Commit Graph

1048 Commits

Author SHA1 Message Date
Fengguang Wu 51d87bc2bf nfsd: fix boolreturn.cocci warnings
fs/nfsd/nfs4state.c:926:8-9: WARNING: return of 0/1 in function 'nfs4_delegation_exists' with return type bool
fs/nfsd/nfs4state.c:2955:9-10: WARNING: return of 0/1 in function 'nfsd4_compound_in_session' with return type bool

 Return statements in functions returning bool should use
 true/false instead of 1/0.
Generated by: scripts/coccinelle/misc/boolreturn.cocci

Fixes: 68b18f5294 ("nfsd: make nfs4_get_existing_delegation less confusing")
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
[bfields: also fix -EAGAIN]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-04-03 15:08:08 -04:00
J. Bruce Fields 353601e7d3 nfsd: create a separate lease for each delegation
Currently we only take one vfs-level delegation (lease) for each file,
no matter how many clients hold delegations on that file.

Let's instead keep a one-to-one mapping between NFSv4 delegations and
VFS delegations.  This turns out to be simpler.

There is still a many-to-one mapping of NFS opens to NFS files, and the
delegations on one file are all associated with one struct file.  The
VFS can still distinguish between these delegations since we're setting
fl_owner to the struct nfs4_delegation now, not to the shared file.

I'm replacing at least one complicated function wholesale, which I don't
like to do, but I haven't figured out how to do this more incrementally.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2018-03-20 17:51:14 -04:00
J. Bruce Fields 86d29b10eb nfsd: move sc_file assignment into alloc_init_deleg
Take an easy chance to simplify the caller a little.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2018-03-20 17:51:13 -04:00
J. Bruce Fields 0af6e690f0 nfsd: factor out common delegation-destruction code
Pull some duplicated code into a common helper.

This changes the order in destroy_delegation a little, but it looks to
me like that shouldn't matter.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2018-03-20 17:51:13 -04:00
J. Bruce Fields 68b18f5294 nfsd: make nfs4_get_existing_delegation less confusing
This doesn't "get" anything.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2018-03-20 17:51:12 -04:00
J. Bruce Fields 0c911f5408 nfsd4: dp->dl_stid.sc_file doesn't need locking
The delegation isn't visible to anyone yet.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2018-03-20 17:51:12 -04:00
J. Bruce Fields 653e514e9e nfsd4: set fl_owner to delegation, not file pointer
For now this makes no difference, as for files having delegations,
there's a one-to-one relationship between an nfs4_file and its
nfs4_delegation.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2018-03-20 17:51:11 -04:00
J. Bruce Fields cba7b3d150 nfsd: simplify nfs4_put_deleg_lease calls
Every single caller gets the file out of the delegation, so let's do
that once in nfs4_put_deleg_lease.

Plus we'll need it there for other reasons.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2018-03-20 17:51:11 -04:00
J. Bruce Fields b8232d3315 nfsd: simplify put of fi_deleg_file
fi_delegees is basically just a reference count on users of
fi_deleg_file, which is cleared when fi_delegees goes to zero.  The
fi_deleg_file check here is redundant.  Also add an assertion to make
sure we don't have unbalanced puts.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2018-03-20 17:51:10 -04:00
Jeff Layton 9258a2d5cd nfsd: move nfs4_client allocation to dedicated slabcache
On x86_64, it's 1152 bytes, so we can avoid wasting 896 bytes each.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-03-19 16:38:13 -04:00
Jeff Layton bd2decac5e nfsd4: send the special close_stateid in v4.0 replies as well
We already send it for v4.1, but RFC7530 also notes that the stateid in
the close reply is bogus.

Always send the special close stateid, even in v4.0 responses. No client
should put any meaning on it whatsoever. For now, we continue to
increment the stateid value, though that might not be necessary either.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-03-19 16:38:12 -04:00
Jeff Layton 68ef3bc316 nfsd: remove blocked locks on client teardown
We had some reports of panics in nfsd4_lm_notify, and that showed a
nfs4_lockowner that had outlived its so_client.

Ensure that we walk any leftover lockowners after tearing down all of
the stateids, and remove any blocked locks that they hold.

With this change, we also don't need to walk the nbl_lru on nfsd_net
shutdown, as that will happen naturally when we tear down the clients.

Fixes: 76d348fadf (nfsd: have nfsd4_lock use blocking locks for v4.1+ locks)
Reported-by: Frank Sorenson <fsorenso@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: stable@vger.kernel.org # 4.9
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-03-19 16:37:21 -04:00
J. Bruce Fields 2502072058 nfsd4: don't set lock stateid's sc_type to CLOSED
There's no point I can see to

	stp->st_stid.sc_type = NFS4_CLOSED_STID;

given release_lock_stateid immediately sets sc_type to 0.

That set of sc_type to 0 should be enough to prevent it being used where
we don't want it to be; NFS4_CLOSED_STID should only be needed for
actual open stateid's that are actually closed.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-02-05 17:13:17 -05:00
Trond Myklebust 4f1764172a nfsd: Detect unhashed stids in nfsd4_verify_open_stid()
The state of the stid is guaranteed by 2 locks:
- The nfs4_client 'cl_lock' spinlock
- The nfs4_ol_stateid 'st_mutex' mutex

so it is quite possible for the stid to be unhashed after lookup,
but before calling nfsd4_lock_ol_stateid(). So we do need to check
for a zero value for 'sc_type' in nfsd4_verify_open_stid().

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Tested-by: Checuk Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org
Fixes: 659aefb68e "nfsd: Ensure we don't recognise lock stateids..."
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-02-05 17:13:16 -05:00
Vasily Averin 81833de1a4 lockd: fix "list_add double add" caused by legacy signal interface
restart_grace() uses hardcoded init_net.
It can cause to "list_add double add" in following scenario:

1) nfsd and lockd was started in several net namespaces
2) nfsd in init_net was stopped (lockd was not stopped because
 it have users from another net namespaces)
3) lockd got signal, called restart_grace() -> set_grace_period()
 and enabled lock_manager in hardcoded init_net.
4) nfsd in init_net is started again,
 its lockd_up() calls set_grace_period() and tries to add
 lock_manager into init_net 2nd time.

Jeff Layton suggest:
"Make it safe to call locks_start_grace multiple times on the same
lock_manager. If it's already on the global grace_list, then don't try
to add it again.  (But we don't intentionally add twice, so for now we
WARN about that case.)

With this change, we also need to ensure that the nfsd4 lock manager
initializes the list before we call locks_start_grace. While we're at
it, move the rest of the nfsd_net initialization into
nfs4_state_create_net. I see no reason to have it spread over two
functions like it is today."

Suggested patch was updated to generate warning in described situation.

Suggested-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27 16:45:11 -05:00
Andrew Elble ae254dac72 nfsd: check for use of the closed special stateid
Prevent the use of the closed (invalid) special stateid by clients.

Signed-off-by: Andrew Elble <aweits@rit.edu>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27 16:45:11 -05:00
Naofumi Honda 64ebe12494 nfsd: fix panic in posix_unblock_lock called from nfs4_laundromat
From kernel 4.9, my two nfsv4 servers sometimes suffer from
    "panic: unable to handle kernel page request"
in posix_unblock_lock() called from nfs4_laundromat().

These panics diseappear if we revert the commit "nfsd: add a LRU list
for blocked locks".

The cause appears to be a typo in nfs4_laundromat(), which is also
present in nfs4_state_shutdown_net().

Cc: stable@vger.kernel.org
Fixes: 7919d0a27f "nfsd: add a LRU list for blocked locks"
Cc: jlayton@redhat.com
Reveiwed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27 16:45:11 -05:00
Andrew Elble 4f34bd0540 nfsd: fix locking validator warning on nfs4_ol_stateid->st_mutex class
The use of the st_mutex has been confusing the validator. Use the
proper nested notation so as to not produce warnings.

Signed-off-by: Andrew Elble <aweits@rit.edu>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27 16:45:10 -05:00
Trond Myklebust 03da3169c6 nfsd: Fix races with check_stateid_generation()
The various functions that call check_stateid_generation() in order
to compare a client-supplied stateid with the nfs4_stid state, usually
need to atomically check for closed state. Those that perform the
check after locking the st_mutex using nfsd4_lock_ol_stateid()
should now be OK, but we do want to fix up the others.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27 16:45:10 -05:00
Trond Myklebust 9271d7e509 nfsd: Ensure we check stateid validity in the seqid operation checks
After taking the stateid st_mutex, we want to know that the stateid
still represents valid state before performing any non-idempotent
actions.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27 16:45:10 -05:00
Trond Myklebust beeca19cf1 nfsd: Fix race in lock stateid creation
If we're looking up a new lock state, and the creation fails, then
we want to unhash it, just like we do for OPEN. However in order
to do so, we need to that no other LOCK requests can grab the
mutex until we have unhashed it (and marked it as closed).

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27 16:45:10 -05:00
Trond Myklebust fd1fd685b3 nfsd4: move find_lock_stateid
Trivial cleanup to simplify following patch.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27 16:45:10 -05:00
Trond Myklebust 659aefb68e nfsd: Ensure we don't recognise lock stateids after freeing them
In order to deal with lookup races, nfsd4_free_lock_stateid() needs
to be able to signal to other stateful functions that the lock stateid
is no longer valid. Right now, nfsd_lock() will check whether or not an
existing stateid is still hashed, but only in the "new lock" path.

To ensure the stateid invalidation is also recognised by the "existing lock"
path, and also by a second call to nfsd4_free_lock_stateid() itself, we can
change the type to NFS4_CLOSED_STID under the stp->st_mutex.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27 16:45:10 -05:00
Trond Myklebust fb500a7cfe nfsd: CLOSE SHOULD return the invalid special stateid for NFSv4.x (x>0)
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27 16:45:10 -05:00
Trond Myklebust d8a1a00055 nfsd: Fix another OPEN stateid race
If nfsd4_process_open2() is initialising a new stateid, and yet the
call to nfs4_get_vfs_file() fails for some reason, then we must
declare the stateid closed, and unhash it before dropping the mutex.

Right now, we unhash the stateid after dropping the mutex, and without
changing the stateid type, meaning that another OPEN could theoretically
look it up and attempt to use it.

Reported-by: Andrew W Elble <aweits@rit.edu>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27 16:45:10 -05:00
Trond Myklebust 15ca08d329 nfsd: Fix stateid races between OPEN and CLOSE
Open file stateids can linger on the nfs4_file list of stateids even
after they have been closed. In order to avoid reusing such a
stateid, and confusing the client, we need to recheck the
nfs4_stid's type after taking the mutex.
Otherwise, we risk reusing an old stateid that was already closed,
which will confuse clients that expect new stateids to conform to
RFC7530 Sections 9.1.4.2 and 16.2.5 or RFC5661 Sections 8.2.2 and 18.2.4.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27 16:45:10 -05:00
Andrew Elble 95da1b3a5a nfsd: deal with revoked delegations appropriately
If a delegation has been revoked by the server, operations using that
delegation should error out with NFS4ERR_DELEG_REVOKED in the >4.1
case, and NFS4ERR_BAD_STATEID otherwise.

The server needs NFSv4.1 clients to explicitly free revoked delegations.
If the server returns NFS4ERR_DELEG_REVOKED, the client will do that;
otherwise it may just forget about the delegation and be unable to
recover when it later sees SEQ4_STATUS_RECALLABLE_STATE_REVOKED set on a
SEQUENCE reply.  That can cause the Linux 4.1 client to loop in its
stage manager.

Signed-off-by: Andrew Elble <aweits@rit.edu>
Reviewed-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07 16:44:02 -05:00
Vasily Averin 7e981a8afa nfsd: use nfs->ns.inum as net ID
Publishing of net pointer is not safe,
let's use nfs->ns.inum instead

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07 16:44:01 -05:00
Elena Reshetova 818a34eb26 fs, nfsd: convert nfs4_file.fi_ref from atomic_t to refcount_t
atomic_t variables are currently used to implement reference
counters with the following properties:
 - counter is initialized to 1 using atomic_set()
 - a resource is freed upon counter reaching zero
 - once counter reaches zero, its further
   increments aren't allowed
 - counter schema uses basic atomic operations
   (set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable nfs4_file.fi_ref is used as pure reference counter.
Convert it to refcount_t and fix up the operations.

Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07 16:43:59 -05:00
Elena Reshetova cff7cb2ece fs, nfsd: convert nfs4_cntl_odstate.co_odcount from atomic_t to refcount_t
atomic_t variables are currently used to implement reference
counters with the following properties:
 - counter is initialized to 1 using atomic_set()
 - a resource is freed upon counter reaching zero
 - once counter reaches zero, its further
   increments aren't allowed
 - counter schema uses basic atomic operations
   (set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable nfs4_cntl_odstate.co_odcount is used as pure reference counter.
Convert it to refcount_t and fix up the operations.

Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07 16:43:59 -05:00
Elena Reshetova a15dfcd529 fs, nfsd: convert nfs4_stid.sc_count from atomic_t to refcount_t
atomic_t variables are currently used to implement reference
counters with the following properties:
 - counter is initialized to 1 using atomic_set()
 - a resource is freed upon counter reaching zero
 - once counter reaches zero, its further
   increments aren't allowed
 - counter schema uses basic atomic operations
   (set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable nfs4_stid.sc_count is used as pure reference counter.
Convert it to refcount_t and fix up the operations.

Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07 16:43:58 -05:00
J. Bruce Fields 53da6a53e1 nfsd4: catch some false session retries
The spec allows us to return NFS4ERR_SEQ_FALSE_RETRY if we notice that
the client is making a call that matches a previous (slot, seqid) pair
but that *isn't* actually a replay, because some detail of the call
doesn't actually match the previous one.

Catching every such case is difficult, but we may as well catch a few
easy ones.  This also handles the case described in the previous patch,
in a different way.

The spec does however require us to catch the case where the difference
is in the rpc credentials.  This prevents somebody from snooping another
user's replies by fabricating retries.

(But the practical value of the attack is limited by the fact that the
replies with the most sensitive data are READ replies, which are not
normally cached.)

Tested-by: Olga Kornievskaia <aglo@umich.edu>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07 16:43:57 -05:00
J. Bruce Fields 085def3ade nfsd4: fix cached replies to solo SEQUENCE compounds
Currently our handling of 4.1+ requests without "cachethis" set is
confusing and not quite correct.

Suppose a client sends a compound consisting of only a single SEQUENCE
op, and it matches the seqid in a session slot (so it's a retry), but
the previous request with that seqid did not have "cachethis" set.

The obvious thing to do might be to return NFS4ERR_RETRY_UNCACHED_REP,
but the protocol only allows that to be returned on the op following the
SEQUENCE, and there is no such op in this case.

The protocol permits us to cache replies even if the client didn't ask
us to.  And it's easy to do so in the case of solo SEQUENCE compounds.

So, when we get a solo SEQUENCE, we can either return the previously
cached reply or NFSERR_SEQ_FALSE_RETRY if we notice it differs in some
way from the original call.

Currently, we're returning a corrupt reply in the case a solo SEQUENCE
matches a previous compound with more ops.  This actually matters
because the Linux client recently started doing this as a way to recover
from lost replies to idempotent operations in the case the process doing
the original reply was killed: in that case it's difficult to keep the
original arguments around to do a real retry, and the client no longer
cares what the result is anyway, but it would like to make sure that the
slot's sequence id has been incremented, and the solo SEQUENCE assures
that: if the server never got the original reply, it will increment the
sequence id.  If it did get the original reply, it won't increment, and
nothing else that about the reply really matters much.  But we can at
least attempt to return valid xdr!

Tested-by: Olga Kornievskaia <aglo@umich.edu>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07 16:43:57 -05:00
J. Bruce Fields de766e5704 nfsd: give out fewer session slots as limit approaches
Instead of granting client's full requests until we hit our DRC size
limit and then failing CREATE_SESSIONs (and hence mounts) completely,
start granting clients smaller slot tables as we approach the limit.

The factor chosen here is pretty much arbitrary.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-10-04 16:25:01 -04:00
Christoph Hellwig eb69853da9 nfsd4: properly type op_func callbacks
Pass union nfsd4_op_u to the op_func callbacks instead of using unsafe
function pointer casts.

It also adds two missing structures to struct nfsd4_op.u to facilitate
this.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-15 17:42:29 +02:00
Christoph Hellwig 57832e7bd8 nfsd4: properly type op_get_currentstateid callbacks
Pass union nfsd4_op_u to the op_set_currentstateid callbacks instead of
using unsafe function pointer casts.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-15 17:42:27 +02:00
Christoph Hellwig b60e985980 nfsd4: properly type op_set_currentstateid callbacks
Given the args union in struct nfsd4_op a name, and pass it to the
op_set_currentstateid callbacks instead of using unsafe function
pointer casts.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-15 17:42:27 +02:00
NeilBrown 2f10fdcb6a nfsd4: remove pointless strdup_if_nonnull
kstrdup() already checks for NULL.

(Brought to our attention by Jason Yann noticing (from sparse output)
that it should have been declared static.)

Signed-off-by: NeilBrown <neilb@suse.com>
Reported-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-04-25 17:25:54 -04:00
Rasmus Villemoes 4ab495bfe5 nfsd: remove superfluous KERN_INFO
dprintk already provides a KERN_* prefix; this KERN_INFO just shows up
as some odd characters in the output.

Simplify the message a bit while we're there.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-02-24 15:45:13 -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
Kinglong Mee d19fb70dd6 NFSD: Fix a null reference case in find_or_create_lock_stateid()
nfsd assigns the nfs4_free_lock_stateid to .sc_free in init_lock_stateid().

If nfsd doesn't go through init_lock_stateid() and put stateid at end,
there is a NULL reference to .sc_free when calling nfs4_put_stid(ns).

This patch let the nfs4_stid.sc_free assignment to nfs4_alloc_stid().

Cc: stable@vger.kernel.org
Fixes: 356a95ece7 "nfsd: clean up races in lock stateid searching..."
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-01-31 12:29:24 -05:00
Chuck Lever f46c445b79 nfsd: Fix general protection fault in release_lock_stateid()
When I push NFSv4.1 / RDMA hard, (xfstests generic/089, for example),
I get this crash on the server:

Oct 28 22:04:30 klimt kernel: general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
Oct 28 22:04:30 klimt kernel: Modules linked in: cts rpcsec_gss_krb5 iTCO_wdt iTCO_vendor_support sb_edac edac_core x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm btrfs irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd xor pcspkr raid6_pq i2c_i801 i2c_smbus lpc_ich mfd_core sg mei_me mei ioatdma shpchp wmi ipmi_si ipmi_msghandler rpcrdma ib_ipoib rdma_ucm acpi_power_meter acpi_pad ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c mlx4_ib mlx4_en ib_core sr_mod cdrom sd_mod ast drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm crc32c_intel igb ahci libahci ptp mlx4_core pps_core dca libata i2c_algo_bit i2c_core dm_mirror dm_region_hash dm_log dm_mod
Oct 28 22:04:30 klimt kernel: CPU: 7 PID: 1558 Comm: nfsd Not tainted 4.9.0-rc2-00005-g82cd754 #8
Oct 28 22:04:30 klimt kernel: Hardware name: Supermicro Super Server/X10SRL-F, BIOS 1.0c 09/09/2015
Oct 28 22:04:30 klimt kernel: task: ffff880835c3a100 task.stack: ffff8808420d8000
Oct 28 22:04:30 klimt kernel: RIP: 0010:[<ffffffffa05a759f>]  [<ffffffffa05a759f>] release_lock_stateid+0x1f/0x60 [nfsd]
Oct 28 22:04:30 klimt kernel: RSP: 0018:ffff8808420dbce0  EFLAGS: 00010246
Oct 28 22:04:30 klimt kernel: RAX: ffff88084e6660f0 RBX: ffff88084e667020 RCX: 0000000000000000
Oct 28 22:04:30 klimt kernel: RDX: 0000000000000007 RSI: 0000000000000000 RDI: ffff88084e667020
Oct 28 22:04:30 klimt kernel: RBP: ffff8808420dbcf8 R08: 0000000000000001 R09: 0000000000000000
Oct 28 22:04:30 klimt kernel: R10: ffff880835c3a100 R11: ffff880835c3aca8 R12: 6b6b6b6b6b6b6b6b
Oct 28 22:04:30 klimt kernel: R13: ffff88084e6670d8 R14: ffff880835f546f0 R15: ffff880835f1c548
Oct 28 22:04:30 klimt kernel: FS:  0000000000000000(0000) GS:ffff88087bdc0000(0000) knlGS:0000000000000000
Oct 28 22:04:30 klimt kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Oct 28 22:04:30 klimt kernel: CR2: 00007ff020389000 CR3: 0000000001c06000 CR4: 00000000001406e0
Oct 28 22:04:30 klimt kernel: Stack:
Oct 28 22:04:30 klimt kernel: ffff88084e667020 0000000000000000 ffff88084e6670d8 ffff8808420dbd20
Oct 28 22:04:30 klimt kernel: ffffffffa05ac80d ffff880835f54548 ffff88084e640008 ffff880835f545b0
Oct 28 22:04:30 klimt kernel: ffff8808420dbd70 ffffffffa059803d ffff880835f1c768 0000000000000870
Oct 28 22:04:30 klimt kernel: Call Trace:
Oct 28 22:04:30 klimt kernel: [<ffffffffa05ac80d>] nfsd4_free_stateid+0xfd/0x1b0 [nfsd]
Oct 28 22:04:30 klimt kernel: [<ffffffffa059803d>] nfsd4_proc_compound+0x40d/0x690 [nfsd]
Oct 28 22:04:30 klimt kernel: [<ffffffffa0583114>] nfsd_dispatch+0xd4/0x1d0 [nfsd]
Oct 28 22:04:30 klimt kernel: [<ffffffffa047bbf9>] svc_process_common+0x3d9/0x700 [sunrpc]
Oct 28 22:04:30 klimt kernel: [<ffffffffa047ca64>] svc_process+0xf4/0x330 [sunrpc]
Oct 28 22:04:30 klimt kernel: [<ffffffffa05827ca>] nfsd+0xfa/0x160 [nfsd]
Oct 28 22:04:30 klimt kernel: [<ffffffffa05826d0>] ? nfsd_destroy+0x170/0x170 [nfsd]
Oct 28 22:04:30 klimt kernel: [<ffffffff810b367b>] kthread+0x10b/0x120
Oct 28 22:04:30 klimt kernel: [<ffffffff810b3570>] ? kthread_stop+0x280/0x280
Oct 28 22:04:30 klimt kernel: [<ffffffff8174e8ba>] ret_from_fork+0x2a/0x40
Oct 28 22:04:30 klimt kernel: Code: c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 55 41 54 53 48 8b 87 b0 00 00 00 48 89 fb 4c 8b a0 98 00 00 00 <49> 8b 44 24 20 48 8d b8 80 03 00 00 e8 10 66 1a e1 48 89 df e8
Oct 28 22:04:30 klimt kernel: RIP  [<ffffffffa05a759f>] release_lock_stateid+0x1f/0x60 [nfsd]
Oct 28 22:04:30 klimt kernel: RSP <ffff8808420dbce0>
Oct 28 22:04:30 klimt kernel: ---[ end trace cf5d0b371973e167 ]---

Jeff Layton says:
> Hm...now that I look though, this is a little suspicious:
>
>    struct nfs4_openowner *oo = openowner(stp->st_openstp->st_stateowner);
>
> I wonder if it's possible for the openstateid to have already been
> destroyed at this point.
>
> We might be better off doing something like this to get the client pointer:
>
>    stp->st_stid.sc_client;
>
> ...which should be more direct and less dependent on other stateids
> staying valid.

With the suggested change, I am no longer able to reproduce the above oops.

v2: Fix unhash_lock_stateid() as well

Fix-suggested-by: Jeff Layton <jlayton@redhat.com>
Fixes: 42691398be ('nfsd: Fix race between FREE_STATEID and LOCK')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-11-01 15:24:43 -04:00
Jeff Layton 0cc11a61b8 nfsd: move blocked lock handling under a dedicated spinlock
Bruce was hitting some lockdep warnings in testing, showing that we
could hit a deadlock with the new CB_NOTIFY_LOCK handling, involving a
rather complex situation involving four different spinlocks.

The crux of the matter is that we end up taking the nn->client_lock in
the lm_notify handler. The simplest fix is to just declare a new
per-nfsd_net spinlock to protect the new CB_NOTIFY_LOCK structures.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-10-24 16:51:21 -04:00
Linus Torvalds 2778556474 Some RDMA work and some good bugfixes, and two new features that could
benefit from user testing:
 
 Anna Schumacker contributed a simple NFSv4.2 COPY implementation.  COPY
 is already supported on the client side, so a call to copy_file_range()
 on a recent client should now result in a server-side copy that doesn't
 require all the data to make a round trip to the client and back.
 
 Jeff Layton implemented callbacks to notify clients when contended locks
 become available, which should reduce latency on workloads with
 contended locks.
 -----BEGIN PGP SIGNATURE-----
 
 iQIcBAABAgAGBQJX/mcsAAoJECebzXlCjuG+MU0P/3SzTLGYXU5yOTAorx255/uf
 fUVKQQhTzzaA2xj3gWWWztYx3y0ZJUVgwU56a+Ap5Z8/goqDQ78H+ePEc+MG7BT/
 /UXS/bITvt0MP/dvPrDzhSltvqx/wpelLPBo29hGLlAQ2dsnD4Y75IbOOQccWqcC
 iD2v6x7lnpWZ7j9Zhwzg/JNQHwISIb7tiLoYBjfcdNDEMU76KIyhxD0Cx9MSeBzH
 9Rq/oEdwGDFS5WqVfNe2jxbngoauq1IupziQ2eQGv2D/POyXCx8fphoYjDz1XaW8
 PxaJtJtM2owPGG+z2CxklJqNaS1Z4F+oppjg+nf4i/ibxmIBaTy8NluASX3vMh69
 CDO1+ly+TiF0l1VqMOQJWRnqn1qGk6fLpF6P1Ac62B0oWpeLGU7nmik7XN1ORgsi
 8ksxRKNAWeprZo3wl5xNrADu/wlZ7XCJTc4QoHEgYT04aHF+j8EMCHv+mtZ8+Bwn
 WWiA8iItZOgXV4vitCRJlvsixjYvmF3djPIoI2Lt5KDWIg+eL89sKwzTALSfeC4m
 Vjb0svzPX1MmZCNP1rCStFbl3gZYXZyqPk+uA6M7H8mjAjVeKxRPowWpMBgvYZHr
 FjCPb878bAuqCeBVbIyOLLcKWBLTw8PsUWZAor3gNg454JGkMjLUyJ/S22Cz5Nbo
 HdjoiTJtbPrHnCwTMXwa
 =nozl
 -----END PGP SIGNATURE-----

Merge tag 'nfsd-4.9' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "Some RDMA work and some good bugfixes, and two new features that could
  benefit from user testing:

   - Anna Schumacker contributed a simple NFSv4.2 COPY implementation.
     COPY is already supported on the client side, so a call to
     copy_file_range() on a recent client should now result in a
     server-side copy that doesn't require all the data to make a round
     trip to the client and back.

   - Jeff Layton implemented callbacks to notify clients when contended
     locks become available, which should reduce latency on workloads
     with contended locks"

* tag 'nfsd-4.9' of git://linux-nfs.org/~bfields/linux:
  NFSD: Implement the COPY call
  nfsd: handle EUCLEAN
  nfsd: only WARN once on unmapped errors
  exportfs: be careful to only return expected errors.
  nfsd4: setclientid_confirm with unmatched verifier should fail
  nfsd: randomize SETCLIENTID reply to help distinguish servers
  nfsd: set the MAY_NOTIFY_LOCK flag in OPEN replies
  nfs: add a new NFS4_OPEN_RESULT_MAY_NOTIFY_LOCK constant
  nfsd: add a LRU list for blocked locks
  nfsd: have nfsd4_lock use blocking locks for v4.1+ locks
  nfsd: plumb in a CB_NOTIFY_LOCK operation
  NFSD: fix corruption in notifier registration
  svcrdma: support Remote Invalidation
  svcrdma: Server-side support for rpcrdma_connect_private
  rpcrdma: RDMA/CM private message data structure
  svcrdma: Skip put_page() when send_reply() fails
  svcrdma: Tail iovec leaves an orphaned DMA mapping
  nfsd: fix dprintk in nfsd4_encode_getdeviceinfo
  nfsd: eliminate cb_minorversion field
  nfsd: don't set a FL_LAYOUT lease for flexfiles layouts
2016-10-13 21:04:42 -07:00
Alexey Dobriyan 81243eacfa cred: simpler, 1D supplementary groups
Current supplementary groups code can massively overallocate memory and
is implemented in a way so that access to individual gid is done via 2D
array.

If number of gids is <= 32, memory allocation is more or less tolerable
(140/148 bytes).  But if it is not, code allocates full page (!)
regardless and, what's even more fun, doesn't reuse small 32-entry
array.

2D array means dependent shifts, loads and LEAs without possibility to
optimize them (gid is never known at compile time).

All of the above is unnecessary.  Switch to the usual
trailing-zero-len-array scheme.  Memory is allocated with
kmalloc/vmalloc() and only as much as needed.  Accesses become simpler
(LEA 8(gi,idx,4) or even without displacement).

Maximum number of gids is 65536 which translates to 256KB+8 bytes.  I
think kernel can handle such allocation.

On my usual desktop system with whole 9 (nine) aux groups, struct
group_info shrinks from 148 bytes to 44 bytes, yay!

Nice side effects:

 - "gi->gid[i]" is shorter than "GROUP_AT(gi, i)", less typing,

 - fix little mess in net/ipv4/ping.c
   should have been using GROUP_AT macro but this point becomes moot,

 - aux group allocation is persistent and should be accounted as such.

Link: http://lkml.kernel.org/r/20160817201927.GA2096@p183.telecom.by
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Vasily Kulikov <segoon@openwall.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-07 18:46:30 -07:00
J. Bruce Fields 7d22fc11c7 nfsd4: setclientid_confirm with unmatched verifier should fail
A setclientid_confirm with (clientid, verifier) both matching an
existing confirmed record is assumed to be a replay, but if the verifier
doesn't match, it shouldn't be.

This would be a very rare case, except that clients following
https://tools.ietf.org/html/rfc7931#section-5.8 may depend on the
failure.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-09-26 15:20:38 -04:00
Jeff Layton 19e4c3477f nfsd: set the MAY_NOTIFY_LOCK flag in OPEN replies
If we are using v4.1+, then we can send notification when contended
locks become free. Inform the client of that fact.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-09-26 15:20:37 -04:00
Jeff Layton 7919d0a27f nfsd: add a LRU list for blocked locks
It's possible for a client to call in on a lock that is blocked for a
long time, but discontinue polling for it. A malicious client could
even set a lock on a file, and then spam the server with failing lock
requests from different lockowners that pile up in a DoS attack.

Add the blocked lock structures to a per-net namespace LRU when hashing
them, and timestamp them. If the lock request is not revisited after a
lease period, we'll drop it under the assumption that the client is no
longer interested.

This also gives us a mechanism to clean up these objects at server
shutdown time as well.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-09-26 15:20:36 -04:00
Jeff Layton 76d348fadf nfsd: have nfsd4_lock use blocking locks for v4.1+ locks
Create a new per-lockowner+per-inode structure that contains a
file_lock. Have nfsd4_lock add this structure to the lockowner's list
prior to setting the lock. Then call the vfs and request a blocking lock
(by setting FL_SLEEP). If we get anything besides FILE_LOCK_DEFERRED
back, then we dequeue the block structure and free it. When the next
lock request comes in, we'll look for an existing block for the same
filehandle and dequeue and reuse it if there is one.

When the lock comes free (a'la an lm_notify call), we dequeue it
from the lockowner's list and kick off a CB_NOTIFY_LOCK callback to
inform the client that it should retry the lock request.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-09-26 15:20:36 -04:00
Jeff Layton dd257933fa nfsd: don't return an unhashed lock stateid after taking mutex
nfsd4_lock will take the st_mutex before working with the stateid it
gets, but between the time when we drop the cl_lock and take the mutex,
the stateid could become unhashed (a'la FREE_STATEID). If that happens
the lock stateid returned to the client will be forgotten.

Fix this by first moving the st_mutex acquisition into
lookup_or_create_lock_state. Then, have it check to see if the lock
stateid is still hashed after taking the mutex. If it's not, then put
the stateid and try the find/create again.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Tested-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Cc: stable@vger.kernel.org # feb9dad5 nfsd: Always lock state exclusively.
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-08-12 16:10:25 -04:00
Chuck Lever 42691398be nfsd: Fix race between FREE_STATEID and LOCK
When running LTP's nfslock01 test, the Linux client can send a LOCK
and a FREE_STATEID request at the same time. The outcome is:

Frame 324    R OPEN stateid [2,O]

Frame 115004 C LOCK lockowner_is_new stateid [2,O] offset 672000 len 64
Frame 115008 R LOCK stateid [1,L]
Frame 115012 C WRITE stateid [0,L] offset 672000 len 64
Frame 115016 R WRITE NFS4_OK
Frame 115019 C LOCKU stateid [1,L] offset 672000 len 64
Frame 115022 R LOCKU NFS4_OK
Frame 115025 C FREE_STATEID stateid [2,L]
Frame 115026 C LOCK lockowner_is_new stateid [2,O] offset 672128 len 64
Frame 115029 R FREE_STATEID NFS4_OK
Frame 115030 R LOCK stateid [3,L]
Frame 115034 C WRITE stateid [0,L] offset 672128 len 64
Frame 115038 R WRITE NFS4ERR_BAD_STATEID

In other words, the server returns stateid L in a successful LOCK
reply, but it has already released it. Subsequent uses of stateid L
fail.

To address this, protect the generation check in nfsd4_free_stateid
with the st_mutex. This should guarantee that only one of two
outcomes occurs: either LOCK returns a fresh valid stateid, or
FREE_STATEID returns NFS4ERR_LOCKS_HELD.

Reported-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Fix-suggested-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-08-11 15:08:39 -04:00
Chuck Lever 885848186f nfsd: Close race between nfsd4_release_lockowner and nfsd4_lock
nfsd4_release_lockowner finds a lock owner that has no lock state,
and drops cl_lock. Then release_lockowner picks up cl_lock and
unhashes the lock owner.

During the window where cl_lock is dropped, I don't see anything
preventing a concurrent nfsd4_lock from finding that same lock owner
and adding lock state to it.

Move release_lockowner() into nfsd4_release_lockowner and hang onto
the cl_lock until after the lock owner's state cannot be found
again.

Found by inspection, we don't currently have a reproducer.

Fixes: 2c41beb0e5 ("nfsd: reduce cl_lock thrashing in ... ")
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-07-15 15:31:31 -04:00
Christophe JAILLET d28c442f5b nfsd: Fix some indent inconsistancy
Silent a few smatch warnings about indentation

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-07-13 15:53:41 -04:00
Andrew Elble ed94164398 nfsd: implement machine credential support for some operations
This addresses the conundrum referenced in RFC5661 18.35.3,
and will allow clients to return state to the server using the
machine credentials.

The biggest part of the problem is that we need to allow the client
to send a compound op with integrity/privacy on mounts that don't
have it enabled.

Add server support for properly decoding and using spo_must_enforce
and spo_must_allow bits. Add support for machine credentials to be
used for CLOSE, OPEN_DOWNGRADE, LOCKU, DELEGRETURN,
and TEST/FREE STATEID.
Implement a check so as to not throw WRONGSEC errors when these
operations are used if integrity/privacy isn't turned on.

Without this, Linux clients with credentials that expired while holding
delegations were getting stuck in an endless loop.

Signed-off-by: Andrew Elble <aweits@rit.edu>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-07-13 15:32:47 -04:00
Andrew Elble dedeb13f9e nfsd: allow mach_creds_match to be used more broadly
Rename mach_creds_match() to nfsd4_mach_creds_match() and un-staticify

Signed-off-by: Andrew Elble <aweits@rit.edu>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-07-13 15:32:47 -04:00
Oleg Drokin 8c7245abda nfsd: Make init_open_stateid() a bit more whole
Move the state selection logic inside from the caller,
always making it return correct stp to use.

Signed-off-by: J . Bruce Fields <bfields@fieldses.org>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-06-15 22:03:53 -04:00
Oleg Drokin 5cc1fb2a09 nfsd: Extend the mutex holding region around in nfsd4_process_open2()
To avoid racing entry into nfs4_get_vfs_file().
Make init_open_stateid() return with locked stateid to be unlocked
by the caller.

Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-06-15 22:03:41 -04:00
Oleg Drokin feb9dad520 nfsd: Always lock state exclusively.
It used to be the case that state had an rwlock that was locked for write
by downgrades, but for read for upgrades (opens). Well, the problem is
if there are two competing opens for the same state, they step on
each other toes potentially leading to leaking file descriptors
from the state structure, since access mode is a bitmap only set once.

Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-06-15 22:03:31 -04:00
Jeff Layton 14b7f4a1ed nfsd: handle seqid wraparound in nfsd4_preprocess_layout_stateid
Move the existing static function to an inline helper, and call it.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-05-13 15:34:47 -04:00
Chuck Lever 4500632f60 nfsd: Lower NFSv4.1 callback message size limit
The maximum size of a backchannel message on RPC-over-RDMA depends
on the connection's inline threshold. Today that threshold is
typically 1024 bytes, making the maximum message size 996 bytes.

The Linux server's CREATE_SESSION operation checks that the size
of callback Calls can be as large as 1044 bytes, to accommodate
RPCSEC_GSS. Thus CREATE_SESSION fails if a client advertises the
true message size maximum of 996 bytes.

But the server's backchannel currently does not support RPCSEC_GSS.
The actual maximum size it needs is much smaller. It is safe to
reduce the limit to enable NFSv4.1 on RDMA backchannel operation.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-03-01 13:06:35 -08:00
Chuck Lever 4ce85c8cf8 nfsd: Update NFS server comments related to RDMA support
The server does indeed now support NFSv4.1 on RDMA transports. It
does not support shifting an RDMA-capable TCP transport (such as
iWARP) to RDMA mode.

Reported-by: Shirley Ma <shirley.ma@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-03-01 13:06:32 -08:00
Kinglong Mee 8edf4b0288 nfsd: Fix a memory leak when meeting unsupported state_protect_how4
Remember free allocated client when meeting unsupported state protect how.

Fixes: 50c7b948ad ("nfsd: minor consolidation of mach_cred handling code")
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-03-01 13:06:31 -08:00
Linus Torvalds cc80fe0eef Smaller bugfixes and cleanup, including a fix for a failures of
kerberized NFSv4.1 mounts, and Scott Mayhew's work addressing ACK storms
 that can affect some high-availability NFS setups.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJWmVZHAAoJECebzXlCjuG+Cn4P/3zwSuwIeLuv9b89vzFXU8Xv
 AbBWHk7WkFXJQGTKdclYjwxqU+l15D5lYHCae1cuD5eXdviraxXf7EcnqrMhJUc0
 oRiQx0rAwlEkKUAVrxGCFP7WKjlX3TsEBV6wPpTCP3BEMzTPDEeaDek7+hICFkLF
 9a/miEXAopm3jxP7WNmXEkdKpFEHklDDwtv6Av7iIKCW6+7XCGp7Prqo4NQKAKp6
 hjE+nvt2HiD06MZhUeyb14cn6547smzt1rbSfK4IB4yHMwLyaoqPrT7ekDh9LDrE
 uGgo+Y2PBbEcTAE6tJ88EjZx7cMCFPn0te+eKPgnpPy9RqrNqSxj5N/b7JAecKgW
 a/09BtvFOoYs8fO5ovqeRY5THrE3IRyMIwn4gt7fCYaaAbG3dwGKG1uklTAVXtb1
 95DkhOb8He2VhOCCoJ6ybbTnRfjB6b/cv7ZuEGlQfvTE+BtU3Jj9I76ruWFhb3zd
 HM1dRI20UfwL/0Y8yYhZ+/rje9SSk2jOmVgSCqY9hnCmEqOqOdUU0X/uumIWaBym
 zfGx9GIM0jQuYVdLQRXtJJbUgJUUN3MilGyU5wx7YoXip5guqTalXqAdQpShzXeW
 s1ATYh/mY5X9ig51KogkkVlm9bXDQAzJBAnDRpLtJZqy5Cgkrj9RSu0ExN1Rmlhw
 LKQCddBQxUSWJ+XWycgK
 =G7V3
 -----END PGP SIGNATURE-----

Merge tag 'nfsd-4.5' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "Smaller bugfixes and cleanup, including a fix for a failures of
  kerberized NFSv4.1 mounts, and Scott Mayhew's work addressing ACK
  storms that can affect some high-availability NFS setups"

* tag 'nfsd-4.5' of git://linux-nfs.org/~bfields/linux:
  nfsd: add new io class tracepoint
  nfsd: give up on CB_LAYOUTRECALLs after two lease periods
  nfsd: Fix nfsd leaks sunrpc module references
  lockd: constify nlmsvc_binding structure
  lockd: use to_delayed_work
  nfsd: use to_delayed_work
  Revert "svcrdma: Do not send XDR roundup bytes for a write chunk"
  lockd: Register callbacks on the inetaddr_chain and inet6addr_chain
  nfsd: Register callbacks on the inetaddr_chain and inet6addr_chain
  sunrpc: Add a function to close temporary transports immediately
  nfsd: don't base cl_cb_status on stale information
  nfsd4: fix gss-proxy 4.1 mounts for some AD principals
  nfsd: fix unlikely NULL deref in mach_creds_match
  nfsd: minor consolidation of mach_cred handling code
  nfsd: helper for dup of possibly NULL string
  svcrpc: move some initialization to common code
  nfsd: fix a warning message
  nfsd: constify nfsd4_callback_ops structure
  nfsd: recover: constify nfsd4_client_tracking_ops structures
  svcrdma: Do not send XDR roundup bytes for a write chunk
2016-01-15 12:49:44 -08:00
Geliang Tang 2e55f3ab45 nfsd: use to_delayed_work
Use to_delayed_work() instead of open-coding it.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-01-07 10:10:49 -05:00
Anna Schumaker aa0d6aed45 nfsd: Pass filehandle to nfs4_preprocess_stateid_op()
This will be needed so COPY can look up the saved_fh in addition to the
current_fh.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-07 23:11:52 -05:00
J. Bruce Fields 414ca017a5 nfsd4: fix gss-proxy 4.1 mounts for some AD principals
The principal name on a gss cred is used to setup the NFSv4.0 callback,
which has to have a client principal name to authenticate to.

That code wants the name to be in the form servicetype@hostname.
rpc.svcgssd passes down such names (and passes down no principal name at
all in the case the principal isn't a service principal).

gss-proxy always passes down the principal name, and passes it down in
the form servicetype/hostname@REALM.  So we've been munging the name
gss-proxy passes down into the format the NFSv4.0 callback code expects,
or throwing away the name if we can't.

Since the introduction of the MACH_CRED enforcement in NFSv4.1, we've
also been using the principal name to verify that certain operations are
done as the same principal as was used on the original EXCHANGE_ID call.

For that application, the original name passed down by gss-proxy is also
useful.

Lack of that name in some cases was causing some kerberized NFSv4.1
mount failures in an Active Directory environment.

This fix only works in the gss-proxy case.  The fix for legacy
rpc.svcgssd would be more involved, and rpc.svcgssd already has other
problems in the AD case.

Reported-and-tested-by: James Ralston <ralston@pobox.com>
Acked-by: Simo Sorce <simo@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-11-24 11:36:31 -07:00
J. Bruce Fields 920dd9bb7d nfsd: fix unlikely NULL deref in mach_creds_match
We really shouldn't allow a client to be created with cl_mach_cred set
unless it also has a principal name.

This also allows us to fail such cases immediately on EXCHANGE_ID as
opposed to waiting and incorrectly returning WRONG_CRED on the following
CREATE_SESSION.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-11-24 10:39:18 -07:00
J. Bruce Fields 50c7b948ad nfsd: minor consolidation of mach_cred handling code
Minor cleanup, no change in functionality.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-11-24 10:39:18 -07:00
J. Bruce Fields 5004385932 nfsd: helper for dup of possibly NULL string
Technically the initialization in the NULL case isn't even needed as the
only caller already has target zeroed out, but it seems safer to keep
copy_cred generic.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-11-24 10:39:17 -07:00
Dan Carpenter d3f03403a8 nfsd: fix a warning message
The WARN() macro takes a condition and a format string.  The condition
was accidentally left out here so it just prints the function name
instead of the message.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-11-23 12:15:31 -07:00
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
Andrew Elble 7fc0564e3a nfsd: fix race with open / open upgrade stateids
We observed multiple open stateids on the server for files that
seemingly should have been closed.

nfsd4_process_open2() tests for the existence of a preexisting
stateid. If one is not found, the locks are dropped and a new
one is created. The problem is that init_open_stateid(), which
is also responsible for hashing the newly initialized stateid,
doesn't check to see if another open has raced in and created
a matching stateid. This fix is to enable init_open_stateid() to
return the matching stateid and have nfsd4_process_open2()
swap to that stateid and switch to the open upgrade path.
In testing this patch, coverage to the newly created
path indicates that the race was indeed happening.

Signed-off-by: Andrew Elble <aweits@rit.edu>
Reviewed-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-11-10 09:29:45 -05:00
Andrew Elble 34ed9872e7 nfsd: eliminate sending duplicate and repeated delegations
We've observed the nfsd server in a state where there are
multiple delegations on the same nfs4_file for the same client.
The nfs client does attempt to DELEGRETURN these when they are presented to
it - but apparently under some (unknown) circumstances the client does not
manage to return all of them. This leads to the eventual
attempt to CB_RECALL more than one delegation with the same nfs
filehandle to the same client. The first recall will succeed, but the
next recall will fail with NFS4ERR_BADHANDLE. This leads to the server
having delegations on cl_revoked that the client has no way to FREE
or DELEGRETURN, with resulting inability to recover. The state manager
on the server will continually assert SEQ4_STATUS_RECALLABLE_STATE_REVOKED,
and the state manager on the client will be looping unable to satisfy
the server.

List discussion also reports a race between OPEN and DELEGRETURN that
will be avoided by only sending the delegation once to the
client. This is also logically in accordance with RFC5561 9.1.1 and 10.2.

So, let's:

1.) Not hand out duplicate delegations.
2.) Only send them to the client once.

RFC 5561:

9.1.1:
"Delegations and layouts, on the other hand, are not associated with a
specific owner but are associated with the client as a whole
(identified by a client ID)."

10.2:
"...the stateid for a delegation is associated with a client ID and may be
used on behalf of all the open-owners for the given client.  A
delegation is made to the client as a whole and not to any specific
process or thread of control within it."

Reported-by: Eric Meddaugh <etmsys@rit.edu>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Olga Kornievskaia <aglo@umich.edu>
Signed-off-by: Andrew Elble <aweits@rit.edu>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-11-10 09:29:44 -05:00
Jeff Layton 9767feb2c6 nfsd: ensure that seqid morphing operations are atomic wrt to copies
Bruce points out that the increment of the seqid in stateids is not
serialized in any way, so it's possible for racing calls to bump it
twice and end up sending the same stateid. While we don't have any
reports of this problem it _is_ theoretically possible, and could lead
to spurious state recovery by the client.

In the current code, update_stateid is always followed by a memcpy of
that stateid, so we can combine the two operations. For better
atomicity, we add a spinlock to the nfs4_stid and hold that when bumping
the seqid and copying the stateid.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-10-23 15:57:33 -04:00
J. Bruce Fields 4eaea13425 nfsd: improve client_has_state to check for unused openowners
At least in the v4.0 case openowners can hang around for a while after
last close, but they shouldn't really block (for example), a new mount
with a different principal.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-10-23 15:57:31 -04:00
J. Bruce Fields 2b63482185 nfsd: fix clid_inuse on mount with security change
In bakeathon testing Solaris client was getting CLID_INUSE error when
doing a krb5 mount soon after an auth_sys mount, or vice versa.

That's not really necessary since in this case the old client doesn't
have any state any more:

	http://tools.ietf.org/html/rfc7530#page-103

	"when the server gets a SETCLIENTID for a client ID that
	currently has no state, or it has state but the lease has
	expired, rather than returning NFS4ERR_CLID_INUSE, the server
	MUST allow the SETCLIENTID and confirm the new client ID if
	followed by the appropriate SETCLIENTID_CONFIRM."

This doesn't fix the problem completely since our client_has_state()
check counts openowners left around to handle close replays, which we
should probably just remove in this case.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-10-23 15:57:30 -04:00
Jeff Layton 35a92fe877 nfsd: serialize state seqid morphing operations
Andrew was seeing a race occur when an OPEN and OPEN_DOWNGRADE were
running in parallel. The server would receive the OPEN_DOWNGRADE first
and check its seqid, but then an OPEN would race in and bump it. The
OPEN_DOWNGRADE would then complete and bump the seqid again.  The result
was that the OPEN_DOWNGRADE would be applied after the OPEN, even though
it should have been rejected since the seqid changed.

The only recourse we have here I think is to serialize operations that
bump the seqid in a stateid, particularly when we're given a seqid in
the call. To address this, we add a new rw_semaphore to the
nfs4_ol_stateid struct. We do a down_write prior to checking the seqid
after looking up the stateid to ensure that nothing else is going to
bump it while we're operating on it.

In the case of OPEN, we do a down_read, as the call doesn't contain a
seqid. Those can run in parallel -- we just need to serialize them when
there is a concurrent OPEN_DOWNGRADE or CLOSE.

LOCK and LOCKU however always take the write lock as there is no
opportunity for parallelizing those.

Reported-and-Tested-by: Andrew W Elble <aweits@rit.edu>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-10-12 17:31:03 -04:00
Andrew Elble a457974f1b nfsd: deal with DELEGRETURN racing with CB_RECALL
We have observed the server sending recalls for delegation stateids
that have already been successfully returned. Change
nfsd4_cb_recall_done() to return success if the client has returned
the delegation. While this does not completely eliminate the sending
of recalls for delegations that have already been returned, this
does prevent unnecessarily declaring the callback path to be down.

Reported-by: Eric Meddaugh <etmsys@rit.edu>
Signed-off-by: Andrew Elble <aweits@rit.edu>
Acked-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-09-02 10:05:28 -04:00
J. Bruce Fields f984a7ce58 nfsd: return CLID_INUSE for unexpected SETCLIENTID_CONFIRM case
Somebody with a Solaris client was hitting this case.  We haven't
figured out why yet, and don't have a reproducer.  Meanwhile Frank
noticed that RFC 7530 actually recommends CLID_INUSE for this case.
Unlikely to help the original reporter, but may as well fix it.

Reported-by: Frank Filz <ffilzlnx@mindspring.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-09-01 13:53:40 -04:00
Jeff Layton 3fcbbd244e nfsd: ensure that delegation stateid hash references are only put once
It's possible that a DELEGRETURN could race with (e.g.) client expiry,
in which case we could end up putting the delegation hash reference more
than once.

Have unhash_delegation_locked return a bool that indicates whether it
was already unhashed. In the case of destroy_delegation we only
conditionally put the hash reference if that returns true.

The other callers of unhash_delegation_locked call it while walking
list_heads that shouldn't yet be detached. If we find that it doesn't
return true in those cases, then throw a WARN_ON as that indicates that
we have a partially hashed delegation, and that something is likely very
wrong.

Tested-by: Andrew W Elble <aweits@rit.edu>
Tested-by: Anna Schumaker <Anna.Schumaker@netapp.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-31 16:32:16 -04:00
Jeff Layton e85687393f nfsd: ensure that the ol stateid hash reference is only put once
When an open or lock stateid is hashed, we take an extra reference to
it. When we unhash it, we drop that reference. The code however does
not properly account for the case where we have two callers concurrently
trying to unhash the stateid. This can lead to list corruption and the
hash reference being put more than once.

Fix this by having unhash_ol_stateid use list_del_init on the st_perfile
list_head, and then testing to see if that list_head is empty before
releasing the hash reference. This means that some of the unhashing
wrappers now become bool return functions so we can test to see whether
the stateid was unhashed before we put the reference.

Reported-by: Andrew W Elble <aweits@rit.edu>
Tested-by: Andrew W Elble <aweits@rit.edu>
Reported-by: Anna Schumaker <Anna.Schumaker@netapp.com>
Tested-by: Anna Schumaker <Anna.Schumaker@netapp.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-31 16:32:15 -04:00
Jeff Layton 51a5456859 nfsd: allow more than one laundry job to run at a time
We can potentially have several nfs4_laundromat jobs running if there
are multiple namespaces running nfsd on the box. Those are effectively
separated from one another though, so I don't see any reason to
serialize them.

Also, create_singlethread_workqueue automatically adds the
WQ_MEM_RECLAIM flag. Since we run this job on a timer, it's not really
involved in any reclaim paths. I see no need for a rescuer thread.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-31 16:32:14 -04:00
J. Bruce Fields c87fb4a378 lockd: NLM grace period shouldn't block NFSv4 opens
NLM locks don't conflict with NFSv4 share reservations, so we're not
going to learn anything new by watiting for them.

They do conflict with NFSv4 locks and with delegations.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-13 10:22:06 -04:00
J. Bruce Fields 9056fff3d5 Merge branch 'for-4.2' into for-4.3 2015-08-10 16:16:03 -04:00
Kinglong Mee c8623999ff nfsd: Remove unused clientid arguments from, find_lockowner_str{_locked}
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-10 16:05:54 -04:00
Kinglong Mee 76f6c9e176 nfsd: Use lk_new_xxx instead of v.new.xxx for nfs4_lockowner
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-10 16:05:53 -04:00
Kinglong Mee e7969315f4 nfsd: Remove macro LOFF_OVERFLOW
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-10 16:05:52 -04:00
Kinglong Mee 7a5e8d5b5c nfsd: Remove duplicate checking of nfsd_net in nfs4_laundromat()
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-10 16:05:51 -04:00
Kinglong Mee efde6b4d4e nfsd: Remove unused values in nfs4_setlease()
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-10 16:05:51 -04:00
Kinglong Mee 871860225b nfsd: Remove nfs4_set_claim_prev()
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-10 16:05:50 -04:00
Kinglong Mee f5e22bb6d9 nfsd: Drop duplicate checking of seqid in nfsd4_create_session()
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-10 16:05:49 -04:00
Kinglong Mee 41eb16702c nfsd: Add missing gen_confirm in nfsd4_setclientid()
Commit 294ac32e99 "nfsd: protect clid and verifier generation with
client_lock" moved gen_confirm() to gen_clid().

After that commit, setclientid will return a bad reply with all-zero
verifier after copy_clid().

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-10 16:05:48 -04:00
Kinglong Mee 19311aa835 nfsd: New counter for generating client confirm verifier
If using clientid_counter, it seems possible that gen_confirm could
generate the same verifier for the same client in some situations.

Add a new counter for client confirm verifier to make sure gen_confirm
generates a different verifier on each call for the same clientid.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Reviewed-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-10 16:05:47 -04:00
Kinglong Mee d50ffded79 nfsd: Fix memory leak of so_owner.data in nfs4_stateowner
v2, new helper nfs4_free_stateowner for freeing so_owner.data and sop

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-10 16:05:46 -04:00
Kinglong Mee 47e970bee7 nfsd: Add layouts checking in client_has_state()
Layout is a state resource, nfsd should check it too.

v2, drop unneeded updating in nfsd4_renew()
v3, fix compile error without CONFIG_NFSD_PNFS

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-10 16:05:46 -04:00
Kinglong Mee af9dbaf48d nfsd: Fix a memory leak of struct file_lock
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-10 16:05:45 -04:00
Jeff Layton 8fcd461db7 nfsd: do nfs4_check_fh in nfs4_check_file instead of nfs4_check_olstateid
Currently, preprocess_stateid_op calls nfs4_check_olstateid which
verifies that the open stateid corresponds to the current filehandle in the
call by calling nfs4_check_fh.

If the stateid is a NFS4_DELEG_STID however, then no such check is done.
This could cause incorrect enforcement of permissions, because the
nfsd_permission() call in nfs4_check_file uses current the current
filehandle, but any subsequent IO operation will use the file descriptor
in the stateid.

Move the call to nfs4_check_fh into nfs4_check_file instead so that it
can be done for all stateid types.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Cc: stable@vger.kernel.org
[bfields: moved fh check to avoid NULL deref in special stateid case]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-07-31 16:30:26 -04:00
Christoph Hellwig af90f707fa nfsd: take struct file setup fully into nfs4_preprocess_stateid_op
This patch changes nfs4_preprocess_stateid_op so it always returns
a valid struct file if it has been asked for that.  For that we
now allocate a temporary struct file for special stateids, and check
permissions if we got the file structure from the stateid.  This
ensures that all callers will get their handling of special stateids
right, and avoids code duplication.

There is a little wart in here because the read code needs to know
if we allocated a file structure so that it can copy around the
read-ahead parameters.  In the long run we should probably aim to
cache full file structures used with special stateids instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-06-22 14:15:03 -04:00
Christoph Hellwig a0649b2d3f nfsd: refactor nfs4_preprocess_stateid_op
Split out two self contained helpers to make the function more readable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-06-19 15:39:52 -04:00
Arnd Bergmann 6ac75368e1 nfsd: work around a gcc-5.1 warning
gcc-5.0 warns about a potential uninitialized variable use in nfsd:

fs/nfsd/nfs4state.c: In function 'nfsd4_process_open2':
fs/nfsd/nfs4state.c:3781:3: warning: 'old_deny_bmap' may be used uninitialized in this function [-Wmaybe-uninitialized]
   reset_union_bmap_deny(old_deny_bmap, stp);
   ^
fs/nfsd/nfs4state.c:3760:16: note: 'old_deny_bmap' was declared here
  unsigned char old_deny_bmap;
                ^

This is a false positive, the code path that is warned about cannot
actually be reached.

This adds an initialization for the variable to make the warning go
away.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-05-29 11:04:03 -04:00