svcrdma: Add common XDR encoders for RDMA and Read segments

Clean up: De-duplicate some code.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Add common XDR decoders for RDMA and Read segments

Clean up: De-duplicate some code.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Use struct xdr_stream to decode ingress transport headers

The logic that checks incoming network headers has to be scrupulous.

De-duplicate: replace open-coded buffer overflow checks with the use
of xdr_stream helpers that are used most everywhere else XDR
decoding is done.

One minor change to the sanity checks: instead of checking the
length of individual segments, cap the length of the whole chunk
to be sure it can fit in the set of pages available in rq_pages.
This should be a better test of whether the server can handle the
chunks in each request.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

xprtrdma: Add proper SPDX tags for NetApp-contributed source

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Update copyright notices

Credit work contributed by Oracle engineers since 2014.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

rpcrdma: Remove C structure definitions of XDR data items

Clean up: C-structure style XDR encoding and decoding logic has
been replaced over the past several merge windows on both the
client and server. These data structures are no longer used.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

svcrdma: Clean up RDMA_ERROR path

Now that svc_rdma_sendto has been renovated, svc_rdma_send_error can
be refactored to reduce code duplication and remove C structure-
based XDR encoding. It is also relocated to the source file that
contains its only caller.

This is a refactoring change only.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

svcrdma: Another sendto chunk list parsing update

Commit 5fdca6531434 ("svcrdma: Renovate sendto chunk list parsing")
missed a spot. svc_rdma_xdr_get_reply_hdr_len() also assumes the
Write list has only one Write chunk. There's no harm in making this
code more general.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

rpcrdma: RDMA/CM private message data structure

Introduce data structure used by both client and server to exchange
implementation details during RDMA/CM connection establishment.

This is an experimental out-of-band exchange between Linux
RPC-over-RDMA Version One implementations, replacing the deprecated
CCP (see RFC 5666bis). The purpose of this extension is to enable
prototyping of features that might be introduced in a subsequent
version of RPC-over-RDMA.

Suggested by Christoph Hellwig and Devesh Sharma.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

xprtrdma: Client-side support for rpcrdma_connect_private

Send an RDMA-CM private message on connect, and look for one during
a connection-established event.

Both sides can communicate their various implementation limits.
Implementations that don't support this sideband protocol ignore it.

Once the client knows the server's inline threshold maxima, it can
adjust the use of Reply chunks, and eliminate most use of Position
Zero Read chunks. Moderately-sized I/O can be done using a pure
inline RDMA Send instead of RDMA operations that require memory
registration.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

rpcrdma: RDMA/CM private message data structure

Introduce data structure used by both client and server to exchange
implementation details during RDMA/CM connection establishment.

This is an experimental out-of-band exchange between Linux
RPC-over-RDMA Version One implementations, replacing the deprecated
CCP (see RFC 5666bis). The purpose of this extension is to enable
prototyping of features that might be introduced in a subsequent
version of RPC-over-RDMA.

Suggested by Christoph Hellwig and Devesh Sharma.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Properly handle RDMA_ERROR replies

These are shorter than RPCRDMA_HDRLEN_MIN, and they need to
complete the waiting RPC.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

rpcrdma: Add RPCRDMA_HDRLEN_ERR

Error headers are shorter than either RDMA_MSG or RDMA_NOMSG.

Since HDRLEN_MIN is already used in several other places that would
be annoying to change, add RPCRDMA_HDRLEN_ERR for the one or two
spots where the shorter length is needed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

rpcrdma: Add RPCRDMA_HDRLEN_ERR

Error headers are shorter than either RDMA_MSG or RDMA_NOMSG.

Since HDRLEN_MIN is already used in several other places that would
be annoying to change, add RPCRDMA_HDRLEN_ERR for the one or two
spots where the shorter length is needed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

xprtrdma: Clean up hdrlen

Clean up: Replace naked integers with a documenting macro.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Modernize htonl and ntohl

Clean up: Replace htonl and ntohl with the be32 equivalents.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

sunrpc: Clean never used include files

Remove include of two headers never used by this file.
Doing so exposed a missing #include <linux/types.h> in
include/linux/sunrpc/rpc_rdma.h.

I did not see any other users dependency but if exist they
should be fixed since these headers are totally irrelevant
to here.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

SUNRPC endianness annotations

rpcrdma stuff lacks endianness annotations for on-the-wire data.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

RPCRDMA: Kconfig and header file with rpcrdma protocol definitions

This file implements the configuration target, protocol template and
constants for the rpcrdma transport framing, for use by the xprtrdma
rpc transport implementation.

Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>