v2:
1) "Over-put" of PipeFS mount point fixed. Fix is ugly, but allows to bisect
the patch set. And it will be removed later in the series.

This patch makes RPC clients PipeFs dentries allocations in it's owner network
namespace context.
RPC client pipefs dentries creation logic has been changed:
1) Pipefs dentries creation by sb was moved to separated function, which will
be used for handling PipeFS mount notification.
2) Initial value of RPC client PipeFS dir dentry is set no NULL now.

RPC client pipefs dentries cleanup logic has been changed:
1) Cleanup is done now in separated rpc_remove_pipedir() function, which takes
care about pipefs superblock locking.

Also this patch removes slashes from cb_program.pipe_dir_name and from
NFS_PIPE_DIRNAME to make rpc_d_lookup_sb() work. This doesn't affect
vfs_path_lookup() results in nfs4blocklayout_init() since this slash is cutted
off anyway in link_path_walk().
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Instead of hacking specific service names into gss_encode_v1_msg, we should
just allow the caller to specify the service name explicitly.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This will be convenient.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Fix bug introduced in patch
85a56480 NFSD: Update XDR decoders in NFSv4 callback client

Although decode_cb_sequence4resok ignores highest slotid and target highest slotid
it must account for their space in their xdr stream when calling xdr_inline_decode

Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Bugs introduced in 85a56480
"NFSD: Update XDR decoders in NFSv4 callback client"

Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Ensure a new callback is added to the client's list of callbacks at most
once.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Otherwise a callback that is aborted before it runs will result in a
list_del on an uninitialized list head.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If we lose the backchannel and then the client repairs the problem,
resend any callbacks.

We use a new cb_done flag to track whether there is still work to be
done for the callback or whether it can be destroyed with the rpc.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Remove handling for a nonexistant case (status && !-EAGAIN).
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If this loses any backchannel, make sure we have a chance to notice that
and set the sequence flags.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Distinguish between when the callback channel is known to be down, and
when it is not yet confirmed.  This will be useful in the 4.1 case.

Also, we don't seem to be using the fact that this field is atomic.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Now that we have a list of connections to choose from, we can teach the
callback code to just pick a suitable connection and use that, instead
of insisting on forever using the connection that the first
create_session was sent with.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

when callback is generated in NFSv4 server, it doesn't set the source
address. When an alias IP is utilized on NFSv4 server and suppose the
client is accessing via that alias IP (e.g. eth0:0), the client invokes
the callback to the IP address that is set on the original device (e.g.
eth0). This behavior results in timeout of xprt.
The patch sets the IP address that the client should invoke callback to.
Signed-off-by: NTakuma Umeya <tumeya@redhat.com>
[bfields@redhat.com: Simplify gen_callback arguments, use helper function]
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

setup_callback_client(), nfsd4_release_cb() and nfsd4_process_cb_update()
do not have users outside the translation unit. Let's declare it as
static.
Signed-off-by: NKirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Now that all client-side XDR decoder routines use xdr_streams, there
should be no need to support the legacy calling sequence [rpc_rqst *,
__be32 *, RPC res *] anywhere.  We can construct an xdr_stream in the
generic RPC code, instead of in each decoder function.

This is a refactoring change.  It should not cause different behavior.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Now that all client-side XDR encoder routines use xdr_streams, there
should be no need to support the legacy calling sequence [rpc_rqst *,
__be32 *, RPC arg *] anywhere.  We can construct an xdr_stream in the
generic RPC code, instead of in each encoder function.

Also, all the client-side encoder functions return 0 now, making a
return value superfluous.  Take this opportunity to convert them to
return void instead.

This is a refactoring change.  It should not cause different behavior.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up.

When I was making other changes in this area, checkscript.pl
complained about the use of leading blanks in the PROC macros in the
xdr files.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up.

Remove old-style NFSv4 XDR macros in favor of the style now used in
fs/nfs/nfs4xdr.c.  These were forgotten during the recent nfs4xdr.c
rewrite.

Additional whitespace cleanup adds to the size of this patch.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up.

Remove old-style NFSv4 XDR macros in favor of the style now used in
fs/nfs/nfs4xdr.c.  These were forgotten during the recent nfs4xdr.c
rewrite.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Already accepted by Bruce
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NFred Isaman <iisaman@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

In the sessions backchannel case, we don't need a krb5 principal name
for the client; we use the already-created forechannel credentials
instead.

Some cleanup, while we're there: make it clearer which code here is 4.0-
or sessions- specific.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The minorversion seems more a property of the client than the callback
channel.

Some time we should probably also enforce consistent minorversion usage
from the client; for now, this is just a cosmetic change.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Only one of the nfsd4_callback_probe callers actually cares about
changing the callback information.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The callback program is allowed to depend on the session which the
callback is going over.

No change in behavior yet, while we still only do callbacks over a
single session for the lifetime of the client.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Currently we don't deal well with a client that has multiple sessions
associated with it (even simultaneously, or serially over the lifetime
of the client).

In particular, we don't attempt to keep the backchannel running after
the original session diseappears.

We will fix that soon.

Once we do that, we need the slot sequence number to be per-session;
otherwise, for example, we cannot correctly handle a case like this:

	- All session 1 connections are lost.
	- The client creates session 2.  We use it for the backchannel
	  (since it's the only working choice).
	- The client gives us a new connection to use with session 1.
	- The client destroys session 2.

At this point our only choice is to go back to using session 1.  When we
do so we must use the sequence number that is next for session 1.  We
therefore need to maintain multiple sequence number streams.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Instead of copying the sessionid, use the new cl_cb_session pointer,
which indicates which session we're using for the backchannel.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Instead of creating the new rpc client from a regular server thread,
set a flag, kick off a null call, and allow the null call to do the work
of setting up the client on the callback workqueue.

Use a spinlock to ensure the callback work gets a consistent view of the
callback parameters.

This allows, for example, changing the callback from contexts where
sleeping is not allowed.  I hope it will also keep the locking simple as
we add more session and trunking features, by serializing most of the
callback-specific work.

This also closes a small race where the the new cb_ident could be used
with an old connection (or vice-versa).
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

I don't see the point of the separate struct.  It seems to just be
getting in the way.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This will eventually allow us, for example, to kick off null callback
from contexts where we can't sleep.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Make the recall callback code more generic, so that other callbacks
will be able to use it too.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

With apologies for the gratuitous rename, the new name seems more
helpful to me.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

These two structs don't really need to be distinct as far as I can tell.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Now that we have both nfsd4_callback and nfsd4_cb_conn structures, I get
confused if variables of both types are always named cb....
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Use NFS4_STATEID_SIZE from include/linux/nfs4
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If a callback is retried at nfsd4_cb_recall_done() due to
some error, the returned rpc reply crashes here:

@@ -514,6 +514,7 @@ decode_cb_sequence(struct xdr_stream *xdr, struct nfsd4_cb_sequence *res,
 	u32 dummy;
 	__be32 *p;

 +	BUG_ON(!res);
 	if (res->cbs_minorversion == 0)
 		return 0;

[BUG_ON added for demonstration]

This is because the nfsd4_cb_done_sequence() has NULLed out
the task->tk_msg.rpc_resp pointer.

Also eventually the rpc would use the new slot without making
sure it is free by calling nfsd41_cb_setup_sequence().

This problem was introduced by a 4.1 protocol addition patch:
	[0421b5c5] nfsd41: Backchannel: Implement cb_recall over NFSv4.1

Which was overlooking the possibility of an RPC callback retries.
For not-4.1 case redoing the _prepare is harmless.
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

When the rarely-used callback-connection-changing setclientid occurs
simultaneously with a delegation recall, we rerun the recall by
requeueing it on a workqueue.  But we also need to take a reference on
the delegation in that case, since the delegation held by the rpc itself
will be released by the rpc_release callback.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>