The main reason for doing this is will be to allow for an asynchronous
RPC mode that we can use for freeing lock stateids as per section
8.2.4 of RFC5661.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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
Use the new FS-Cache invalidation facility from NFS to deal with foreign
changes being detected on the server rather than attempting to retire the old
cookie and get a new one.
The problem with the old method was that NFS did not wait for all outstanding
storage and retrieval ops on the cache to complete. There was no automatic
wait between the calls to ->readpages() and calls to invalidate_inode_pages2()
as the latter can only wait on locked pages that have been added to the
pagecache (which they haven't yet on entry to ->readpages()).
This was leading to oopses like the one below when an outstanding read got cut
off from its cookie by a premature release.
BUG: unable to handle kernel NULL pointer dereference at 00000000000000a8
IP: [<ffffffffa0075118>] __fscache_read_or_alloc_pages+0x1dd/0x315 [fscache]
PGD 15889067 PUD 15890067 PMD 0
Oops: 0000 [#1] SMP
CPU 0
Modules linked in: cachefiles nfs fscache auth_rpcgss nfs_acl lockd sunrpc
Pid: 4544, comm: tar Not tainted 3.1.0-rc4-fsdevel+ #1064 /DG965RY
RIP: 0010:[<ffffffffa0075118>] [<ffffffffa0075118>] __fscache_read_or_alloc_pages+0x1dd/0x315 [fscache]
RSP: 0018:ffff8800158799e8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8800070d41e0 RCX: ffff8800083dc1b0
RDX: 0000000000000000 RSI: ffff880015879960 RDI: ffff88003e627b90
RBP: ffff880015879a28 R08: 0000000000000002 R09: 0000000000000002
R10: 0000000000000001 R11: ffff880015879950 R12: ffff880015879aa4
R13: 0000000000000000 R14: ffff8800083dc158 R15: ffff880015879be8
FS: 00007f671e9d87c0(0000) GS:ffff88003bc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00000000000000a8 CR3: 000000001587f000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process tar (pid: 4544, threadinfo ffff880015878000, task ffff880015875040)
Stack:
ffffffffa00b1759 ffff8800070dc158 ffff8800000213da ffff88002a286508
ffff880015879aa4 ffff880015879be8 0000000000000001 ffff88002a2866e8
ffff880015879a88 ffffffffa00b20be 00000000000200da ffff880015875040
Call Trace:
[<ffffffffa00b1759>] ? nfs_fscache_wait_bit+0xd/0xd [nfs]
[<ffffffffa00b20be>] __nfs_readpages_from_fscache+0x7e/0x13f [nfs]
[<ffffffff81095fe7>] ? __alloc_pages_nodemask+0x156/0x662
[<ffffffffa0098763>] nfs_readpages+0xee/0x187 [nfs]
[<ffffffff81098a5e>] __do_page_cache_readahead+0x1be/0x267
[<ffffffff81098942>] ? __do_page_cache_readahead+0xa2/0x267
[<ffffffff81098d7b>] ra_submit+0x1c/0x20
[<ffffffff8109900a>] ondemand_readahead+0x28b/0x29a
[<ffffffff810990ce>] page_cache_sync_readahead+0x38/0x3a
[<ffffffff81091d8a>] generic_file_aio_read+0x2ab/0x67e
[<ffffffffa008cfbe>] nfs_file_read+0xa4/0xc9 [nfs]
[<ffffffff810c22c4>] do_sync_read+0xba/0xfa
[<ffffffff810a62c9>] ? might_fault+0x4e/0x9e
[<ffffffff81177a47>] ? security_file_permission+0x7b/0x84
[<ffffffff810c25dd>] ? rw_verify_area+0xab/0xc8
[<ffffffff810c29a4>] vfs_read+0xaa/0x13a
[<ffffffff810c2a79>] sys_read+0x45/0x6c
[<ffffffff813ac37b>] system_call_fastpath+0x16/0x1b
Reported-by: Mark Moseley <moseleymark@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
If an RPC call is interrupted, assume that the server hasn't processed
the RPC call so that the next time we use the slot, we know that if we
get a NFS4ERR_SEQ_MISORDERED or NFS4ERR_SEQ_FALSE_RETRY, we just have
to bump the sequence number.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Shave a few bytes off the slot table size by moving the RPC timestamp
into the sequence results.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the server returns NFS4ERR_SEQ_MISORDERED, it could be a sign
that the slot was retired at some point. Retry the attempt after
reinitialising the slot sequence number to 1.
Also add a handler for NFS4ERR_SEQ_FALSE_RETRY. Just bump the slot
sequence number and retry...
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently, when an RPCSEC_GSS context has expired or is non-existent
and the users (Kerberos) credentials have also expired or are non-existent,
the client receives the -EKEYEXPIRED error and tries to refresh the context
forever. If an application is performing I/O, or other work against the share,
the application hangs, and the user is not prompted to refresh/establish their
credentials. This can result in a denial of service for other users.
Users are expected to manage their Kerberos credential lifetimes to mitigate
this issue.
Move the -EKEYEXPIRED handling into the RPC layer. Try tk_cred_retry number
of times to refresh the gss_context, and then return -EACCES to the application.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Most (all) NFS4ERR_BADSLOT errors are due to the client failing to
respect the server's sr_highest_slotid limit. This mainly happens
due to reordered RPC requests.
The way to handle it is simply to drop the slot that we're using,
and retry using the new highest_slotid limits.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Commit 1f1ea6c "NFSv4: Fix buffer overflow checking in
__nfs4_get_acl_uncached" accidently dropped the checking for too small
result buffer length.
If someone uses getxattr on "system.nfs4_acl" on an NFSv4 mount
supporting ACLs, the ACL has not been cached and the buffer suplied is
too short, we still copy the complete ACL, resulting in kernel and user
space memory corruption.
Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Cc: stable@kernel.org
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently, we see a lot of bouncing for the value of highest_used_slotid
due to the fact that slots are getting freed, instead of getting instantly
transmitted to the next waiting task.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We want to preserve the rpc_task priority for things like writebacks,
that may have differing levels of urgency.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
All it does is pass its arguments through to another function. Let's
cut out the middleman...
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Privileged rpc calls are those that are run by the state recovery thread,
in cases where we're trying to recover the system after a server reboot
or a network partition. In those cases, we want to fence off all other
rpc calls (see nfs4_begin_drain_session()) so that they don't end up
using stateids or clientids that are in the process of being recovered.
Prior to this patch, we had to set up special callback functions in
order to declare an rpc call as being privileged.
By adding a new field to the sequence arguments, this patch simplifies
things considerably, and allows us to declare the rpc call as privileged
before it is run.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
It is more important to preserve the task priority behaviour, which ensures
that things like reclaim writes take precedence over background and kupdate
writes.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We shouldn't need to pass the 'cache_reply' parameter if we
initialise the sequence_args/sequence_res in the caller.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Nobody calls nfs4_setup_sequence or nfs41_setup_sequence without
also calling rpc_call_start() on success. This commit therefore
folds the rpc_call_start call into nfs41_setup_sequence().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
There is no point in using nfs4_setup_sequence or nfs4_sequence_done
in pure NFSv4.1 functions. We already know that those have sessions...
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the server requests a lower target_highest_slotid, then ensure
that we ping it with at least one RPC call containing an
appropriate SEQUENCE op. This ensures that the server won't need to
send a recall callback in order to shrink the slot table.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
nfs4_wait_clnt_recover and nfs4_client_recover_expired_lease are both
generic state related functions. As such, they belong in nfs4state.c,
and not nfs4proc.c
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Coalesce nfs4_check_drain_bc_complete and nfs4_check_drain_fc_complete
into a single function that can be called when the slot table is known
to be empty, then change nfs4_callback_free_slot() and nfs4_free_slot()
to use it.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the NFSv4.1 session slot allocation fails due to an ENOMEM condition,
then set the task->tk_timeout to 1/4 second to ensure that we do retry
the slot allocation more quickly.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The state manager no longer needs any special machinery to stop the
session flow and resize the slot table. It is all done on the fly by
the SEQUENCE op code now.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Instead of an array of slots, use a singly linked list of slots that
can be dynamically appended to or shrunk.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Allow the server to control the size of the session slot table
by adjusting the value of sr_target_max_slots in the reply to the
SEQUENCE operation.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Ensure that the NFSv4.1 CB_RECALL_SLOT callback updates the slot table
target max slotid safely.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
When the server tells us that it is dynamically resizing the session
replay cache, we should reset the sequence number for those slots
that have been deallocated.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Dynamic slot allocation in NFSv4.1 depends on the client being able to
track the server's target value for the highest slotid in the
slot table. See the reference in Section 2.10.6.1 of RFC5661.
To avoid ordering problems in the case where 2 SEQUENCE replies contain
conflicting updates to this target value, we also introduce a generation
counter, to track whether or not an RPC containing a SEQUENCE operation
was launched before or after the last update.
Also rename the nfs4_slot_table target_max_slots field to
'target_highest_slotid' to avoid confusion with a slot
table size or number of slots.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Change the argument to take the pointer to the slot, instead of
just the slotid.
We know that the new value of highest_used_slot must be less than
the current value. No need to scan the whole table.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up the NFSv4.1 slot allocation by replacing nfs_find_slot() with
a function nfs_alloc_slot() that returns a pointer to the nfs4_slot
instead of an offset into the slot table.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Instead of doing slot table pointer gymnastics every time we want to
know which slot we're using.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Move the session pointer into the slot table, then have struct nfs4_slot
point to that slot table.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We must always bump the clientid sequence number after a successful
call to CREATE_SESSION on the server. The result of
nfs4_verify_channel_attrs() is irrelevant to that requirement.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If we're mounting a new filesystem, ensure that the session has negotiated
large enough request and reply sizes to match the wsize and rsize mount
arguments.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Don't store the target request and response sizes in the same
variables used to store the server's replies to those targets.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If I mount an NFS v4.1 server to a single client multiple times and then
run xfstests over each mountpoint I usually get the client into a state
where recovery deadlocks. The server informs the client of a
cb_path_down sequence error, the client then does a
bind_connection_to_session and checks the status of the lease.
I found that bind_connection_to_session sets the NFS4_SESSION_DRAINING
flag on the client, but this flag is never unset before
nfs4_check_lease() reaches nfs4_proc_sequence(). This causes the client
to deadlock, halting all NFS activity to the server. nfs4_proc_sequence()
is only called by the state manager, so I can change it to run in privileged
mode to bypass the NFS4_SESSION_DRAINING check and avoid the deadlock.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
Return errno - not an NFS4ERR_. This worked because NFS4ERR_ACCESS == EACCES.
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Use nfs_sb_deactive_async instead of nfs_sb_deactive when in a workqueue
context. This avoids a deadlock where rpc_shutdown_client loops forever
in a workqueue kworker context, trying to kill all RPC tasks associated with
the client, while one or more of these tasks have already been assigned to the
same kworker (and will never run rpc_exit_task).
This approach is needed because RPC tasks that have already been assigned
to a kworker by queue_work cannot be canceled, as explained in the comment
for workqueue.c:insert_wq_barrier.
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
[Trond: add module_get/put.]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the state recovery machinery is triggered by the call to
nfs4_async_handle_error() then we can deadlock.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
If we do not release the sequence id in cases where we fail to get a
session slot, then we can deadlock if we hit a recovery scenario.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
Currently, we will schedule session recovery and then return to the
caller of nfs4_handle_exception. This works for most cases, but causes
a hang on the following test case:
Client Server
------ ------
Open file over NFS v4.1
Write to file
Expire client
Try to lock file
The server will return NFS4ERR_BADSESSION, prompting the client to
schedule recovery. However, the client will continue placing lock
attempts and the open recovery never seems to be scheduled. The
simplest solution is to wait for session recovery to run before retrying
the lock.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
nfs4_open_recover_helper zeros the nfs4_opendata result structures, removing
the result access_request information which leads to an XDR decode error.
Move the setting of the result access_request field to nfs4_init_opendata_res
which sets all the other required nfs4_opendata result fields and is shared
between the open and recover open paths.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
