Since commit c98451bd, the loop in nlm_lookup_host() unconditionally
compares the host's h_srcaddr field to the incoming source address.
For client-side nlm_host entries, both are always AF_UNSPEC, so this
check is unnecessary.

Since commit 781b61a6, which added support for AF_INET6 addresses to
nlm_cmp_addr(), nlm_cmp_addr() now returns FALSE for AF_UNSPEC
addresses, which causes nlm_lookup_host() to create a fresh nlm_host
entry every time it is called on the client.

These extra entries will eventually expire once the server is
unmounted, so the impact of this regression, introduced with lockd
IPv6 support in 2.6.28, should be minor.

We could fix this by adding an arm in nlm_cmp_addr() for AF_UNSPEC
addresses, but really, nlm_lookup_host() shouldn't be matching on the
srcaddr field for client-side nlm_host lookups.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

If nfsd was shut down before the grace period ended, we could end up
with a freed object still on grace_list.  Thanks to Jeff Moyer for
reporting the resulting list corruption warnings.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Tested-by: NJeff Moyer <jmoyer@redhat.com>

The nlm_host_rebooted() function uses nlm_cmp_addr() to find an
nsm_handle that matches the rebooted peer.  In order for this to work,
the passed-in address must have a proper address family.

This fixes a post-2.6.28 regression introduced by commit 781b61a6, which
added AF_INET6 support to nlm_cmp_addr().  Before that commit,
nlm_cmp_addr() didn't care about the address family; it compared only
the sin_addr.s_addr field for equality.
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>

Commit 24e36663, which first appeared in 2.6.19, changed lockd so that
the client side starts a UDP listener only if there is a UDP NFSv2/v3
mount.  Its description notes:

    This... 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.

Unfortunately it is a problem for Linux itself.  The rpc.statd daemon
on Linux uses UDP for contacting the local lockd, no matter which
protocol is used for NFS mounts.  Without a local lockd UDP listener,
NFSv2/v3 lock recovery from Linux NFS clients always fails.

Revert parts of commit 24e36663 so lockd_up() always starts both
listeners.
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>

The nlm_reboot structure is used to store information provided by the
NSM_NOTIFY procedure.  This procedure is not specified by the NLM or NSM
protocols, other than to say that the procedure can be used to transmit
information private to a particular NLM/NSM implementation.

For Linux, the callback arguments include the name of the monitored host,
the new NSM state of the host, and a 16-byte private opaque.

As a clean up, remove the unused fields and the server-side XDR logic that
decodes them.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

lockd accepts SM_NOTIFY calls only from a privileged process on the
local system.  If lockd uses an AF_INET6 listener, the sender's address
(ie the local rpc.statd) will be the IPv6 loopback address, not the
IPv4 loopback address.

Make sure the privilege test in nlmsvc_proc_sm_notify() and
nlm4svc_proc_sm_notify() works for both AF_INET and AF_INET6 family
addresses by refactoring the test into a helper and adding support for
IPv6 addresses.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Adjust the signature and callers of nlmclnt_grant() to pass a "struct
sockaddr *" instead of a "struct sockaddr_in *" in order to support IPv6
addresses.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Fix up nlmsvc_lookup_host() to pass AF_INET6 source addresses to
nlm_lookup_host().
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Pass a struct sockaddr * and a length to nlmclnt_lookup_host() to
accomodate non-AF_INET family addresses.

As a side benefit, eliminate the hostname_len argument, as the hostname
is always NUL-terminated.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Use struct sockaddr * and length in nlm_lookup_host_info to all callers
to pass in either AF_INET or AF_INET6 addresses.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The nlm_lookup_host() function already has a large number of arguments,
and I'm about to add a few more.  As a clean up, convert the function
to use a single data structure argument.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The current lockd does not reject reclaims that arrive outside of the
grace period.

Accepting a reclaim means promising to the client that no conflicting
locks were granted since last it held the lock.  We can meet that
promise if we assume the only lockers are nfs clients, and that they are
sufficiently well-behaved to reclaim only locks that they held before,
and that only reclaim locks have been permitted so far.  Once we leave
the grace period (and start permitting non-reclaims), we can no longer
keep that promise.  So we must start rejecting reclaims at that point.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Do all the grace period checks in svclock.c.  This simplifies the code a
bit, and will ease some later changes.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Rewrite grace period code to unify management of grace period across
lockd and nfsd.  The current code has lockd and nfsd cooperate to
compute a grace period which is satisfactory to them both, and then
individually enforce it.  This creates a slight race condition, since
the enforcement is not coordinated.  It's also more complicated than
necessary.

Here instead we have lockd and nfsd each inform common code when they
enter the grace period, and when they're ready to leave the grace
period, and allow normal locking only after both of them are ready to
leave.

We also expect the locks_start_grace()/locks_end_grace() interface here
to be simpler to build on for future cluster/high-availability work,
which may require (for example) putting individual filesystems into
grace, or enforcing grace periods across multiple cluster nodes.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Clean up: Having two separate functions doesn't add clarity, so
eliminate one of them.  Use contemporary kernel coding conventions
where appropriate.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Adopt an approach similar to the RPC server's auth cache (from Aurelien
Charbon and Brian Haley).

Note nlm_lookup_host()'s existing IP address hash function has the same
issue with correctness on little-endian systems as the original IPv4 auth
cache hash function, so I've also updated it with a hash function similar
to the new auth cache hash function.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Update the nlm_cmp_addr() helper to support AF_INET6 as well as AF_INET
addresses.  New version takes two "struct sockaddr *" arguments instead of
"struct sockaddr_in *" arguments.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

To store larger addresses in the nsm_handle structure, make sm_addr a
sockaddr_storage.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

To store larger addresses in the nlm_host structure, make h_saddr a
sockaddr_storage.  And let's call it something more self-explanatory:
"saddr" could easily be mistaken for "server address".
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

To store larger addresses in the nlm_host structure, make h_addr a
sockaddr_storage, and add an address length field.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Make sure an address family is specified for source addresses passed to
nlm_lookup_host().  nlm_lookup_host() will need this when it becomes
capable of dealing with AF_INET6 addresses.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Knowing which source address is used for communicating with remote NLM
services can be helpful for debugging configuration problems on hosts
with multiple addresses.

Keep the dprintk debugging here, but adapt it so it displays AF_INET6
addresses properly.  There are also a couple of dprintk clean-ups as
well.

At some point we will aggregate the helpers that display presentation
format addresses into a single set of shared helpers.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

We're about to introduce some extra debugging messages in nlm_lookup_host().
Bring the coding style up to date first so we can cleanly introduce the new
debugging messages.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

End lockd's grace period using schedule_delayed_work() instead of a
check on every pass through the main loop.

After a later patch, we'll depend on lockd to end its grace period even
if it's not currently handling requests; so it shouldn't depend on being
woken up from the main loop to do so.

Also, Nakano Hiroaki (who independently produced a similar patch)
noticed that the current behavior is buggy in the face of jiffies
wraparound:

	"lockd uses time_before() to determine whether the grace period
	has expired. This would seem to be enough to avoid timer
	wrap-around issues, but, unfortunately, that is not the case.
	The time_* family of comparison functions can be safely used to
	compare jiffies relatively close in time, but they stop working
	after approximately LONG_MAX/2 ticks. nfsd can suffer this
	problem because the time_before() comparison in lockd() is not
	performed until the first request comes in, which means that if
	there is no lockd traffic for more than LONG_MAX/2 ticks we are
	screwed.

	"The implication of this is that once time_before() starts
	misbehaving any attempt from a NFS client to execute fcntl()
	will be received with a NLM_LCK_DENIED_GRACE_PERIOD message for
	25 days (assuming HZ=1000). In other words, the 50 seconds grace
	period could turn into a grace period of 50 days or more.

	"Note: This bug was analyzed independently by Oda-san
	<oda@valinux.co.jp> and myself."
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Cc: Nakano Hiroaki <nakano.hiroaki@oss.ntt.co.jp>
Cc: Itsuro Oda <oda@valinux.co.jp>

The check here is currently harmless but unnecessary, since, as the
comment notes, there aren't any blocked-lock callbacks to process
during the grace period anyway.

And eventually we want to allow multiple grace periods that come and go
for different filesystems over the course of the lifetime of lockd, at
which point this check is just going to get in the way.
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>

Use a special error value FILE_LOCK_DEFERRED to mean that a locking
operation returned asynchronously.  This is returned by

  posix_lock_file() for sleeping locks to mean that the lock has been
  queued on the block list, and will be woken up when it might become
  available and needs to be retried (either fl_lmops->fl_notify() is
  called or fl_wait is woken up).

  f_op->lock() to mean either the above, or that the filesystem will
  call back with fl_lmops->fl_grant() when the result of the locking
  operation is known.  The filesystem can do this for sleeping as well
  as non-sleeping locks.

This is to make sure, that return values of -EAGAIN and -EINPROGRESS by
filesystems are not mistaken to mean an asynchronous locking.

This also makes error handling in fs/locks.c and lockd/svclock.c slightly
cleaner.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: David Teigland <teigland@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix nlm_fopen() to return NLM_FAILED (or NLM_LCK_DENIED_NOLOCKS) instead
of NLM_LCK_DENIED.  The latter means the lock request failed because of a
conflicting lock (i.e.  a temporary error), which is wrong in this case.

Also fix the client to return ENOLCK instead of EAGAIN if a blocking lock
request returns with NLM_LOCK_DENIED.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: David Teigland <teigland@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fs/lockd/svcproc.c:115:11: warning: incorrect type in initializer (different base types)
fs/lockd/svcproc.c:115:11:    expected int [signed] rc
fs/lockd/svcproc.c:115:11:    got restricted __be32 [usertype] <noident>
... and so on...
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Push it into those callback functions that actually need it.

Note that all the NFS operations use their own locking, so don't need the
BKL. Ditto for the rpcbind client.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

fcntl(F_GETLK) on an nfs client incorrectly returns
the values for the conflicting lock. fl_len value is
always 1.
If the conflicting lock is (0, 4095) the F_GETLK
request for (1024, 10) returns (0, 1), which doesn't
even cover the requested range, and is quite confusing.
The fix is trivial, set fl_end from the fl_end value
recieved from the nfs server.
Signed-off-by: NFelix Blyakher <felixb@sgi.com>
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Pass a more generic socket address type to nlmsvc_unlock_all_by_ip() to
allow for future support of IPv6.  Also provide additional sanity
checking in failover_unlock_ip() when constructing the server's IP
address.

As an added bonus, provide clean kerneldoc comments on related NLM
interfaces which were recently added.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

It may not be obvious (till you look at the definition of
nlm_alloc_call()) that a function like nlmsvc_create_block() should
consume a reference on success or failure, so I find it clearer if it
takes the reference it needs itself.

And both callers already do this immediately before the call anyway.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

nlmsvc_lock calls nlmsvc_lookup_host to find a nlm_host struct. The
callers of this function, however, call nlmsvc_retrieve_args or
nlm4svc_retrieve_args, which also return a nlm_host struct.

Change nlmsvc_lock to take a host arg instead of calling
nlmsvc_lookup_host itself and change the callers to pass a pointer to
the nlm_host they've already found.

Since nlmsvc_testlock() now just uses the caller's reference, we no
longer need to get or release it.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

nlmsvc_testlock calls nlmsvc_lookup_host to find a nlm_host struct. The
callers of this functions, however, call nlmsvc_retrieve_args or
nlm4svc_retrieve_args, which also return a nlm_host struct.

Change nlmsvc_testlock to take a host arg instead of calling
nlmsvc_lookup_host itself and change the callers to pass a pointer to
the nlm_host they've already found.

We take a reference to host in the place where nlmsvc_testlock()
previous did a new lookup, so the reference counting is unchanged from
before.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

No need to check for a NULL argument twice.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>