We must only increment the sequence id if the client has seen and responded
to a request.  If we failed to deliver it to the client we must resend with
the same sequence id.  So just like the client track errors at the transport
level differently from those returned in the XDR.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Add support to issue layout recalls to clients.  For now we only support
full-file recalls to get a simple and stable implementation.  This allows
to embedd a nfsd4_callback structure in the layout_state and thus avoid
any memory allocations under spinlocks during a recall.  For normal
use cases that do not intent to share a single file between multiple
clients this implementation is fully sufficient.

To ensure layouts are recalled on local filesystem access each layout
state registers a new FL_LAYOUT lease with the kernel file locking code,
which filesystems that support pNFS exports that require recalls need
to break on conflicting access patterns.

The XDR code is based on the old pNFS server implementation by
Andy Adamson, Benny Halevy, Boaz Harrosh, Dean Hildebrand, Fred Isaman,
Marc Eshel, Mike Sager and Ricardo Labiaga.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The currect code for nfsd41_cb_get_slot() and nfsd4_cb_done() has no
locking in order to guarantee atomicity, and so allows for races of
the form.

Task 1                                  Task 2
======                                  ======
if (test_and_set_bit(0) != 0) {
                                        clear_bit(0)
                                        rpc_wake_up_next(queue)
        rpc_sleep_on(queue)
        return false;
}

This patch breaks the race condition by adding a retest of the bit
after the call to rpc_sleep_on().
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We now have cb_to_delegation and to_delegation, which do the same thing
and are defined separately in different .c files. Move the
cb_to_delegation definition into a header file and eliminate the
redundant to_delegation definition.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJeff Layton <jlayton@primarydata.com>

Add a higher level abstraction than the rpc_ops for callback operations.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Split out initializing the nfs4_callback structure from using it.  For
the NULL callback this gets rid of tons of pointless re-initializations.

Note that I don't quite understand what protects us from running multiple
NULL callbacks at the same time, but at least this chance doesn't make
it worse..
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Add a helper to queue up a callback.  CB_NULL has a bit of special casing
because it is special in the specification, but all other new callback
operations will be able to share code with this and a few more changes
to refactor the callback code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We can always get at the private data by using container_of, no need for
a void pointer.  Also introduce a little to_delegation helper to avoid
opencoding the container_of everywhere.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This is incorrect when a callback is has to be restarted, in which case
the XDR decoding of the second iteration will see a NULL cb argument.

[hch: updated description]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

For any error that is not EBADHANDLE or NFS4ERR_BAD_STATEID,
nfsd4_cb_recall_done first marks the connection down, then
retries until dl_retries hits zero, then marks the connection down
again and sets cb_done.  This changes the code to only retry
for EBADHANDLE or NFS4ERR_BAD_STATEID, and factors setting
cb_done into a single point in the function.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

All stateids are associated with a nfs4_file. Let's consolidate.
Replace delegation->dl_file with the dl_stid.sc_file, and
nfs4_ol_stateid->st_file with st_stid.sc_file.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

When we remove the client_mutex, we'll need to be able to ensure that
these objects aren't destroyed while we're not holding locks.

Add a ->free() callback to the struct nfs4_stid, so that we can
release a reference to the stid without caring about the contents.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Now that the nfs4_file has a filehandle in it, we no longer need to
keep a per-delegation copy of it. Switch to using the one in the
nfs4_file instead.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Replace a comma between expression statements by a semicolon. This changes
the semantics of the code, but given the current indentation appears to be
what is intended.

A simplified version of the Coccinelle semantic patch that performs this
transformation is as follows:
// <smpl>
@r@
expression e1,e2;
@@

 e1
-,
+;
 e2;
// </smpl>
Signed-off-by: NHimangi Saraogi <himangi774@gmail.com>
Acked-by: NJulia Lawall <julia.lawall@lip6.fr>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The current code always selects XPRT_TRANSPORT_BC_TCP for the back
channel, even when the forward channel was not TCP (eg, RDMA). When
a 4.1 mount is attempted with RDMA, the server panics in the TCP BC
code when trying to send CB_NULL.

Instead, construct the transport protocol number from the forward
channel transport or'd with XPRT_TRANSPORT_BC. Transports that do
not support bi-directional RPC will not have registered a "BC"
transport, causing create_backchannel_client() to fail immediately.

Fixes: https://bugzilla.linux-nfs.org/show_bug.cgi?id=265Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

state_lock is a heavily contended global lock. We don't want to grab
that while simultaneously holding the inode->i_lock.

Add a new per-nfs4_file lock that we can use to protect the
per-nfs4_file delegation list. Hold that while walking the list in the
break_deleg callback and queue the workqueue job for each one.

The workqueue job can then take the state_lock and do the list
manipulations without the i_lock being held prior to starting the
rpc call.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

It's just an obfuscated INIT_WORK call. Just make the work_func_t a
non-static symbol and use a normal INIT_WORK call.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

...otherwise the logic in the timeout handling doesn't work correctly.
Spotted-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Besides checking rpc_xprt out of xs_setup_bc_tcp,
increase it's reference (it's important).
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Make sure the client gives us an adequate backchannel.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

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

Lease time is a part of NFSv4 state engine, which is constructed per network
namespace.
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

And use it's net where possible.
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

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

For now this only adds support for AUTH_NULL.  (Previously we assumed
AUTH_UNIX.)  We'll also need AUTH_GSS, which is trickier.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

I've found it confusing having the only references to
nfsd4_do_callback_rpc() in a different file.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We're currently ignoring the callback security parameters specified in
create_session, and just assuming the client wants auth_sys, because
that's all the current linux client happens to care about.  But this
could cause us callbacks to fail to a client that wanted something
different.

For now, all we're doing is no longer ignoring the uid and gid passed in
the auth_sys case.  Further patches will add support for auth_null and
gss (and possibly use more of the auth_sys information; the spec wants
us to use exactly the credential we're passed, though it's hard to
imagine why a client would care).
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

remove duplicate init in nfsd4_cb_recall
Signed-off-by: NNamjae Jeon <linkinjeon@gmail.com>
Signed-off-by: NVivek Trivedi <vtrivedi018@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Commit d5497fc6 "nfsd4: move rq_flavor
into svc_cred" forgot to remove cl_flavor from the client, leaving two
places (cl_flavor and cl_cred.cr_flavor) for the flavor to be stored.
After that patch, the latter was the one that was updated, but the
former was the one that the callback used.

Symptoms were a long delay on utime().  This is because the utime()
generated a setattr which recalled a delegation, but the cb_recall was
ignored by the client because it had the wrong security flavor.

Cc: stable@vger.kernel.org
Tested-by: NJamie Heilman <jamie@audible.transient.net>
Reported-by: NJamie Heilman <jamie@audible.transient.net>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

For the most part readers of cl_cb_state only need a value that is
"eventually" right.  And the value is set only either 1) in response to
some change of state, in which case it's set to UNKNOWN and then a
callback rpc is sent to probe the real state, or b) in the handling of a
response to such a callback.  UNKNOWN is therefore always a "temporary"
state, and for the other states we're happy to accept last writer wins.

So I think we're OK here.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Instead of keeping the principal name associated with a request in a
structure that's private to auth_gss and using an accessor function,
move it to svc_cred.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This isn't actually correct, but it works with the Linux client, and
agrees with the behavior we used to have before commit 80fc015b.

Later patches will implement the spec-mandated behavior (which is to use
the security parameters explicitly given by the client in create_session
or backchannel_ctl).
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We'll need a way to flag the nfs4_client as already being recorded on
stable storage so that we don't continually upcall. Currently, that's
recorded in the cl_firststate field of the client struct. Using an
entire u32 to store a flag is rather wasteful though.

The cl_cb_flags field is only using 2 bits right now, so repurpose that
to a generic flags field. Rename NFSD4_CLIENT_KILL to
NFSD4_CLIENT_CB_KILL to make it evident that it's part of the callback
flags. Add a mask that we can use for existing checks that look to see
whether any flags are set, so that the new flags don't interfere.

Convert all references to cl_firstate to the NFSD4_CLIENT_STABLE flag,
and add a new NFSD4_CLIENT_RECLAIM_COMPLETE flag.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Make sure this is set whenever there is no callback channel.

If a client does not set up a callback channel at all, then it will get
this flag set from the very start.  That's OK, it can just ignore the
flag if it doesn't care.  If a client does care, I think it's better to
inform it of the problem as early as possible.
Reported-by: NRick Macklem <rmacklem@uoguelph.ca>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

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

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>