Instead of open coding a __dynamic_array(), use the __string() and
__assign_str() helper macros that exist for this kind of use case.

Part of an effort to remove deprecated strlcpy() [1] completely from the
kernel[2].

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Fixes: 3c92fba5 ("NFSD: Enhance the nfsd_cb_setup tracepoint")
Signed-off-by: NAzeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

The trace event recorded incorrect values for the registered family,
protocol, and port because the arguments are in the wrong order.

Fixes: b4af5932 ("SUNRPC: Trace server-side rpcbind registration events")
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Since the ->xprt_ctxt pointer was added to svc_deferred_req, it has not
been sufficient to use kfree() to free a deferred request.  We may need
to free the ctxt as well.

As freeing the ctxt is all that ->xpo_release_rqst() does, we repurpose
it to explicit do that even when the ctxt is not stored in an rqst.
So we now have ->xpo_release_ctxt() which is given an xprt and a ctxt,
which may have been taken either from an rqst or from a dreq.  The
caller is now responsible for clearing that pointer after the call to
->xpo_release_ctxt.

We also clear dr->xprt_ctxt when the ctxt is moved into a new rqst when
revisiting a deferred request.  This ensures there is only one pointer
to the ctxt, so the risk of double freeing in future is reduced.  The
new code in svc_xprt_release which releases both the ctxt and any
rq_deferred depends on this.

Fixes: 773f91b2 ("SUNRPC: Fix NFSD's request deferral on RDMA transports")
Signed-off-by: NNeilBrown <neilb@suse.de>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

When an RPC request is deferred, the rq_xprt_ctxt pointer is moved out
of the svc_rqst into the svc_deferred_req.
When the deferred request is revisited, the pointer is copied into
the new svc_rqst - and also remains in the svc_deferred_req.

In the (rare?) case that the request is deferred a second time, the old
svc_deferred_req is reused - it still has all the correct content.
However in that case the rq_xprt_ctxt pointer is NOT cleared so that
when xpo_release_xprt is called, the ctxt is freed (UDP) or possible
added to a free list (RDMA).
When the deferred request is revisited for a second time, it will
reference this ctxt which may be invalid, and the free the object a
second time which is likely to oops.

So change svc_defer() to *always* clear rq_xprt_ctxt, and assert that
the value is now stored in the svc_deferred_req.

Fixes: 773f91b2 ("SUNRPC: Fix NFSD's request deferral on RDMA transports")
Signed-off-by: NNeilBrown <neilb@suse.de>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Dan points out that sock_alloc_file() releases @sock on error, but
so do all of svc_setup_socket's callers, resulting in a double-
release if sock_alloc_file() returns an error.

Rather than allocating a struct file for all new sockets, allocate
one only for sockets created during a TCP accept. For the moment,
those are the only ones that will ever be used with RPC-with-TLS.
Reported-by: NDan Carpenter <dan.carpenter@linaro.org>
Fixes: ae0d7770 ("SUNRPC: Ensure server-side sockets have a sock->file")
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Jiri Slaby says:
> I bisected to this ... as it breaks nfs3-only servers in 6.3.
> I.e. /etc/nfs.conf containing:
> [nfsd]
> vers4=no
>
> The client sees:
>  mount("10.0.2.15:/tmp", "/mnt", "nfs", 0, "vers=4.2,addr=10.0.2.15,clientad"...) = -1 EIO (Input/output error)
>  write(2, "mount.nfs: mount system call fai"..., 45
>  mount.nfs: mount system call failed for /mnt
>
> And the kernel says:
>  nfs4_discover_server_trunking unhandled error -5. Exiting with error EIO
Reported-by: NJiri Slaby <jirislaby@kernel.org>
Link: https://bugzilla.suse.com/show_bug.cgi?id=1210995
Fixes: 4bcf0343 ("SUNRPC: Set rq_accept_statp inside ->accept methods")
Tested-by: NJiri Slaby <jirislaby@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

gcc with W=1 and ! CONFIG_SYSCTL
fs/lockd/svc.c:80:51: error: ‘nlm_port_max’ defined but not used [-Werror=unused-const-variable=]
   80 | static const int                nlm_port_min = 0, nlm_port_max = 65535;
      |                                                   ^~~~~~~~~~~~
fs/lockd/svc.c:80:33: error: ‘nlm_port_min’ defined but not used [-Werror=unused-const-variable=]
   80 | static const int                nlm_port_min = 0, nlm_port_max = 65535;
      |                                 ^~~~~~~~~~~~

The only use of these variables is when CONFIG_SYSCTL
is defined, so their definition should be likewise conditional.
Signed-off-by: NTom Rix <trix@redhat.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

gcc with W=1 and ! CONFIG_PROC_FS
fs/nfsd/nfsctl.c:161:30: error: ‘exports_proc_ops’
  defined but not used [-Werror=unused-const-variable=]
  161 | static const struct proc_ops exports_proc_ops = {
      |                              ^~~~~~~~~~~~~~~~

The only use of exports_proc_ops is when CONFIG_PROC_FS
is defined, so its definition should be likewise conditional.
Signed-off-by: NTom Rix <trix@redhat.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Scott reports SUNRPC self-test failures regarding the output IV on arm64
when using the SIMD accelerated implementation of AES in CBC mode with
ciphertext stealing ("cts(cbc(aes))" in crypto API speak).

These failures are the result of the fact that, while RFC 3962 does
specify what the output IV should be and includes test vectors for it,
the general concept of an output IV is poorly defined, and generally,
not specified by the various algorithms implemented by the crypto API.
Only algorithms that support transparent chaining (e.g., CBC mode on a
block boundary) have requirements on the output IV, but ciphertext
stealing (CTS) is fundamentally about how to encapsulate CBC in a way
where the length of the entire message may not be an integral multiple
of the cipher block size, and the concept of an output IV does not exist
here because it has no defined purpose past the end of the message.

The generic CTS template takes advantage of this chaining capability of
the CBC implementations, and as a result, happens to return an output
IV, simply because it passes its IV buffer directly to the encapsulated
CBC implementation, which operates on full blocks only, and always
returns an IV. This output IV happens to match how RFC 3962 defines it,
even though the CTS template itself does not contain any output IV logic
whatsoever, and, for this reason, lacks any test vectors that exercise
this accidental output IV generation.

The arm64 SIMD implementation of cts(cbc(aes)) does not use the generic
CTS template at all, but instead, implements the CBC mode and ciphertext
stealing directly, and therefore does not encapsule a CBC implementation
that returns an output IV in the same way. The arm64 SIMD implementation
complies with the specification and passes all internal tests, but when
invoked by the SUNRPC code, fails to produce the expected output IV and
causes its selftests to fail.

Given that the output IV is defined as the penultimate block (where the
final block may smaller than the block size), we can quite easily derive
it in the caller by copying the appropriate slice of ciphertext after
encryption.

Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Jeff Layton <jlayton@kernel.org>
Reported-by: NScott Mayhew <smayhew@redhat.com>
Tested-by: NScott Mayhew <smayhew@redhat.com>
Signed-off-by: NArd Biesheuvel <ardb@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Enable administrators to require clients to use transport layer
security when accessing particular exports.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

This patch adds opportunitistic RPC-with-TLS to the Linux in-kernel
NFS server. If the client requests RPC-with-TLS and the user space
handshake agent is running, the server will set up a TLS session.

There are no policy settings yet. For example, the server cannot
yet require the use of RPC-with-TLS to access its data.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Tetsuo Handa points out:
> Since GFP_KERNEL is "GFP_NOFS | __GFP_FS", usage like
> "GFP_KERNEL | GFP_NOFS" does not make sense.

The original intent was to hold the inode lock while estimating
the buffer requirements for the requested information. Frank van
der Linden, the author of NFSD's xattr code, says:

> ... you need inode_lock to get an atomic view of an xattr. Since
> both nfsd_getxattr and nfsd_listxattr to the standard trick of
> querying the xattr length with a NULL buf argument (just getting
> the length back), allocating the right buffer size, and then
> querying again, they need to hold the inode lock to avoid having
> the xattr changed from under them while doing that.
>
> From that then flows the requirement that GFP_FS could cause
> problems while holding i_rwsem, so I added GFP_NOFS.

However, Dave Chinner states:
> You can do GFP_KERNEL allocations holding the i_rwsem just fine.
> All that it requires is the caller holds a reference to the
> inode ...

Since these code paths acquire a dentry, they do indeed hold a
reference. It is therefore safe to use GFP_KERNEL for these memory
allocations. In particular, that's what this code is already doing;
but now the C source code looks sane too.

At a later time we can revisit in order to remove the inode lock in
favor of simply retrying if the estimated buffer size is too small.
Reported-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

The following request sequence to the same file causes the NFS client and
server getting into an infinite loop with COMMIT and NFS4ERR_DELAY:

OPEN
REMOVE
WRITE
COMMIT

Problem reported by recall11, recall12, recall14, recall20, recall22,
recall40, recall42, recall48, recall50 of nfstest suite.

This patch restores the handling of race condition in nfsd_file_do_acquire
with unlink to that prior of the regression.

Fixes: ac3a2585 ("nfsd: rework refcounting in filecache")
Signed-off-by: NDai Ngo <dai.ngo@oracle.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

This is an eye-catcher for tracepoints that record the XID: it means
svc_rqst() has not received a full RPC Call with an XID yet.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

To support kTLS, the server-side TCP socket receive path needs to
watch for CMSGs.
Acked-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

A single RPC transaction that touches only a couple of pages means
rq_pvec will not be even close to full in svc_xpt_release(). This is
a common case.

Instead, just leave the pages in rq_pvec until it is completely
full. This improves the efficiency of the batch release mechanism
on workloads that involve small RPC messages.

The rq_pvec is also fully emptied just before thread exit.
Reviewed-by: NCalum Mackay <calum.mackay@oracle.com>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Instead of invoking put_page() one-at-a-time, pass the "response"
portion of rq_pages directly to release_pages() to reduce the number
of times each nfsd thread invokes a page allocator API.

Since svc_xprt_release() is not invoked while a client is waiting
for an RPC Reply, this is not expected to directly impact mean
request latencies on a lightly or moderately loaded server. However
as workload intensity increases, I expect somewhat better
scalability: the same number of server threads should be able to
handle more work.
Reviewed-by: NCalum Mackay <calum.mackay@oracle.com>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Clean-up: There doesn't seem to be a reason why this function is
stuck in a header. One thing it prevents is the convenient addition
of tracing. Moving it to a source file also makes the rq_respages
clean-up logic easier to find.
Reviewed-by: NCalum Mackay <calum.mackay@oracle.com>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

When queueing a dispose list to the appropriate "freeme" lists, it
pointlessly queues the objects one at a time to an intermediate list.

Remove a few helpers and just open code a list_move to make it more
clear and efficient. Better document the resulting functions with
kerneldoc comments.
Signed-off-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Clean up: All callers of svc_process() ignore its return value, so
svc_process() can safely be converted to return void. Ditto for
svc_send().

The return value of ->xpo_sendto() is now used only as part of a
trace event.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

The TLS handshake upcall mechanism requires a non-NULL sock->file on
the socket it hands to user space. svc_sock_free() already releases
sock->file properly if one exists.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

There have been several bugs over the years where the NFSD splice
actor has attempted to write outside the rq_pages array.

This is a "should never happen" condition, but if for some reason
the pipe splice actor should attempt to walk past the end of
rq_pages, it needs to terminate the READ operation to prevent
corruption of the pointer addresses in the fields just beyond the
array.

A server crash is thus prevented. Since the code is not behaving,
the READ operation returns -EIO to the client. None of the READ
payload data can be trusted if the splice actor isn't operating as
expected.
Suggested-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>

There is no need to declare two tables to just create directories,
this can be easily be done with a prefix path with register_sysctl().

Simplify this registration.
Signed-off-by: NLuis Chamberlain <mcgrof@kernel.org>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

The get_expiry() function currently returns a timestamp, and uses the
special return value of 0 to indicate an error.

Unfortunately this causes a problem when 0 is the correct return value.

On a system with no RTC it is possible that the boot time will be seen
to be "3".  When exportfs probes to see if a particular filesystem
supports NFS export it tries to cache information with an expiry time of
"3".  The intention is for this to be "long in the past".  Even with no
RTC it will not be far in the future (at most a second or two) so this
is harmless.
But if the boot time happens to have been calculated to be "3", then
get_expiry will fail incorrectly as it converts the number to "seconds
since bootime" - 0.

To avoid this problem we change get_expiry() to report the error quite
separately from the expiry time.  The error is now the return value.
The expiry time is reported through a by-reference parameter.
Reported-by: NJerry Zhang <jerry@skydio.com>
Tested-by: NJerry Zhang <jerry@skydio.com>
Signed-off-by: NNeilBrown <neilb@suse.de>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Signed-off-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

lockd needs to be able to hash filehandles for tracepoints. Move the
nfs_fhandle_hash() helper to a common nfs include file.
Signed-off-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Currently lockd just dequeues the block and ignores it if the client
sends a GRANT_RES with a status of nlm_lck_denied. That status is an
indicator that the client has rejected the lock, so the right thing to
do is to unlock the lock we were trying to grant.
Reported-by: NYongcheng Yang <yoyang@redhat.com>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2063818Signed-off-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

After the wait for a grant is done (for whatever reason), nlmclnt_block
updates the status of the nlm_rqst with the status of the block. At the
point it does this, however, the block is still queued its status could
change at any time.

This is particularly a problem when the waiting task is signaled during
the wait. We can end up giving up on the lock just before the GRANTED_MSG
callback comes in, and accept it even though the lock request gets back
an error, leaving a dangling lock on the server.

Since the nlm_wait never lives beyond the end of nlmclnt_lock, put it on
the stack and add functions to allow us to enqueue and dequeue the
block. Enqueue it just before the lock/wait loop, and dequeue it
just after we exit the loop instead of waiting until the end of
the function. Also, scrape the status at the time that we dequeue it to
ensure that it's final.
Reported-by: NYongcheng Yang <yoyang@redhat.com>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2063818Signed-off-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

The next patch needs struct nlm_wait in fs/lockd/clntproc.c, so move
the definition to a shared header file. As an added clean-up, drop
the unused b_reclaim field.
Signed-off-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Signed-off-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

It's easily possible for the server to have an outstanding lock when we
go to shut down. When that happens, we often get a warning like this in
the kernel log:

    lockd: couldn't shutdown host module for net f0000000!

This is because the shutdown procedures skip removing any hosts that
still have outstanding resources (locks). Eventually, things seem to get
cleaned up anyway, but the log message is unsettling, and server
shutdown doesn't seem to be working the way it was intended.

Ensure that we tear down any resources held on behalf of a client when
tearing one down for server shutdown.
Reported-by: NYongcheng Yang <yoyang@redhat.com>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2063818Signed-off-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

While we were converting the nfs4_file hashtable to use the kernel's
resizable hashtable data structure, Neil Brown observed that the
list variant (rhltable) would be better for managing nfsd_file items
as well. The nfsd_file hash table will contain multiple entries for
the same inode -- these should be kept together on a list. And, it
could be possible for exotic or malicious client behavior to cause
the hash table to resize itself on every insertion.

A nice simplification is that rhltable_lookup() can return a list
that contains only nfsd_file items that match a given inode, which
enables us to eliminate specialized hash table helper functions and
use the default functions provided by the rhashtable implementation).

Since we are now storing nfsd_file items for the same inode on a
single list, that effectively reduces the number of hash entries
that have to be tracked in the hash table. The mininum bucket count
is therefore lowered.

Light testing with fstests generic/531 show no regressions.
Suggested-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

On most filesystems, there is no reason to delay reaping an nfsd_file
just because its underlying inode is still under writeback. nfsd just
relies on client activity or the local flusher threads to do writeback.

The main exception is NFS, which flushes all of its dirty data on last
close. Add a new EXPORT_OP_FLUSH_ON_CLOSE flag to allow filesystems to
signal that they do this, and only skip closing files under writeback on
such filesystems.

Also, remove a redundant NULL file pointer check in
nfsd_file_check_writeback, and clean up nfs's export op flag
definitions.
Signed-off-by: NJeff Layton <jlayton@kernel.org>
Acked-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Signed-off-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

The last thing that filp_close does is an fput, so don't bother taking
and putting the extra reference.
Signed-off-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

David Howells mentioned that he found this bit of code confusing, so
sprinkle in some comments to clarify.
Reported-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

An error from break_lease is non-fatal, so we needn't destroy the
nfsd_file in that case. Just put the reference like we normally would
and return the error.
Signed-off-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

test_bit returns bool, so we can just compare the result of that to the
key->gc value without the "!!".
Signed-off-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Since v4 files are expected to be long-lived, there's little value in
closing them out of the cache when there is conflicting access.

Change the comparator to also match the gc value in the key. Change both
of the current users of that key to set the gc value in the key to
"true".
Signed-off-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Signed-off-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>