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delegation(s) have been revoked, it may continually test delegations at the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>

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>

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: 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>

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>

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: 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: 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+

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/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 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>

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>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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>

NFSv4.1: 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: 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: 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: 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>

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

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>

NFSv4.1: 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: Convert v4 into a module

This patch exports symbols needed by the v4 module. In addition, I also
switch over to using IS_ENABLED() to check if CONFIG_NFS_V4 or
CONFIG_NFS_V4_MODULE are set.

The module (nfs4.ko) will be created in the same directory as nfs.ko and
will be automatically loaded the first time you try to mount over NFS v4.

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

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>

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>

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: 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>

NFSv41: Fix nfs_async_inode_return_delegation() ugliness

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

NFSv4: Don't ignore the NFS_INO_REVAL_FORCED flag in nfs_revalidate_inode()

If the NFS_INO_REVAL_FORCED flag is set, that means that we don't yet have
an up to date attribute cache. Even if we hold a delegation, we must
put a GETATTR on the wire.

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

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>

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>

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 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>

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

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: 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>

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: 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>

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: 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>

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>

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!