Commit Graph

22 Commits

Author SHA1 Message Date
Fred Isaman
9a837856cf NFSv4.1: Fix regression in callback retry handling
When initializing a freshly created slot for the calllback channel,
the seq_nr needs to be 0, not 1.  Otherwise validate_seqid
and nfs4_slot_wait_on_seqid get confused and believe that the
mpty slot corresponds to a previously sent reply.

Signed-off-by: Fred Isaman <fred.isaman@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-12-01 17:21:38 -05:00
Shuah Khan
0ac84b72c0 fs/nfs: Fix used uninitialized warn in nfs4_slot_seqid_in_use()
Fix the following warn:

fs/nfs/nfs4session.c: In function ‘nfs4_slot_seqid_in_use’:
fs/nfs/nfs4session.c:203:54: warning: ‘cur_seq’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  if (nfs4_slot_get_seqid(tbl, slotid, &cur_seq) == 0 &&
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~
      cur_seq == seq_nr && test_bit(slotid, tbl->used_slots))
      ~~~~~~~~~~~~~~~~~

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-11-07 16:11:30 -05:00
Arnd Bergmann
68a564006a NFSv4.1: work around -Wmaybe-uninitialized warning
A bugfix introduced a harmless gcc warning in nfs4_slot_seqid_in_use
if we enable -Wmaybe-uninitialized again:

fs/nfs/nfs4session.c:203:54: error: 'cur_seq' may be used uninitialized in this function [-Werror=maybe-uninitialized]

gcc is not smart enough to conclude that the IS_ERR/PTR_ERR pair
results in a nonzero return value here. Using PTR_ERR_OR_ZERO()
instead makes this clear to the compiler.

The warning originally did not appear in v4.8 as it was globally
disabled, but the bugfix that introduced the warning got backported
to stable kernels which again enable it, and this is now the only
warning in the v4.7 builds.

Fixes: e09c978aae ("NFSv4.1: Fix Oopsable condition in server callback races")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-10-24 13:54:43 -04:00
Trond Myklebust
045d2a6d07 NFSv4.1: Delay callback processing when there are referring triples
If CB_SEQUENCE tells us that the processing of this request depends on
the completion of one or more referring triples (see RFC 5661 Section
2.10.6.3), delay the callback processing until after the RPC requests
being referred to have completed.
If we end up delaying for more than 1/2 second, then fall back to
returning NFS4ERR_DELAY in reply to the callback.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-08-28 14:23:26 -04:00
Trond Myklebust
e09c978aae NFSv4.1: Fix Oopsable condition in server callback races
The slot table hasn't been an array since v3.7. Ensure that we
use nfs4_lookup_slot() to access the slot correctly.

Fixes: 87dda67e73 ("NFSv4.1: Allow SEQUENCE to resize the slot table...")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # v3.8+
2016-08-28 14:23:22 -04:00
Trond Myklebust
810d82e683 NFSv4.x: Allow multiple callbacks in flight
Hook the callback channel into the same session management machinery
as we use for the forward channel.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-01-25 09:36:21 -05:00
Trond Myklebust
b1c0df5fad NFSv4.1: Don't set up a backchannel if the server didn't agree to do so
If the server doesn't agree to out backchannel setup request, then
don't set one up.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-02-18 12:30:47 -08:00
Trond Myklebust
20b9a90245 NFSv4.1: nfs4_destroy_session must call rpc_destroy_waitqueue
There may still be timers active on the session waitqueues. Make sure
that we kill them before freeing the memory.

Cc: stable@vger.kernel.org # 3.12+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-02-01 15:13:39 -05:00
Chuck Lever
1cec16abf2 When CONFIG_NFS_V4_1 is not enabled, "make C=2" emits this warning:
linux/fs/nfs/nfs4session.c:337:6: warning:
 symbol 'nfs41_set_target_slotid' was not declared. Should it be static?

Move nfs41_set_target_slotid() and nfs41_update_target_slotid() back
behind CONFIG_NFS_V4_1, since, in the final revision of this work,
they are used only in NFSv4.1 and later.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-09-04 12:26:30 -04:00
Chuck Lever
eb2a1cd3c9 NFS: Add global helper for releasing slot table resources
The nfs4_destroy_slot_tables() function is renamed to avoid
confusion with the new helper.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-09-03 15:26:34 -04:00
Chuck Lever
744aa52530 NFS: Add global helper to set up a stand-along nfs4_slot_table
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-09-03 15:26:34 -04:00
Chuck Lever
9d33059c1b NFS: Enable slot table helpers for NFSv4.0
I'd like to re-use NFSv4.1's slot table machinery for NFSv4.0
transport blocking.  Re-organize some of nfs4session.c so the slot
table code is built even when NFS_V4_1 is disabled.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-09-03 15:26:33 -04:00
Chuck Lever
e8d92382dd NFS: When displaying session slot numbers, use "%u" consistently
Clean up, since slot and sequence numbers are all unsigned anyway.

Among other things, squelch compiler warnings:

linux/fs/nfs/nfs4proc.c: In function ‘nfs4_setup_sequence’:
linux/fs/nfs/nfs4proc.c:703:2: warning: signed and unsigned type in
	conditional expression [-Wsign-compare]

and

linux/fs/nfs/nfs4session.c: In function ‘nfs4_alloc_slot’:
linux/fs/nfs/nfs4session.c:151:31: warning: signed and unsigned type in
	conditional expression [-Wsign-compare]

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-09-03 15:26:30 -04:00
Chuck Lever
73d8bde5e4 NFS: Never use user credentials for lease renewal
Never try to use a non-UID 0 user credential for lease management,
as that credential can change out from under us.  The server will
block NFSv4 lease recovery with NFS4ERR_CLID_INUSE.

Since the mechanism to acquire a credential for lease management
is now the same for all minor versions, replace the minor version-
specific callout with a single function.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-08-07 13:06:08 -04:00
Andy Adamson
18aad3d552 NFSv4.1 Refactor nfs4_init_session and nfs4_init_channel_attrs
nfs4_init_session was originally written to be called prior to
nfs4_init_channel_attrs, setting the session target_max response and request
sizes that nfs4_init_channel_attrs would pay attention to.

In the current code flow, nfs4_init_session, just like nfs4_init_ds_session
for the data server case, is called after the session is all negotiated, and
is actually used in a RECLAIM COMPLETE call to the server.

Remove the un-needed fc_target_max response and request fields from
nfs4_session and just set the max_resp_sz and max_rqst_sz in
nfs4_init_channel_attrs.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-06-28 15:55:19 -04:00
Andy Adamson
774d5f14ee NFSv4.1 Fix a pNFS session draining deadlock
On a CB_RECALL the callback service thread flushes the inode using
filemap_flush prior to scheduling the state manager thread to return the
delegation. When pNFS is used and I/O has not yet gone to the data server
servicing the inode, a LAYOUTGET can preceed the I/O. Unlike the async
filemap_flush call, the LAYOUTGET must proceed to completion.

If the state manager starts to recover data while the inode flush is sending
the LAYOUTGET, a deadlock occurs as the callback service thread holds the
single callback session slot until the flushing is done which blocks the state
manager thread, and the state manager thread has set the session draining bit
which puts the inode flush LAYOUTGET RPC to sleep on the forechannel slot
table waitq.

Separate the draining of the back channel from the draining of the fore channel
by moving the NFS4_SESSION_DRAINING bit from session scope into the fore
and back slot tables.  Drain the back channel first allowing the LAYOUTGET
call to proceed (and fail) so the callback service thread frees the callback
slot. Then proceed with draining the forechannel.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-05-20 14:20:14 -04:00
Trond Myklebust
ac20d163fc NFSv4.1: Deal effectively with interrupted RPC calls.
If an RPC call is interrupted, assume that the server hasn't processed
the RPC call so that the next time we use the slot, we know that if we
get a NFS4ERR_SEQ_MISORDERED or NFS4ERR_SEQ_FALSE_RETRY, we just have
to bump the sequence number.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-12-15 15:39:59 -05:00
Trond Myklebust
8e63b6a8ad NFSv4.1: Move the RPC timestamp out of the slot.
Shave a few bytes off the slot table size by moving the RPC timestamp
into the sequence results.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-12-15 15:21:52 -05:00
Trond Myklebust
b0ef9647a0 NFSv4.1: Be conservative about the client highest slotid
If the server sends us a target that looks like an outlier, but
is lower than the existing target, then respect it anyway.
However defer actually updating the generation counter until
we get a target that doesn't look like an outlier.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-12-11 12:29:10 -05:00
Trond Myklebust
1fa8064429 NFSv4.1: Try to eliminate outliers when updating target_highest_slotid
Look for sudden changes in the first and second derivatives in order
to eliminate outlier changes to target_highest_slotid (which are
due to out-of-order RPC replies).

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-12-06 00:30:53 +01:00
Trond Myklebust
b75ad4cda5 NFSv4.1: Ensure smooth handover of slots from one task to the next waiting
Currently, we see a lot of bouncing for the value of highest_used_slotid
due to the fact that slots are getting freed, instead of getting instantly
transmitted to the next waiting task.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-12-06 00:30:52 +01:00
Trond Myklebust
73e39aaa83 NFSv4.1: Cleanup move session slot management to fs/nfs/nfs4session.c
NFSv4.1 session management is getting complex enough to deserve
a separate file.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-12-06 00:30:45 +01:00