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>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

commit 0cb98abb5bd13b9a636bde603d952d722688b428 upstream.

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>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c1dffe0bf7f9c3d57d9f237a7cb2a81e62babd2b upstream.

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
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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effectively been revoked, and so it removes that delegation irrespectively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>

Error code is set in the error handling cases but never used. Fix it.

Fixes: 937e3133 ("NFSv4.1: Ensure we clear the SP4_MACH_CRED flags in nfs4_sp4_select_mode()")
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Warning level 2 was used: -Wimplicit-fallthrough=2
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

When we update the change attribute, we should also clear the flag that
says it is out of date.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If the object being renamed from one directory to another is also
a directory, then 'nlink' will change for both directories.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Ensure that we always bump or drop the nlink count on the parent directory
when we do a mkdir or a rmdir(). This needs to be done by hand as we don't
have pre/post op attributes.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If the server tells us that out layoutreturn raced with another layout
update, then we must ensure that the new layout segments are not in use
before we resend with an updated layout stateid.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

The patch to fix the case where a lock request was interrupted ended up
changing default handling of errors such as NFS4ERR_DENIED and caused the
client to immediately resend the lock request. Let's do a partial revert
of that request so that the default is now to exit, but change the way
we handle resends to take into account the fact that the user may have
interrupted the request.
Reported-by: NKenneth Johansson <ken@kenjo.org>
Fixes: a3cf9bca ("NFSv4: Don't add a new lock on an interrupted wait..")
Cc: Benjamin Coddington <bcodding@redhat.com>
Cc: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>

After a live data migration event at the NFS server, the client may send
I/O requests to the wrong server, causing a live hang due to repeated
recovery events.  On the wire, this will appear as an I/O request failing
with NFS4ERR_BADSESSION, followed by successful CREATE_SESSION, repeatedly.
NFS4ERR_BADSSESSION is returned because the session ID being used was
issued by the other server and is not valid at the old server.

The failure is caused by async worker threads having cached the transport
(xprt) in the rpc_task structure.  After the migration recovery completes,
the task is redispatched and the task resends the request to the wrong
server based on the old value still present in tk_xprt.

The solution is to recompute the tk_xprt field of the rpc_task structure
so that the request goes to the correct server.
Signed-off-by: NBill Baker <bill.baker@oracle.com>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NHelen Chao <helen.chao@oracle.com>
Fixes: fb43d172 ("SUNRPC: Use the multipath iterator to assign a ...")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

When reclaiming a delegation via CLAIM_PREVIOUS open, the server can
indicate that the delegation has been recalled since it was issued by
setting the "recalled" flag in the delegation.

Ensure that we respect the flag by initiating a delegation return when
it is set.
Signed-off-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Even if the results of the permissions checks failed, we should parse
the results of the layout on open call so that we can return the
layout if required.
Note that we also want to ignore the sequence counter for whether or not
a layout recall occurred. If the recall pertained to our OPEN, then the
callback will know, and will attempt to wait for us to finih processing
anyway.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Parallel to FILE_CREATED, goes into ->f_mode instead of *opened.
NFS is a bit of a wart here - it doesn't have file at the point
where FILE_CREATED used to be set, so we need to propagate it
there (for now).  IMA is another one (here and everywhere)...

Note that this needs do_dentry_open() to leave old bits in ->f_mode
alone - we want it to preserve FMODE_CREATED if it had been already
set (no other bit can be there).
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

If the layout was invalidated due to a reboot, then don't try to send
a layoutreturn for it.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Right now, we can call nfs_commit_inode() while holding the session slot,
which could lead to NFSv4 deadlocks. Ensure we only keep the slot if
the server returned a layout that we have to process.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

If the server returns NFS4ERR_SEQ_FALSE_RETRY or NFS4ERR_RETRY_UNCACHED_REP,
then it thinks we're trying to replay an existing request. If so, then
let's just bump the sequence ID and retry the operation.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

We want to compare the slot_id to the highest slot number advertised by the
server.

Fixes: 3be0f80b ("NFSv4.1: Fix up replays of interrupted requests")
Cc: stable@vger.kernel.org # 4.15+
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Commit 69dd716c ("NFSv4: Add socket proto argument to
setclientid") (2007) added the transport protocol name to the client
ID string, but the patch description doesn't explain why this was
necessary.

At that time, the only transport protocol name that would have been
used is "tcp" (for both IPv4 and IPv6), resulting in no additional
distinctiveness of the client ID string.

Since there is one client instance, the server should recognize it's
state whether the client is connecting via TCP or RDMA. Same client,
same lease.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

It is possible for two distinct clients to have the same cl_ipaddr:

 - if the client admin disables callback with clientaddr=0.0.0.0 on
   more than one client

 - if two clients behind separate NATs use the same private subnet
   number

 - if the client admin specifies the same address via clientaddr=
   mount option (pointing the server at the same NAT box, for
   example)

Because of the way the Linux NFSv4.0 client constructs its client
ID string by default, such clients could interfere with each others'
lease state when mounting the same server:

	scnprintf(str, len, "Linux NFSv4.0 %s/%s %s",
		clp->cl_ipaddr,
		rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR),
		rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_PROTO));

cl_ipaddr is set to the value of the clientaddr= mount option. Two
clients whose addresses are 192.168.3.77 that mount the same server
(whose public IP address is, say, 3.4.5.6) would both generate the
same client ID string when sending a SETCLIENTID:

  Linux NFSv4.0 192.168.3.77/3.4.5.6 tcp

and thus the server would not be able to distinguish the clients'
leases. If both clients are using AUTH_SYS when sending SETCLIENTID
then the server could possibly permit the two clients to interfere
with or purge each others' leases.

To better ensure that Linux's NFSv4.0 client ID strings are distinct
in these cases, remove cl_ipaddr from the client ID string and
replace it with something more likely to be unique. Note that the
replacement looks a lot like the uniform client ID string.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Fix a compiler warning:
fs/nfs/nfs4proc.c:910:13: warning: 'nfs4_layoutget_release' defined but not used [-Wunused-function]
 static void nfs4_layoutget_release(void *calldata)
             ^~~~~~~~~~~~~~~~~~~~~~
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

If we hold a delegation, we don't need to care about whether or not
the inode attributes are up to date. We know we can cache the results
of this call regardless.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

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

Again, when revalidating the inode, we don't need to ask for attributes
for which we are authoritative.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Allow the getattr() callback to check things like whether or not we hold
a delegation so that it can adjust the attributes that it is asking for.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

When we hold a delegation, we should not need to request attributes such
as the file size or the change attribute. For some servers, avoiding
asking for these unneeded attributes can improve the overall system
performance.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

If the server recalls the layout that was just handed out, we risk hitting
a race as described in RFC5661 Section 2.10.6.3 unless we ensure that we
release the sequence slot after processing the LAYOUTGET operation that
was sent as part of the OPEN compound.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

The flag was not always being cleared after LAYOUTGET on OPEN.
Signed-off-by: NFred Isaman <fred.isaman@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: NFred Isaman <fred.isaman@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Move the actual freeing of the struct nfs4_layoutget into fs/nfs/pnfs.c
where it can be reused by the layoutget on open code.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

This triggers when have no pre-existing inode to attach to.
The preexisting case is saved for later.
Signed-off-by: NFred Isaman <fred.isaman@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

It will be needed now by the pnfs code.
Signed-off-by: NFred Isaman <fred.isaman@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: NFred Isaman <fred.isaman@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>