Now that the shutdown sequence guarantees callbacks are shut down before
the client is destroyed, we no longer have a use for cl_count.

We'll probably reinstate a reference count on the client some day, but
it will be held by users other than callbacks.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The NFSv4 server's fl_break callback can sleep (dropping the BKL), in
order to allocate a new rpc task to send a recall to the client.

As far as I can tell this doesn't cause any races in the current code,
but the analysis is difficult.  Also, the sleep here may complicate the
move away from the BKL.

So, just schedule some work to do the job for us instead.  The work will
later also prove useful for restarting a call after the callback
information is changed.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Any null probe rpc will be synchronously destroyed by the
rpc_shutdown_client() in expire_client(), so the rpc task cannot outlast
the nfs4 client.  Therefore there's no need for that task to hold a
reference on the client.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Instead of allocating this small structure, just include it in the
delegation.

The nfsd4_callback structure isn't really necessary yet, but we plan to
add to it all the information necessary to perform a callback.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Instead of accessing the lease time directly, some users call
nfs4_lease_time(), and some a macro, NFSD_LEASE_TIME, defined as
nfs4_lease_time().  Neither layer of indirection serves any purpose.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

There's no need to allocate this cred more than once.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The server's callback client should stop trying to connect to the
client's callback server as soon as it gets ECONNREFUSED.

The NFS server's callback client does not call rpc_ping(), but appears
to have it's own "ping" procedure, so it wasn't covered by commit
caabea8a.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The new .h files have paths at the top that are now out of date.  While
we're here, just remove all of those from fs/nfsd; they never served any
purpose.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Lots of include/linux/nfsd/* headers are only used by
nfsd module. Move them to the source directory
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Now that the headers are fixed and carry their own wait, all fs/nfsd/
source files can include a minimal set of headers. and still compile just
fine.

This patch should improve the compilation speed of the nfsd module.
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This patch enables the use of the nfsv4.1 backchannel.
Signed-off-by: NAlexandros Batsakis <batsakis@netapp.com>
[initialize rpc_create_args.bc_xprt too]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com>
[nfsd41: cb_recall callback]
[Share v4.0 and v4.1 back channel xdr]
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NRicardo Labiaga <ricardo.labiaga@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[Share v4.0 and v4.1 back channel xdr]
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfsd41: use nfsd4_cb_sequence for callback minorversion]
[nfsd41: conditionally decode_sequence in nfs4_xdr_dec_cb_recall]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfsd41: Backchannel: Add sequence arguments to callback RPC arguments]
Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com>
[pulled-in definition of nfsd4_cb_done]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Implement the cb_sequence callback conforming to draft-ietf-nfsv4-minorversion1

Note: highest slot id and target highest slot id do not have to be 0
as was previously implemented.  They can be greater than what the
nfs server sent if the client supports a larger slot table on the
backchannel.  At this point we just ignore that.
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com>
[Rework the back channel xdr using the shared v4.0 and v4.1 framework.]
Signed-off-by: NAndy Adamson <andros@netapp.com>
[fixed indentation]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfsd41: use nfsd4_cb_sequence for callback minorversion]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfsd41: fix verification of CB_SEQUENCE highest slot id[
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfsd41: Backchannel: Remove old backchannel serialization]
[nfsd41: Backchannel: First callback sequence ID should be 1]
Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfsd41: decode_cb_sequence does not need to actually decode ignored fields]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Follows the model used by the NFS client.  Setup the RPC prepare and done
function pointers so that we can populate the sequence information if
minorversion == 1.  rpc_run_task() is then invoked directly just like
existing NFS client operations do.

nfsd4_cb_prepare() determines if the sequence information needs to be setup.
If the slot is in use, it adds itself to the wait queue.

nfsd4_cb_done() wakes anyone sleeping on the callback channel wait queue
after our RPC reply has been received.  It also sets the task message
result pointer to NULL to clearly indicate we're done using it.
Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com>
[define and initialize cl_cb_seq_nr here]
[pulled out unused defintion of nfsd4_cb_done]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Follow the model we use in the client. Make the sequence arguments
part of the regular RPC arguments.  None of the callbacks that are
soon to be implemented expect results that need to be passed back
to the caller, so we don't define a separate RPC results structure.
For session validation, the cb_sequence decoding will use a pointer
to the sequence arguments that are part of the RPC argument.
Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com>
[define struct nfsd4_cb_sequence here]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Keep the xprt used for create_session in cl_cb_xprt.
Mark cl_callback.cb_minorversion = 1 and remember
the client provided cl_callback.cb_prog rpc program number.
Use it to probe the callback path.

Use the client's network address to initialize as the
callback's address as expected by the xprt creation
routines.

Define xdr sizes and code nfs4_cb_compound header to be able
to send a null callback rpc.

Signed-off-by: Andy Adamson<andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com>
[get callback minorversion from fore channel's]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfsd41: change bc_sock to bc_xprt]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[pulled definition for cl_cb_xprt]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfsd41: set up backchannel's cb_addr]
[moved rpc_create_args init to "nfsd: modify nfsd4.1 backchannel to use new xprt class"]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Callbacks are always made using the machine's identity, so we can use a
single auth_generic credential shared among callbacks to all clients and
let the rpc code take care of the rest.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

On setting up the callback to the client, we attempt to use the same
authentication flavor the client did.  We find an rpc cred to use by
calling rpcauth_lookup_credcache(), which assumes that the given
authentication flavor has a credentials cache.  However, this is not
required to be true--in particular, auth_null does not use one.
Instead, we should call the auth's lookup_cred() method.

Without this, a client attempting to mount using nfsv4 and auth_null
triggers a null dereference.

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

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

...rather than as a separate address and port fields. This will be
necessary for implementing callbacks over IPv6. Also, convert
gen_callback to use the standard rpcuaddr2sockaddr routine rather than
its own private one.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Acked-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Prepare to share backchannel code with NFSv4.1.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com>
[nfsd41: use nfsd4_cb_sequence for callback minorversion]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Mimic the client and prepare to share the back channel xdr with NFSv4.1.
Bump the number of operations in each encode routine, then backfill the
number of operations.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

As with the probe, this removes the need for another kthread.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Move this out of a local variable into the nfs4_delegation object in
preparation for making this an async rpc call (at which point we'll need
any state like this in a common object that's preserved across function
calls).
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

There's no point in keeping this field around--it's always zero.

(Background: the protocol allows you to tell the client that the file is
about to be truncated, as an optimization to save the client from
writing back dirty pages that will just be discarded.  We don't
implement this hint.  If we do some day, adding this field back in will
be the least of the work involved.)
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The nfs4_cb_recall struct is used only in nfs4_delegation, so its
pointer to the containing delegation is unnecessary--we could just use
container_of().

But there's no real reason to have this a separate struct at all--just
move these fields to nfs4_delegation.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

I want to use the name for a struct that actually does represent a
single callback.

(Actually, I've never been sure it helps to a separate struct for the
callback information.  Some day maybe those fields could just be dumped
into struct nfs4_client.  I don't know.)
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

We don't really need a synchronous rpc, and moving to an asynchronous
rpc allows us to do without this extra kthread.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Lookup the callback cred once and then use it for all subsequent
callbacks.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The code is a little simpler, and it should be easier to avoid races, if
we just do all rpc client creation/destruction from nfsd or laundromat
threads and do only the rpc calls themselves asynchronously.  The rpc
creation doesn't involve any significant waiting (it doesn't call the
client, for example), so there's no reason not to do this.

Also don't bother destroying the client on failure of the rpc null
probe.  We may want to retry the probe later anyway.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This is just a minor code simplification.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

We tried to do something overly complicated with the callback rpc
timeouts here.  And they're wrong--the result is that by the time a
single callback times out, it's already too late to tell the client
(using the cb_path_down return to RENEW) that the callback is down.

Use a much shorter, simpler timeout.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

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

The errors returned aren't used.  Just return 0 and make them available
to a dprintk().  Also, consistently use -ERRNO errors instead of nfs
errors.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Reviewed-by: NBenny Halevy <bhalevy@panasas.com>

As part of reducing the scope of the client_mutex, and in order to
remove the need for mutexes from the callback code (so that callbacks
can be done as asynchronous rpc calls), move manipulations of the
file_hashtable under the recall_lock.

Update the relevant comments while we're here.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Cc: Alexandros Batsakis <batsakis@netapp.com>
Reviewed-by: NBenny Halevy <bhalevy@panasas.com>

Since free_client() is guaranteed to only be called once, and to only
touch the client structure itself (not any common data structures), it
has no need for the state lock.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Cc: Alexandros Batsakis <batsakis@netapp.com>

not having the state locked before putting the client/delegation causes a bug.
Also removed the comment from the function header about the state being already locked
Signed-off-by: NAlexandros Batsakis <batsakis@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

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

There's no use for nfs4_cb_null_ops's declaration in fs/nfsd/nfs4callback.c
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This patch adds server-side support for callbacks other than AUTH_SYS.
Signed-off-by: NOlga Kornievskaia <aglo@citi.umich.edu>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>