It is possible for servers to return NFS4ERR_BAD_STATEID when
the state management code is recovering locks or is reclaiming state when
returning a delegation. Ensure that we handle that case.
While we're at it, add in handlers for NFS4ERR_STALE,
NFS4ERR_ADMIN_REVOKED, NFS4ERR_OPENMODE, NFS4ERR_DENIED and
NFS4ERR_STALE_STATEID, since the protocol appears to allow for them too.

Also handle ENOMEM...

Finally, rather than add new NFSv4.0-specific errors and error handling into
the generic delegation code, move that open file and locking state error
handling into the NFSv4 layer.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Apparently a lot of people need to disable IPv6 completely on their
distributor-built systems, which have CONFIG_IPV6_MODULE enabled at
build time.

They do this by blacklisting the ipv6.ko module.  This causes the
creation of the NFSv4 callback service listener to fail if
CONFIG_IPV6_MODULE is set, but the module cannot be loaded.

Now that the kernel's PF_INET6 RPC listeners are completely separate
from PF_INET listeners, we can always start PF_INET.  Then the NFS
client can try to start a PF_INET6 listener, but it isn't required
to be available.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Let the actual delegreturn stuff be run in the state manager thread rather
than allocating a separate kthread.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We really shouldn't be resetting the sequence ids when doing state
expiration recovery, since we don't know if the server still remembers our
previous state owners. There are servers out there that do attempt to
preserve client state even if the lease has expired. Such a server would
only release that state if a conflicting OPEN request occurs.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Fix up a potential race...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

It is really a more general purpose state management thread at this point.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Add a delegation cleanup phase to the state management loop, and do the
NFS4ERR_CB_PATH_DOWN recovery there.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

NFSv4 defines a number of state errors which the client does not currently
handle. Among those we should worry about are:
  NFS4ERR_ADMIN_REVOKED - the server's administrator revoked our locks
  			  and/or delegations.
  NFS4ERR_BAD_STATEID - the client and server are out of sync, possibly
                        due to a delegation return racing with an OPEN
			request.
  NFS4ERR_OPENMODE - the client attempted to do something not sanctioned
  		     by the open mode of the stateid. Should normally just
		     occur as a result of a delegation return race.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Now that we're using the flags to indicate state that needs to be
recovered, as well as having implemented proper refcounting and spinlocking
on the state and open_owners, we can get rid of nfs_client->cl_sem. The
only remaining case that was dubious was the file locking, and that case is
now covered by the nfsi->rwsem.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The unlock path is currently failing to take the nfs_client->cl_sem read
lock, and hence the recovery path may see locks disappear from underneath
it.
Also ensure that it takes the nfs_inode->rwsem read lock so that it there
is no conflict with delegation recalls.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Instead of doing a full setclientid, try doing a RENEW call first.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If the client for some reason is not able to recover all its state within
the time allotted for the grace period, and the server reboots again, the
client is not allowed to recover the state that was 'lost' using reboot
recovery.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Ditto for nfs4_get_setclientid_cred().
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

nfs4_drop_state_owner() can now become static.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

An audit of the current RPC timeout functions shows that they don't really
ever need to run in the softirq context. As long as the softirq is
able to signal that the wakeup is due to a timeout (which it can do by
setting task->tk_status to -ETIMEDOUT) then the callback functions can just
run as standard task->tk_callback functions (in the rpciod/process
context).

The only possible border-line case would be xprt_timer() for the case of
UDP, when the callback is used to reduce the size of the transport
congestion window. In testing, however, the effect of moving that update
to a callback would appear to be minor.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/nfs4state.c:788:34: warning: Using plain integer as NULL pointer
fs/nfs/delegation.c:52:34: warning: Using plain integer as NULL pointer
fs/nfs/idmap.c:312:12: warning: Using plain integer as NULL pointer
fs/nfs/callback_xdr.c:257:6: warning: Using plain integer as NULL pointer
fs/nfs/callback_xdr.c:270:6: warning: Using plain integer as NULL pointer
fs/nfs/callback_xdr.c:281:6: warning: Using plain integer as NULL pointer
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The warning message for a v4 server returning various bad sequence-ids is
missing spaces.
Signed-off-by: NDan Muntz <dmuntz@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

To ensure the NFS client displays IPv6 addresses properly, replace
address family-specific NIPQUAD() invocations with a call to the RPC
client to get a formatted string representing the remote peer's
address.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Reduce the time spent locking the rpc_sequence structure by queuing the
nfs_seqid only when we are ready to take the lock (when calling
nfs_wait_on_sequence).
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Sharing the open sequence queue causes a deadlock when we try to take
both a lock sequence id and and open sequence id.

This fixes the regression reported by Dimitri Puzin and Jeff Garzik: See

	http://bugzilla.kernel.org/show_bug.cgi?id=9712

for details.
Reported-and-tested-by: NDimitri Puzin <bugs@psycast.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: NJeff Garzik <jgarzik@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Otherwise, we do end up breaking close-to-open semantics. We also end up
breaking some of the silly-rename tests in Connectathon on some setups.

Please refer to the bug-report at
	http://bugzilla.linux-nfs.org/show_bug.cgi?id=150Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We don't really need to clear &state->inode_states inside
nfs4_set_mode_locked, and doing so without holding the inode->i_lock would
in any case be a bug...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Consider the case where the user has mounted the remote filesystem
server:/foo on the two local directories /bar and /baz using the
nosharedcache mount option. The files /bar/file and /baz/file are
represented by different inodes in the local namespace, but refer to the
same file /foo/file on the server.
Consider the case where a process opens both /bar/file and /baz/file, then
closes /bar/file: because the nfs4_state is not shared between /bar/file
and /baz/file, the kernel will see that the nfs4_state for /bar/file is no
longer referenced, so it will send off a CLOSE rpc call. Unless the
open_owners differ, then that CLOSE call will invalidate the open state on
/baz/file too.

Conclusion: we cannot share open state owners between two different
non-shared mount instances of the same filesystem.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We really don't need to grab both the state->so_owner and the
inode->i_lock.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The test for state->state == 0 does not tell you that the stateid is in the
process of being freed. It really tells you that the stateid is not yet
initialised...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Currently we just use a 32-bit counter.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

It is a void function...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

That just confuses certain NFSv4 servers.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>