Commit Graph

185 Commits

Author SHA1 Message Date
Trond Myklebust
eff7936877 nfsd: Fix a memory scribble in the callback channel
The offset of the entry in struct rpc_version has to match the version
number.

Reported-by: Dave Jones <davej@codemonkey.org.uk>
Fixes: 1c5876ddbd ("sunrpc: move p_count out of struct rpc_procinfo")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-07-17 13:15:06 -04:00
Christoph Hellwig
02be49f6b7 nfsd4: const-ify nfs_cb_version4
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-15 17:42:20 +02:00
Christoph Hellwig
499b498810 sunrpc: mark all struct rpc_procinfo instances as const
struct rpc_procinfo contains function pointers, and marking it as
constant avoids it being able to be used as an attach vector for
code injections.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-05-15 17:42:20 +02:00
Christoph Hellwig
1c5876ddbd sunrpc: move p_count out of struct rpc_procinfo
p_count is the only writeable memeber of struct rpc_procinfo, which is
a good candidate to be const-ified as it contains function pointers.

This patch moves it into out out struct rpc_procinfo, and into a
separate writable array that is pointed to by struct rpc_version and
indexed by p_statidx.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-15 17:42:18 +02:00
Christoph Hellwig
d39916c487 nfsd: fix decoder callback prototypes
Declare the p_decode callbacks with the proper prototype instead of
casting to kxdrdproc_t and losing all type safety.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
2017-05-15 17:42:14 +02:00
Christoph Hellwig
1502c81b44 nfsd: fix encoder callback prototypes
Declare the p_encode callbacks with the proper prototype instead of
casting to kxdreproc_t and losing all type safety.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
2017-05-15 17:42:10 +02:00
Kinglong Mee
827433801c nfsd/callback: Drop a useless data copy when comparing sessionid
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-02-17 16:26:02 -05:00
Kinglong Mee
e86a40bc73 nfsd/callback: skip the callback tag
The callback tag is NULL, and hdr->nops is unused too right now, but.
But if we were to ever test with a nonzero callback tag, nops will get a
bad value.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-02-17 16:26:01 -05:00
Kinglong Mee
f7d1ddbe76 nfsd/callback: Cleanup callback cred on shutdown
The rpccred gotten from rpc_lookup_machine_cred() should be put when
state is shutdown.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-02-17 16:26:00 -05:00
J. Bruce Fields
8838203667 nfsd: update workqueue creation
No real change in functionality, but the old interface seems to be
deprecated.

We don't actually care about ordering necessarily, but we do depend on
running at most one work item at a time: nfsd4_process_cb_update()
assumes that no other thread is running it, and that no new callbacks
are starting while it's running.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-11-14 11:13:43 -05:00
Jeff Layton
a188620ebd nfsd: plumb in a CB_NOTIFY_LOCK operation
Add the encoding/decoding for CB_NOTIFY_LOCK operations.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-09-26 15:20:35 -04:00
Jeff Layton
89dfdc964b nfsd: eliminate cb_minorversion field
We already have that info in the client pointer. No need to pass around
a copy.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-09-16 16:15:52 -04:00
J. Bruce Fields
d50039ea5e nfsd4/rpc: move backchannel create logic into rpc code
Also simplify the logic a bit.

Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: Trond Myklebust <trondmy@primarydata.com>
2016-06-15 10:32:25 -04:00
J. Bruce Fields
d4f72cb7fa nfsd: don't base cl_cb_status on stale information
The rpc client we use to send callbacks may change occasionally.  (In
the 4.0 case, the client can use setclientid/setclientid_confirm to
update the callback parameters.  In the 4.1+ case, sessions and
connections can come and go.)

The update is done from the callback thread by nfsd4_process_cb_update,
which shuts down the old rpc client and then creates a new one.

The client shutdown kills any ongoing rpc calls.  There won't be any new
ones till the new one's created and the callback thread moves on.

When an rpc encounters a problem that may suggest callback rpc's
aren't working any longer, it normally sets NFSD4_CB_DOWN, so the server
can tell the client something's wrong.

But if the rpc notices CB_UPDATE is set, then the failure may just be a
normal result of shutting down the callback client.  Or it could just be
a coincidence, but in any case, it means we're runing with the old
about-to-be-discarded client, so the failure's not interesting.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-12-23 10:08:14 -05:00
Julia Lawall
c4cb897462 nfsd: constify nfsd4_callback_ops structure
The nfsd4_callback_ops structure is never modified, so declare it as const.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-11-23 12:15:31 -07:00
Kinglong Mee
7ba6cad6c8 nfsd: New helper nfsd4_cb_sequence_done() for processing more cb errors
According to Christoph's advice, this patch introduce a new helper
nfsd4_cb_sequence_done() for processing more callback errors, following
the example of the client's nfs41_sequence_done().

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-13 08:57:06 -04:00
Kinglong Mee
276f03e3ba nfsd: Update callback sequnce id only CB_SEQUENCE success
When testing pnfs layout, nfsd got error NFS4ERR_SEQ_MISORDERED.
It is caused by nfs return NFS4ERR_DELAY before validate_seqid(),
don't update the sequnce id, but nfsd updates the sequnce id !!!

According to RFC5661 20.9.3,
" If CB_SEQUENCE returns an error, then the state of the slot
(sequence ID, cached reply) MUST NOT change. "

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-06-04 16:51:30 -04:00
Kinglong Mee
4399396eec nfsd: Reset cb_status in nfsd4_cb_prepare() at retrying
nfsd enters a infinite loop and prints message every 10 seconds:

May 31 18:33:52 test-server kernel: Error sending entire callback!
May 31 18:34:01 test-server kernel: Error sending entire callback!

This is caused by a cb_layoutreturn getting error -10008
(NFS4ERR_DELAY), the client crashing, and then nfsd entering the
infinite loop:

  bc_sendto --> call_timeout --> nfsd4_cb_done --> nfsd4_cb_layout_done
  with error -10008 --> rpc_delay(task, HZ/100) --> bc_sendto ...

Reproduced using xfstests 074 with nfs client's kdump on,
CONFIG_DEFAULT_HUNG_TASK_TIMEOUT set, and client's blkmapd down:

1. nfs client's write operation will get the layout of file,
   and then send getdeviceinfo,
2. but layout segment is not recorded by client because blkmapd is down,
3. client writes data by sending WRITE to server,
4. nfs server recalls the layout of the file before WRITE,
5. network error causes the client reset the session and return NFS4ERR_DELAY,
6. so client's WRITE operation is waiting the reply.
   If the task hangs 120s, the client will crash.
7. so that, the next bc_sendto will fail with TIMEOUT,
   and cb_status is NFS4ERR_DELAY.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-06-04 16:43:39 -04:00
Christoph Hellwig
4bd9e9b77f nfsd: skip CB_NULL probes for 4.1 or later
With sessions in v4.1 or later we don't need to manually probe the backchannel
connection, so we can declare it up instantly after setting up the RPC client.

Note that we really should split nfsd4_run_cb_work in the long run, this is
just the least intrusive fix for now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-05-04 12:02:42 -04:00
Christoph Hellwig
cba5f62b18 nfsd: fix callback restarts
Checking the rpc_client pointer is not a reliable way to detect
backchannel changes: cl_cb_client is changed only after shutting down
the rpc client, so the condition cl_cb_client = tk_client will always be
true.

Check the RPC_TASK_KILLED flag instead, and rewrite the code to avoid
the buggy cl_callbacks list and fix the lifetime rules due to double
calls of the ->prepare callback operations method for this retry case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-05-04 12:02:41 -04:00
Christoph Hellwig
ef2a1b3e10 nfsd: split transport vs operation errors for callbacks
We must only increment the sequence id if the client has seen and responded
to a request.  If we failed to deliver it to the client we must resend with
the same sequence id.  So just like the client track errors at the transport
level differently from those returned in the XDR.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-05-04 12:02:40 -04:00
Christoph Hellwig
c5c707f96f nfsd: implement pNFS layout recalls
Add support to issue layout recalls to clients.  For now we only support
full-file recalls to get a simple and stable implementation.  This allows
to embedd a nfsd4_callback structure in the layout_state and thus avoid
any memory allocations under spinlocks during a recall.  For normal
use cases that do not intent to share a single file between multiple
clients this implementation is fully sufficient.

To ensure layouts are recalled on local filesystem access each layout
state registers a new FL_LAYOUT lease with the kernel file locking code,
which filesystems that support pNFS exports that require recalls need
to break on conflicting access patterns.

The XDR code is based on the old pNFS server implementation by
Andy Adamson, Benny Halevy, Boaz Harrosh, Dean Hildebrand, Fred Isaman,
Marc Eshel, Mike Sager and Ricardo Labiaga.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2015-02-02 18:09:43 +01:00
Trond Myklebust
c6c15e1ed3 nfsd: Fix slot wake up race in the nfsv4.1 callback code
The currect code for nfsd41_cb_get_slot() and nfsd4_cb_done() has no
locking in order to guarantee atomicity, and so allows for races of
the form.

Task 1                                  Task 2
======                                  ======
if (test_and_set_bit(0) != 0) {
                                        clear_bit(0)
                                        rpc_wake_up_next(queue)
        rpc_sleep_on(queue)
        return false;
}

This patch breaks the race condition by adding a retest of the bit
after the call to rpc_sleep_on().

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-11-19 15:45:44 -05:00
Jeff Layton
34549ab09e nfsd: eliminate "to_delegation" define
We now have cb_to_delegation and to_delegation, which do the same thing
and are defined separately in different .c files. Move the
cb_to_delegation definition into a header file and eliminate the
redundant to_delegation definition.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
2014-10-01 12:28:01 -04:00
Christoph Hellwig
0162ac2b97 nfsd: introduce nfsd4_callback_ops
Add a higher level abstraction than the rpc_ops for callback operations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-09-26 16:29:29 -04:00
Christoph Hellwig
f0b5de1b6b nfsd: split nfsd4_callback initialization and use
Split out initializing the nfs4_callback structure from using it.  For
the NULL callback this gets rid of tons of pointless re-initializations.

Note that I don't quite understand what protects us from running multiple
NULL callbacks at the same time, but at least this chance doesn't make
it worse..

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-09-26 16:29:28 -04:00
Christoph Hellwig
326129d02a nfsd: introduce a generic nfsd4_cb
Add a helper to queue up a callback.  CB_NULL has a bit of special casing
because it is special in the specification, but all other new callback
operations will be able to share code with this and a few more changes
to refactor the callback code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-09-26 16:29:27 -04:00
Christoph Hellwig
2faf3b4350 nfsd: remove nfsd4_callback.cb_op
We can always get at the private data by using container_of, no need for
a void pointer.  Also introduce a little to_delegation helper to avoid
opencoding the container_of everywhere.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-09-26 16:29:26 -04:00
Benny Halevy
341b51df1f nfsd: do not clear rpc_resp in nfsd4_cb_done_sequence
This is incorrect when a callback is has to be restarted, in which case
the XDR decoding of the second iteration will see a NULL cb argument.

[hch: updated description]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-09-26 16:29:25 -04:00
Christoph Hellwig
444b6e910d nfsd: fix nfsd4_cb_recall_done error handling
For any error that is not EBADHANDLE or NFS4ERR_BAD_STATEID,
nfsd4_cb_recall_done first marks the connection down, then
retries until dl_retries hits zero, then marks the connection down
again and sets cb_done.  This changes the code to only retry
for EBADHANDLE or NFS4ERR_BAD_STATEID, and factors setting
cb_done into a single point in the function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-09-26 16:29:25 -04:00
Trond Myklebust
11b9164ada nfsd: Add a struct nfs4_file field to struct nfs4_stid
All stateids are associated with a nfs4_file. Let's consolidate.
Replace delegation->dl_file with the dl_stid.sc_file, and
nfs4_ol_stateid->st_file with st_stid.sc_file.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-31 12:51:34 -04:00
Trond Myklebust
6011695da2 nfsd: Add reference counting to the lock and open stateids
When we remove the client_mutex, we'll need to be able to ensure that
these objects aren't destroyed while we're not holding locks.

Add a ->free() callback to the struct nfs4_stid, so that we can
release a reference to the stid without caring about the contents.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-31 12:43:53 -04:00
Jeff Layton
650ecc8f8f nfsd: remove dl_fh field from struct nfs4_delegation
Now that the nfs4_file has a filehandle in it, we no longer need to
keep a per-delegation copy of it. Switch to using the one in the
nfs4_file instead.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-29 14:49:58 -04:00
Himangi Saraogi
fc8e5a644c nfsd4: convert comma to semicolon
Replace a comma between expression statements by a semicolon. This changes
the semantics of the code, but given the current indentation appears to be
what is intended.

A simplified version of the Coccinelle semantic patch that performs this
transformation is as follows:
// <smpl>
@r@
expression e1,e2;
@@

 e1
-,
+;
 e2;
// </smpl>

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-23 14:20:49 -04:00
Chuck Lever
3c45ddf823 svcrdma: Select NFSv4.1 backchannel transport based on forward channel
The current code always selects XPRT_TRANSPORT_BC_TCP for the back
channel, even when the forward channel was not TCP (eg, RDMA). When
a 4.1 mount is attempted with RDMA, the server panics in the TCP BC
code when trying to send CB_NULL.

Instead, construct the transport protocol number from the forward
channel transport or'd with XPRT_TRANSPORT_BC. Transports that do
not support bi-directional RPC will not have registered a "BC"
transport, causing create_backchannel_client() to fail immediately.

Fixes: https://bugzilla.linux-nfs.org/show_bug.cgi?id=265
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-18 11:35:45 -04:00
Jeff Layton
02e1215f9f nfsd: Avoid taking state_lock while holding inode lock in nfsd_break_one_deleg
state_lock is a heavily contended global lock. We don't want to grab
that while simultaneously holding the inode->i_lock.

Add a new per-nfs4_file lock that we can use to protect the
per-nfs4_file delegation list. Hold that while walking the list in the
break_deleg callback and queue the workqueue job for each one.

The workqueue job can then take the state_lock and do the list
manipulations without the i_lock being held prior to starting the
rpc call.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-16 21:06:12 -04:00
Jeff Layton
e8051c837b nfsd: eliminate nfsd4_init_callback
It's just an obfuscated INIT_WORK call. Just make the work_func_t a
non-static symbol and use a normal INIT_WORK call.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-16 14:18:58 -04:00
Jeff Layton
3758cf7e14 nfsd: set timeparms.to_maxval in setup_callback_client
...otherwise the logic in the timeout handling doesn't work correctly.

Spotted-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-04-18 14:34:31 +02:00
Kinglong Mee
d531c008d7 NFSD/SUNRPC: Check rpc_xprt out of xs_setup_bc_tcp
Besides checking rpc_xprt out of xs_setup_bc_tcp,
increase it's reference (it's important).

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-03-30 10:47:36 -04:00
J. Bruce Fields
06b332a522 nfsd4: check backchannel attributes on create_session
Make sure the client gives us an adequate backchannel.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-09 16:53:56 -04:00
J. Bruce Fields
8be2d2344c nfsd4: minor cb_recall simplification
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-04 13:25:14 -04:00
Stanislav Kinsbursky
3d7337115d nfsd: make NFSv4 lease time per net
Lease time is a part of NFSv4 state engine, which is constructed per network
namespace.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-11-28 10:39:46 -05:00
Stanislav Kinsbursky
c212cecfa2 nfsd: make nfs4_client network namespace dependent
And use it's net where possible.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-11-15 07:40:42 -05:00
Fengguang Wu
2b4cf668a7 nfsd4: get_backchannel_cred should be static
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-11-14 11:23:00 -05:00
J. Bruce Fields
12fc3e92d4 nfsd4: backchannel should use client-provided security flavor
For now this only adds support for AUTH_NULL.  (Previously we assumed
AUTH_UNIX.)  We'll also need AUTH_GSS, which is trickier.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-11-07 19:40:05 -05:00
J. Bruce Fields
57725155dc nfsd4: common helper to initialize callback work
I've found it confusing having the only references to
nfsd4_do_callback_rpc() in a different file.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-11-07 19:40:04 -05:00
J. Bruce Fields
c6bb3ca27d nfsd4: use callback security parameters in create_session
We're currently ignoring the callback security parameters specified in
create_session, and just assuming the client wants auth_sys, because
that's all the current linux client happens to care about.  But this
could cause us callbacks to fail to a client that wanted something
different.

For now, all we're doing is no longer ignoring the uid and gid passed in
the auth_sys case.  Further patches will add support for auth_null and
gss (and possibly use more of the auth_sys information; the spec wants
us to use exactly the credential we're passed, though it's hard to
imagine why a client would care).

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-11-07 19:31:35 -05:00
Namjae Jeon
8c8651b8e2 nfsd: remove duplicate init in nfsd4_cb_recall
remove duplicate init in nfsd4_cb_recall

Signed-off-by: Namjae Jeon <linkinjeon@gmail.com>
Signed-off-by: Vivek Trivedi <vtrivedi018@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-09-10 17:46:18 -04:00
J. Bruce Fields
39307655a1 nfsd4: fix security flavor of NFSv4.0 callback
Commit d5497fc693 "nfsd4: move rq_flavor
into svc_cred" forgot to remove cl_flavor from the client, leaving two
places (cl_flavor and cl_cred.cr_flavor) for the flavor to be stored.
After that patch, the latter was the one that was updated, but the
former was the one that the callback used.

Symptoms were a long delay on utime().  This is because the utime()
generated a setattr which recalled a delegation, but the cb_recall was
ignored by the client because it had the wrong security flavor.

Cc: stable@vger.kernel.org
Tested-by: Jamie Heilman <jamie@audible.transient.net>
Reported-by: Jamie Heilman <jamie@audible.transient.net>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-08-20 18:38:36 -04:00
J. Bruce Fields
9068bed1a3 nfsd4: remove unnecessary comment
For the most part readers of cl_cb_state only need a value that is
"eventually" right.  And the value is set only either 1) in response to
some change of state, in which case it's set to UNKNOWN and then a
callback rpc is sent to probe the real state, or b) in the handling of a
response to such a callback.  UNKNOWN is therefore always a "temporary"
state, and for the other states we're happy to accept last writer wins.

So I think we're OK here.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-06-20 08:59:41 -04:00