The state manager no longer needs any special machinery to stop the
session flow and resize the slot table. It is all done on the fly by
the SEQUENCE op code now.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Instead of an array of slots, use a singly linked list of slots that
can be dynamically appended to or shrunk.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Ensure that the NFSv4.1 CB_RECALL_SLOT callback updates the slot table
target max slotid safely.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Move the session pointer into the slot table, then have struct nfs4_slot
point to that slot table.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

An optional boot parameter is introduced to allow client
administrators to specify a string that the Linux NFS client can
insert into its nfs_client_id4 id string, to make it both more
globally unique, and to ensure that it doesn't change even if the
client's nodename changes.

If this boot parameter is not specified, the client's nodename is
used, as before.

Client installation procedures can create a unique string (typically,
a UUID) which remains unchanged during the lifetime of that client
instance.  This works just like creating a UUID for the label of the
system's root and boot volumes.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

"Server trunking" is a fancy named for a multi-homed NFS server.
Trunking might occur if a client sends NFS requests for a single
workload to multiple network interfaces on the same server.  There
are some implications for NFSv4 state management that make it useful
for a client to know if a single NFSv4 server instance is
multi-homed.  (Note this is only a consideration for NFSv4, not for
legacy versions of NFS, which are stateless).

If a client cares about server trunking, no NFSv4 operations can
proceed until that client determines who it is talking to.  Thus
server IP trunking discovery must be done when the client first
encounters an unfamiliar server IP address.

The nfs_get_client() function walks the nfs_client_list and matches
on server IP address.  The outcome of that walk tells us immediately
if we have an unfamiliar server IP address.  It invokes
nfs_init_client() in this case.  Thus, nfs4_init_client() is a good
spot to perform trunking discovery.

Discovery requires a client to establish a fresh client ID, so our
client will now send SETCLIENTID or EXCHANGE_ID as the first NFS
operation after a successful ping, rather than waiting for an
application to perform an operation that requires NFSv4 state.

The exact process for detecting trunking is different for NFSv4.0 and
NFSv4.1, so a minorversion-specific init_client callout method is
introduced.

CLID_INUSE recovery is important for the trunking discovery process.
CLID_INUSE is a sign the server recognizes the client's nfs_client_id4
id string, but the client is using the wrong principal this time for
the SETCLIENTID operation.  The SETCLIENTID must be retried with a
series of different principals until one works, and then the rest of
trunking discovery can proceed.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Confine it to the nfs4_do_close() code.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

We want to be able to pass on the information that the page was not
dirtied under a lock. Instead of adding a flag parameter, do this
by passing a pointer to a 'struct nfs_lock_owner' that may be NULL.

Also reuse this structure in struct nfs_lock_context to carry the
fl_owner_t and pid_t.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Some systems have a modprobe.d/nfs.conf file that sets an nfs4 alias
pointing to nfs.ko, rather than nfs4.ko.  This can prevent the v4 module
from loading on mount, since the kernel sees that something named "nfs4"
has already been loaded.  To work around this, I've renamed the modules
to "nfsv2.ko" "nfsv3.ko" and "nfsv4.ko".

I also had to move the nfs4_fs_type back to nfs.ko to ensure that `mount
-t nfs4` still works.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

Otherwise we break backwards compatibility when v4 becomes a modules.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Somehow I missed this in my previous patch series, but these functions
are only needed by the v4 code and should be moved to a v4-only file.  I
wasn't exactly sure where I should put these functions, so I moved them
into nfs4super.c where I could make them static.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

I'm already looking up the nfs subversion in nfs_fs_mount(), so I have
easy access to rpc_ops that used to be difficult to reach.  This allows
me to set up a different mount path for NFS v2/3 and NFS v4.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This patch adds in the code to track multiple versions of the NFS
protocol.  I created default structures for v2, v3 and v4 so that each
version can continue to work while I convert them into kernel modules.
I also removed the const parameter from the rpc_version array so that I
can change it at runtime.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Fix numerous repeated warnings by making the stub function
void instead of non-void:

fs/nfs/nfs4_fs.h: In function 'nfs4_unregister_sysctl':
fs/nfs/nfs4_fs.h:385:1: warning: no return statement in function returning non-void
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Cc:	Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This allows me to move the v4 mounting and unmounting functions out of
the generic client and into a file that is only compiled when CONFIG_NFS_V4
is enabled.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

And split them out of the generic client into their own file.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

I want to initialize all of NFS v4 in a single function that will
eventually be used as the v4 module init function.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The NFS v4 file inode operations are already already in nfs4proc.c, so
this patch just needs to move the directory operations to the same file.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This gives pnfs a chance to do a layout commit inside the v4 code.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This gives NFS v4 a way to set up callbacks and sessions without v2 or
v3 having to do them as well.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

NFS v4 needs a way to shut down callbacks and sessions, but v2 and v3
don't.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The open recovery code does not need to request a new value for the
mdsthreshold, and so does not allocate a struct nfs4_threshold.
The problem is that encode_getfattr_open() will still request an
mdsthreshold, and so we end up Oopsing in decode_attr_mdsthreshold.

This patch fixes encode_getfattr_open so that it doesn't request an
mdsthreshold when the caller isn't asking for one. It also fixes
decode_attr_mdsthreshold so that it errors if the server returns
an mdsthreshold that we didn't ask for (instead of Oopsing).
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: Andy Adamson <andros@netapp.com>

Let nfs4_schedule_session_recovery() handle the details of choosing
between resetting the session, and other session related recovery.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Ensure that we destroy our lease on last unmount
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: Weston Andros Adamson <dros@netapp.com>

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

The state manager can handle SEQ4_STATUS_CB_PATH_DOWN* flags with a
BIND_CONN_TO_SESSION instead of destroying the session and creating a new one.
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This patch adds the BIND_CONN_TO_SESSION operation which is needed for
upcoming SP4_MACH_CRED work and useful for recovering from broken connections
without destroying the session.
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

nfs4_reset_all_state() refreshes the boot verifier a server sees to
trigger that server to wipe this client's state.  This function is
invoked when an NFSv4.1 server reports that it has revoked some or
all of a client's NFSv4 state.

To facilitate server trunking discovery, we will eventually want to
move the cl_boot_time field to a more global structure.  The Uniform
Client String model (and specifically, server trunking detection)
requires that all servers see the same boot verifier until the client
actually does reboot, and not a fresh verifier every time the client
unmounts and remounts the server.

Without the cl_boot_time field, however, nfs4_reset_all_state() will
have to find some other way to force the server to purge the client's
NFSv4 state.

Because these verifiers are opaque (ie, the server doesn't know or
care that they happen to be timestamps), we can force the server
to wipe NFSv4 state by updating the boot verifier as we do now, then
immediately afterwards establish a fresh client ID using the old boot
verifier again.

Hopefully there are no extra paranoid server implementations that keep
track of the client's boot verifiers and prevent clients from reusing
a previous one.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up:  this structure is unused.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up:  When naming fields and data types, follow established
conventions to facilitate accurate grep/cscope searches.

Additionally, for consistency, move the scope field into the NFSv4-
specific part of the nfs_client, and free that memory in the logic
that shuts down NFSv4 nfs_clients.

Introduced by commit 99fe60d0 "nfs41: exchange_id operation", April
1 2009.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This function is really getting the root filehandle and not the root
dentry of the filesystem.  I also removed the rpc_ops lookup from
nfs4_get_rootfh() under the assumption that if we reach this function
then we already know we are using NFS v4.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This simplifies the code for v2 and v3 and gives v4 a chance to decide
on referrals without needing to modify the generic client.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

And also remove the unneeded rpc_op.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

I create a new proc_lookup_mountpoint() to use when submounting an NFS
v4 share.  This function returns an rpc_clnt to use for performing an
fs_locations() call on a referral's mountpoint.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Whenever lookup sees wrongsec do a secinfo and retry the lookup to find
attributes of the file or directory, such as "is this a referral
mountpoint?".  This also allows me to remove handling -NFS4ERR_WRONSEC
as part of getattr xdr decoding.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The NFSv4 spec is ambiguous about whether or not it is permissible
to reuse open owner names, so play it safe. This patch adds a timestamp
to the state_owner structure, and combines that with the IDA based
uniquifier.
Fixes a regression whereby the Linux server returns NFS4ERR_BAD_SEQID.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>