NFSv4: nfs4_do_open() is incorrectly triggering state recovery

We're seeing spurious calls to nfs4_schedule_stateid_recovery() from
nfs4_do_open() in situations where there is no trigger coming from the
server.
In theory the code path being triggered is supposed to notice that state
recovery happened while we were processing the open call result from the
server, before the open stateid is published. However in the years since
that code was added, we've also added the 'session draining' mechanism,
which ensures that the state recovery will wait until all the session
slots have been returned. In nfs4_do_open() the session slot is only
returned on exit of the function, so we don't need the legacy mechanism.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

nfs: adapt to breakup of struct file_lock

Most of the existing APIs have remained the same, but subsystems that
access file_lock fields directly need to reach into struct
file_lock_core now.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20240131-flsplit-v3-41-c6129007ee8d@kernel.org
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

nfs: convert to using new filelock helpers

Convert to using the new file locking helper functions. Also, in later
patches we're going to introduce some temporary macros with names that
clash with the variable name in nfs4_proc_unlck. Rename it.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20240131-flsplit-v3-11-c6129007ee8d@kernel.org
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

NFSv4: fairly test all delegations on a SEQ4_ revocation

When the client is required to use TEST_STATEID to discover which
delegation(s) have been revoked, it may continually test delegations at the
head of the list if the server continues to be unsatisfied and send
SEQ4_STATUS_RECALLABLE_STATE_REVOKED. For a large number of delegations
this behavior is prone to live-lock because the client may never be able to
test and free revoked state at the end of the list since the
SEQ4_STATUS_RECALLABLE_STATE_REVOKED will cause us to flag delegations at
the head of the list to be tested. This problem is further exacerbated by
the state manager's willingness to be scheduled out on a busy system while
testing the list of delegations.

Keep a generation counter for each attempt to test all delegations, and
skip delegations that have already been tested in the current pass.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Torkil Svensgaard <torkil@drcmr.dk>
Tested-by: Ruben Vestergaard <rubenv@drcmr.dk>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

nfs: use locks_inode_context helper

nfs currently doesn't access i_flctx safely. This requires a
smp_load_acquire, as the pointer is set via cmpxchg (a release
operation).

Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Layton <jlayton@kernel.org>

NFSv4: Fix a potential state reclaim deadlock

If the server reboots while we are engaged in a delegation return, and
there is a pNFS layout with return-on-close set, then the current code
can end up deadlocking in pnfs_roc() when nfs_inode_set_delegation()
tries to return the old delegation.
Now that delegreturn actually uses its own copy of the stateid, it
should be safe to just always update the delegation stateid in place.

Fixes: 078000d02d57 ("pNFS: We want return-on-close to complete when evicting the inode")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Charge NFSv4 open state trackers to kmemcg

Allow kmemcg to limit the number of NFSv4 delegation, lock and open
state trackers.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fixes for nfs4_inode_return_delegation()

We mustn't call nfs_wb_all() on anything other than a regular file.
Furthermore, we can exit early when we don't hold a delegation.

Reported-by: David Wysochanski <dwysocha@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Add lease breakpoints in case of a delegation recall or return

When we add support for application level leases and knfsd delegations
to the NFS client, we we want to have them safely underpinned by a
"real" delegation to provide the caching guarantees. If that real
delegation is recalled, then we need to ensure that the application
leases/delegations are recalled too.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix delegation return in cases where we have to retry

If we're unable to immediately recover all locks because the server is
unable to immediately service our reclaim calls, then we want to retry
after we've finished servicing all the other asynchronous delegation
returns on our queue.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Don't store NFS_INO_REVAL_FORCED

NFS_INO_REVAL_FORCED is intended to tell us that the cache needs
revalidation despite the fact that we hold a delegation. We shouldn't
need to store it anymore, though.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Fix up incorrect documentation

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: nfs_delegation_find_inode_server must first reference the superblock

Before referencing the inode, we must ensure that the superblock can be
referenced. Otherwise, we can end up with iput() calling superblock
operations that are no longer valid or accessible.

Fixes: e39d8a186ed0 ("NFSv4: Fix an Oops during delegation callbacks")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Beware when dereferencing the delegation cred

When we look up the delegation cred, we are usually doing so in
conjunction with a read of the stateid, and we want to ensure
that the look up is atomic with that read.

Fixes: 57f188e04773 ("NFSv4: nfs_update_inplace_delegation() should update delegation cred")
[sfr@canb.auug.org.au: Fixed up borken Fixes: line from Trond :-)]
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Clean up nfs_delegation_reap_expired()

Convert to use nfs_client_for_each_server() for efficiency.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Clean up nfs_delegation_reap_unclaimed()

Convert nfs_delegation_reap_unclaimed() to use nfs_client_for_each_server()
for efficiency.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Clean up nfs_client_return_marked_delegations()

Convert it to use the nfs_client_for_each_server() helper, and
make it more efficient by skipping delegations for inodes we
know are in the process of being freed. Also improve the efficiency
of the cursor by skipping delegations that are being freed.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: nfs_update_inplace_delegation() should update delegation cred

If the cred assigned to the delegation that we're updating differs
from the one we're updating too, then we need to update that field
too.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Ensure the delegation cred is pinned when we call delegreturn

Ensure we don't release the delegation cred during the call to
nfs4_proc_delegreturn().

Fixes: ee05f456772d ("NFSv4: Fix races between open and delegreturn")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Ensure the delegation is pinned in nfs_do_return_delegation()

The call to nfs_do_return_delegation() needs to be taken without
any RCU locks. Add a refcount to make sure the delegation remains
pinned in memory until we're done.

Fixes: ee05f456772d ("NFSv4: Fix races between open and delegreturn")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Fix revalidation of dentries with delegations

If a dentry was not initially looked up while we were holding a
delegation, then we do still need to revalidate that it still holds
the same name. If there are multiple hard links to the same file,
then all the hard links need validation.

Reported-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
[Anna: Put nfs_unset_verifier_delegated() under CONFIG_NFS_V4]
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Limit the total number of cached delegations

Delegations can be expensive to return, and can cause scalability issues
for the server. Let's therefore try to limit the number of inactive
delegations we hold.
Once the number of delegations is above a certain threshold, start
to return them on close.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Add accounting for the number of active delegations held

In order to better manage our delegation caching, add a counter
to track the number of active delegations.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Try to return the delegation immediately when marked for return on close

Add a routine to return the delegation immediately upon close of the
file if it was marked for return-on-close.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Clear NFS_DELEGATION_RETURN_IF_CLOSED when the delegation is returned

If a delegation is marked as needing to be returned when the file is
closed, then don't clear that marking until we're ready to return
it.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: nfs_inode_evict_delegation() should set NFS_DELEGATION_RETURNING

In particular, the pnfs return-on-close code will check for that flag,
so ensure we set it appropriately.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Handle NFS4ERR_OLD_STATEID in delegreturn

If the server returns NFS4ERR_OLD_STATEID in response to our delegreturn,
we want to sync to the most recent seqid for the delegation stateid. However
if we are already at the most recent, we have two possibilities:

- an OPEN reply is still outstanding and will return a new seqid
- an earlier OPEN reply was dropped on the floor due to a timeout.

In the latter case, we may end up unable to complete the delegreturn,
so we want to bump the seqid to a value greater than the cached value.
While this may cause us to lose the delegation in the former case,
it should now be safe to assume that the client will replay the OPEN
if necessary in order to get a new valid stateid.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix races between open and delegreturn

If the server returns the same delegation in an open that we just used
in a delegreturn, we need to ensure we don't apply that stateid if
the delegreturn has freed it on the server.
To do so, we ensure that we do not free the storage for the delegation
until either it is replaced by a new one, or we throw the inode out of
cache.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: nfs_inode_find_state_and_recover() fix stateid matching

In nfs_inode_find_state_and_recover() we want to mark for recovery
only those stateids that match or are older than the supplied
stateid parameter.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix nfs4_inode_make_writeable()

Fix the checks in nfs4_inode_make_writeable() to ignore the case where
we hold no delegations. Currently, in such a case, we automatically
flush writes.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Don't reclaim delegations that have been returned or revoked

If the delegation has already been revoked, we want to avoid reclaiming
it on reboot.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Ignore requests to return the delegation if it was revoked

If the delegation was revoked, or is already being returned, just
clear the NFS_DELEGATION_RETURN and NFS_DELEGATION_RETURN_IF_CLOSED
flags and keep going.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Revoke the delegation on success in nfs4_delegreturn_done()

If the delegation was successfully returned, then mark it as revoked.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Update the stateid seqid in nfs_revoke_delegation()

If we revoke a delegation, but the stateid's seqid is newer, then
ensure we update the seqid when marking the delegation as revoked.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Clear the NFS_DELEGATION_REVOKED flag in nfs_update_inplace_delegation()

If the server sent us a new delegation stateid that is more recent than
the one that got revoked, then clear the NFS_DELEGATION_REVOKED flag.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Hold the delegation spinlock when updating the seqid

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Don't remove the delegation from the super_list more than once

Add a check to ensure that we haven't already removed the delegation
from the inode after we take all the relevant locks.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Rename nfs_inode_return_delegation_noreclaim()

Rename nfs_inode_return_delegation_noreclaim() to
nfs_inode_evict_delegation(), which better describes what it
does.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: fail nfs4_refresh_delegation_stateid() when the delegation was revoked

If the delegation was revoked, we don't want to retry the delegreturn.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Delegation recalls should not find revoked delegations

If we're processsing a delegation recall, ignore the delegations that
have already been revoked or returned.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Fix an RCU lock leak in nfs4_refresh_delegation_stateid()

A typo in nfs4_refresh_delegation_stateid() means we're leaking an
RCU lock, and always returning a value of 'false'. As the function
description states, we were always supposed to return 'true' if a
matching delegation was found.

Fixes: 12f275cdd163 ("NFSv4: Retry CLOSE and DELEGRETURN on NFS4ERR_OLD_STATEID.")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Don't allow a cached open with a revoked delegation

If the delegation is marked as being revoked, we must not use it
for cached opens.

Fixes: 869f9dfa4d6d ("NFSv4: Fix races between nfs_remove_bad_delegation() and delegation return")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.1: Only reap expired delegations

Fix nfs_reap_expired_delegations() to ensure that we only reap delegations
that are actually expired, rather than triggering on random errors.

Fixes: 45870d6909d5a ("NFSv4.1: Test delegation stateids when server...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix delegation state recovery

Once we clear the NFS_DELEGATED_STATE flag, we're telling
nfs_delegation_claim_opens() that we're done recovering all open state
for that stateid, so we really need to ensure that we test for all
open modes that are currently cached and recover them before exiting
nfs4_open_delegation_recall().

Fixes: 24311f884189d ("NFSv4: Recovery of recalled read delegations...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.3+

treewide: Add SPDX license identifier for missed files

Add SPDX license identifiers to all files which:

- Have no license information of any form

- Have EXPORT_.*_SYMBOL_GPL inside which was used in the
initial scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

NFSv4: don't mark all open state for recovery when handling recallable state revoked flag

Only delegations and layouts can be recalled, so it shouldn't be
necessary to recover all opens when handling the status bit
SEQ4_STATUS_RECALLABLE_STATE_REVOKED. We'll still wind up calling
nfs41_open_expired() when a TEST_STATEID returns NFS4ERR_DELEG_REVOKED.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Reviewed-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Fix a soft lockup in the delegation recovery code

Fix a soft lockup when NFS client delegation recovery is attempted
but the inode is in the process of being freed. When the
igrab(inode) call fails, and we have to restart the recovery process,
we need to ensure that we won't attempt to recover the same delegation
again.

Fixes: 45870d6909d5a ("NFSv4.1: Test delegation stateids when server...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Fix up documentation warnings

Fix up some compiler warnings about function parameters, etc not being
correctly described or formatted.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS/NFSD/SUNRPC: replace generic creds with 'struct cred'.

SUNRPC has two sorts of credentials, both of which appear as
"struct rpc_cred".
There are "generic credentials" which are supplied by clients
such as NFS and passed in 'struct rpc_message' to indicate
which user should be used to authorize the request, and there
are low-level credentials such as AUTH_NULL, AUTH_UNIX, AUTH_GSS
which describe the credential to be sent over the wires.

This patch replaces all the generic credentials by 'struct cred'
pointers - the credential structure used throughout Linux.

For machine credentials, there is a special 'struct cred *' pointer
which is statically allocated and recognized where needed as
having a special meaning. A look-up of a low-level cred will
map this to a machine credential.

Signed-off-by: NeilBrown <neilb@suse.com>
Acked-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Fix an Oops during delegation callbacks

If the server sends a CB_GETATTR or a CB_RECALL while the filesystem is
being unmounted, then we can Oops when releasing the inode in
nfs4_callback_getattr() and nfs4_callback_recall().

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.x: fix lock recovery during delegation recall

Running "./nfstest_delegation --runtest recall26" uncovers that
client doesn't recover the lock when we have an appending open,
where the initial open got a write delegation.

Instead of checking for the passed in open context against
the file lock's open context. Check that the state is the same.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Convert lookups of the open context to RCU

Reduce contention on the inode->i_lock by ensuring that we use RCU
when looking up the NFS open context.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Fix an rcu deadlock in nfs_delegation_find_inode()

I was able to reproduce this pretty regularily using xfstests
generic/013 on NFS v4.0.

Reported-by: Ross Zwisler <Ross.Zwisler@linux.intel.com>
Fixes: 6c342655022d (NFSv4: Return NFS4ERR_DELAY when a delegation recall fails due to igrab())
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Return NFS4ERR_DELAY when a delegation recall fails due to igrab()

If the attempt to recall the delegation fails because the inode is
in the process of being evicted from cache, then use NFS4ERR_DELAY
to ask the server to retry later.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Ensure the inode is clean when we set a delegation

If there are attributes that are still invalid when we set a delegation,
then we need to set the NFS_INO_REVAL_FORCED flag.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Avoid quadratic search when freeing delegations.

There are three places that walk all delegation for an nfs_client and
restart whenever they find something interesting - potentially
resulting in a quadratic search: If there are 10,000 uninteresting
delegations followed by 10,000 interesting one, then the code
skips over 100,000,000 delegations, which can take a noticeable amount
of time.

Of these nfs_delegation_reap_unclaimed() and
nfs_reap_expired_delegations() are only called during unusual events:
a server reboots or reports expired delegations, probably due to a
network partition. Optimizing these is not particularly important.

The third, nfs_client_return_marked_delegations(), is called
periodically via nfs_expire_unreferenced_delegations(). It could
cause periodic problems on a busy server.

New delegations are added to the end of the list, so if there are
10,000 open files with delegations, and 10,000 more recently opened files
that received delegations but are now closed, then
nfs_client_return_marked_delegations() can take seconds to skip over
the 10,000 open files 10,000 times. That is a waste of time.

The avoid this waste a place-holder (an inode) is kept when locks are
dropped, so that the place can usually be found again after taking
rcu_readlock(). This place holder ensure that we find the right
starting point in the list of nfs_servers, and makes is probable that
we find the right starting point in the list of delegations.
We might need to occasionally restart at the head of that list.

It might be possible that the place_holder inode could lose its
delegation separately, and then get a new one using the same (freed
and then reallocated) 'struct nfs_delegation'. Were this to happen,
the new delegation would be at the end of the list and we would miss
returning some other delegations. This would have the effect of
unnecessarily delaying the return of some unused delegations until the
next time this function is called - typically 90 seconds later. As
this is not a correctness issue and is vanishingly unlikely to happen,
it does not seem worth addressing.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: use cond_resched() when restarting walk of delegation list.

In three places we walk the list of delegations for an nfs_client
until an interesting one is found, then we act of that delegation
and restart the walk.

New delegations are added to the end of a list and the interesting
delegations are usually old, so in many case we won't repeat
a long walk over and over again, but it is possible - particularly if
the first server in the list has a large number of uninteresting
delegations.

In each cache the work done on interesting delegations will often
complete without sleeping, so this could loop many times without
giving up the CPU.

So add a cond_resched() at an appropriate point to avoid hogging the
CPU for too long.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: slight optimization for walking list for delegations

There are 3 places where we walk the list of delegations
for an nfs_client.
In each case there are two nested loops, one for nfs_servers
and one for nfs_delegations.

When we find an interesting delegation we try to get an active
reference to the server. If that fails, it is pointless to
continue to look at the other delegation for the server as
we will never be able to get an active reference.
So instead of continuing in the inner loop, break out
and continue in the outer loop.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix the nfs_inode_set_delegation() arguments

Neither nfs_inode_set_delegation() nor nfs_inode_reclaim_delegation() are
generic code. They have no business delving into NFSv4 OPEN xdr structures,
so let's replace the "struct nfs_openres" parameter.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Don't return the delegation when not needed by NFSv4.x (x>0)

Starting with NFSv4.1, the server is able to deduce the client id from
the SEQUENCE op which means it can always figure out whether or not
the client is holding a delegation on a file that is being changed.
For that reason, RFC5661 does not require a delegation to be unconditionally
recalled on operations such as SETATTR, RENAME, or REMOVE.

Note that for now, we continue to return READ delegations since that is
still expected by the Linux knfsd server.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

nfs: convert to new i_version API

For NFS, we just use the "raw" API since the i_version is mostly
managed by the server. The exception there is when the client
holds a write delegation, but we only need to bump it once
there anyway to handle CB_GETATTR.

Tested-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>

NFSv4: Retry CLOSE and DELEGRETURN on NFS4ERR_OLD_STATEID.

If we're racing with an OPEN, then retry the operation instead of
declaring it a success.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
[Andrew W Elble: Fix a typo in nfs4_refresh_open_stateid]
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Use an atomic_long_t to count the number of requests

Rather than forcing us to take the inode->i_lock just in order to bump
the number.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Optimise away forced revalidation when we know the attributes are OK

The NFS_INO_REVAL_FORCED flag needs to be set if we just got a delegation,
and we see that there might still be some ambiguity as to whether or not
our attribute or data cache are valid.
In practice, this means that a call to nfs_check_inode_attributes() will
have noticed a discrepancy between cached attributes and measured ones,
so let's move the setting of NFS_INO_REVAL_FORCED to there.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFS: Always call nfs_inode_find_state_and_recover() when revoking a delegation

Don't rely on nfs_inode_detach_delegation() succeeding. That can race...

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Tested-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Fix a race in nfs_inode_reclaim_delegation()

If we race with a delegreturn before taking the spin lock, we
currently end up dropping the delegation stateid.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Tested-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: nfs_inode_find_state_and_recover() should check all stateids

Modify the helper nfs_inode_find_state_and_recover() so that it
can check all open/lock/delegation state trackers on that inode for
whether or not they need are affected by a revoked stateid error.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Tested-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Ensure we don't re-test revoked and freed stateids

This fixes a potential infinite loop in nfs_reap_expired_delegations.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Tested-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.1: Deal with server reboots during delegation expiration recovery

Ensure that if the server reboots while we're testing and recovering
from revoked delegations, we exit to allow the state manager to
handle matters.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Tested-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.1: Test delegation stateids when server declares "some state revoked"

According to RFC5661, if any of the SEQUENCE status bits
SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED,
SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED, SEQ4_STATUS_ADMIN_STATE_REVOKED,
or SEQ4_STATUS_RECALLABLE_STATE_REVOKED are set, then we need to use
TEST_STATEID to figure out which stateids have been revoked, so we
can acknowledge the loss of state using FREE_STATEID.

While we already do this for open and lock state, we have not been doing
so for all the delegations.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Tested-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.x: Allow callers of nfs_remove_bad_delegation() to specify a stateid

Allow the callers of nfs_remove_bad_delegation() to specify the stateid
that needs to be marked as bad.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Tested-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: nfs4_copy_delegation_stateid() must fail if the delegation is invalid

We must not allow the use of delegations that have been revoked or are
being returned.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Fixes: 869f9dfa4d6d ("NFSv4: Fix races between nfs_remove_bad_delegation()...")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # v3.19+
Tested-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Don't report revoked delegations as valid in nfs_have_delegation()

If the delegation is revoked, then it can't be used for caching.

Fixes: 869f9dfa4d6d ("NFSv4: Fix races between nfs_remove_bad_delegation()...")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # v3.19+
Tested-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Use the right stateid for delegations in setattr, read and write

When we're using a delegation to represent our open state, we should
ensure that we use the stateid that was used to create that delegation.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Don't use synchronous delegation recall in exception handling

The code needs to be able to work from inside an asynchronous context.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Recovery of recalled read delegations is broken

When a read delegation is being recalled, and we're reclaiming the
cached opens, we need to make sure that we only reclaim read-only
modes.
A previous attempt to do this, relied on retrieving the delegation
type from the nfs4_opendata structure. Unfortunately, as Kinglong
pointed out, this field can only be set when performing reboot recovery.

Furthermore, if we call nfs4_open_recover(), then we end up clobbering
the state->flags for all modes that we're not recovering...

The fix is to have the delegation recall code pass this information
to the recovery call, and then refactor the recovery code so that
nfs4_open_delegation_recall() does not need to call nfs4_open_recover().

Reported-by: Kinglong Mee <kinglongmee@gmail.com>
Fixes: 39f897fdbd46 ("NFSv4: When returning a delegation, don't...")
Tested-by: Kinglong Mee <kinglongmee@gmail.com>
Cc: NeilBrown <neilb@suse.com>
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Respect the server imposed limit on how many changes we may cache

The NFSv4 delegation spec allows the server to tell a client to limit how
much data it cache after the file is closed. In return, the server
guarantees enough free space to avoid ENOSPC situations, etc.
Prior to this patch, we assumed we could always cache aggressively after
close. Unfortunately, this causes problems with servers that set the
limit to 0 and therefore do not offer any ENOSPC guarantees.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Express delegation limit in units of pages

Since we're tracking modifications to the page cache on a per-page
basis, it makes sense to express the limit to how much we may cache
in units of pages.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Return delegations synchronously in evict_inode

Kinglong Mee reports that asynchronous delegations are being killed
by the call to rpc_shutdown_client() when unmounting. This can lead
to state leakage on the server until the client lease expires.

Reported-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Append delegations to the per-client list instead of prepending

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: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Ensure we skip delegations that are already being returned

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: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Pin the superblock while we're returning the delegation

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: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Ensure we honour NFS_DELEGATION_RETURNING in nfs_inode_set_delegation()

Ensure that nfs_inode_set_delegation() doesn't inadvertently detach a
delegation that is already in the process of being returned.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Ensure that we don't reap a delegation that is being returned

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Don't call put_rpccred() under the rcu_read_lock()

put_rpccred() can sleep.

Fixes: 8f649c3762547 ("NFSv4: Fix the locking in nfs_inode_reclaim_delegation()")
Cc: stable@vger.kernel.org # 2.6.35+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Kill unused nfs_inode->delegation_state field

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Deal with atomic upgrades of an existing delegation

Ensure that we deal correctly with the case where the server sends us a
newer instance of the same delegation. If the stateids match, but the
sequence numbers differ, then treat the new delegation as if it were
an atomic upgrade.

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

locks: add a dedicated spinlock to protect i_flctx lists

We can now add a dedicated spinlock without expanding struct inode.
Change to using that to protect the various i_flctx lists.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>

locks: convert posix locks to file_lock_context

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>

locks: move flock locks to file_lock_context

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>

NFS: Don't try to reclaim delegation open state if recovery failed

If state recovery failed, then we should not attempt to reclaim delegated
state.

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

NFSv4: Fix races between nfs_remove_bad_delegation() and delegation return

Any attempt to call nfs_remove_bad_delegation() while a delegation is being
returned is currently a no-op. This means that we can end up looping
forever in nfs_end_delegation_return() if something causes the delegation
to be revoked.
This patch adds a mechanism whereby the state recovery code can communicate
to the delegation return code that the delegation is no longer valid and
that it should not be used when reclaiming state.
It also changes the return value for nfs4_handle_delegation_recall_error()
to ensure that nfs_end_delegation_return() does not reattempt the lock
reclaim before state recovery is done.

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

nfs4: add nfs4_check_delegation

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFS: Fix a delegation callback race

The clean-up in commit 36281caa839f ended up removing a NULL pointer check
that is needed in order to prevent an Oops in
nfs_async_inode_return_delegation().

Reported-by: "Yan, Zheng" <zheng.z.yan@intel.com>
Link: http://lkml.kernel.org/r/5313E9F6.2020405@intel.com
Fixes: 36281caa839f (NFSv4: Further clean-ups of delegation stateid validation)
Cc: stable@vger.kernel.org # 3.4+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Add tracepoints for debugging delegations

Set up tracepoints to track when delegations are set, reclaimed,
returned by the client, or recalled by the server.

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

locks: protect most of the file_lock handling with i_lock

Having a global lock that protects all of this code is a clear
scalability problem. Instead of doing that, move most of the code to be
protected by the i_lock instead. The exceptions are the global lists
that the ->fl_link sits on, and the ->fl_block list.

->fl_link is what connects these structures to the
global lists, so we must ensure that we hold those locks when iterating
over or updating these lists.

Furthermore, sound deadlock detection requires that we hold the
blocked_list state steady while checking for loops. We also must ensure
that the search and update to the list are atomic.

For the checking and insertion side of the blocked_list, push the
acquisition of the global lock into __posix_lock_file and ensure that
checking and update of the blocked_list is done without dropping the
lock in between.

On the removal side, when waking up blocked lock waiters, take the
global lock before walking the blocked list and dequeue the waiters from
the global list prior to removal from the fl_block list.

With this, deadlock detection should be race free while we minimize
excessive file_lock_lock thrashing.

Finally, in order to avoid a lock inversion problem when handling
/proc/locks output we must ensure that manipulations of the fl_block
list are also protected by the file_lock_lock.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

nfs: remove unnecessary check for NULL inode->i_flock from nfs_delegation_claim_locks

The second check was added in commit 65b62a29 but it will never be true.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFSv4: Fix CB_RECALL_ANY to only return delegations that are not in use

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

NFSv4: Clean up nfs_expire_all_delegations

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

NFSv4: Fix nfs_server_return_all_delegations

If the state manager thread is already running, we may end up
racing with it in nfs_client_return_marked_delegations. Better to
just allow the state manager thread to do the job.

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

NFSv4: Be less aggressive about returning delegations for open files

Currently, if the application that holds the file open isn't doing
I/O, we may end up returning the delegation. This means that we can
no longer cache the file as aggressively, and often also that we
multiply the state that both the server and the client needs to track.

This patch adds a check for open files to the routine that scans
for delegations that are unreferenced.

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

NFSv4: Clean up delegation recall error handling

Unify the error handling in nfs4_open_delegation_recall and
nfs4_lock_delegation_recall.

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

NFSv4: Ensure delegation recall and byte range lock removal don't conflict

Add a mutex to the struct nfs4_state_owner to ensure that delegation
recall doesn't conflict with byte range lock removal.

Note that we nest the new mutex _outside_ the state manager reclaim
protection (nfsi->rwsem) in order to avoid deadlocks.

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

NFSv4.1: Don't lose locks when a server reboots during delegation return

If the server reboots while we are converting a delegation into
OPEN/LOCK stateids as part of a delegation return, the current code
will simply exit with an error. This causes us to lose both
delegation state and locking state (i.e. locking atomicity).

Deal with this by exposing the delegation stateid during delegation
return, so that we can recover the delegation, and then resume
open/lock recovery.

Note that not having to hold the nfs_inode->rwsem across the
calls to nfs_delegation_claim_opens() also fixes a deadlock against
the NFSv4.1 reboot recovery code.

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

NFS: Create a return_delegation rpc op

Delegations are a v4 feature, so push return_delegation out of the
generic client by creating a new rpc_op and renaming the old function to
be in the nfs v4 "namespace"

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFS: Create a have_delegation rpc_op

Delegations are a v4 feature, so push them out of the generic code.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFS: Use nfs4_destroy_server() to clean up NFS v4

I can use this function to return delegations and unset the pnfs layout
driver rather than continuing to do these things in the generic client.
With this change, we no longer need an nfs4_kill_super().

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFSv4: nfs_client_return_marked_delegations can't flush data

Since even filemap_flush() needs to lock pages that are dirty, we
cannot risk calling it from the state manager context. Therefore,
we need to move the call to filemap_flush() to
nfs_async_inode_return_delegation().

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

NFS: nfs_inode_return_delegation() should always flush dirty data

The assumption is that if you are in a situation where you need to
return the delegation, then you should probably stop caching the
data anyway.

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

NFS: Fix a number of sparse warnings

Fix a number of "warning: symbol 'foo' was not declared. Should it be
static?" conditions.

Fix 2 cases of "warning: Using plain integer as NULL pointer"

fs/nfs/delegation.c:263:31: warning: restricted fmode_t degrades to integer
- We want to allow upgrades to a WRITE delegation, but should otherwise
consider servers that hand out duplicate delegations to be borken.

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

NFSv4.0: Re-establish the callback channel on NFS4ERR_CB_PATHDOWN

When the NFSv4.0 server tells us that it can no-longer talk to us
on the callback channel, we should attempt a new SETCLIENTID in
order to re-transmit the callback channel information.

Note that as long as we do not change the boot verifier, this is
a safe procedure; the server is required to keep our state.

Also move the function nfs_handle_cb_pathdown to fs/nfs/nfs4state.c,
and change the name in order to mark it as being specific to NFSv4.0.

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

NFS: Don't copy read delegation stateids in setattr

The server will just return an NFS4ERR_OPENMODE anyway.

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

NFSv4.1 handle DS stateid errors

Handle DS READ and WRITE stateid errors by recovering the stateid on the MDS.

NFS4ERR_OLD_STATEID is ignored as the client always sends a
state sequenceid of zero for DS READ and WRITE stateids.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFSv4: Add helpers for basic copying of stateids

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

NFSv4: Further clean-ups of delegation stateid validation

Change the name to reflect what we're really doing: testing two
stateids for whether or not they match according the the rules in
RFC3530 and RFC5661.
Move the code from callback_proc.c to nfs4proc.c

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

NFSv4.1: Fix matching of the stateids when returning a delegation

nfs41_validate_delegation_stateid is broken if we supply a stateid with
a non-zero sequence id. Instead of trying to match the sequence id,
the function assumes that we always want to error. While this is
true for a delegation callback, it is not true in general.

Also fix a typo in nfs4_callback_recall.

Reported-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFS: Properly handle the case where the delegation is revoked

If we know that the delegation stateid is bad or revoked, we need to
remove that delegation as soon as possible, and then mark all the
stateids that relied on that delegation for recovery. We cannot use
the delegation as part of the recovery process.

Also note that NFSv4.1 uses a different error code (NFS4ERR_DELEG_REVOKED)
to indicate that the delegation was revoked.

Finally, ensure that setlk() and setattr() can both recover safely from
a revoked delegation.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

NFS: Use the inode->i_version to cache NFSv4 change attribute information

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

NFSv4: Don't use the delegation->inode in nfs_mark_return_delegation()

nfs_mark_return_delegation() is usually called without any locking, and
so it is not safe to dereference delegation->inode. Since the inode is
only used to discover the nfs_client anyway, it makes more sense to
have the callers pass a valid pointer to the nfs_server as a parameter.

Reported-by: Ian Kent <raven@themaw.net>
Cc: stable@kernel.org
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

nfs,rcu: convert call_rcu(nfs_free_delegation_callback) to kfree_rcu()

The rcu callback nfs_free_delegation_callback() just calls a kfree(),
so we use kfree_rcu() instead of the call_rcu(nfs_free_delegation_callback).

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFS: Fix an NFS client lockdep issue

There is no reason to be freeing the delegation cred in the rcu callback,
and doing so is resulting in a lockdep complaint that rpc_credcache_lock
is being called from both softirq and non-softirq contexts.

Reported-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org

NFS: Move cl_delegations to the nfs_server struct

Delegations are per-inode, not per-nfs_client. When a server file
system is migrated, delegations on the client must be moved from the
source to the destination nfs_server. Make it easier to manage a
mount point's delegation list across a migration event by moving the
list to the nfs_server struct.

Clean up: I added documenting comments to public functions I changed
in this patch. For consistency I added comments to all the other
public functions in fs/nfs/delegation.c.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFS: Introduce nfs_detach_delegations()

Clean up: Refactor code that takes clp->cl_lock and calls
nfs_detach_delegations_locked() into its own function.

While we're changing the call sites, get rid of the second parameter
and the logic in nfs_detach_delegations_locked() that uses it, since
callers always set that parameter of nfs_detach_delegations_locked()
to NULL.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

BKL: remove extraneous #include <smp_lock.h>

The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/locks.c: prepare for BKL removal

This prepares the removal of the big kernel lock from the
file locking code. We still use the BKL as long as fs/lockd
uses it and ceph might sleep, but we can flip the definition
to a private spinlock as soon as that's done.
All users outside of fs/lockd get converted to use
lock_flocks() instead of lock_kernel() where appropriate.

Based on an earlier patch to use a spinlock from Matthew
Wilcox, who has attempted this a few times before, the
earliest patch from over 10 years ago turned it into
a semaphore, which ended up being slower than the BKL
and was subsequently reverted.

Someone should do some serious performance testing when
this becomes a spinlock, since this has caused problems
before. Using a spinlock should be at least as good
as the BKL in theory, but who knows...

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Miklos Szeredi <mszeredi@suse.cz>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Sage Weil <sage@newdream.net>
Cc: linux-kernel@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org

NFS: Clean up the callers of nfs_wb_all()

There is no need to flush out writes before calling nfs_wb_all().

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

NFSv41: Fix nfs_async_inode_return_delegation() ugliness

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

NFSv4: Don't use GFP_KERNEL allocations in state recovery

We do not want to have the state recovery thread kick off and wait for a
memory reclaim, since that may deadlock when the writebacks end up
waiting for the state recovery thread to complete.

The safe thing is therefore to use GFP_NOFS in all open, close,
delegation return, lock, etc. operations that may be called by the
state recovery thread.

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

NFS: Fix RCU issues in the NFSv4 delegation code

Fix a number of RCU issues in the NFSv4 delegation code.

(1) delegation->cred doesn't need to be RCU protected as it's essentially an
invariant refcounted structure.

By the time we get to nfs_free_delegation(), the delegation is being
released, so no one else should be attempting to use the saved
credentials, and they can be cleared.

However, since the list of delegations could still be under traversal at
this point by such as nfs_client_return_marked_delegations(), the cred
should be released in nfs_do_free_delegation() rather than in
nfs_free_delegation(). Simply using rcu_assign_pointer() to clear it is
insufficient as that doesn't stop the cred from being destroyed, and nor
does calling put_rpccred() after call_rcu(), given that the latter is
asynchronous.

(2) nfs_detach_delegation_locked() and nfs_inode_set_delegation() should use
rcu_derefence_protected() because they can only be called if
nfs_client::cl_lock is held, and that guards against anyone changing
nfsi->delegation under it. Furthermore, the barrier imposed by
rcu_dereference() is superfluous, given that the spin_lock() is also a
barrier.

(3) nfs_detach_delegation_locked() is now passed a pointer to the nfs_client
struct so that it can issue lockdep advice based on clp->cl_lock for (2).

(4) nfs_inode_return_delegation_noreclaim() and nfs_inode_return_delegation()
should use rcu_access_pointer() outside the spinlocked region as they
merely examine the pointer and don't follow it, thus rendering unnecessary
the need to impose a partial ordering over the one item of interest.

These result in an RCU warning like the following:

[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
fs/nfs/delegation.c:332 invoked rcu_dereference_check() without protection!

other info that might help us debug this:

rcu_scheduler_active = 1, debug_locks = 0
2 locks held by mount.nfs4/2281:
#0: (&type->s_umount_key#34){+.+...}, at: [<ffffffff810b25b4>] deactivate_super+0x60/0x80
#1: (iprune_sem){+.+...}, at: [<ffffffff810c332a>] invalidate_inodes+0x39/0x13a

stack backtrace:
Pid: 2281, comm: mount.nfs4 Not tainted 2.6.34-rc1-cachefs #110
Call Trace:
[<ffffffff8105149f>] lockdep_rcu_dereference+0xaa/0xb2
[<ffffffffa00b4591>] nfs_inode_return_delegation_noreclaim+0x5b/0xa0 [nfs]
[<ffffffffa0095d63>] nfs4_clear_inode+0x11/0x1e [nfs]
[<ffffffff810c2d92>] clear_inode+0x9e/0xf8
[<ffffffff810c3028>] dispose_list+0x67/0x10e
[<ffffffff810c340d>] invalidate_inodes+0x11c/0x13a
[<ffffffff810b1dc1>] generic_shutdown_super+0x42/0xf4
[<ffffffff810b1ebe>] kill_anon_super+0x11/0x4f
[<ffffffffa009893c>] nfs4_kill_super+0x3f/0x72 [nfs]
[<ffffffff810b25bc>] deactivate_super+0x68/0x80
[<ffffffff810c6744>] mntput_no_expire+0xbb/0xf8
[<ffffffff810c681b>] release_mounts+0x9a/0xb0
[<ffffffff810c689b>] put_mnt_ns+0x6a/0x79
[<ffffffffa00983a1>] nfs_follow_remote_path+0x5a/0x146 [nfs]
[<ffffffffa0098334>] ? nfs_do_root_mount+0x82/0x95 [nfs]
[<ffffffffa00985a9>] nfs4_try_mount+0x75/0xaf [nfs]
[<ffffffffa0098874>] nfs4_get_sb+0x291/0x31a [nfs]
[<ffffffff810b2059>] vfs_kern_mount+0xb8/0x177
[<ffffffff810b2176>] do_kern_mount+0x48/0xe8
[<ffffffff810c810b>] do_mount+0x782/0x7f9
[<ffffffff810c8205>] sys_mount+0x83/0xbe
[<ffffffff81001eeb>] system_call_fastpath+0x16/0x1b

Also on:

fs/nfs/delegation.c:215 invoked rcu_dereference_check() without protection!
[<ffffffff8105149f>] lockdep_rcu_dereference+0xaa/0xb2
[<ffffffffa00b4223>] nfs_inode_set_delegation+0xfe/0x219 [nfs]
[<ffffffffa00a9c6f>] nfs4_opendata_to_nfs4_state+0x2c2/0x30d [nfs]
[<ffffffffa00aa15d>] nfs4_do_open+0x2a6/0x3a6 [nfs]
...

And:

fs/nfs/delegation.c:40 invoked rcu_dereference_check() without protection!
[<ffffffff8105149f>] lockdep_rcu_dereference+0xaa/0xb2
[<ffffffffa00b3bef>] nfs_free_delegation+0x3d/0x6e [nfs]
[<ffffffffa00b3e71>] nfs_do_return_delegation+0x26/0x30 [nfs]
[<ffffffffa00b406a>] __nfs_inode_return_delegation+0x1ef/0x1fe [nfs]
[<ffffffffa00b448a>] nfs_client_return_marked_delegations+0xc9/0x124 [nfs]
...

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFSv4: Fix the locking in nfs_inode_reclaim_delegation()

Ensure that we correctly rcu-dereference the delegation itself, and that we
protect against removal while we're changing the contents.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

nfs41: v2 fix cb_recall bug

in NFSv4.1 the seqid part of a stateid in CB_RECALL must be 0

Signed-off-by: Alexandros Batsakis <batsakis@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

nfs41: V2 initial support for CB_RECALL_ANY

For now the clients returns _all_ the delegations of the specificed type
it holds

Signed-off-by: Alexandros Batsakis <batsakis@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

nfs4: V2 return/expire delegations depending on their type

Signed-off-by: Alexandros Batsakis <batsakis@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

nfs4: minor delegation cleaning

Signed-off-by: Alexandros Batsakis <batsakis@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFSv4: Fix a potential state manager deadlock when returning delegations

The nfsv4 state manager could potentially deadlock inside
__nfs_inode_return_delegation() if the server reboots, so that the calls to
nfs_msync_inode() end up waiting on state recovery to complete.

Also ensure that if a server reboot or network partition causes us to have
to stop returning delegations, that NFS4CLNT_DELEGRETURN is set so that
the state manager can resume any outstanding delegation returns after it
has dealt with the state recovery situation.

Finally, ensure that the state manager doesn't wait for the DELEGRETURN
call to complete. It doesn't need to, and that too can cause a deadlock.

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

headers: smp_lock.h redux

* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT

This will make hardirq.h inclusion cheaper for every PREEMPT=n config
(which includes allmodconfig/allyesconfig, BTW)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

NFS: Ensure we always hold the BKL when dereferencing inode->i_flock

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

NFSv4: Move error handling out of the delegation generic code

The NFSv4 delegation recovery code is required by the protocol to handle
more errors. Rather than add NFSv4.0 specific errors into 'generic'
delegation code, we should move the error handling into the NFSv4 layer.

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

NFSv4: Convert delegation->type field to fmode_t

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

NFSv4: Return unreferenced delegations more promptly

If the client is not using a delegation, the right thing to do is to return
it as soon as possible. This helps reduce the amount of state the server
has to track, as well as reducing the potential for conflicts with other
clients.

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

NFSv4: Clean up the asynchronous delegation return

Reuse the state management thread in order to return delegations when we
get a callback.

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

NFSv4: Clean up nfs_expire_all_delegations()

Let the actual delegreturn stuff be run in the state manager thread rather
than allocating a separate kthread.

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

NFSv4: Rename the state reclaimer thread

It is really a more general purpose state management thread at this point.

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

NFSv4: Clean up NFS4ERR_CB_PATH_DOWN error management...

Add a delegation cleanup phase to the state management loop, and do the
NFS4ERR_CB_PATH_DOWN recovery there.

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

NFSv4: Clean up the support for returning multiple delegations

Add a flag to mark delegations as requiring return, then run a garbage
collector. In the future, this will allow for more flexible delegation
management, where delegations may be marked for return if it turns out
that they are not being referenced.

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

NFSv4: Remove nfs_client->cl_sem

Now that we're using the flags to indicate state that needs to be
recovered, as well as having implemented proper refcounting and spinlocking
on the state and open_owners, we can get rid of nfs_client->cl_sem. The
only remaining case that was dubious was the file locking, and that case is
now covered by the nfsi->rwsem.

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

NFS: Use atomic bitops when changing struct nfs_delegation->flags

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

NFSv4: Fix up the dereferencing of delegation->inode

Without an extra lock, we cannot just assume that the delegation->inode is
valid when we're traversing the rcu-protected nfs_client lists. Use the
delegation->lock to ensure that it is truly valid.

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

NFSv4: Fix up another delegation related race

When we can update_open_stateid(), we need to be certain that we don't
race with a delegation return. While we could do this by grabbing the
nfs_client->cl_lock, a dedicated spin lock in the delegation structure
will scale better.

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

nfs: replace remaining __FUNCTION__ occurrences

__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

nfs: fix sparse warnings

fs/nfs/nfs4state.c:788:34: warning: Using plain integer as NULL pointer
fs/nfs/delegation.c:52:34: warning: Using plain integer as NULL pointer
fs/nfs/idmap.c:312:12: warning: Using plain integer as NULL pointer
fs/nfs/callback_xdr.c:257:6: warning: Using plain integer as NULL pointer
fs/nfs/callback_xdr.c:270:6: warning: Using plain integer as NULL pointer
fs/nfs/callback_xdr.c:281:6: warning: Using plain integer as NULL pointer

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFSv4: Deal more correctly with duplicate delegations

If a (broken?) server hands out two different delegations for the same
file, then we should return one of them.

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

NFS: Add an asynchronous delegreturn operation for use in nfs_clear_inode

Otherwise, there is a potential deadlock if the last dput() from an NFSv4
close() or other asynchronous operation leads to nfs_clear_inode calling
the synchronous delegreturn.

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

NFS: eliminate NIPQUAD(clp->cl_addr.sin_addr)

To ensure the NFS client displays IPv6 addresses properly, replace
address family-specific NIPQUAD() invocations with a call to the RPC
client to get a formatted string representing the remote peer's
address.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFSv4: Fix an rpc_cred reference leakage in fs/nfs/delegation.c

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

NFSv4: Fix a typo in nfs_inode_reclaim_delegation

We were intending to put the previous instance of delegation->cred
before setting a new one.

Thanks to David Howells for spotting this.

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

NFS: Replace file->private_data with calls to nfs_file_open_context()

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

NFSv4: Don't call put_rpccred() from an rcu callback

Doing so would require us to introduce bh-safe locks into put_rpccred().
This patch fixes the lockdep complaint reported by Marc Dietrich:

inconsistent {softirq-on-W} -> {in-softirq-W} usage.
swapper/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
(rpc_credcache_lock){-+..}, at: [<c01dc487>]
_atomic_dec_and_lock+0x17/0x60
{softirq-on-W} state was registered at:
[<c013e870>] __lock_acquire+0x650/0x1030
[<c013f2b1>] lock_acquire+0x61/0x80
[<c02db9ac>] _spin_lock+0x2c/0x40
[<c01dc487>] _atomic_dec_and_lock+0x17/0x60
[<dced55fd>] put_rpccred+0x5d/0x100 [sunrpc]
[<dced56c1>] rpcauth_unbindcred+0x21/0x60 [sunrpc]
[<dced3fd4>] a0 [sunrpc]
[<dcecefe0>] rpc_call_sync+0x30/0x40 [sunrpc]
[<dcedc73b>] rpcb_register+0xdb/0x180 [sunrpc]
[<dced65b3>] svc_register+0x93/0x160 [sunrpc]
[<dced6ebe>] __svc_create+0x1ee/0x220 [sunrpc]
[<dced7053>] svc_create+0x13/0x20 [sunrpc]
[<dcf6d722>] nfs_callback_up+0x82/0x120 [nfs]
[<dcf48f36>] nfs_get_client+0x176/0x390 [nfs]
[<dcf49181>] nfs4_set_client+0x31/0x190 [nfs]
[<dcf49983>] nfs4_create_server+0x63/0x3b0 [nfs]
[<dcf52426>] nfs4_get_sb+0x346/0x5b0 [nfs]
[<c017b444>] vfs_kern_mount+0x94/0x110
[<c0190a62>] do_mount+0x1f2/0x7d0
[<c01910a6>] sys_mount+0x66/0xa0
[<c0104046>] syscall_call+0x7/0xb
[<ffffffff>] 0xffffffff
irq event stamp: 5277830
hardirqs last enabled at (5277830): [<c017530a>] kmem_cache_free+0x8a/0xc0
hardirqs last disabled at (5277829): [<c01752d2>] kmem_cache_free+0x52/0xc0
softirqs last enabled at (5277798): [<c0124173>] __do_softirq+0xa3/0xc0
softirqs last disabled at (5277817): [<c01241d7>] do_softirq+0x47/0x50

other info that might help us debug this:
no locks held by swapper/0.

stack backtrace:
[<c0104fda>] show_trace_log_lvl+0x1a/0x30
[<c0105c02>] show_trace+0x12/0x20
[<c0105d15>] dump_stack+0x15/0x20
[<c013ccc3>] print_usage_bug+0x153/0x160
[<c013d8b9>] mark_lock+0x449/0x620
[<c013e824>] __lock_acquire+0x604/0x1030
[<c013f2b1>] lock_acquire+0x61/0x80
[<c02db9ac>] _spin_lock+0x2c/0x40
[<c01dc487>] _atomic_dec_and_lock+0x17/0x60
[<dced55fd>] put_rpccred+0x5d/0x100 [sunrpc]
[<dcf6bf83>] nfs_free_delegation_callback+0x13/0x20 [nfs]
[<c012f9ea>] __rcu_process_callbacks+0x6a/0x1c0
[<c012fb52>] rcu_process_callbacks+0x12/0x30
[<c0124218>] tasklet_action+0x38/0x80
[<c0124125>] __do_softirq+0x55/0xc0
[<c01241d7>] do_softirq+0x47/0x50
[<c0124605>] irq_exit+0x35/0x40
[<c0112463>] smp_apic_timer_interrupt+0x43/0x80
[<c0104a77>] apic_timer_interrupt+0x33/0x38
[<c02690df>] cpuidle_idle_call+0x6f/0x90
[<c01023c3>] cpu_idle+0x43/0x70
[<c02d8c27>] rest_init+0x47/0x50
[<c03bcb6a>] start_kernel+0x22a/0x2b0
[<00000000>] 0x0
=======================

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

NFSv4: Defer inode revalidation when setting up a delegation

Currently we force a synchronous call to __nfs_revalidate_inode() in
nfs_inode_set_delegation(). This not only ensures that we cannot call
nfs_inode_set_delegation from an asynchronous context, but it also slows
down any call to open().

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

NFSv4: Use RCU to protect delegations

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

NFSv4: Support recalling delegations by stateid part 2

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

NFSv4: Support recalling delegations by stateid

There appear to be some rogue servers out there that issue multiple
delegations with different stateids for the same file. Ensure that when we
return delegations, we do so on a per-stateid basis rather than a per-file
basis.

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

NFSv4: Cleanup: pass the nfs_open_context to open recovery code

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

NFS: Replace vfsmount and dentry in nfs_open_context with struct path

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

NFS: Fix some 'sparse' warnings...

- fs/nfs/dir.c:610:8: warning: symbol 'nfs_llseek_dir' was not declared.
Should it be static?
- fs/nfs/dir.c:636:5: warning: symbol 'nfs_fsync_dir' was not declared.
Should it be static?
- fs/nfs/write.c:925:19: warning: symbol 'req' shadows an earlier one
- fs/nfs/write.c:61:6: warning: symbol 'nfs_commit_rcu_free' was not
declared. Should it be static?
- fs/nfs/nfs4proc.c:793:5: warning: symbol 'nfs4_recover_expired_lease'
was not declared. Should it be static?

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

[PATCH] fs: Removing useless casts

* Removing useless casts
* Removing useless wrapper
* Conversion from kmalloc+memset to kzalloc

Signed-off-by: Panagiotis Issaris <takis@issaris.org>
Acked-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

NFS: Generalise the nfs_client structure

Generalise the nfs_client structure by:

(1) Moving nfs_client to a more general place (nfs_fs_sb.h).

(2) Renaming its maintenance routines to be non-NFS4 specific.

(3) Move those maintenance routines to a new non-NFS4 specific file (client.c)
and move the declarations to internal.h.

(4) Make nfs_find/get_client() take a full sockaddr_in to include the port
number (will be required for NFS2/3).

(5) Make nfs_find/get_client() take the NFS protocol version (again will be
required to differentiate NFS2, 3 & 4 client records).

Also:

(6) Make nfs_client construction proceed akin to inodes, marking them as under
construction and providing a function to indicate completion.

(7) Make nfs_get_client() wait interruptibly if it finds a client that it can
share, but that client is currently being constructed.

(8) Make nfs4_create_client() use (6) and (7) instead of locking cl_sem.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFS: Rename nfs_server::nfs4_state

Rename nfs_server::nfs4_state to nfs_client as it will be used to represent the
client state for NFS2 and NFS3 also.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFS: Rename struct nfs4_client to struct nfs_client

Rename struct nfs4_client to struct nfs_client so that it can become the basis
for a general client record for NFS2 and NFS3 in addition to NFS4.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Remove obsolete #include <linux/config.h>

Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

NFSv4: Send the delegation stateid for SETATTR calls

In the case where we hold a delegation stateid, use that in for inside
SETATTR calls.

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

NFSv4: Fix an Oops in nfs_do_expire_all_delegations

If the loop errors, we need to exit.

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

NFSv4: Ensure DELEGRETURN returns attributes

Upon return of a write delegation, the server will almost always bump the
change attribute. Ensure that we pick up that change so that we don't
invalidate our data cache unnecessarily.

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

NFSv4: Ensure change attribute returned by GETATTR callback conforms to spec

According to RFC3530 we're supposed to cache the change attribute
at the time the client receives a write delegation.
If the inode is clean, a CB_GETATTR callback by the server to the
client is supposed to return the cached change attribute.
If, OTOH, the inode is dirty, the client should bump the cached
change attribute by 1.

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

NFSv4: Send RENEW requests to the server only when we're holding state

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

[PATCH] kfree cleanup: fs

This is the fs/ part of the big kfree cleanup patch.

Remove pointless checks for NULL prior to calling kfree() in fs/.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

NFSv4: Recover locks too when returning a delegation

Delegations allow us to cache posix and BSD locks, however when the
delegation is recalled, we need to "flush the cache" and send
the cached LOCK requests to the server.

This patch sets up the mechanism for doing so.

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

NFSv4: Return delegation upon rename or removal of file.

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

[PATCH] NFS: Fix cache consistency races

If the data cache has been marked as potentially invalid by nfs_refresh_inode,
we should invalidate it rather than assume that changes are due to our own
activity.

Also ensure that we always start with a valid cache before declaring it
to be protected by a delegation.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] NFS: Header file cleanup...

- Move NFSv4 state definitions into a private header file.
- Clean up gunk in nfs_fs.h

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

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!