The logic for checking in nfs41_check_open_stateid() whether the state
is supported by a delegation is inverted. In addition, it makes more
sense to perform that check before we check for expired locks.

Fixes: 8a64c4ef ("NFSv4.1: Even if the stateid is OK,...")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Once we clear the NFS_DELEGATED_STATE flag, we're telling
nfs_delegation_claim_opens() that we're done recovering all open state
for that stateid, so we really need to ensure that we test for all
open modes that are currently cached and recover them before exiting
nfs4_open_delegation_recall().

Fixes: 24311f88 ("NFSv4: Recovery of recalled read delegations...")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.3+

It is unsafe to dereference delegation outside the rcu lock, and in
any case, the refcount is guaranteed held if cred is non-zero.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Add a per-transport maximum limit in the socket case, and add
helpers to allow the NFSv4 code to discover that limit.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

If the stateid is the zero or invalid stateid, then it is pointless
to attempt to use it for recovery. In that case, try to fall back
to using the open state stateid, or just doing a general recovery
of all state on a given inode.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Compile nfs4_proc_get_lease_time, enc_get_lease_time and
dec_get_lease_time for nfs4.0. Use nfs4_sequence_done instead of
nfs41_sequence_done in nfs4_proc_get_lease_time,
Signed-off-by: NDonald Buczek <buczek@molgen.mpg.de>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

With NFSv4.1, different network connections need to be explicitly
bound to a session.  During session startup, this is not possible
so only a single connection must be used for session startup.

So add a task flag to disable the default round-robin choice of
connections (when nconnect > 1) and force the use of a single
connection.
Then use that flag on all requests for session management - for
consistence, include NFSv4.0 management (SETCLIENTID) and session
destruction
Reported-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

When mapping the NFSv4 context to an open mode and access mode,
we need to treat the FMODE_EXEC flag differently. For the open
mode, FMODE_EXEC means we need read share access. For the access
mode checking, we need to verify that the user actually has
execute access.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

We can end up in nfs4_opendata_alloc during task exit, in which case
current->fs has already been cleaned up.  This leads to a crash in
current_umask().

Fix this by only setting creation opendata if we are actually doing an open
with O_CREAT.  We can drop the check for NULL nfs4_open_createattrs, since
O_CREAT will never be set for the recovery path.
Suggested-by: NTrond Myklebust <trondmy@hammerspace.com>
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

When a waiter is waked by CB_NOTIFY_LOCK, it will retry
nfs4_proc_setlk(). The waiter may fail to nfs4_proc_setlk() and sleep
again. However, the waiter is already removed from clp->cl_lock_waitq
when handling CB_NOTIFY_LOCK in nfs4_wake_lock_waiter(). So any
subsequent CB_NOTIFY_LOCK won't wake this waiter anymore. We should
put the waiter back to clp->cl_lock_waitq before retrying.

Cc: stable@vger.kernel.org #4.9+
Signed-off-by: NYihao Wu <wuyihao@linux.alibaba.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Commit b7dbcc0e "NFSv4.1: Fix a race where CB_NOTIFY_LOCK fails to wake a waiter"
found this bug. However it didn't fix it.

This commit replaces schedule_timeout() with wait_woken() and
default_wake_function() with woken_wake_function() in function
nfs4_retry_setlk() and nfs4_wake_lock_waiter(). wait_woken() uses
memory barriers in its implementation to avoid potential race condition
when putting a process into sleeping state and then waking it up.

Fixes: a1d617d8 ("nfs: allow blocking locks to be awoken by lock callbacks")
Cc: stable@vger.kernel.org #4.9+
Signed-off-by: NYihao Wu <wuyihao@linux.alibaba.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If the server is unable to immediately execute an RPC call, and returns
an NFS4ERR_DELAY then we can assume it is safe to interrupt the operation
in order to handle ordinary signals. This allows the application to
service timer interrupts that would otherwise have to wait until the
server is again able to respond.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean up the RPC task sleep interfaces by replacing the task->tk_timeout
'hidden parameter' to rpc_sleep_on() with a new function that takes an
absolute timeout.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

None of the callers set the 'action' argument, so let's just remove it.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Allow the async rpc task for finish and update the open state if needed,
then free the slot. Otherwise, the async rpc unable to decode the reply.
Signed-off-by: NOlga Kornievskaia <kolga@netapp.com>
Fixes: ae55e59d ("pnfs: Don't release the sequence slot...")
Cc: stable@vger.kernel.org # v4.18+
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Commit 7b587e1a ("NFS: use locks_copy_lock() to copy locks.")
changed the lock copying from memcpy() to the dedicated
locks_copy_lock() function. The latter correctly increments the
nfs4_lock_state.ls_count via nfs4_fl_copy_lock(), however, this refcount
has already been incremented in the nfs4_alloc_{lock,unlock}data().
Kmemleak subsequently reports an unreferenced nfs4_lock_state object as
below (arm64 platform):

unreferenced object 0xffff8000fce0b000 (size 256):
  comm "systemd-sysuser", pid 1608, jiffies 4294892825 (age 32.348s)
  hex dump (first 32 bytes):
    20 57 4c fb 00 80 ff ff 20 57 4c fb 00 80 ff ff   WL..... WL.....
    00 57 4c fb 00 80 ff ff 01 00 00 00 00 00 00 00  .WL.............
  backtrace:
    [<000000000d15010d>] kmem_cache_alloc+0x178/0x208
    [<00000000d7c1d264>] nfs4_set_lock_state+0x124/0x1f0
    [<000000009c867628>] nfs4_proc_lock+0x90/0x478
    [<000000001686bd74>] do_setlk+0x64/0xe8
    [<00000000e01500d4>] nfs_lock+0xe8/0x1f0
    [<000000004f387d8d>] vfs_lock_file+0x18/0x40
    [<00000000656ab79b>] do_lock_file_wait+0x68/0xf8
    [<00000000f17c4a4b>] fcntl_setlk+0x224/0x280
    [<0000000052a242c6>] do_fcntl+0x418/0x730
    [<000000004f47291a>] __arm64_sys_fcntl+0x84/0xd0
    [<00000000d6856e01>] el0_svc_common+0x80/0xf0
    [<000000009c4bd1df>] el0_svc_handler+0x2c/0x80
    [<00000000b1a0d479>] el0_svc+0x8/0xc
    [<0000000056c62a0f>] 0xffffffffffffffff

This patch removes the original refcount_inc(&lsp->ls_count) that was
paired with the memcpy() lock copying.

Fixes: 7b587e1a ("NFS: use locks_copy_lock() to copy locks.")
Cc: <stable@vger.kernel.org> # 5.0.x-
Cc: NeilBrown <neilb@suse.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

If the LAYOUTGET rpc call exits early without an error, convert it to
EAGAIN.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Ensure that if we call nfs41_sequence_process() a second time for the
same rpc_task, then we only process the results once.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

If we have to retransmit a request, we should ensure that we reinitialise
the sequence results structure, since in the event of a signal
we need to treat the request as if it had not been sent.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org

A 'false retry' in NFSv4.1 occurs when the client attempts to transmit a
new RPC call using a slot+sequence number combination that references an
already cached one. Currently, the Linux NFS client will do this if a
user process interrupts an RPC call that is in progress.
The problem with doing so is that we defeat the main mechanism used by
the server to differentiate between a new call and a replayed one. Even
if the server is able to perfectly cache the arguments of the old call,
it cannot know if the client intended to replay or send a new call.

The obvious fix is to bump the sequence number pre-emptively if an
RPC call is interrupted, but in order to deal with the corner cases
where the interrupted call is not actually received and processed by
the server, we need to interpret the error NFS4ERR_SEQ_MISORDERED
as a sign that we need to either wait or locate a correct sequence
number that lies between the value we sent, and the last value that
was acked by a SEQUENCE call on that slot.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Tested-by: NJason Tibbitts <tibbs@math.uh.edu>

Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Fix up some compiler warnings about function parameters, etc not being
correctly described or formatted.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Multipathing: In case of NFSv3, rpc_clnt_test_and_add_xprt() adds
the xprt to xprt switch (i.e. xps) if rpc_call_null_helper() returns
success. But in case of NFSv4.1, it needs to do EXCHANGEID to verify
the path along with check for session trunking.

Add the xprt in nfs4_test_session_trunk() only when
nfs4_detect_session_trunking() returns success. Also release refcount
hold by rpc_clnt_setup_test_and_add_xprt().
Signed-off-by: NSantosh kumar pradhan <santoshkumar.pradhan@wdc.com>
Tested-by: NSuresh Jayaraman <suresh.jayaraman@wdc.com>
Reported-by: NAditya Agnihotri <aditya.agnihotri@wdc.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

SUNRPC has two sorts of credentials, both of which appear as
"struct rpc_cred".
There are "generic credentials" which are supplied by clients
such as NFS and passed in 'struct rpc_message' to indicate
which user should be used to authorize the request, and there
are low-level credentials such as AUTH_NULL, AUTH_UNIX, AUTH_GSS
which describe the credential to be sent over the wires.

This patch replaces all the generic credentials by 'struct cred'
pointers - the credential structure used throughout Linux.

For machine credentials, there is a special 'struct cred *' pointer
which is statically allocated and recognized where needed as
having a special meaning.  A look-up of a low-level cred will
map this to a machine credential.
Signed-off-by: NNeilBrown <neilb@suse.com>
Acked-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Use the common 'struct cred' to pass credentials for readdir.
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Rather than keying the access cache with 'struct rpc_cred',
use 'struct cred'.  Then use cred_fscmp() to compare
credentials rather than comparing the raw pointer.

A benefit of this approach is that in the common case we avoid the
rpc_lookup_cred_nonblock() call which can be slow when the cred cache is large.
This also keeps many fewer items pinned in the rpc cred cache, so the
cred cache is less likely to get large.
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

This lock is no longer necessary.

If nfs4_get_renew_cred() needs to hunt through the open-state
creds for a user cred, it still takes the lock to stablize
the rbtree, but otherwise there are no races.

Note that this completely removes the lock from nfs4_renew_state().
It appears that the original need for the locking here was removed
long ago, and there is no longer anything to protect.
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Using memcpy() to copy lock requests leaves the various
list_head in an inconsistent state.
As we will soon attach a list of conflicting request to
another pending request, we need these lists to be consistent.
So change NFS to use locks_init_lock/locks_copy_lock instead
of memcpy.
Signed-off-by: NNeilBrown <neilb@suse.com>
Reviewed-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NJeff Layton <jlayton@kernel.org>

Trivial fix to a spelling mistake of the error access name EACCESS,
rename to EACCES
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

We need to ensure that inode and dentry revalidation occurs correctly
on reopen of a file that is already open. Currently, we can end up
not revalidating either in the case of NFSv4.0, due to the 'cached open'
path.
Let's fix that by ensuring that we only do cached open for the special
cases of open recovery and delegation return.
Reported-by: NStan Hu <stanhu@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Reduce contention on the inode->i_lock by ensuring that we use RCU
when looking up the NFS open context.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Add a helper for the case when the nfs4 open state has been set to use
a delegation stateid, and we want to revert to using the open stateid.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

The previous fix broke recovery of delegated stateids because it assumes
that if we did not mark the delegation as suspect, then the delegation has
effectively been revoked, and so it removes that delegation irrespectively
of whether or not it is valid and still in use. While this is "mostly
harmless" for ordinary I/O, we've seen pNFS fail with LAYOUTGET spinning
in an infinite loop while complaining that we're using an invalid stateid
(in this case the all-zero stateid).

What we rather want to do here is ensure that the delegation is always
correctly marked as needing testing when that is the case. So we want
to close the loophole offered by nfs4_schedule_stateid_recovery(),
which marks the state as needing to be reclaimed, but not the
delegation that may be backing it.

Fixes: 0e3d3e5d ("NFSv4.1 fix infinite loop on IO BAD_STATEID error")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

When we update the layout stateid in nfs4_layoutreturn_refresh_stateid, we
should also update the range in order to let the server know we're actually
returning everything.

Fixes: 16c278dbfa63 ("pnfs: Fix handling of NFS4ERR_OLD_STATEID replies...")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

The back channel size is allowed to be 1 or greater.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

A COPY with unstable write data needs a simple sync commit.
Filehandle value is gotten as a part of the inner loop so in
case of a reboot retry it should get the new value.
Signed-off-by: NOlga Kornievskaia <kolga@netapp.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Make this function available to nfs42proc.c
Signed-off-by: NOlga Kornievskaia <kolga@netapp.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Signed-off-by: NOlga Kornievskaia <kolga@netapp.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>