

Add explicit includes for jail.h to the files that need them and
remove the "hidden" one from vimage.h.

Fix handling of ".." in nfs_lookup() for the forced dismount case
by cribbing the change made to the regular nfs client in r194358.

Approved by: kib (mentor)

Since vn_lock() with the LK_RETRY flag never returns an error
for FreeBSD-CURRENT, the code that checked for and returned the
error was broken. Change it to check for VI_DOOMED set after
vn_lock() and return an error for that case. I believe this
should only happen for forced dismounts.

Approved by: kib (mentor)

Unbreak options VIMAGE kernel builds.

Approved by: julian (mentor)

Change the code in the experimental nfs client to avoid flushing
writes upon close when a write delegation is held by the client.
This should be safe to do, now that nfsv4 Close operations are
delayed until ncl_inactive() is called for the vnode.

Approved by: kib (mentor)

Change the experimental NFSv4 client so that it does not do
the NFSv4 Close operations until ncl_inactive(). This is
necessary so that the Open StateIDs are available for doing
I/O on mmap'd files after VOP_CLOSE(). I also changed some
indentation for the nfscl_getclose() function.

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)