Stateid's hold a read reference for a read open, a write reference for a
write open, and an additional one of each for each read+write open.  The
latter wasn't getting put on a downgrade, so something like:

	open RW
	open R
	downgrade to R

was resulting in a file leak.

Also fix an imbalance in an error path.

Regression from 7d947842 "nfsd4: fix
downgrade/lock logic".

Cc: stable@kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Without this, for example,

	open read
	open read+write
	close

will result in a struct file leak.

Regression from 7d947842 "nfsd4: fix
downgrade/lock logic".

Cc: stable@kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This operation is used by the client to check the validity of a list of
stateids.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This operation is used by the client to tell the server to free a
stateid.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This also fixes a number of sparse warnings.
Signed-off-by: NDaniel Mack <zonque@gmail.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Compiling gave me this warning:
fs/nfsd/nfs4state.c: In function ‘nfsd4_bind_conn_to_session’:
fs/nfsd/nfs4state.c:1623:9: warning: variable ‘status’ set but not used
[-Wunused-but-set-variable]

The local variable "status" was being set by nfsd4_map_bcts_dir() and
then ignored before calling nfsd4_new_conn().
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Servers are supposed to return nfserr_complete_already to clients that
attempt to send multiple RECLAIM_COMPLETEs.
Signed-off-by: NMi Jinlong <mijinlong@cn.fujitsu.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Make sure nfs server errors out if request contains more ops
than channel allows.
Signed-off-by: NMi Jinlong <mijinlong@cn.fujitsu.com>
[bfields@redhat.com: use helper function]
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Teach the NFS server to reject invalid create_session flags.

Also do some minor formatting adjustments.
Signed-off-by: NMi Jinlong <mijinlong@cn.fujitsu.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

23fcf2ec (nfsd4: fix oops on lock failure)

The above patch breaks free path for stp->st_file. If stp was inserted
into sop->so_stateids, we have to free stp->st_file refcount. Because
stp->st_file refcount itself is taken whether or not any refcounts are
taken on the stp->st_file->fi_fds[].
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: stable@kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Introduced by acfdf5c3.

Cc: stable@kernel.org
Reported-by: NGerhard Heift <ml-nfs-linux-20110412-ef47@gheift.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Lock stateid's can have access_bmap 0 if they were only partially
initialized (due to a failed lock request); handle that case in
free_generic_stateid.

------------[ cut here ]------------
kernel BUG at fs/nfsd/nfs4state.c:380!
invalid opcode: 0000 [#1] SMP
last sysfs file: /sys/kernel/mm/ksm/run
Modules linked in: nfs fscache md4 nls_utf8 cifs ip6table_filter ip6_tables ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat bridge stp llc nfsd lockd nfs_acl auth_rpcgss sunrpc ipv6 ppdev parport_pc parport pcnet32 mii pcspkr microcode i2c_piix4 BusLogic floppy [last unloaded: mperf]

Pid: 1468, comm: nfsd Not tainted 2.6.38+ #120 VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform
EIP: 0060:[<e24f180d>] EFLAGS: 00010297 CPU: 0
EIP is at nfs4_access_to_omode+0x1c/0x29 [nfsd]
EAX: ffffffff EBX: dd758120 ECX: 00000000 EDX: 00000004
ESI: dd758120 EDI: ddfe657c EBP: dd54dde0 ESP: dd54dde0
 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process nfsd (pid: 1468, ti=dd54c000 task=ddc92580 task.ti=dd54c000)
Stack:
 dd54ddf0 e24f19ca 00000000 ddfe6560 dd54de08 e24f1a5d dd758130 deee3a20
 ddfe6560 31270000 dd54df1c e24f52fd 0000000f dd758090 e2505dd0 0be304cf
 dbb51d68 0000000e ddfe657c ddcd8020 dd758130 dd758128 dd7580d8 dd54de68
Call Trace:
 [<e24f19ca>] free_generic_stateid+0x1c/0x3e [nfsd]
 [<e24f1a5d>] release_lockowner+0x71/0x8a [nfsd]
 [<e24f52fd>] nfsd4_lock+0x617/0x66c [nfsd]
 [<e24e57b6>] ? nfsd_setuser+0x199/0x1bb [nfsd]
 [<e24e056c>] ? nfsd_setuser_and_check_port+0x65/0x81 [nfsd]
 [<c07a0052>] ? _cond_resched+0x8/0x1c
 [<c04ca61f>] ? slab_pre_alloc_hook.clone.33+0x23/0x27
 [<c04cac01>] ? kmem_cache_alloc+0x1a/0xd2
 [<c04835a0>] ? __call_rcu+0xd7/0xdd
 [<e24e0dfb>] ? fh_verify+0x401/0x452 [nfsd]
 [<e24f0b61>] ? nfsd4_encode_operation+0x52/0x117 [nfsd]
 [<e24ea0d7>] ? nfsd4_putfh+0x33/0x3b [nfsd]
 [<e24f4ce6>] ? nfsd4_delegreturn+0xd4/0xd4 [nfsd]
 [<e24ea2c9>] nfsd4_proc_compound+0x1ea/0x33e [nfsd]
 [<e24de6ee>] nfsd_dispatch+0xd1/0x1a5 [nfsd]
 [<e1d6e1c7>] svc_process_common+0x282/0x46f [sunrpc]
 [<e1d6e578>] svc_process+0xdc/0xfa [sunrpc]
 [<e24de0fa>] nfsd+0xd6/0x115 [nfsd]
 [<e24de024>] ? nfsd_shutdown+0x24/0x24 [nfsd]
 [<c0454322>] kthread+0x62/0x67
 [<c04542c0>] ? kthread_worker_fn+0x114/0x114
 [<c07a6ebe>] kernel_thread_helper+0x6/0x10
Code: eb 05 b8 00 00 27 4f 8d 65 f4 5b 5e 5f 5d c3 83 e0 03 55 83 f8 02 89 e5 74 17 83 f8 03 74 05 48 75 09 eb 09 b8 02 00 00 00 eb 0b <0f> 0b 31 c0 eb 05 b8 01 00 00 00 5d c3 55 89 e5 57 56 89 d6 8d
EIP: [<e24f180d>] nfs4_access_to_omode+0x1c/0x29 [nfsd] SS:ESP 0068:dd54dde0
---[ end trace 2b0bf6c6557cb284 ]---

The trace route is:

 -> nfsd4_lock()
   -> if (lock->lk_is_new) {
     -> alloc_init_lock_stateid()

        3739: stp->st_access_bmap = 0;

   ->if (status && lock->lk_is_new && lock_sop)
     -> release_lockowner()
      -> free_generic_stateid()
       -> nfs4_access_bmap_to_omode()
          -> nfs4_access_to_omode()

        380: BUG();   *****

This problem was introduced by 0997b173.
Reported-by: NMi Jinlong <mijinlong@cn.fujitsu.com>
Tested-by: NMi Jinlong <mijinlong@cn.fujitsu.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

According to rfc5661,

  ca_maxresponsesize_cached:

     Like ca_maxresponsesize, but the maximum size of a reply that
     will be stored in the reply cache (Section 2.10.6.1).  For each
     channel, the server MAY decrease this value, but MUST NOT
     increase it.

the latest kernel(2.6.38-rc8) may increase the value for ignoring
request's ca_maxresponsesize_cached value. We should not ignore it.
Signed-off-by: NMi Jinlong <mijinlong@cn.fujitsu.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Make sure we properly reference count the struct files that a lock
depends on, and release them when the lock stateid is released.

This fixes a major leak of struct files when using locking over nfsv4.

Cc: stable@kernel.org
Reported-by: NRick Koshi <nfs-bug-report@more-right-rudder.com>
Tested-by: NIvo Přikryl <prikryl@eurosat.cz>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Minor cleanup in preparation for a bugfix--moving some code to avoid
forward references, etc.  No change in functionality.

Cc: stable@kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

These macros had never been used for several years.
So, remove them.
Signed-off-by: NShan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

In case of a nonempty list, the return on error here is obviously bogus;
it ends up being a pointer to the list head instead of to any valid
delegation on the list.

In particular, if nfsd4_delegreturn() hits this case, and you're quite unlucky,
then renew_client may oops, and it may take an embarassingly long time to
figure out why.  Facepalm.

BUG: unable to handle kernel NULL pointer dereference at 0000000000000090
IP: [<ffffffff81292965>] nfsd4_delegreturn+0x125/0x200
...

Cc: stable@kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Instead of acquiring one lease each time another client opens a file,
nfsd can acquire just one lease to represent all of them, and reference
count it to determine when to release it.

This fixes a regression introduced by
c45821d2 "locks: eliminate fl_mylease
callback": after that patch, only the struct file * is used to determine
who owns a given lease.  But since we recently converted the server to
share a single struct file per open, if we acquire multiple leases on
the same file from nfsd, it then becomes impossible on unlocking a lease
to determine which of those leases (all of whom share the same struct
file *) we meant to remove.

Thanks to Takashi Iwai <tiwai@suse.de> for catching a bug in a previous
version of this patch.
Tested-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Modify fi_delegations only under the recall_lock, allowing us to use
that list on lease breaks.

Also some trivial cleanup to simplify later changes.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

These aren't all that useful, and get in the way of the next steps.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Splitting some code into a separate function which we'll be adding some
more to.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Also share some common exit code.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We'll be adding some more code here soon.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If we lose the backchannel and then the client repairs the problem,
resend any callbacks.

We use a new cb_done flag to track whether there is still work to be
done for the callback or whether it can be destroyed with the rpc.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If this loses any backchannel, make sure we have a chance to notice that
and set the sequence flags.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This makes sure we set the sequence flag when necessary.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Implement the SEQ4_STATUS_CB_PATH_DOWN flag.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Distinguish between when the callback channel is known to be down, and
when it is not yet confirmed.  This will be useful in the 4.1 case.

Also, we don't seem to be using the fact that this field is atomic.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Now that we have a list of connections to choose from, we can teach the
callback code to just pick a suitable connection and use that, instead
of insisting on forever using the connection that the first
create_session was sent with.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Basic xdr and processing for BIND_CONN_TO_SESSION.  This adds a
connection to the list of connections associated with a session.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We want to traverse this from the callback code.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

when callback is generated in NFSv4 server, it doesn't set the source
address. When an alias IP is utilized on NFSv4 server and suppose the
client is accessing via that alias IP (e.g. eth0:0), the client invokes
the callback to the IP address that is set on the original device (e.g.
eth0). This behavior results in timeout of xprt.
The patch sets the IP address that the client should invoke callback to.
Signed-off-by: NTakuma Umeya <tumeya@redhat.com>
[bfields@redhat.com: Simplify gen_callback arguments, use helper function]
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The nfs server only supports read delegations for now, so we don't care
how conflicts are determined.  All we care is that unlocks are
recognized as matching the leases they are meant to remove.  After the
last patch, a comparison of struct files will work for that purpose.  So
we no longer need this callback.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

When we converted to sharing struct filess between nfs4 opens I went too
far and also used the same mechanism for delegations.  But keeping
a reference to the struct file ensures it will outlast the lease, and
allows us to remove the lease with the same file as we added it.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

nfsd controls the lifetime of the lease, not the lock code, so there's
no need for this callback on lease destruction.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We no longer need a few of these special cases.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Instead of failing to find client entries which don't match the
minorversion, we should be finding them, then either erroring out or
expiring them as appropriate.

This also fixes a problem which would cause the 4.1 server to fail to
recognize clients after a second reboot.
Reported-by: NCasey Bodley <cbodley@citi.umich.edu>
Reviewed-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>