If the caller does not specify the O_SYNC flag, then it is legitimate
to return from O_DIRECT without doing a pNFS layoutcommit operation.
However if the file is opened O_DIRECT|O_SYNC then we'd better get it
right.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

We don't just want to sync out buffered writes, but also O_DIRECT ones.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

File unlock needs to update both data and metadata on the NFS server
in order to act as a synchronisation point for other clients.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Then apply it to nfs_setattr() and nfs_getattr().
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

pnfs_set_layoutcommit() and pnfs_commit_set_layoutcommit() are 100% identical
except for the function arguments. Refactor to eliminate the difference.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If the NFS_INO_LAYOUTCOMMIT flag was unset, then we _must_ ensure that
we also reset the last write byte (lwb) for that layout. The current
code depends on us clearing the lwb when we clear NFS_INO_LAYOUTCOMMIT,
which is not the case when we call pnfs_clear_layoutcommit().
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Minor optimisation for the case where the layout has return-on-close
enabled.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

I appear to have missed this when adding the ftrace probes.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Make it easier to grep for these functions by name.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

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>

There really is no reason to do so.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Use of synchronize_rcu() when unmounting and potentially freeing a lot
of deviceids is problematic. There really is no reason why we can't just
use kfree_rcu() here.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

This follows up "nfs: fix dio deadlock when O_DIRECT flag is flipped"
and removes the unnecessary CONFIG_NFS_SWAP switch.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Do so on the assumption that for most use cases, that list will turn into
a more or less LRU-ordered list, and so the list traversals in
nfs_client_return_marked_delegations() are likely to be shorter before
hitting a candidate to return.
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>

We do not want to allow a race with another NFS mount to cause
nfs41_walk_client_list() to establish a lease on our nfs_client before
we're done checking for trunking.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

nfs_vm_page_mkwrite() should wait until the page cache invalidation
is finished. This is the second patch in a 2 patch series to deprecate
the NFS client's reliance on nfs_release_page() in the context of
nfs_invalidate_mapping().
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

When invalidating the page cache for a regular file, we want to first
sync all dirty data to disk and then call invalidate_inode_pages2().
The latter relies on nfs_launder_page() and nfs_release_page() to deal
respectively with dirty pages, and unstable written pages.

When commit 95905446 ("NFS: avoid deadlocks with loop-back mounted
NFS filesystems.") changed the behaviour of nfs_release_page(), then it
made it possible for invalidate_inode_pages2() to fail with an EBUSY.
Unfortunately, that error is then propagated back to read().

Let's therefore work around the problem for now by protecting the call
to sync the data and invalidate_inode_pages2() so that they are atomic
w.r.t. the addition of new writes.
Later on, we can revisit whether or not we still need nfs_launder_page()
and nfs_release_page().
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

In nfs_client_return_marked_delegations() and nfs_delegation_reap_unclaimed()
we want to optimise the loop traversal by skipping delegations that are
already in the process of being returned.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

This patch ensures that the superblock doesn't go ahead and disappear
underneath us while the state manager thread is returning delegations.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Ensure that nfs_inode_set_delegation() doesn't inadvertently detach a
delegation that is already in the process of being returned.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.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>

put_rpccred() can sleep.

Fixes: 8f649c37 ("NFSv4: Fix the locking in nfs_inode_reclaim_delegation()")
Cc: stable@vger.kernel.org # 2.6.35+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If the server does not return a valid set of attributes that we can
use to either create a file or refresh the inode, then there is no
value in calling nfs_prime_dcache().

However if we're just refreshing the inode using the attributes that
the server returned, then it shouldn't matter whether or not we have
a filehandle, as long as we check the fsid+fileid combination.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

When we call readdirplus, set the fileid normally returned by readdir
as the mounted-on-fileid, since that is commonly the case if there is
a mountpoint. To ensure that we get it right, we only set the flag if
the readdir fileid differs from the one returned in the readdirplus
attributes.

This again means that we can avoid the issues described in commit
2ef47eb1 ("NFS: Fix use of nfs_attr_use_mounted_on_fileid()"),
which only fixed NFSv4.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If we're traversing a directory which contains a submounted filesystem,
or one that has a referral, the NFS server that is processing the READDIR
request will often return information for the underlying (mounted-on)
directory. It may, or may not, also return filehandle information.

If this happens, and the lookup in nfs_prime_dcache() returns the
dentry for the submounted directory, the filehandle comparison will
fail, and we call d_invalidate(). Post-commit 8ed936b5
("vfs: Lazily remove mounts on unlinked files and directories."), this
means the entire subtree is unmounted.

The following minimal patch addresses this problem by punting on
the invalidation if there is a submount.

Kudos to Neil Brown <neilb@suse.de> for having tracked down this
issue (see link).
Reported-by: NNix <nix@esperi.org.uk>
Link: http://lkml.kernel.org/r/87iofju9ht.fsf@spindle.srvr.nix
Cc: stable@vger.kernel.org # 3.18+
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>

nfs_post_op_update_inode() is called after a self-induced attribute
update. Ensure that it also sets the barrier.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Tested-by: NChuck Lever <chuck.lever@oracle.com>

Prior to this patch, we used to always OK attribute updates that extended
the file size on the assumption that we might be performing writeback.
Now that we have attribute barriers to protect the writeback related updates,
we should remove this hack, as it can cause truncate() operations to
apparently be reverted if/when a readahead or getattr RPC call races
with our on-the-wire SETATTR.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Tested-by: NChuck Lever <chuck.lever@oracle.com>

Ensure that other operations that race with delegreturn and layoutcommit
cannot revert the attribute 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 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 we update the attribute barrier even if there were no
invalidations, provided that this value is newer than the old one.
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>

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Tested-by: NChuck Lever <chuck.lever@oracle.com>

The O_DIRECT code will grab the inode->i_mutex and flush out buffered
writes, before scheduling a read or a write. However there is no
equivalent in the buffered write code to wait for O_DIRECT to complete.

Fixes a reported issue in xfstests generic/133, when first performing an
O_DIRECT write followed by a buffered write.
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>

Currently, the client requests a back channel or a bidirectional
connection when binding a new TCP channel to an existing session.
Fix that to ask for a forward channel or bidirectional.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>