If a NFS client receives a delegation for a file after it has taken
a lock on that file, we can currently end up in a situation where
we mistakenly skip unlocking that file.
The following patch swaps an erroneous check in nfs4_proc_unlck for
whether or not the file has a delegation to one which checks whether
or not we hold a lock stateid for that file.
Reported-by: Chuck Lever <Chuck.Lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org [>=3.7]
Tested-by: Chuck Lever <Chuck.Lever@oracle.com>
Debugging aid to help identify servers that incorrectly apply open mode
checks to setattr requests that are not changing the file size.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The NFSv4 and NFSv4.1 specs are both clear that the server should only check
stateid open mode if a SETATTR specifies the size attribute. If the
open mode is not one that allows writing, then it returns NFS4ERR_OPENMODE.
In the case where the SETATTR is not changing the size, the client will
still pass it the delegation stateid to ensure that the server does not
recall that delegation. In that case, the server should _ignore_ the
delegation open mode, and simply apply standard permission checks.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* rpcsec_gss-from_cel: (21 commits)
NFS: Retry SETCLIENTID with AUTH_SYS instead of AUTH_NONE
NFSv4: Don't clear the machine cred when client establish returns EACCES
NFSv4: Fix issues in nfs4_discover_server_trunking
NFSv4: Fix the fallback to AUTH_NULL if krb5i is not available
NFS: Use server-recommended security flavor by default (NFSv3)
SUNRPC: Don't recognize RPC_AUTH_MAXFLAVOR
NFS: Use "krb5i" to establish NFSv4 state whenever possible
NFS: Try AUTH_UNIX when PUTROOTFH gets NFS4ERR_WRONGSEC
NFS: Use static list of security flavors during root FH lookup recovery
NFS: Avoid PUTROOTFH when managing leases
NFS: Clean up nfs4_proc_get_rootfh
NFS: Handle missing rpc.gssd when looking up root FH
SUNRPC: Remove EXPORT_SYMBOL_GPL() from GSS mech switch
SUNRPC: Make gss_mech_get() static
SUNRPC: Refactor nfsd4_do_encode_secinfo()
SUNRPC: Consider qop when looking up pseudoflavors
SUNRPC: Load GSS kernel module by OID
SUNRPC: Introduce rpcauth_get_pseudoflavor()
SUNRPC: Define rpcsec_gss_info structure
NFS: Remove unneeded forward declaration
...
If we already checked the user access permissions on the original open,
then don't bother checking again on recovery. Doing so can cause a
deadlock with NFSv4.1, since the may_open() operation is not privileged.
Furthermore, we can't report an access permission failure here anyway.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
When we're doing open-by-filehandle in NFSv4.1, we shouldn't need to
do the cache consistency revalidation on the directory. It is
therefore more efficient to just use open_noattr, which returns the
file attributes, but not the directory attributes.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We should always clear it before initiating file recovery.
Also ensure that we clear it after a CLOSE and/or after TEST_STATEID fails.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Defensive patch to ensure that we copy the state->open_stateid, which
can never be set to the delegation stateid.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Fix nfs4_select_rw_stateid() so that it chooses the open stateid
(or an all-zero stateid) if the delegation does not match the selected
read/write mode.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If we're doing NFSv4.1 against a server that has persistent sessions,
then we should not need to call SETATTR in order to reset the file
attributes immediately after doing an exclusive create.
Note that since the create mode depends on the type of session that
has been negotiated with the server, we should not choose the
mode until after we've got a session slot.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently, _nfs4_do_setattr() will use the delegation stateid if no
writeable open file stateid is available.
If the server revokes that delegation stateid, then the call to
nfs4_handle_exception() will fail to handle the error due to the
lack of a struct nfs4_state, and will just convert the error into
an EIO.
This patch just removes the requirement that we must have a
struct nfs4_state in order to invalidate the delegation and
retry.
Reported-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Otherwise we deadlock if state recovery is initiated while we
sleep.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Don't hold the NFSv4 sequence id while we check for open permission.
The call to ACCESS may block due to reboot recovery.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
When we send a RENEW or SEQUENCE operation in order to probe if the
lease is still valid, we want it to be able to time out since the
lease we are probing is likely to time out too. Currently, because
we use soft mount semantics for these RPC calls, the return value
is EIO, which causes the state manager to exit with an "unhandled
error" message.
This patch changes the call semantics, so that the RPC layer returns
ETIMEDOUT instead of EIO. We then have the state manager default to
a simple retry instead of exiting.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
All error cases are handled by the switch() statement, meaning that the
call to nfs4_handle_exception() is unreachable.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
A server shouldn't normally return NFS4ERR_GRACE if the client holds a
delegation, since no conflicting lock reclaims can be granted, however
the spec does not require the server to grant the open in this
instance
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
A server shouldn't normally return NFS4ERR_GRACE if the client holds a
delegation, since no conflicting lock reclaims can be granted, however
the spec does not require the server to grant the lock in this
instance.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
Most NFSv4 servers implement AUTH_UNIX, and administrators will
prefer this over AUTH_NULL. It is harmless for our client to try
this flavor in addition to the flavors mandated by RFC 3530/5661.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the Linux NFS client receives an NFS4ERR_WRONGSEC error while
trying to look up an NFS server's root file handle, it retries the
lookup operation with various security flavors to see what flavor
the NFS server will accept for pseudo-fs access.
The list of flavors the client uses during retry consists only of
flavors that are currently registered in the kernel RPC client.
This list may not include any GSS pseudoflavors if auth_rpcgss.ko
has not yet been loaded.
Let's instead use a static list of security flavors that the NFS
standard requires the server to implement (RFC 3530bis, section
3.2.1). The RPC client should now be able to load support for
these dynamically; if not, they are skipped.
Recovery behavior here is prescribed by RFC 3530bis, section
15.33.5:
> For LOOKUPP, PUTROOTFH and PUTPUBFH, the client will be unable to
> use the SECINFO operation since SECINFO requires a current
> filehandle and none exist for these two [sic] operations. Therefore,
> the client must iterate through the security triples available at
> the client and reattempt the PUTROOTFH or PUTPUBFH operation. In
> the unfortunate event none of the MANDATORY security triples are
> supported by the client and server, the client SHOULD try using
> others that support integrity. Failing that, the client can try
> using AUTH_NONE, but because such forms lack integrity checks,
> this puts the client at risk.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently, the compound operation the Linux NFS client sends to the
server to confirm a client ID looks like this:
{ SETCLIENTID_CONFIRM; PUTROOTFH; GETATTR(lease_time) }
Once the lease is confirmed, it makes sense to know how long before
the client will have to renew it. And, performing these operations
in the same compound saves a round trip.
Unfortunately, this arrangement assumes that the security flavor
used for establishing a client ID can also be used to access the
server's pseudo-fs.
If the server requires a different security flavor to access its
pseudo-fs than it allowed for the client's SETCLIENTID operation,
the PUTROOTFH in this compound fails with NFS4ERR_WRONGSEC. Even
though the SETCLIENTID_CONFIRM succeeded, our client's trunking
detection logic interprets the failure of the compound as a failure
by the server to confirm the client ID.
As part of server trunking detection, the client then begins another
SETCLIENTID pass with the same nfs4_client_id. This fails with
NFS4ERR_CLID_INUSE because the first SETCLIENTID/SETCLIENTID_CONFIRM
already succeeded in confirming that client ID -- it was the
PUTROOTFH operation that caused the SETCLIENTID_CONFIRM compound to
fail.
To address this issue, separate the "establish client ID" step from
the "accessing the server's pseudo-fs root" step. The first access
of the server's pseudo-fs may require retrying the PUTROOTFH
operation with different security flavors. This access is done in
nfs4_proc_get_rootfh().
That leaves the matter of how to retrieve the server's lease time.
nfs4_proc_fsinfo() already retrieves the lease time value, though
none of its callers do anything with the retrieved value (nor do
they mark the lease as "renewed").
Note that NFSv4.1 state recovery invokes nfs4_proc_get_lease_time()
using the lease management security flavor. This may cause some
heartburn if that security flavor isn't the same as the security
flavor the server requires for accessing the pseudo-fs.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The long lines with no vertical white space make this function
difficult for humans to read. Add a proper documenting comment
while we're here.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
When rpc.gssd is not running, any NFS operation that needs to use a
GSS security flavor of course does not work.
If looking up a server's root file handle results in an
NFS4ERR_WRONGSEC, nfs4_find_root_sec() is called to try a bunch of
security flavors until one works or all reasonable flavors have
been tried. When rpc.gssd isn't running, this loop seems to fail
immediately after rpcauth_create() craps out on the first GSS
flavor.
When the rpcauth_create() call in nfs4_lookup_root_sec() fails
because rpc.gssd is not available, nfs4_lookup_root_sec()
unconditionally returns -EIO. This prevents nfs4_find_root_sec()
from retrying any other flavors; it drops out of its loop and fails
immediately.
Having nfs4_lookup_root_sec() return -EACCES instead allows
nfs4_find_root_sec() to try all flavors in its list.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the open_context for the file is not yet fully initialised,
then open recovery cannot succeed, and since nfs4_state_find_open_context
returns an ENOENT, we end up treating the file as being irrecoverable.
What we really want to do, is just defer the recovery until later.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
With unlink is an asynchronous operation in the sillyrename case, it
expects nfs4_async_handle_error() to map the error correctly.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Now that we do CLAIM_FH opens, we may run into situations where we
get a delegation but don't have perfect knowledge of the file path.
When returning the delegation, we might therefore not be able to
us CLAIM_DELEGATE_CUR opens to convert the delegation into OPEN
stateids and locks.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Sometimes, we actually _want_ to do open-by-filehandle, for instance
when recovering opens after a network partition, or when called
from nfs4_file_open.
Enable that functionality using a new capability NFS_CAP_ATOMIC_OPEN_V1,
and which is only enabled for NFSv4.1 servers that support it.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Follow the practice described in section 8.2.2 of RFC5661: When sending a
read/write or setattr stateid, set the seqid field to zero in order to
signal that the NFS server should apply the most recent locking state.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up the setting of the nfs_server->caps, by shoving it all
into nfs4_server_common_setup().
Then add an 'initial capabilities' field into struct nfs4_minor_version_ops.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Adds logic to ensure that if the server returns a BAD_STATEID,
or other state related error, then we check if the stateid has
already changed. If it has, then rather than start state recovery,
we should just resend the failed RPC call with the new stateid.
Allow nfs4_select_rw_stateid to notify that the stateid is unstable by
having it return -EWOULDBLOCK if an RPC is underway that might change the
stateid.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If we replay a READ or WRITE call, we should not be changing the
stateid. Currently, we may end up doing so, because the stateid
is only selected at xdr encode time.
This patch ensures that we select the stateid after we get an NFSv4.1
session slot, and that we keep that same stateid across retries.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If state recovery fails with an ESTALE or a ENOENT, then we shouldn't
keep retrying. Instead, mark the stateid as being invalid and
fail the I/O with an EIO error.
For other operations such as POSIX and BSD file locking, truncate
etc, fail with an EBADF to indicate that this file descriptor is no
longer valid.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
In order to be able to safely return the layout in nfs4_proc_setattr,
we need to block new uses of the layout, wait for all outstanding
users of the layout to complete, commit the layout and then return it.
This patch adds a helper in order to do all this safely.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Boaz Harrosh <bharrosh@panasas.com>
We need to clear the NFS_LSEG_LAYOUTCOMMIT bits atomically with the
NFS_INO_LAYOUTCOMMIT bit, otherwise we may end up with situations
where the two are out of sync.
The first half of the problem is to ensure that pnfs_layoutcommit_inode
clears the NFS_LSEG_LAYOUTCOMMIT bit through pnfs_list_write_lseg.
We still need to keep the reference to those segments until the RPC call
is finished, so in order to make it clear _where_ those references come
from, we add a helper pnfs_list_write_lseg_done() that cleans up after
pnfs_list_write_lseg.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Benny Halevy <bhalevy@tonian.com>
Cc: stable@vger.kernel.org
The client will currently try LAYOUTGETs forever if a server is returning
NFS4ERR_LAYOUTTRYLATER or NFS4ERR_RECALLCONFLICT - even if the client no
longer needs the layout (ie process killed, unmounted).
This patch uses the DS timeout value (module parameter 'dataserver_timeo'
via rpc layer) to set an upper limit of how long the client tries LATOUTGETs
in this situation. Once the timeout is reached, IO is redirected to the MDS.
This also changes how the client checks if a layout is on the clp list
to avoid a double list_add.
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If we don't release the open seqid before we wait for state recovery,
then we may end up deadlocking the state recovery thread.
This patch addresses a new deadlock that was introduced by
commit c21443c2c7 (NFSv4: Fix a reboot
recovery race when opening a file)
Reported-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Ensure that if nfs_wait_on_sequence() causes our rpc task to wait for
an NFSv4 state serialisation lock, then we also drop the session slot.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
If the server reboots after it has replied to our OPEN, but before we
call nfs4_opendata_to_nfs4_state(), then the reboot recovery thread
will not see a stateid for this open, and so will fail to recover it.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Add a mutex to the struct nfs4_state_owner to ensure that delegation
recall doesn't conflict with byte range lock removal.
Note that we nest the new mutex _outside_ the state manager reclaim
protection (nfsi->rwsem) in order to avoid deadlocks.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Adjust the return values so that they return EAGAIN to the caller in
cases where we might want to retry the delegation recall after
the state recovery has run.
Note that we can't wait and retry in this routine, because the caller
may be the state manager thread.
If delegation recall fails due to a session or reboot related issue,
also ensure that we mark the stateid as delegated so that
nfs_delegation_claim_opens can find it again later.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the server reboots while we are converting a delegation into
OPEN/LOCK stateids as part of a delegation return, the current code
will simply exit with an error. This causes us to lose both
delegation state and locking state (i.e. locking atomicity).
Deal with this by exposing the delegation stateid during delegation
return, so that we can recover the delegation, and then resume
open/lock recovery.
Note that not having to hold the nfs_inode->rwsem across the
calls to nfs_delegation_claim_opens() also fixes a deadlock against
the NFSv4.1 reboot recovery code.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We currently have a deadlock in which the state recovery thread
ends up blocking due to one of the locks which it is trying to
recover holding the nfs_inode->rwsem.
The situation is as follows: the state recovery thread is
scheduled in order to recover from a reboot. It immediately
drains the session, forcing all ordinary NFSv4.1 calls to
nfs41_setup_sequence() to be put to sleep. This includes the
file locking process that holds the nfs_inode->rwsem.
When the thread gets to nfs4_reclaim_locks(), it tries to
grab a write lock on nfs_inode->rwsem, and boom...
Fix is to have the lock drop the nfs_inode->rwsem while it is
doing RPC calls. We use a sequence lock in order to signal to
the locking process whether or not a state recovery thread has
run on that inode, in which case it should retry the lock.
Reported-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This reverts commit 324d003b0c.
The deadlock turned out to be caused by a workqueue limitation that has
now been worked around in the RPC code (see comment in rpc_free_task).
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
nfs_open_permission_mask() should only check MAY_EXEC for files that
are opened with __FMODE_EXEC.
Also fix NFSv4 access-in-open path in a similar way -- openflags must be
used because fmode will not always have FMODE_EXEC set.
This patch fixes https://bugzilla.kernel.org/show_bug.cgi?id=49101
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
