Commit Graph

188 Commits

Author SHA1 Message Date
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
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
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
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
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
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
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
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
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
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
Jeff Layton
cc8a55320b nfsd: serialize layout stateid morphing operations
In order to allow the client to make a sane determination of what
happened with racing LAYOUTGET/LAYOUTRETURN/CB_LAYOUTRECALL calls, we
must ensure that the seqids return accurately represent the order of
operations. The simplest way to do that is to ensure that operations on
a single stateid are serialized.

This patch adds a mutex to the layout stateid, and locks it when
checking the layout stateid's seqid. The mutex is held over the entire
operation and released after the seqid is bumped.

Note that in the case of CB_LAYOUTRECALL we must move the increment of
the seqid and setting into a new cb "prepare" operation. The lease
infrastructure will call the lm_break callback with a spinlock held, so
and we can't take the mutex in that codepath.

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-10-23 15:57:32 -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
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
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
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
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
Sachin Bhamare
8287f009bd nfsd: fix pNFS return on close semantics
For the sake of forgetful clients, the server should return the layouts
to the file system on 'last close' of a file (assuming that there are no
delegations outstanding to that particular client) or on delegreturn
(assuming that there are no opens on a file from that particular
client).

In theory the information is all there in current data structures, but
it's not efficiently available; nfs4_file->fi_ref includes references on
the file across all clients, but we need a per-(client, file) count.
Walking through lots of stateid's to calculate this on each close or
delegreturn would be painful.

This patch introduces infrastructure to maintain per-client opens and
delegation counters on a per-file basis.

[hch: ported to the mainline pNFS support, merged various fixes from Jeff]
Signed-off-by: Sachin Bhamare <sachin.bhamare@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-05-04 12:02:39 -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
Christoph Hellwig
9cf514ccfa nfsd: implement pNFS operations
Add support for the GETDEVICEINFO, LAYOUTGET, LAYOUTCOMMIT and
LAYOUTRETURN NFSv4.1 operations, as well as backing code to manage
outstanding layouts and devices.

Layout management is very straight forward, with a nfs4_layout_stateid
structure that extends nfs4_stid to manage layout stateids as the
top-level structure.  It is linked into the nfs4_file and nfs4_client
structures like the other stateids, and contains a linked list of
layouts that hang of the stateid.  The actual layout operations are
implemented in layout drivers that are not part of this commit, but
will be added later.

The worst part of this commit is the management of the pNFS device IDs,
which suffers from a specification that is not sanely implementable due
to the fact that the device-IDs are global and not bound to an export,
and have a small enough size so that we can't store the fsid portion of
a file handle, and must never be reused.  As we still do need perform all
export authentication and validation checks on a device ID passed to
GETDEVICEINFO we are caught between a rock and a hard place.  To work
around this issue we add a new hash that maps from a 64-bit integer to a
fsid so that we can look up the export to authenticate against it,
a 32-bit integer as a generation that we can bump when changing the device,
and a currently unused 32-bit integer that could be used in the future
to handle more than a single device per export.  Entries in this hash
table are never deleted as we can't reuse the ids anyway, and would have
a severe lifetime problem anyway as Linux export structures are temporary
structures that can go away under load.

Parts of the XDR data, structures and marshaling/unmarshaling code, as
well as many concepts are derived from the old pNFS server implementation
from Andy Adamson, Benny Halevy, Dean Hildebrand, Marc Eshel, Fred Isaman,
Mike Sager, Ricardo Labiaga and many others.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2015-02-02 18:09:42 +01:00
Christoph Hellwig
4d227fca1b nfsd: make find_any_file available outside nfs4state.c
Signed-off-by: Christoph Hellwig <hch@lst.de>
2015-02-02 18:09:41 +01:00
Christoph Hellwig
e6ba76e194 nfsd: make find/get/put file available outside nfs4state.c
Signed-off-by: Christoph Hellwig <hch@lst.de>
2015-02-02 18:09:41 +01:00
Christoph Hellwig
cd61c52231 nfsd: make lookup/alloc/unhash_stid available outside nfs4state.c
Signed-off-by: Christoph Hellwig <hch@lst.de>
2015-02-02 18:09:40 +01:00
Jeff Layton
67db103448 nfsd: fi_delegees doesn't need to be an atomic_t
fi_delegees is always handled under the fi_lock, so there's no need to
use an atomic_t for this field.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-01-07 14:05:35 -05:00
Jeff Layton
5b095e9992 nfsd: convert nfs4_file searches to use RCU
The global state_lock protects the file_hashtbl, and that has the
potential to be a scalability bottleneck.

Address this by making the file_hashtbl use RCU. Add a rcu_head to the
nfs4_file and use that when freeing ones that have been hashed. In order
to conserve space, we union the fi_rcu field with the fi_delegations
list_head which must be clear by the time the last reference to the file
is dropped.

Convert find_file_locked to use RCU lookup primitives and not to require
that the state_lock be held, and convert find_file to do a lockless
lookup. Convert find_or_add_file to attempt a lockless lookup first, and
then fall back to doing a locked search and insert if that fails to find
anything.

Also, minimize the number of times we need to calculate the hash value
by passing it in as an argument to the search and insert functions, and
optimize the order of arguments in nfsd4_init_file.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-11-07 16:56:11 -05:00
Jeff Layton
ccc6398ea5 nfsd: clean up comments over nfs4_file definition
They're a bit outdated wrt to some recent changes.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-10-23 14:05:11 -04:00
Linus Torvalds
ef4a48c513 File locking related changes for v3.18 (pile #1)
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJUNZK4AAoJEAAOaEEZVoIVI08P/iM7eaIVRnqaqtWw/JBzxiba
 EMDlJYUBSlv6lYk9s8RJT4bMmcmGAKSYzVAHSoPahzNcqTDdFLeDTLGxJ8uKBbjf
 d1qRRdH1yZHGUzCvJq3mEendjfXn435Y3YburUxjLfmzrzW7EbMvndiQsS5dhAm9
 PEZ+wrKF/zFL7LuXa1YznYrbqOD/GRsJAXGEWc3kNwfS9avephVG/RI3GtpI2PJj
 RY1mf8P7+WOlrShYoEuUo5aqs01MnU70LbqGHzY8/QKH+Cb0SOkCHZPZyClpiA+G
 MMJ+o2XWcif3BZYz+dobwz/FpNZ0Bar102xvm2E8fqByr/T20JFjzooTKsQ+PtCk
 DetQptrU2gtyZDKtInJUQSDPrs4cvA13TW+OEB1tT8rKBnmyEbY3/TxBpBTB9E6j
 eb/V3iuWnywR3iE+yyvx24Qe7Pov6deM31s46+Vj+GQDuWmAUJXemhfzPtZiYpMT
 exMXTyDS3j+W+kKqHblfU5f+Bh1eYGpG2m43wJVMLXKV7NwDf8nVV+Wea962ga+w
 BAM3ia4JRVgRWJBPsnre3lvGT5kKPyfTZsoG+kOfRxiorus2OABoK+SIZBZ+c65V
 Xh8VH5p3qyCUBOynXlHJWFqYWe2wH0LfbPrwe9dQwTwON51WF082EMG5zxTG0Ymf
 J2z9Shz68zu0ok8cuSlo
 =Hhee
 -----END PGP SIGNATURE-----

Merge tag 'locks-v3.18-1' of git://git.samba.org/jlayton/linux

Pull file locking related changes from Jeff Layton:
 "This release is a little more busy for file locking changes than the
  last:

   - a set of patches from Kinglong Mee to fix the lockowner handling in
     knfsd
   - a pile of cleanups to the internal file lease API.  This should get
     us a bit closer to allowing for setlease methods that can block.

  There are some dependencies between mine and Bruce's trees this cycle,
  and I based my tree on top of the requisite patches in Bruce's tree"

* tag 'locks-v3.18-1' of git://git.samba.org/jlayton/linux: (26 commits)
  locks: fix fcntl_setlease/getlease return when !CONFIG_FILE_LOCKING
  locks: flock_make_lock should return a struct file_lock (or PTR_ERR)
  locks: set fl_owner for leases to filp instead of current->files
  locks: give lm_break a return value
  locks: __break_lease cleanup in preparation of allowing direct removal of leases
  locks: remove i_have_this_lease check from __break_lease
  locks: move freeing of leases outside of i_lock
  locks: move i_lock acquisition into generic_*_lease handlers
  locks: define a lm_setup handler for leases
  locks: plumb a "priv" pointer into the setlease routines
  nfsd: don't keep a pointer to the lease in nfs4_file
  locks: clean up vfs_setlease kerneldoc comments
  locks: generic_delete_lease doesn't need a file_lock at all
  nfsd: fix potential lease memory leak in nfs4_setlease
  locks: close potential race in lease_get_mtime
  security: make security_file_set_fowner, f_setown and __f_setown void return
  locks: consolidate "nolease" routines
  locks: remove lock_may_read and lock_may_write
  lockd: rip out deferred lock handling from testlock codepath
  NFSD: Get reference of lockowner when coping file_lock
  ...
2014-10-11 13:21:34 -04:00
Jeff Layton
0c637be884 nfsd: don't keep a pointer to the lease in nfs4_file
Now that we don't need to pass in an actual lease pointer to
vfs_setlease on unlock, we can stop tracking a pointer to the lease in
the nfs4_file.

Switch all of the places that check the fi_lease to check fi_deleg_file
instead. We always set that at the same time so it will have the same
semantics.

Cc: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2014-10-07 14:06:12 -04:00
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
Jeff Layton
d682e750ce nfsd: serialize nfsdcltrack upcalls for a particular client
In a later patch, we want to add a flag that will allow us to reduce the
need for upcalls. In order to handle that correctly, we'll need to
ensure that racing upcalls for the same client can't occur. In practice
it should be rare for this to occur with a well-behaved client, but it
is possible.

Convert one of the bits in the cl_flags field to be an upcall bitlock,
and use it to ensure that upcalls for the same client are serialized.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
2014-09-17 16:33:16 -04:00
Jeff Layton
7f5ef2e900 nfsd: add a v4_end_grace file to /proc/fs/nfsd
Allow a privileged userland process to end the v4 grace period early.
Writing "Y", "y", or "1" to the file will cause the v4 grace period to
be lifted.  The basic idea with this will be to allow the userland
client tracking program to lift the grace period once it knows that no
more clients will be reclaiming state.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
2014-09-17 16:33:14 -04:00
Jeff Layton
919b8049f0 nfsd: remove redundant boot_time parm from grace_done client tracking op
Since it's stored in nfsd_net, we don't need to pass it in separately.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
2014-09-17 16:33:12 -04:00
Jeff Layton
14a571a8ec nfsd: add some comments to the nfsd4 object definitions
Add some comments that describe what each of these objects is, and how
they related to one another.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-08-05 16:09:20 -04:00
Jeff Layton
b687f6863e nfsd: remove the client_mutex and the nfs4_lock/unlock_state wrappers
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-08-05 15:00:54 -04:00
Jeff Layton
285abdee53 nfsd: remove old fault injection infrastructure
Remove the old nfsd_for_n_state function and move nfsd_find_client
higher up into the file to get rid of forward declaration. Remove
the struct nfsd_fault_inject_op arguments from the operations as
they are no longer needed by any of them.

Finally, remove the old "standard" get and set routines, which
also eliminates the client_mutex from this code.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-08-05 10:55:10 -04:00
Jeff Layton
98d5c7c5bd nfsd: add more granular locking to *_delegations fault injectors
...instead of relying on the client_mutex.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-08-05 10:55:09 -04:00
Jeff Layton
82e05efaec nfsd: add more granular locking to forget_openowners fault injector
...instead of relying on the client_mutex.

Also, fix up the printk output that is generated when the file is read.
It currently says that it's reporting the number of open files, but
it's actually reporting the number of openowners.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-08-05 10:55:08 -04:00
Jeff Layton
016200c373 nfsd: add more granular locking to forget_locks fault injector
...instead of relying on the client_mutex.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-08-05 10:55:07 -04:00