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>

Allow the server to control the size of the session slot table
by adjusting the value of sr_target_max_slots in the reply to the
SEQUENCE operation.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If the server wants to leave us with only one slot, or it wants
to "shrink" our slot table to something larger than we have now,
then so be it.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Don't confuse the table size and the target_highest_slotid...
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>

When the server tells us that it is dynamically resizing the session
replay cache, we should reset the sequence number for those slots
that have been deallocated.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Dynamic slot allocation in NFSv4.1 depends on the client being able to
track the server's target value for the highest slotid in the
slot table.  See the reference in Section 2.10.6.1 of RFC5661.

To avoid ordering problems in the case where 2 SEQUENCE replies contain
conflicting updates to this target value, we also introduce a generation
counter, to track whether or not an RPC containing a SEQUENCE operation
was launched before or after the last update.

Also rename the nfs4_slot_table target_max_slots field to
'target_highest_slotid' to avoid confusion with a slot
table size or number of slots.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Change the argument to take the pointer to the slot, instead of
just the slotid.

We know that the new value of highest_used_slot must be less than
the current value. No need to scan the whole table.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up the NFSv4.1 slot allocation by replacing nfs_find_slot() with
a function nfs_alloc_slot() that returns a pointer to the nfs4_slot
instead of an offset into the slot table.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Replace the session pointer + slotid with a pointer to the
allocated slot.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Instead of doing slot table pointer gymnastics every time we want to
know which slot we're using.
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>

Store the renewal time inside the session slot instead.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

All that memory is going to be initialised to non-zero by
nfs4_add_and_init_slots anyway.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We must always bump the clientid sequence number after a successful
call to CREATE_SESSION on the server. The result of
nfs4_verify_channel_attrs() is irrelevant to that requirement.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If we're mounting a new filesystem, ensure that the session has negotiated
large enough request and reply sizes to match the wsize and rsize mount
arguments.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Don't store the target request and response sizes in the same
variables used to store the server's replies to those targets.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We can't send a SEQUENCE op unless the session is OK, so it is pointless
to handle the CHECK_LEASE state before we've dealt with SESSION_RESET
and BIND_CONN_TO_SESSION.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If I mount an NFS v4.1 server to a single client multiple times and then
run xfstests over each mountpoint I usually get the client into a state
where recovery deadlocks.  The server informs the client of a
cb_path_down sequence error, the client then does a
bind_connection_to_session and checks the status of the lease.

I found that bind_connection_to_session sets the NFS4_SESSION_DRAINING
flag on the client, but this flag is never unset before
nfs4_check_lease() reaches nfs4_proc_sequence().  This causes the client
to deadlock, halting all NFS activity to the server.  nfs4_proc_sequence()
is only called by the state manager, so I can change it to run in privileged
mode to bypass the NFS4_SESSION_DRAINING check and avoid the deadlock.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

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

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

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

...and ensure that we set the return value for nfs_page_async_flush()
to zero! (Reported-by: Dros Adamson)
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

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

An EAGAIN return value would be unexpected, but there is no reason to
BUG...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Convert the ones that are not trivial to check into WARN_ON_ONCE().
Remove checks for things such as NFS2_MAXPATHLEN, which are trivially
done by the caller.

Add a comment to the case of nfs3_xdr_enc_setacl3args. What is being
done there is just wrong...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If the nfs_client fails to initialise correctly, then it will
return an error condition.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Return errno - not an NFS4ERR_. This worked because NFS4ERR_ACCESS == EACCES.
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

Use nfs_sb_deactive_async instead of nfs_sb_deactive when in a workqueue
context.  This avoids a deadlock where rpc_shutdown_client loops forever
in a workqueue kworker context, trying to kill all RPC tasks associated with
the client, while one or more of these tasks have already been assigned to the
same kworker (and will never run rpc_exit_task).

This approach is needed because RPC tasks that have already been assigned
to a kworker by queue_work cannot be canceled, as explained in the comment
for workqueue.c:insert_wq_barrier.
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
[Trond: add module_get/put.]
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Since commit c7f404b4 ('vfs: new superblock methods to override
/proc/*/mount{s,info}'), nfs_path() is used to generate the mounted
device name reported back to userland.

nfs_path() always generates a trailing slash when the given dentry is
the root of an NFS mount, but userland may expect the original device
name to be returned verbatim (as it used to be).  Make this
canonicalisation optional and change the callers accordingly.

[jrnieder@gmail.com: use flag instead of bool argument]
Reported-and-tested-by: NChris Hiestand <chiestand@salk.edu>
Reference: http://bugs.debian.org/669314Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Cc: <stable@vger.kernel.org> # v2.6.39+
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

In very busy v3 environment, rpc.mountd can respond to the NULL
procedure but not the MNT procedure in a timely manner causing
the MNT procedure to time out. The problem is the mount system
call returns EIO which causes the mount to fail, instead of
ETIMEDOUT, which would cause the mount to be retried.

This patch sets the RPC_TASK_SOFT|RPC_TASK_TIMEOUT flags to
the rpc_call_sync() call in nfs_mount() which causes
ETIMEDOUT to be returned on timed out connections.
Signed-off-by: NSteve Dickson <steved@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

The new layout pointer in pnfs_find_alloc_layout() may be NULL because of
out of memory. we must do some check work, otherwise pnfs_free_layout_hdr()
will go wrong because it can not deal with a NULL pointer.
Signed-off-by: NYanchuan Nian <ycnian@gmail.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The DNS resolver's use of the sunrpc cache involves a 'ttl' number
(relative) rather that a timeout (absolute).  This confused me when
I wrote
  commit c5b29f88
     "sunrpc: use seconds since boot in expiry cache"

and I managed to break it.  The effect is that any TTL is interpreted
as 0, and nothing useful gets into the cache.

This patch removes the use of get_expiry() - which really expects an
expiry time - and uses get_uint() instead, treating the int correctly
as a ttl.

This fixes a regression that has been present since 2.6.37, causing
certain NFS accesses in certain environments to incorrectly fail.
Reported-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NChuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If the state recovery machinery is triggered by the call to
nfs4_async_handle_error() then we can deadlock.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

If we do not release the sequence id in cases where we fail to get a
session slot, then we can deadlock if we hit a recovery scenario.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

Currently, we will schedule session recovery and then return to the
caller of nfs4_handle_exception.  This works for most cases, but causes
a hang on the following test case:

	Client				Server
	------				------
	Open file over NFS v4.1
	Write to file
					Expire client
	Try to lock file

The server will return NFS4ERR_BADSESSION, prompting the client to
schedule recovery.  However, the client will continue placing lock
attempts and the open recovery never seems to be scheduled.  The
simplest solution is to wait for session recovery to run before retrying
the lock.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org