Stop gathering the data that feeds the 'th' line in /proc/net/rpc/nfsd
because the questionable data provided is not worth the scalability
impact of calculating it.  Instead, always report zeroes.  The current
approach suffers from three major issues:

1. update_thread_usage() increments buckets by call service
   time or call arrival time...in jiffies.  On lightly loaded
   machines, call service times are usually < 1 jiffy; on
   heavily loaded machines call arrival times will be << 1 jiffy.
   So a large portion of the updates to the buckets are rounded
   down to zero, and the histogram is undercounting.

2. As seen previously on the nfs mailing list, the format in which
   the histogram is presented is cryptic, difficult to explain,
   and difficult to use.

3. Updating the histogram requires taking a global spinlock and
   dirtying the global variables nfsd_last_call, nfsd_busy, and
   nfsdstats *twice* on every RPC call, which is a significant
   scaling limitation.

Testing on a 4 CPU 4 NIC Altix using 4 IRIX clients each doing
1K streaming reads at full line rate, shows the stats update code
(inlined into nfsd()) takes about 1.7% of each CPU.  This patch drops
the contribution from nfsd() into the profile noise.

This patch is a forward-ported version of knfsd-remove-nfsd-threadstats
which has been shipping in the SGI "Enhanced NFS" product since 2006.
In that time, exactly one customer has noticed that the threadstats
were missing.  It has been previously posted:

http://article.gmane.org/gmane.linux.nfs/10376

and more recently requested to be posted again.
Signed-off-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The Linux NFS server can be started via a user-space write to
/proc/fs/nfs/threads or to /proc/fs/nfs/portlist.  In the first case,
all default listeners are started (both UDP and TCP).  In the second,
a listener is started only for one specified transport.

The NFS server has to make sure lockd stays up until the last listener
transport goes away.  To support both start-up interfaces, it should
do one lockd_up() for each NFSD listener.

The nfsd_init_socks() function used to do one lockd_up() call for each
svc_create_xprt().  Recently commit
26a41409 mistakenly changed
nfsd_init_socks() to do only one lockd_up() call even though it still
does two svc_create_xprt() calls.

The end result is a lockd_down() BUG during NFSD shutdown processing
because nfsd_last_threads() does a lockd_down() call for each entry
on the sv_permsocks list, but the start-up code doesn't do a matching
number of lockd_up() calls.

Add a second lockd_up() in nfsd_init_socks() to make sure the number
of lockd_up() calls matches the number of entries on the NFS servers's
sv_permsocks list.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Clean up: Now that lockd_up() starts listeners for both transports, the
"proto" argument is no longer needed.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Introduce and initialize an address family field in the svc_serv structure.

This field will determine what family to use for the service's listener
sockets and what families are advertised via the local rpcbind daemon.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

knfsd currently uses 2 signal masks when processing requests. A "loose"
mask (SHUTDOWN_SIGS) that it uses when receiving network requests, and
then a more "strict" mask (ALLOWED_SIGS, which is just SIGKILL) that it
allows when doing the actual operation on the local storage.

This is apparently unnecessarily complicated. The underlying filesystem
should be able to sanely handle a signal in the middle of an operation.
This patch removes the signal mask handling from knfsd altogether. When
knfsd is started as a kthread, all signals are ignored. It then allows
all of the signals in SHUTDOWN_SIGS. There's no need to set the mask
as well.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

We need the nfsd_mutex before accessing nfsd_serv->sv_nrthreads or we
can't even guarantee nfsd_serv will still be there.
Signed-off-by: NNeil Brown <neilb@suse.de>
Acked-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Since we no longer make any distinction between shutdown signals with
nfsd, then it becomes easier to just standardize on a particular signal
to use to bring it down (SIGINT, in this case).
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This patch is rather large, but I couldn't figure out a way to break it
up that would remain bisectable. It does several things:

- change svc_thread_fn typedef to better match what kthread_create expects
- change svc_pool_map_set_cpumask to be more kthread friendly. Make it
  take a task arg and and get rid of the "oldmask"
- have svc_set_num_threads call kthread_create directly
- eliminate __svc_create_thread
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The special handling for SIGHUP in knfsd is a holdover from much
earlier versions of Linux where reloading the export table was
more expensive. That facility is not really needed anymore and
to my knowledge, is seldom-used.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Several of the nfsd filesystem interfaces allow changes to parameters
that don't have any effect on a running nfsd service. They are only ever
checked when nfsd is started. This patch fixes it so that changes to
those procfiles return -EBUSY if nfsd is already running to make it
clear that changes on the fly don't work.

The patch should also close some relatively harmless races between
changing the info in those interfaces and starting nfsd, since these
variables are being moved under the protection of the nfsd_mutex.

Finally, the nfsv4recoverydir file always returns -EINVAL if read. This
patch fixes it to return the recoverydir path as expected.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This removes the BKL from the RPC service creation codepath. The BKL
really isn't adequate for this job since some of this info needs
protection across sleeps.

Also, add some comments to try and clarify how the locking should work
and to make it clear that the BKL isn't necessary as long as there is
adequate locking between tasks when touching the svc_serv fields.
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Likewise, distros usually leave CONFIG_NFSD_TCP enabled.

TCP support in the Linux NFS server is stable enough that we can leave it
on always.  CONFIG_NFSD_TCP adds about 10 lines of code, and defaults to
"Y" anyway.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Move sk_list and sk_ready to svc_xprt. This involves close because these
lists are walked by svcs when closing all their transports. So I combined
the moving of these lists to svc_xprt with making close transport independent.

The svc_force_sock_close has been changed to svc_close_all and takes a list
as an argument. This removes some svc internals knowledge from the svcs.

This code races with module removal and transport addition.

Thanks to Simon Holm Thøgersen for a compile fix.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Cc: Simon Holm Thøgersen <odie@cs.aau.dk>

Modify the various kernel RPC svcs to use the svc_create_xprt service.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

We have some slabs that the nfs4 server uses to store state objects.
We're currently creating and destroying those slabs whenever the server
is brought up or down.  That seems excessive; may as well just do that
in module initialization and exit.

Also add some minor header cleanup.  (Thanks to Andrew Morton for that
and a compile fix.)
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>
Acked-by: NNeil Brown <neilb@suse.de>

I moved this check into map_new_errors, but forgot to delete the
original.  Oops.
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>
Acked-by: NNeil Brown <neilb@suse.de>

The nfserr_dropit happens routinely on upcalls (so a kmalloc failure is
almost never the actual cause), but I occasionally get a complant from
some tester that's worried because they ran across this message after
turning on debugging to research some unrelated problem.
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>
Acked-by: NNeil Brown <neilb@suse.de>

Make the first actual use of the secinfo information by using it to return
nfserr_wrongsec when an export is found that doesn't allow the flavor used on
this request.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NAndy Adamson <andros@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves.  This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.

It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.

The patch causes all kernel threads to be nonfreezable by default (ie.  to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE.  It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear.  Additionally, it updates documentation to
describe the freezing of tasks more accurately.

[akpm@linux-foundation.org: build fixes]
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NNigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

First thing mm.h does is including sched.h solely for can_do_mlock() inline
function which has "current" dereference inside. By dealing with can_do_mlock()
mm.h can be detached from sched.h which is good. See below, why.

This patch
a) removes unconditional inclusion of sched.h from mm.h
b) makes can_do_mlock() normal function in mm/mlock.c
c) exports can_do_mlock() to not break compilation
d) adds sched.h inclusions back to files that were getting it indirectly.
e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
   getting them indirectly

Net result is:
a) mm.h users would get less code to open, read, preprocess, parse, ... if
   they don't need sched.h
b) sched.h stops being dependency for significant number of files:
   on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
   after patch it's only 3744 (-8.3%).

Cross-compile tested on

	all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
	alpha alpha-up
	arm
	i386 i386-up i386-defconfig i386-allnoconfig
	ia64 ia64-up
	m68k
	mips
	parisc parisc-up
	powerpc powerpc-up
	s390 s390-up
	sparc sparc-up
	sparc64 sparc64-up
	um-x86_64
	x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig

as well as my two usual configs.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Sometimes we need to create an RPC service but not register it with the local
portmapper.  NFSv4 delegation callback, for example.

Change the svc_makesock() API to allow optionally creating temporary or
permanent sockets, optionally registering with the local portmapper, and make
it return the ephemeral port of the new socket.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Due to silly typos, if the nfs versions are explicitly set, no NFSACL versions
get enabled.

Also improve an error message that would have made this bug a little easier to
find.
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NTrond Myklebust <trond.myklebust@fys.uio.no>
Acked-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NTrond Myklebust <trond.myklebust@fys.uio.no>
Acked-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

There is some confusion about the meaning of 'bufsz' for a sunrpc server.
In some cases it is the largest message that can be sent or received.  In
other cases it is the largest 'payload' that can be included in a NFS
message.

In either case, it is not possible for both the request and the reply to be
this large.  One of the request or reply may only be one page long, which
fits nicely with NFS.

So we remove 'bufsz' and replace it with two numbers: 'max_payload' and
'max_mesg'.  Max_payload is the size that the server requests.  It is used
by the server to check the max size allowed on a particular connection:
depending on the protocol a lower limit might be used.

max_mesg is the largest single message that can be sent or received.  It is
calculated as the max_payload, rounded up to a multiple of PAGE_SIZE, and
with PAGE_SIZE added to overhead.  Only one of the request and reply may be
this size.  The other must be at most one page.

Cc: Greg Banks <gnb@sgi.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

totalram is measured in pages, not bytes, so PAGE_SHIFT must be used when
trying to find 1/4096 of RAM.

Cc:  "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The max possible is the maximum RPC payload.  The default depends on amount of
total memory.

The value can be set within reason as long as no nfsd threads are currently
running.  The value can also be ready, allowing the default to be determined
after nfsd has started.
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add /proc/fs/nfsd/pool_threads which allows the sysadmin (or a userspace
daemon) to read and change the number of nfsd threads in each pool.  The
format is a list of space-separated integers, one per pool.
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Replace the existing list of all nfsd threads with new code using
svc_create_pooled().
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

add svc_get() for those occasions when we need to temporarily bump up
svc_serv->sv_nrthreads as a pseudo refcount.
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If lockd_up fails - what should we expect?  Do we have to later call
lockd_down?

Well the nfs client thinks "no", the nfs server thinks "yes".  lockd thinks
"yes".

The only answer that really makes sense is "no" !!

So:
  Make lockd_up only increment  nlmsvc_users on success.
  Make nfsd handle errors from lockd_up properly.
  Make sure lockd_up(0) never fails when lockd is running
    so that the 'reclaimer' call to lockd_up doesn't need to
    be error checked.

Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It isn't needed as it is available in rqstp->rq_server, and dropping it allows
some local vars to be dropped.

[akpm@osdl.org: build fix]
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Userspace should create and bind a socket (but not connectted) and write the
'fd' to portlist.  This will cause the nfs server to listen on that socket.

To close a socket, the name of the socket - as read from 'portlist' can be
written to 'portlist' with a preceding '-'.
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Separate out the code for creating a new service, and for creating initial
sockets.

Some of these new functions will have multiple callers soon.

[akpm@osdl.org: cleanups]
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We have an array 'nfsd_version' which lists the available versions of nfsd,
and 'nfsd_versions' (poor choice there :-() which lists the currently active
versions.

Then we have a bitmap - nfsd_versbits which says which versions are wanted.
The bits in this bitset cause content to be copied from nfsd_version to
nfsd_versions when nfsd starts.

This patch removes nfsd_versbits and moves information directly from
nfsd_version to nfsd_versions when requests for version changes arrive.

Note that this doesn't make it possible to change versions while the server is
running.  This is because serv->sv_xdrsize is calculated when a service is
created, and used when threads are created, and xdrsize depends on the active
versions.
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Currently lockd listens on UDP always, and TCP if CONFIG_NFSD_TCP is set.

However as lockd performs services of the client as well, this is a problem.
If CONFIG_NfSD_TCP is not set, and a tcp mount is used, the server will not be
able to call back to lockd.

So:
 - add an option to lockd_up saying which protocol is needed
 - Always open sockets for which an explicit port was given, otherwise
   only open a socket of the type required
 - Change nfsd to do one lockd_up per socket rather than one per thread.

This
 - removes the dependancy on CONFIG_NFSD_TCP
 - means that lockd may open sockets other than at startup
 - means that lockd will *not* listen on UDP if the only
   mounts are TCP mount (and nfsd hasn't started).

The latter is the only one that concerns me at all - I don't know if this
might be a problem with some servers.
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

nfsd has some cleanup that it wants to do when the last thread exits, and
there will shortly be some more.  So collect this all into one place and
define a callback for an rpc service to call when the service is about to be
destroyed.

[akpm@osdl.org: cleanups, build fix]
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Use ARRAY_SIZE macro instead of sizeof(x)/sizeof(x[0]) and remove a
duplicate of ARRAY_SIZE.  Some trailing whitespaces are also deleted.
Signed-off-by: NTobias Klauser <tklauser@nuerscht.ch>
Cc: David Howells <dhowells@redhat.com>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Acked-by: NTrond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: Chris Mason <mason@suse.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Nathan Scott <nathans@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

A recent patch to
   Allow run-time selection of NFS versions to export

meant that NO nfsacl service versions were exported.  This patch restored
that functionality.
Signed-off-by: NAndreas Gruenbacher <agruen@suse.de>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>