The brand new GCC 5.1.0 warns by default on using a boolean in the
switch condition. This results in the following warning:

fs/nfs/nfs4proc.c: In function 'nfs4_proc_get_rootfh':
fs/nfs/nfs4proc.c:3100:10: warning: switch condition has boolean value [-Wswitch-bool]
  switch (auth_probe) {
          ^

This code was obviously using switch to make use of the fall-through
semantics (without the usual comment, though).
Rewrite that code using if statements to avoid the warning and make
the code a bit more readable on the way.
Signed-off-by: NAndre Przywara <andre.przywara@arm.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

This file is only used internally to the NFS v4 module, so it doesn't
need to be in the global include path.  I also renamed it from
nfs_idmap.h to nfs4idmap.h to emphasize that it's an NFSv4-only include
file.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

2ef47eb1 (NFS: Fix use of nfs_attr_use_mounted_on_fileid()) was a good
start to fixing a circular directory structure warning for NFS v4
"junctioned" mountpoints.  Unfortunately, further testing continued to
generate this error.

My server is configured like this:

anna@nfsd ~ % df
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1       9.1G  2.0G  6.5G  24% /
/dev/vdc1      1014M   33M  982M   4% /exports
/dev/vdc2      1014M   33M  982M   4% /exports/vol1
/dev/vdc3      1014M   33M  982M   4% /exports/vol1/vol2

anna@nfsd ~ % cat /etc/exports
/exports/          *(rw,async,no_subtree_check,no_root_squash)
/exports/vol1/     *(rw,async,no_subtree_check,no_root_squash)
/exports/vol1/vol2 *(rw,async,no_subtree_check,no_root_squash)

I've been running chown across the entire mountpoint twice in a row to
hit this problem.  The first run succeeds, but the second one fails with
the circular directory warning along with:

anna@client ~ % dmesg
[Apr 3 14:28] NFS: server 192.168.100.204 error: fileid changed
              fsid 0:39: expected fileid 0x100080, got 0x80

WHere 0x80 is the mountpoint's fileid and 0x100080 is the mounted-on
fileid.

This patch fixes the issue by requesting an updated mounted-on fileid
from the server during nfs_update_inode(), and then checking that the
fileid stored in the nfs_inode matches either the fileid or mounted-on
fileid returned by the server.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

that's the bulk of filesystem drivers dealing with inodes of their own
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The spec says that once all layouts that reference a given deviceid
have been returned, then we are only allowed to continue to cache
the deviceid if the metadata server supports notifications.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

We are only allowed to cache deviceinfo if the server supports notifications
and actually promises to call us back when changes occur. Right now, we
request those notifications, but then we don't check the server's reply.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If the call to exchange-id returns with the EXCHGID4_FLAG_CONFIRMED_R flag
set, then that means our lease was established by a previous mount instance.
Ensure that we detect this situation, and that we clear the state held by
that mount.
Reported-by: NJorge Mora <Jorge.Mora@netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

After 566fcec6 the client uses the "current stateid" from the
nfs4_state structure to close a file.  This could potentially contain a
delegation stateid, which is disallowed by the protocol and causes
servers to return NFS4ERR_BAD_STATEID.  This patch restores the
(correct) behavior of sending the open stateid to close a file.
Reported-by: NOlga Kornievskaia <kolga@netapp.com>
Fixes: 566fcec6 (NFSv4: Fix an atomicity problem in CLOSE)
Signed-off-by: NAnna Schumaker <Anna.Schumaker@netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Ensure that we don't regress the changes that were made to the
directory.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Tested-by: NChuck Lever <chuck.lever@oracle.com>

Ensure that other operations that race with our write RPC calls
cannot revert the file size updates that were made on the server.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Tested-by: NChuck Lever <chuck.lever@oracle.com>

Ensure that other operations which raced with our setattr RPC call
cannot revert the file attribute changes that were made on the server.
To do so, we artificially bump the attribute generation counter on
the inode so that all calls to nfs_fattr_init() that precede ours
will be dropped.

The motivation for the patch came from Chuck Lever's reports of readaheads
racing with truncate operations and causing the file size to be reverted.
Reported-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Tested-by: NChuck Lever <chuck.lever@oracle.com>

The share access mode is now specified as an argument in the nfs4_opendata,
and so nfs4_open_recover_helper() needs to call nfs4_map_atomic_open_share()
in order to set it.

Fixes: 6ae37339 ("NFSv4.1: Ask for no delegation on OPEN if using O_DIRECT")
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

We don't need to fake up an entire session in order retrieve the arguments.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If the server doesn't agree to out backchannel setup request, then
don't set one up.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Don't decode directly into the shared struct session
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If we're sending an asynchronous layoutreturn, then we need to ensure
that the inode and the super block remain pinned.

Cc: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: NPeng Tao <tao.peng@primarydata.com>

If we're sending an asynchronous layoutcommit, then we need to ensure
that the inode and the super block remain pinned.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: NPeng Tao <tao.peng@primarydata.com>

If we have to do a return-on-close in the delegreturn code, then
we must ensure that the inode and super block remain referenced.

Cc: Peng Tao <tao.peng@primarydata.com>
Cc: stable@vger.kernel.org # 3.17.x
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: NPeng Tao <tao.peng@primarydata.com>

If we're using NFSv4.1, then we have the ability to let the server know
whether or not we believe that returning a delegation as part of our OPEN
request would be useful.
The feature needs to be used with care, since the client sending the request
doesn't necessarily know how other clients are using that file, and how
they may be affected by the delegation.
For this reason, our initial use of the feature will be to let the server
know when the client believes that handing out a delegation would not be
useful.
The first application for this function is when opening the file using
O_DIRECT.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The flexfile layout is a new layout that extends the
file layout. It is currently being drafted as a specification at
https://datatracker.ietf.org/doc/draft-ietf-nfsv4-layout-types/Signed-off-by: NWeston Andros Adamson <dros@primarydata.com>
Signed-off-by: NTom Haynes <loghyr@primarydata.com>
Signed-off-by: NTao Peng <bergwolf@primarydata.com>

Also take care to stop waiting if someone clears retry bit.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>

When it is set, generic pnfs would try to send layoutreturn right
before last close/delegation_return regard less NFS_LAYOUT_ROC is
set or not. LD can then make sure layoutreturn is always sent
rather than being omitted.

The difference against NFS_LAYOUT_RETURN is that
NFS_LAYOUT_RETURN_BEFORE_CLOSE does not block usage of the layout so
LD can set it and expect generic layer to try pnfs path at the
same time.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTom Haynes <loghyr@primarydata.com>

Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTom Haynes <loghyr@primarydata.com>

So that pnfs path is not disabled for ever.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTom Haynes <Thomas.Haynes@primarydata.com>

And if we are to return the same type of layouts, don't bother
sending more layoutgets.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTom Haynes <Thomas.Haynes@primarydata.com>

Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTom Haynes <Thomas.Haynes@primarydata.com>

flexclient needs this as there is no nfs_server to DS connection.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTom Haynes <Thomas.Haynes@primarydata.com>

Optimise the layout return on close code by ensuring that

1) Add a check for whether we hold a layout before taking any spinlocks
2) Only take the spin lock once
3) Use nfs_state->state to speed up open file checks
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Note, however, that we still serialise on the open stateid if the lock
stateid is unconfirmed. Hopefully that will not prove too much of a
burden for first time locks; it should leave the ability to parallelise
OPENs unchanged, since they no longer call the serialisation primitives.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Ensure that we test the lock stateid remained unchanged while we were
updating the VFS tracking of the byte range lock. Have the process
replay the lock to the server if we detect that was not the case.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

This patch ensures that the server cannot reorder our LOCK/LOCKU
requests if they are sent in parallel on the wire.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The original text in RFC3530 was terribly confusing since it conflated
lockowners and lock stateids. RFC3530bis clarifies that you must use
open_to_lock_owner when there is no lock state for that file+lockowner
combination.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

When we update the lock stateid, we really do need to ensure that this is
done under the state->state_lock, and that we are indeed only updating
confirmed locks with a newer version of the same stateid.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Remove the serialisation of OPEN/OPEN_DOWNGRADE and CLOSE calls for the
case of NFSv4.1 and newer.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

When we relax the sequencing on the NFSv4.1 OPEN/CLOSE code, we will want
to use the value NULL to indicate that no sequencing is needed.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If an OPEN RPC call races with a CLOSE or OPEN_DOWNGRADE so that it
updates the nfs_state structure before the CLOSE/OPEN_DOWNGRADE has
a chance to do so, then we know that the state->flags need to be
recalculated from scratch.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If we are to remove the serialisation of OPEN/CLOSE, then we need to
ensure that the stateid sent as part of a CLOSE operation does not
change after we test the state in nfs4_close_prepare.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Remove an incorrect check for NFS_DELEGATION_NEED_RECLAIM in
can_open_delegated(). We are allowed to cache opens even in
a situation where we're doing reboot recovery.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Ensure that we cache the NFSv4/v4.1 client owner_id so that we can
verify it when we're doing trunking detection.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

This patch adds support for using the NFS v4.2 operation DEALLOCATE to
punch holes in a file.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>