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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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.
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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
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
kerberized NFSv4.1 mounts, and Scott Mayhew's work addressing ACK storms
that can affect some high-availability NFS setups.
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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
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
