GitLab

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

We should not assume that nfs41_init_clientid() will always want to
initialise the session. If it is being called due to a server reboot, then
we just want to reset the session after re-establishing the clientid.

Fix this by getting rid of the 'reset' parameter in
nfs4_proc_create_session(), and instead relying on whether or not the
session slot table pointer is non-NULL.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

This patch invokes RECLAIM_COMPLETE after the client is done
reclaiming state.

There are interpretations of the spec that suggest that
RECLAIM_COMPLETE should also be issued after a new clientid
has been obtained from the server and even if there is no
state to reclaim.  This tells the server that the client
has no state to reclaim even if the client isn't aware the
server may have rebooted.
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Implements RECLAIM_COMPLETE as an asynchronous RPC.
NFS4ERR_DELAY is retried, NFS4ERR_DEADSESSION invokes the error handling
but does not result in a retry, since we don't want to have a lingering
RECLAIM_COMPLETE call sent in the middle of a possible new state recovery
cycle.  If a session reset occurs, a new wave of reclaim operations will
follow, containing their own RECLAIM_COMPLETE call.  We don't want a
retry to get on the way of recovery by incorrectly indicating to the
server that we're done reclaiming state.

A subsequent patch invokes the functionality.
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Otherwise we have no guarantees that other processes won't start another
RPC call while we're resetting the session.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

the server can indicate a number of error conditions by setting the
appropriate bits in the SEQUENCE operation. The client re-establishes
state with the server when it receives one of those, with the action
depending on the specific case.
Signed-off-by: Alexandros Batsakis <batsakis@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Replace sync and async handlers setting of the NFS4CLNT_SESSION_SETUP bit with
setting NFS4CLNT_CHECK_LEASE, and let the state manager decide to reset the session.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

If the session is reset during state recovery, the state manager thread can
sleep on the slot_tbl_waitq causing a deadlock.

Add a completion framework to the session.  Have the state manager thread set
a new session state (NFS4CLNT_SESSION_DRAINING) and wait for the session slot
table to drain.

Signal the state manager thread in nfs41_sequence_free_slot when the
NFS4CLNT_SESSION_DRAINING bit is set and the session is drained.
Reported-by: Trond Myklebust <trond@netapp.com>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Do not fall through and set NFS4CLNT_SESSION_RESET bit on NFS4ERR_EXPIRED
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

The bit is no longer used for session setup, only for session reset.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Reported-by: Trond Myklebust <trond.myklebust@netapp.com>

Resetting the clientid from the state manager could result in not confirming
the clientid due to create session not being called.

Move the create session call from the NFS4CLNT_SESSION_SETUP state manager
initialize session case into the NFS4CLNT_LEASE_EXPIRED case establish_clid
call.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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

The nfs4_state_manager should not be looking at the error values when
deciding whether or not to loop round in order to handle a higher priority
state recovery task. It should rather be looking at the clp->cl_state.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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

nfs4_recovery_handle_error() will correctly handle errors such as
NFS4ERR_CB_PATH_DOWN, however because they are still passed back to the
main loop in nfs4_state_manager(), they can cause the latter to exit
prematurely.

Fix this by letting nfs4_recovery_handle_error() change the error value in
cases where there is no action required by the caller.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

In practice, we need to ensure that we call nfs4_state_end_reclaim_reboot
in 2 cases:

 - If we lose the lease while we were reclaiming state
OR
 - After we're done with reboot recovery
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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

Commit 76db6d95 (nfs41: add session setup
to the state manager) introduces an infinite loop possibility in the NFSv4
state manager. By first checking nfs4_has_session() before clearing the
NFS4CLNT_SESSION_SETUP flag, it allows for a situation where someone sets
that flag, but it never gets cleared, and so the state manager loops.

In fact commit c3fad1b1

 (nfs41: add session
reset to state manager) causes this to happen every time we get a network
partition error.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: Daniel J Blueman <daniel.blueman@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The oops http://www.kerneloops.org/raw.php?rawid=537858&msgid=

 appears to
be due to the nfs4_lock_state->ls_state field being uninitialised. This
happens if the call to nfs4_free_lock_state() is triggered at the end of
nfs4_get_lock_state().

The fix is to move the initialisation of ls_state into the allocator.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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

It is possible for servers to return NFS4ERR_BAD_STATEID when
the state management code is recovering locks or is reclaiming state when
returning a delegation. Ensure that we handle that case.
While we're at it, add in handlers for NFS4ERR_STALE,
NFS4ERR_ADMIN_REVOKED, NFS4ERR_OPENMODE, NFS4ERR_DENIED and
NFS4ERR_STALE_STATEID, since the protocol appears to allow for them too.

Also handle ENOMEM...

Finally, rather than add new NFSv4.0-specific errors and error handling into
the generic delegation code, move that open file and locking state error
handling into the NFSv4 layer.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Unlike minorversion0, in nfsv4.1 the open and lock seqids need
not be incremented by the client and should always be set to zero.

This is implemented using a new nfs_rpc_ops methods -
increment_open_seqid and increment_lock_seqid
Signed-off-by: Rahul Iyer <iyer@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: check for session not minorversion]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Stops an infinite loop of EXCHANGE_ID.
Signed-off-by: Andy Adamson <andros@netapp.com>
[fixed checkpatch warnings]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>

Unlike SETCLIENTID, EXCHANGE_ID requires a machine credential. Do not search
for credentials other than the machine credential.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

EXCHANGE_ID has different credential requirements than SETCLIENTID.
Prepare for a separate credential function.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

nfsv4.1 clientid is established via EXCHANGE_ID rather than
SETCLIENTID{,_CONFIRM}

This is implemented using a new establish_clid method in
nfs4_state_recovery_ops.

nfs41: establish clientid via exchange id only if cred != NULL

>From 2.6.26 reclaimer() uses machine cred for setting up the client id
therefore it is never expected to be NULL.
Signed-off-by: Rahul Iyer <iyer@netapp.com>
[removed dprintk]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: lease renewal]
[revamped patch for new nfs4_state_manager design]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Use the machine cred for sending SEQUENCE to renew
the client's lease.

[revamp patch for new state management design starting 2.6.29]
[nfs41: support minorversion 1 for nfs4_check_lease]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: get cred in exchange_id when cred arg is NULL]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: use cl_machined_cred instead of cl_ex_cred]
    Since EXCHANGE_ID insists on using the machine credential, cl_ex_cred is
    not needed. nfs4_proc_exchange_id() is only called if the machine credential
    is available. Remove the credential logic from nfs4_proc_exchange_id.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

[moved nfs4_get_renew_cred related changes to
 "nfs41: introduce get_state_renewal_cred"]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Move the code to reset a session from the session_reclaimer to the
nfs4_state_manager.  Destroy the session, and create a new one. Treat
NFS4ERR_BADSESSION and NFS4ERR_DEADSESSION as a successful
nfs4_proc_destroy_session. Signal nfs4_proc_create_session that this is a
session reset so that the session slot table is re-used.

If the clientid is stale, set both NFS4CLNT_LEASE_EXPIRED and
NFS4CLNT_SESSION_SETUP bits and retry.

Use a switch statement in nfs4_session_recovery_handle_error for future
patche which will add handling for other errors.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>

[nfs41: session reset in nfs4_recovery_handle_error]
Signed-off-by: Andy Adamson <andros@netapp.com>
[nfs41: reset session on nfs4_do_reclaim session reset error]
    If nfs4_do_reclaim gets a session reset error, nfs4_recovery_handle_error
    will set the NFS4CLNT_SESSION_SETUP bit, and the state manager should
    continue processing to reset the session.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[move nfs4_proc_destroy_session declaration here]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

At mount, nfs_alloc_client sets the cl_state NFS4CLNT_LEASE_EXPIRED bit
and nfs4_alloc_session sets the NFS4CLNT_SESSION_SETUP bit, so both bits are
set when nfs4_lookup_root calls nfs4_recover_expired_lease which schedules
the nfs4_state_manager and waits for it to complete.

Place the session setup after the clientid establishment in nfs4_state_manager
so that the session is setup right after the clientid has been established
without rescheduling the state manager.

Unlike nfsv4.0, the nfs_client struct is not ready to use until the session
has been established.  Postpone marking the nfs_client struct to NFS_CS_READY
until after a successful CREATE_SESSION call so that other threads cannot use
the client until the session is established.

If the EXCHANGE_ID call fails and the session has not been setup (the
NFS4CLNT_SESSION_SETUP bit is set), mark the client with the error and return.

If the session setup CREATE_SESSION call fails with NFS4ERR_STALE_CLIENTID
which could occur due to server reboot or network partition inbetween the
EXCHANGE_ID and CREATE_SESSION call, reset the NFS4CLNT_LEASE_EXPIRED and
NFS4CLNT_SESSION_SETUP bits and try again.

If the CREATE_SESSION call fails with other errors, mark the client with
the error and return.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>

[nfs41: NFS_CS_SESSION_SETUP cl_cons_state for back channel setup]
  On session setup, the CREATE_SESSION reply races with the server back channel
  probe which needs to succeed to setup the back channel. Set a new
  cl_cons_state NFS_CS_SESSION_SETUP just prior to the CREATE_SESSION call
  and add it as a valid state to nfs_find_client so that the client back channel
  can find the nfs_client struct and won't drop the server backchannel probe.
  Use a new cl_cons_state so that NFSv4.0 back channel behaviour which only
  sets NFS_CS_READY is unchanged.
  Adjust waiting on the nfs_client_active_wq accordingly.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>

[nfs41: rename NFS_CS_SESSION_SETUP to NFS_CS_SESSION_INITING]
Signed-off-by: Andy Adamson <andros@netapp.com>
[nfs41: set NFS_CL_SESSION_INITING in alloc_session]
Signed-off-by: Andy Adamson <andros@netapp.com>
[nfs41: move session setup into a function]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[moved nfs4_proc_create_session declaration here]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

To be returned to the mount command when trying to mount a v4 server
using minorversion 1.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Apparently a lot of people need to disable IPv6 completely on their
distributor-built systems, which have CONFIG_IPV6_MODULE enabled at
build time.

They do this by blacklisting the ipv6.ko module.  This causes the
creation of the NFSv4 callback service listener to fail if
CONFIG_IPV6_MODULE is set, but the module cannot be loaded.

Now that the kernel's PF_INET6 RPC listeners are completely separate
from PF_INET listeners, we can always start PF_INET.  Then the NFS
client can try to start a PF_INET6 listener, but it isn't required
to be available.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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

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>

We really shouldn't be resetting the sequence ids when doing state
expiration recovery, since we don't know if the server still remembers our
previous state owners. There are servers out there that do attempt to
preserve client state even if the lease has expired. Such a server would
only release that state if a conflicting OPEN request occurs.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Fix up a potential race...
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

It is really a more general purpose state management thread at this point.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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 defines a number of state errors which the client does not currently
handle. Among those we should worry about are:
  NFS4ERR_ADMIN_REVOKED - the server's administrator revoked our locks
  			  and/or delegations.
  NFS4ERR_BAD_STATEID - the client and server are out of sync, possibly
                        due to a delegation return racing with an OPEN
			request.
  NFS4ERR_OPENMODE - the client attempted to do something not sanctioned
  		     by the open mode of the stateid. Should normally just
		     occur as a result of a delegation return race.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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>