In the replay case, the

	renew_client(session->se_client);

happens after we've droppped the sessionid_lock, and without holding a
reference on the session; so there's nothing preventing the session
being freed before we get here.

Thanks to Benny Halevy for catching a bug in an earlier version of this
patch.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Acked-by: NBenny Halevy <bhalevy@panasas.com>

Enforce the rules about compound op ordering.

Motivated by implementing RECLAIM_COMPLETE, for which the client is
implicit in the current session, so it is important to ensure a
succesful SEQUENCE proceeds the RECLAIM_COMPLETE.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The rfc allows a client to change the callback parameters, but we didn't
previously implement it.

Teach the callbacks to rerun themselves (by placing themselves on a
workqueue) when they recognize that their rpc task has been killed and
that the callback connection has changed.

Then we can change the callback connection by setting up a new rpc
client, modifying the nfs4 client to point at it, waiting for any work
in progress to complete, and then shutting down the old client.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Mainly I just want to separate the arguments used for setting up the tcp
client from the rest.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

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>

We should clear these flags on any new create_session, not just on the
first one.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

I haven't found this useful.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Once we've expired the client, there's no further purpose to the
callbacks; go ahead and shut down the callback client rather than
waiting for the last reference to go.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Allow explicit configuration of the grace period time as well as the
lease period time.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This is another layer of indirection that doesn't really buy us
anything.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The original code here assumed we'd allow the user to change the lease
any time, but only allow the change to take effect on restart.  Since
then we modified the code to allow setting the lease on when the server
is down.  Update the rest of the code to reflect that fact, clarify
variable names, and add document.

Also, the code insisted that the grace period always be the longer of
the old and new lease periods, but that's overly conservative--as long
as it lasts at least the old lease period, old clients should still know
to recover in time.
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>

We'll introduce FMODE_RANDOM which will be runtime modified.  So protect
all runtime modification to f_mode with f_lock to avoid races.
Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: <stable@kernel.org>			[2.6.33.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.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>

None of this stuff is used outside nfsd, so move it out of the common
linux include directory.

Actually, probably none of the stuff in include/linux/nfsd/nfsd.h really
belongs there, so later we may remove that file entirely.
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>

We do the same calculation in a couple places; use a helper function,
and add a little documentation, in the hopes of preventing bugs like
that fixed in the last patch.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Unbalanced calculations on creation and destruction of sessions could
cause our estimate of cache memory used to become negative, sometimes
resulting in spurious SERVERFAULT returns to client CREATE_SESSION
requests.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

ca_maxresponsesize and ca_maxrequest size include the RPC header.

sv_max_mesg is sv_max_payolad plus a page for overhead and is used in
svc_init_buffer to allocate server buffer space for both the request and reply.
Note that this means we can service an RPC compound that requires
ca_maxrequestsize (MAXWRITE) or ca_max_responsesize (MAXREAD) but that we do
not support an RPC compound that requires both ca_maxrequestsize and
ca_maxresponsesize.
Signed-off-by: NAndy Adamson <andros@netapp.com>
[bfields@citi.umich.edu: more documentation updates]
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move common initialization of 'struct nfs4_client' inside create_client().
Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com>

[nfsd41: Remember the auth flavor to use for callbacks]
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>

RPC callback requests will wait on this wait queue if the backchannel
is out of slots.
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>

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>

The failure here is pretty unlikely, but we should handle it anyway.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Use NFSD_SLOT_CACHE_SIZE size buffers for sessions DRC instead of holding nfsd
pages in cache.

Connectathon testing has shown that 1024 bytes for encoded compound operation
responses past the sequence operation is sufficient, 512 bytes is a little too
small. Set NFSD_SLOT_CACHE_SIZE to 1024.

Allocate memory for the session DRC in the CREATE_SESSION operation
to guarantee that the memory resource is available for caching responses.
Allocate each slot individually in preparation for slot table size negotiation.

Remove struct nfsd4_cache_entry and helper functions for the old page-based
DRC.

The iov_len calculation in nfs4svc_encode_compoundres is now always
correct.  Replay is now done in nfsd4_sequence under the state lock, so
the session ref count is only bumped on non-replay. Clean up the
nfs4svc_encode_compoundres session logic.

The nfsd4_compound_state statp pointer is also not used.
Remove nfsd4_set_statp().

Move useful nfsd4_cache_entry fields into nfsd4_slot.

Signed-off-by: Andy Adamson <andros@netapp.com
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

nfserr_resource is not a legal error for NFSv4.1. Replace it with
nfserr_serverfault for EXCHANGE_ID and CREATE_SESSION processing.

We will also need to map nfserr_resource to other errors in routines shared
by NFSv4.0 and NFSv4.1
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This fixes a bug in the sequence operation reply.

The sequence operation returns the highest slotid it will accept in the future
in sr_highest_slotid, and the highest slotid it prefers the client to use.
Since we do not re-negotiate the session slot table yet, these should both
always be set to the session ca_maxrequests.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

By using the requested ca_maxresponsesize_cached * ca_maxresponses to bound
a forechannel drc request size, clients can tailor a session to usage.

For example, an I/O session (READ/WRITE only) can have a much smaller
ca_maxresponsesize_cached (for only WRITE compound responses) and a lot larger
ca_maxresponses to service a large in-flight data window.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Compounds consisting of only a sequence operation don't need any
additional caching beyond the sequence information we store in the slot
entry.  Fix nfsd4_is_solo_sequence to identify this case correctly.

The additional check for a failed sequence in nfsd4_store_cache_entry()
is redundant, since the nfsd4_is_solo_sequence call lower down catches
this case.

The final ce_cachethis set in nfsd4_sequence is also redundant.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Until we work out the state locking so we can use a spin lock to protect
the cl_lru, we need to take the state_lock to renew the client.
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfsd41: Do not renew state on error]
Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfsd41: Simplify exit code]
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

When a SETCLIENTID call comes in, one of the args given is the svc_rqst.
This struct contains an rq_addr field which holds the address that sent
the call. If this is an IPv6 address, then we can use the sin6_scope_id
field in this address to populate the sin6_scope_id field in the
callback address.

AFAICT, the rq_addr.sin6_scope_id is non-zero if and only if the client
mounted the server's link-local address.
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>

The framework to add this is all in place. Now, add the code to allow
support for establishing a callback channel on an IPv6 socket.
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>

...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>

It's currently a __be32, which isn't big enough to hold an IPv6 address.
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>