NFSv4.0 does not have TEST_STATEID/FREE_STATEID functionality, so
unlike NFSv4.1, the recovery procedure when stateids have expired or
have been revoked requires us to just forget the delegation.

http://lkml.kernel.org/r/CAN-5tyHwG=Cn2Q9KsHWadewjpTTy_K26ee+UnSvHvG4192p-Xw@mail.gmail.com
Cc: stable@vger.kernel.org
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Somehow the nfs_v4_1_minor_ops had the NFS_CAP_SEEK flag set, enabling
SEEK over v4.1.  This is wrong, and can make servers crash.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Tested-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

This reverts commit 4fa2c54b.

This reverts commit f39c0104.

Commit 2f60ea6b ("NFSv4: The NFSv4.0 client must send RENEW calls if it holds a delegation") set the NFS4_RENEW_TIMEOUT flag in nfs4_renew_state, and does
not put an nfs41_proc_async_sequence call, the NFSv4.1 lease renewal heartbeat
call, on the wire to renew the NFSv4.1 state if the flag was not set.

The NFS4_RENEW_TIMEOUT flag is set when "now" is after the last renewal
(cl_last_renewal) plus the lease time divided by 3. This is arbitrary and
sometimes does the following:

In normal operation, the only way a future state renewal call is put on the
wire is via a call to nfs4_schedule_state_renewal, which schedules a
nfs4_renew_state workqueue task. nfs4_renew_state determines if the
NFS4_RENEW_TIMEOUT should be set, and the calls nfs41_proc_async_sequence,
which only gets sent if the NFS4_RENEW_TIMEOUT flag is set.
Then the nfs41_proc_async_sequence rpc_release function schedules
another state remewal via nfs4_schedule_state_renewal.

Without this change we can get into a state where an application stops
accessing the NFSv4.1 share, state renewal calls stop due to the
NFS4_RENEW_TIMEOUT flag _not_ being set. The only way to recover
from this situation is with a clientid re-establishment, once the application
resumes and the server has timed out the lease and so returns
NFS4ERR_BAD_SESSION on the subsequent SEQUENCE operation.

An example application:
open, lock, write a file.

sleep for 6 * lease (could be less)

ulock, close.

In the above example with NFSv4.1 delegations enabled, without this change,
there are no OP_SEQUENCE state renewal calls during the sleep, and the
clientid is recovered due to lease expiration on the close.

This issue does not occur with NFSv4.1 delegations disabled, nor with
NFSv4.0, with or without delegations enabled.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Link: http://lkml.kernel.org/r/1411486536-23401-1-git-send-email-andros@netapp.com
Fixes: 2f60ea6b (NFSv4: The NFSv4.0 client must send RENEW calls...)
Cc: stable@vger.kernel.org # 3.2.x
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The SEEK operation is used when an application makes an lseek call with
either the SEEK_HOLE or SEEK_DATA flags set.  I fall back on
nfs_file_llseek() if the server does not have SEEK support.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Currently asynchronous NFSv4 request will be retried with
exponential timeout (from 1/10 to 15 seconds), but async
requests will always use a 15second retry.

Some "async" requests are really synchronous though.  The
async mechanism is used to allow the request to continue if
the requesting process is killed.
In those cases, an exponential retry is appropriate.

For example, if two different clients both open a file and
get a READ delegation, and one client then unlinks the file
(while still holding an open file descriptor), that unlink
will used the "silly-rename" handling which is async.
The first rename will result in NFS4ERR_DELAY while the
delegation is reclaimed from the other client.  The rename
will not be retried for 15 seconds, causing an unlink to take
15 seconds rather than 100msec.

This patch only added exponential timeout for async unlink and
async rename.  Other async calls, such as 'close' are sometimes
waited for so they might benefit from exponential timeout too.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

James Drew reports another bug whereby the NFS client is now sending
an OPEN_DOWNGRADE in a situation where it should really have sent a
CLOSE: the client is opening the file for O_RDWR, but then trying to
do a downgrade to O_RDONLY, which is not allowed by the NFSv4 spec.
Reported-by: NJames Drews <drews@engr.wisc.edu>
Link: http://lkml.kernel.org/r/541AD7E5.8020409@engr.wisc.edu
Fixes: aee7af35 (NFSv4: Fix problems with close in the presence...)
Cc: stable@vger.kernel.org # 2.6.33+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Both blocks layout and objects layout want to use it to avoid CB_LAYOUTRECALL
but that should only happen if client is doing truncation to a smaller size.
For other cases, we let server decide if it wants to recall client's layouts.
Change PNFS_LAYOUTRET_ON_SETATTR to follow the logic and not to send
layoutreturn unnecessarily.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Boaz Harrosh <boaz@plexistor.com>
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The current GETDEVICELIST implementation is buggy in that it doesn't handle
cursors correctly, and in that it returns an error if the server returns
NFSERR_NOTSUPP.  Given that there is no actual need for GETDEVICELIST,
it has various issues and might get removed for NFSv4.2 stop using it in
the blocklayout driver, and thus the Linux NFS client as whole.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

commit 4fa2c54b
    NFS: nfs4_do_open should add negative results to the dcache.

used "d_drop(); d_add();" to ensure that a dentry was hashed
as a negative cached entry.
This is not safe if the dentry has an non-NULL ->d_inode.
It will trigger a BUG_ON in d_instantiate().
In that case, d_delete() is needed.

Also, only d_add if the dentry is currently unhashed, it seems
pointless removed and re-adding it unchanged.
Reported-by: NChristoph Hellwig <hch@infradead.org>
Fixes: 4fa2c54b
Cc: Jeff Layton <jeff.layton@primarydata.com>
Link: http://lkml.kernel.org/r/20140908144525.GB19811@infradead.orgSigned-off-by: NNeilBrown <neilb@suse.de>
Acked-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Currently we fall through to nfs4_async_handle_error when we get
a bad stateid error back from layoutget.  nfs4_async_handle_error
with a NULL state argument will never retry the operations but return
the error to higher layer, causing an avoiable fallback to MDS I/O.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

can_open_cached() reads values out of the state structure, meaning that
we need the so_lock to have a correct return value.  As a bonus, this
helps clear up some potentially confusing code.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If we did an OPEN_DOWNGRADE, then the right thing to do on success, is
to apply the new open mode to the struct nfs4_state. Instead, we were
unconditionally clearing the state, making it appear to our state
machinery as if we had just performed a CLOSE.

Fixes: 226056c5 (NFSv4: Use correct locking when updating nfs4_state...)
Cc: stable@vger.kernel.org # 3.15+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

In the presence of delegations, we can no longer assume that the
state->n_rdwr, state->n_rdonly, state->n_wronly reflect the open
stateid share mode, and so we need to calculate the initial value
for calldata->arg.fmode using the state->flags.
Reported-by: NJames Drews <drews@engr.wisc.edu>
Fixes: 88069f77 (NFSv41: Fix a potential state leakage when...)
Cc: stable@vger.kernel.org # 2.6.33+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Fix Commit 60ea6812 (NFS: Migration support for RELEASE_LOCKOWNER)
If getting expired error, client will enter a infinite loop as,

client                            server
   RELEASE_LOCKOWNER(old clid) ----->
                <--- expired error
   RENEW(old clid)             ----->
                <--- expired error
   SETCLIENTID                 ----->
                <--- a new clid
   SETCLIENTID_CONFIRM (new clid) -->
                <--- ok
   RELEASE_LOCKOWNER(old clid) ----->
                <--- expired error
   RENEW(new clid)             ----->
                <-- ok
   RELEASE_LOCKOWNER(old clid) ----->
                <--- expired error
   RENEW(new clid)             ----->
                <-- ok
                ... ...
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
[Trond: replace call to nfs4_async_handle_error() with
 nfs4_schedule_lease_recovery()]
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If you have an NFSv4 mounted directory which does not container 'foo'
and:

  ls -l foo
  ssh $server touch foo
  cat foo

then the 'cat' will fail (usually, depending a bit on the various
cache ages).  This is correct as negative looks are cached by default.
However with the same initial conditions:

  cat foo
  ssh $server touch foo
  cat foo

will usually succeed.  This is because an "open" does not add a
negative dentry to the dcache, while a "lookup" does.

This can have negative performance effects.  When "gcc" searches for
an include file, it will try to "open" the file in every director in
the search path.  Without caching of negative "open" results, this
generates much more traffic to the server than it should (or than
NFSv3 does).

The root of the problem is that _nfs4_open_and_get_state() will call
d_add_unique() on a positive result, but not on a negative result.
Compare with nfs_lookup() which calls d_materialise_unique on both
a positive result and on ENOENT.

This patch adds a call d_add() in the ENOENT case for
_nfs4_open_and_get_state() and also calls nfs_set_verifier().

With it, many fewer "open" requests for known-non-existent files are
sent to the server.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The current CB_COMPOUND handling code tries to compare the principal
name of the request with the cl_hostname in the client. This is not
guaranteed to ever work, particularly if the client happened to mount
a CNAME of the server or a non-fqdn.

Fix this by instead comparing the cr_principal string with the acceptor
name that we get from gssd. In the event that gssd didn't send one
down (i.e. it was too old), then we fall back to trying to use the
cl_hostname as we do today.
Signed-off-by: NJeff Layton <jlayton@poochiereds.net>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Nothing checks its return value.
Signed-off-by: NJeff Layton <jlayton@poochiereds.net>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If file is not opened by anyone, we do layout return on close
in delegation return.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If client has valid delegation, do not return layout on close at all.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

POSIX states that open("foo", O_CREAT|O_RDONLY, 000) should succeed if
the file "foo" does not already exist. With the current NFS client,
it will fail with an EACCES error because of the permissions checks in
nfs4_opendata_access().

Fix is to turn that test off if the server says that we created the file.
Reported-by: N"Frank S. Filz" <ffilzlnx@mindspring.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

struct nfs_pgio_data only exists as a member of nfs_pgio_header, but is
passed around everywhere, because there used to be multiple _data structs
per _header. Many of these functions then use the _data to find a pointer
to the _header.  This patch cleans this up by merging the nfs_pgio_data
structure into nfs_pgio_header and passing nfs_pgio_header around instead.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NWeston Andros Adamson <dros@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Fix nfs4_negotiate_security to create an rpc_clnt used to test each SECINFO
returned pseudoflavor. Check credential creation  (and gss_context creation)
which is important for RPC_AUTH_GSS pseudoflavors which can fail for multiple
reasons including mis-configuration.

Don't call nfs4_negotiate in nfs4_submount as it was just called by
nfs4_proc_lookup_mountpoint (nfs4_proc_lookup_common)
Signed-off-by: NAndy Adamson <andros@netapp.com>
[Trond: fix corrupt return value from nfs_find_best_sec()]
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

This constant has the wrong value.  And we don't use it.  And it's been
removed from the 4.2 spec anyway.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Place the call to resend the failed GETATTR under the error handler so that
when appropriate, the GETATTR is retried more than once.

The server can fail the GETATTR op in the OPEN compound with a recoverable
error such as NFS4ERR_DELAY. In the case of an O_EXCL open, the server has
created the file, so a retrans of the OPEN call will fail with NFS4ERR_EXIST.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The read and write paths do exactly the same thing for the rpc_prepare
rpc_op.  This patch combines them together into a single function.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

At this point, the only difference between nfs_read_data and
nfs_write_data is the write verifier.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Reads and writes have very similar arguments.  This patch combines them
together and documents the few fields used only by write.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The read_pageio_init method is just a very convoluted way to grab the
right nfs_pageio_ops vector.  The vector to chose is not a choice of
protocol version, but just a pNFS vs MDS I/O choice that can simply be
done inside nfs_pageio_init_read based on the presence of a layout
driver, and a new force_mds flag to the special case of falling back
to MDS I/O on a pNFS-capable volume.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The write_pageio_init method is just a very convoluted way to grab the
right nfs_pageio_ops vector.  The vector to chose is not a choice of
protocol version, but just a pNFS vs MDS I/O choice that can simply be
done inside nfs_pageio_init_write based on the presence of a layout
driver, and a new force_mds flag to the special case of falling back
to MDS I/O on a pNFS-capable volume.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If we interrupt the nfs4_wait_for_completion_rpc_task() call in
nfs4_run_open_task(), then we don't prevent the RPC call from
completing. So freeing up the opendata->f_attr.mdsthreshold
in the error path in _nfs4_do_open() leads to a use-after-free
when the XDR decoder tries to decode the mdsthreshold information
from the server.

Fixes: 82be417a (NFSv4.1 cache mdsthreshold values on OPEN)
Tested-by: NSteve Dickson <SteveD@redhat.com>
Cc: stable@vger.kernel.org # 3.5+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

NFSv4.0 clients use the SETCLIENTID operation to inform NFS servers
how to contact a client's callback service.  If a server cannot
contact a client's callback service, that server will not delegate
to that client, which results in a performance loss.

Our client advertises "rdma" as the callback netid when the forward
channel is "rdma".  But our client always starts only "tcp" and
"tcp6" callback services.

Instead of advertising the forward channel netid, advertise "tcp"
or "tcp6" as the callback netid, based on the value of the
clientaddr mount option, since those are what our client currently
supports.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=69171Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Now that nfs_rename uses the async infrastructure, we can remove this.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Tested-by: NAnna Schumaker <Anna.Schumaker@netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If the open stateid could not be recovered, or the file locks were lost,
then we should fail the truncate() operation altogether.
Reported-by: NAndy Adamson <andros@netapp.com>
Link: http://lkml.kernel.org/r/1393954269-3974-1-git-send-email-andros@netapp.comSigned-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

When nfs4_set_rw_stateid() can fails by returning EIO to indicate that
the stateid is completely invalid, then it makes no sense to have it
trigger a retry of the READ or WRITE operation. Instead, we should just
have it fall through and attempt a recovery.

This fixes an infinite loop in which the client keeps replaying the same
bad stateid back to the server.
Reported-by: NAndy Adamson <andros@netapp.com>
Link: http://lkml.kernel.org/r/1393954269-3974-1-git-send-email-andros@netapp.com
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

nfs4_release_lockowner needs to set the rpc_message reply to point to
the nfs4_sequence_res in order to avoid another Oopsable situation
in nfs41_assign_slot.

Fixes: fbd4bfd1 (NFS: Add nfs4_sequence calls for RELEASE_LOCKOWNER)
Cc: stable@vger.kernel.org # 3.12+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

RFC3530 and RFC5661 both prescribe that the 'opaque' field of the
open stateid returned by new OPEN/OPEN_DOWNGRADE/CLOSE calls for
the same file and open owner should match.
If this is not the case, assume that the open state has been lost,
and that we need to recover it.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The stateid and state->flags should be updated atomically under
protection of the state->seqlock.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

This patch is in preparation for the NFSv4.1 parallel open capability.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>