draft-ietf-nfsv4-nfs-ulb-v2-02.txt   draft-ietf-nfsv4-nfs-ulb-v2-03.txt 
Network File System Version 4 C. Lever Network File System Version 4 C. Lever
Internet-Draft Oracle Internet-Draft Oracle
Intended status: Standards Track 4 July 2020 Intended status: Standards Track 6 October 2020
Expires: 5 January 2021 Expires: 9 April 2021
Network File System (NFS) Upper-Layer Binding To RPC-Over-RDMA Version 2 Network File System (NFS) Upper-Layer Binding To RPC-Over-RDMA Version 2
draft-ietf-nfsv4-nfs-ulb-v2-02 draft-ietf-nfsv4-nfs-ulb-v2-03
Abstract Abstract
This document specifies Upper-Layer Bindings of Network File System This document specifies Upper-Layer Bindings of Network File System
(NFS) protocol versions to RPC-over-RDMA version 2. (NFS) protocol versions to RPC-over-RDMA version 2.
Note Note
Discussion of this draft takes place on the NFSv4 working group Discussion of this draft takes place on the NFSv4 working group
mailing list (nfsv4@ietf.org), which is archived at mailing list (nfsv4@ietf.org), which is archived at
skipping to change at page 1, line 45 skipping to change at page 1, line 45
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on 5 January 2021. This Internet-Draft will expire on 9 April 2021.
Copyright Notice Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Please review these documents carefully, as they describe your rights Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components and restrictions with respect to this document. Code Components
extracted from this document must include Simplified BSD License text extracted from this document must include Simplified BSD License text
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3
3. Reply Size Estimation . . . . . . . . . . . . . . . . . . . . 4 3. Upper-Layer Binding for NFS Versions 2 and 3 . . . . . . . . 4
4. Upper-Layer Binding for NFS Versions 2 and 3 . . . . . . . . 4 3.1. Reply Size Estimation . . . . . . . . . . . . . . . . . . 4
4.1. Reply Size Estimation . . . . . . . . . . . . . . . . . . 4 3.2. RPC Binding Considerations . . . . . . . . . . . . . . . 5
4.2. RPC Binding Considerations . . . . . . . . . . . . . . . 5 3.3. Transport Considerations . . . . . . . . . . . . . . . . 5
4.3. Transport Considerations . . . . . . . . . . . . . . . . 5 4. Upper-Layer Bindings for NFS Version 2 and 3 Auxiliary
5. Upper-Layer Bindings for NFS Version 2 and 3 Auxiliary
Protocols . . . . . . . . . . . . . . . . . . . . . . . . 6 Protocols . . . . . . . . . . . . . . . . . . . . . . . . 6
5.1. MOUNT, NLM, and NSM Protocols . . . . . . . . . . . . . . 6 4.1. MOUNT, NLM, and NSM Protocols . . . . . . . . . . . . . . 7
5.2. NFSACL Protocol . . . . . . . . . . . . . . . . . . . . . 7 4.2. NFSACL Protocol . . . . . . . . . . . . . . . . . . . . . 7
6. Upper-Layer Binding For NFS Version 4 . . . . . . . . . . . . 7 5. Upper-Layer Binding For NFS Version 4 . . . . . . . . . . . . 7
6.1. DDP-Eligibility . . . . . . . . . . . . . . . . . . . . . 7 5.1. DDP-Eligibility . . . . . . . . . . . . . . . . . . . . . 7
6.2. Reply Size Estimation . . . . . . . . . . . . . . . . . . 8 5.2. Reply Size Estimation . . . . . . . . . . . . . . . . . . 9
6.3. RPC Binding Considerations . . . . . . . . . . . . . . . 9 5.3. RPC Binding Considerations . . . . . . . . . . . . . . . 10
6.4. NFS COMPOUND Requests . . . . . . . . . . . . . . . . . . 9 5.4. NFS COMPOUND Requests . . . . . . . . . . . . . . . . . . 10
6.5. NFS Callback Requests . . . . . . . . . . . . . . . . . . 12 5.5. NFS Callback Requests . . . . . . . . . . . . . . . . . . 12
6.6. Session-Related Considerations . . . . . . . . . . . . . 13 5.6. Session-Related Considerations . . . . . . . . . . . . . 13
6.7. Transport Considerations . . . . . . . . . . . . . . . . 14 5.7. Transport Considerations . . . . . . . . . . . . . . . . 14
7. Extending NFS Upper-Layer Bindings . . . . . . . . . . . . . 15 6. Extending NFS Upper-Layer Bindings . . . . . . . . . . . . . 15
8. Security Considerations . . . . . . . . . . . . . . . . . . . 16 7. Security Considerations . . . . . . . . . . . . . . . . . . . 16
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 16 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
10.1. Normative References . . . . . . . . . . . . . . . . . . 16 9.1. Normative References . . . . . . . . . . . . . . . . . . 16
10.2. Informative References . . . . . . . . . . . . . . . . . 17 9.2. Informative References . . . . . . . . . . . . . . . . . 17
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 18 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 18
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 18 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 18
1. Introduction 1. Introduction
The RPC-over-RDMA version 2 transport may employ direct data The RPC-over-RDMA version 2 transport may employ direct data
placement to convey data payloads associated with RPC transactions placement to convey data payloads associated with RPC transactions,
[I-D.ietf-nfsv4-rpcrdma-version-two]. RPC client and server as described in [I-D.ietf-nfsv4-rpcrdma-version-two]. RPC client and
implementations using RPC-over-RDMA version 2 must agree which XDR server implementations using RPC-over-RDMA version 2 must agree which
data items and RPC procedures are eligible to use direct data XDR data items and RPC procedures are eligible to use direct data
placement (DDP) to ensure successful interoperation. placement (DDP) to ensure successful interoperation.
An Upper-Layer Binding specifies this agreement for one or more An Upper-Layer Binding specifies this agreement for one or more
versions of one RPC program. Other operational details, such as RPC versions of one RPC program. Other operational details, such as RPC
binding assignments, pairing Write chunks with result data items, and binding assignments, pairing Write chunks with result data items, and
reply size estimation, are also specified by this Binding. reply size estimation, are also specified by such a Binding.
This document contains material required of Upper-Layer Bindings, as This document contains material required of Upper-Layer Bindings, as
specified in [I-D.ietf-nfsv4-rpcrdma-version-two], for the following specified in Appendix A of [I-D.ietf-nfsv4-rpcrdma-version-two], for
NFS protocol versions: the following NFS protocol versions:
* NFS version 2 [RFC1094] * NFS version 2 [RFC1094]
* NFS version 3 [RFC1813] * NFS version 3 [RFC1813]
* NFS version 4.0 [RFC7530] * NFS version 4.0 [RFC7530]
* NFS version 4.1 [RFC5661] * NFS version 4.1 [RFC8881]
* NFS version 4.2 [RFC7862] * NFS version 4.2 [RFC7862]
The current document also provides Upper-Layer Bindings for auxiliary The current document also provides Upper-Layer Bindings for auxiliary
protocols used with NFS versions 2 and 3 (see Section 5). protocols used with NFS versions 2 and 3 (see Section 4).
This document assumes the reader is already familiar with concepts This document assumes the reader is already familiar with concepts
and terminology defined in [I-D.ietf-nfsv4-rpcrdma-version-two] and and terminology defined throughout
the documents it references. [I-D.ietf-nfsv4-rpcrdma-version-two] and the documents it references.
2. Requirements Language 2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in "OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
3. Reply Size Estimation 3. Upper-Layer Binding for NFS Versions 2 and 3
During the construction of each RPC Call message, a Requester is
responsible for allocating appropriate resources for receiving the
corresponding Reply message. If the Requester expects that the RPC
Reply message could be larger than its inline threshold, it MAY
provide Write chunks wherein the Responder can place results and
Reply chunks wherein the Responder can place the reply's Payload
stream. A message continuation facility is also available in RPC-
over-RDMA version 2 to convey RPC messages that are larger than the
transport's inline threshold.
4. Upper-Layer Binding for NFS Versions 2 and 3
The Upper-Layer Binding specification in this section applies to NFS The Upper-Layer Binding specification in this section applies to NFS
version 2 [RFC1094] and NFS version 3 [RFC1813]. For brevity, in version 2 [RFC1094] and NFS version 3 [RFC1813]. For brevity, in
this document, a "Legacy NFS client" refers to an NFS client using this document, a "Legacy NFS client" refers to an NFS client using
version 2 or version 3 of the NFS RPC program (100003) to communicate version 2 or version 3 of the NFS RPC program (100003) to communicate
with an NFS server. Likewise, a "Legacy NFS server" is an NFS server with an NFS server. Likewise, a "Legacy NFS server" is an NFS server
communicating with clients using NFS version 2 or NFS version 3. communicating with clients using NFS version 2 or NFS version 3.
The following XDR data items in NFS versions 2 and 3 are DDP- The following XDR data items in NFS versions 2 and 3 are DDP-
eligible: eligible:
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* The pathname result in the NFS READLINK procedure * The pathname result in the NFS READLINK procedure
All other argument or result data items in NFS versions 2 and 3 are All other argument or result data items in NFS versions 2 and 3 are
not DDP-eligible. not DDP-eligible.
Whether or not an NFS operation is considered non-idempotent, a Whether or not an NFS operation is considered non-idempotent, a
transport error might not indicate whether the server has processed transport error might not indicate whether the server has processed
the arguments of the RPC Call, or whether the server has accessed or the arguments of the RPC Call, or whether the server has accessed or
modified client memory associated with that RPC. modified client memory associated with that RPC.
4.1. Reply Size Estimation 3.1. Reply Size Estimation
A Legacy NFS client determines the maximum reply size for each During the construction of each RPC Call message, a Requester is
operation using the criteria outlined in Section 3. responsible for allocating appropriate transport resources to receive
the corresponding Reply message. These resources must be capable of
holding the entire Reply, therefore the Requester needs to estimate
the maximum possible size of the expected Reply message.
4.2. RPC Binding Considerations * In many cases, the expected Reply can fit in one or a few RDMA
Send messages. The Requester need not provision any RDMA
resources, relying instead on message continuation to handle the
entire Reply message.
* In cases where the Requester deems direct data placement to be the
most efficient transfer mechanism, it provisions Write chunks
wherein the Responder can place results. In these cases, the
Requester must reliably estimate the maximum size of each result
that is to be placed in a Write chunk.
* When the Requester expects an especially large Reply message, it
can provision a combination of a Reply chunk and Write chunks for
result data items. In such cases, the Requester must reliably
estimate the maximum size of each result that is to be placed in a
Write chunk and the maximum size of the remainder to be placed in
the Reply chunk.
A legacy NFS client needs to make every effort to avoid
retransmission of non-idempotent NFS requests due to underestimated
Reply resources. Thanks to the mechanism of message continuation in
RPC-over-RDMA version 2, the need for such retransmission is greatly
reduced.
3.2. RPC Binding Considerations
Legacy NFS servers traditionally listen for clients on UDP and TCP Legacy NFS servers traditionally listen for clients on UDP and TCP
port 2049. Additionally, they register these ports with a local port 2049. Additionally, they register these ports with a local
portmapper service [RFC1833]. portmapper service [RFC1833].
A Legacy NFS server supporting RPC-over-RDMA version 2 and A Legacy NFS server supporting RPC-over-RDMA version 2 and
registering itself with the RPC portmapper MAY choose an arbitrary registering itself with the RPC portmapper MAY choose an arbitrary
port, or MAY use the alternative well-known port number for its RPC- port, or MAY use the alternative well-known port number for its RPC-
over-RDMA service (see Section 9). The chosen port MAY be registered over-RDMA service (see Section 8). The chosen port MAY be registered
with the RPC portmapper using the netids assigned in with the RPC portmapper using the netids assigned in Section 12 of
[I-D.ietf-nfsv4-rpcrdma-version-two]. [I-D.ietf-nfsv4-rpcrdma-version-two].
4.3. Transport Considerations 3.3. Transport Considerations
Legacy NFS client implementations often rely on a transport-layer Legacy NFS client implementations often rely on a transport-layer
keep-alive mechanism to detect when a legacy server has become keep-alive mechanism to detect when a legacy server has become
unresponsive. When an NFS server is no longer responsive, client- unresponsive. When an NFS server is no longer responsive, client-
side keep-alive terminates the connection, which in turn triggers side keep-alive terminates the connection, which in turn triggers
reconnection and retransmission of outstanding RPC transactions. reconnection and retransmission of outstanding RPC transactions.
4.3.1. Keep-Alive 3.3.1. Keep-Alive
Some RDMA transports (such as the Reliable Connected QP type on Some RDMA transports (such as the Reliable Connected QP type on
InfiniBand) have no keep-alive mechanism. Without a disconnect or InfiniBand) have no keep-alive mechanism. Without a disconnect or
new RPC traffic, such connections can remain alive long after an NFS new RPC traffic, such connections can remain alive long after an NFS
server has become unresponsive or unreachable. Once an NFS client server has become unresponsive or unreachable. Once an NFS client
has consumed all available RPC-over-RDMA version 2 credits on that has consumed all available RPC-over-RDMA version 2 credits on that
transport connection, it awaits a reply indefinitely before sending transport connection, it awaits a reply indefinitely before sending
another RPC request. another RPC request.
Legacy NFS clients SHOULD reserve one RPC-over-RDMA version 2 credit Legacy NFS clients SHOULD reserve one RPC-over-RDMA version 2 credit
to use for periodic server or connection health assessment. Either to use for periodic server or connection health assessment. Either
peer can use this credit to drive an RPC request on an otherwise idle peer can use this credit to drive an RPC request on an otherwise idle
connection, triggering either an affirmative server response or a connection, triggering either an affirmative server response or a
connection termination. connection termination.
4.3.2. Replay Detection 3.3.2. Replay Detection
Legacy NFS servers typically employ request replay detection to Legacy NFS servers typically employ request replay detection to
reduce the risk of data corruption that could result when an NFS reduce the risk of data and file namespace corruption that could
client retransmits a non-idempotent NFS request. A legacy NFS server result when an NFS client retransmits a non-idempotent NFS request.
can send a cached response when a replay is detected, rather than A legacy NFS server can send a cached response when a replay is
executing the request again. Replay detection is not perfect, but it detected, rather than executing the request again. Replay detection
is usually adequate. is not perfect, but it is usually adequate.
For legacy NFS servers, replay detection commonly utilizes heuristic For legacy NFS servers, replay detection commonly utilizes heuristic
indicators such as the IP address of the NFS client, the source port indicators such as the IP address of the NFS client, the source port
of the connection, the transaction ID of the request, and the of the connection, the transaction ID of the request, and the
contents of the request's RPC and upper-layer protocol headers. In contents of the request's RPC and upper-layer protocol headers. In
short, replay detection is typically based on a connection tuple and short, replay detection is typically based on a connection tuple and
the request's XID. A legacy NFS client is careful to re-use the same the request's XID. A legacy NFS client is careful to re-use the same
source port, if practical, when reconnecting so that legacy NFS source port, if practical, when reconnecting so that legacy NFS
servers are better able to detect retransmissions. servers are better able to detect retransmissions.
However, a legacy NFS client operating over an RDMA transport has no However, a legacy NFS client operating over an RDMA transport has no
control over connection source ports. It is almost certain that an control over connection source ports. It is almost certain that an
RPC request that is retransmitted on a new connection can never be RPC request that is retransmitted on a new connection can never be
detected as a replay if the legacy NFS server includes the connection detected as a replay if the legacy NFS server includes the connection
source port in its replay detection heuristics. source port in its replay detection heuristics.
Therefore a legacy NFS server using an RDMA transport should never Therefore a legacy NFS server using an RDMA transport should never
use a legacy NFS client connection's source port as part of its NFS use a legacy NFS client connection's source port as part of its NFS
request replay detection mechanism. request replay detection mechanism.
5. Upper-Layer Bindings for NFS Version 2 and 3 Auxiliary Protocols 4. Upper-Layer Bindings for NFS Version 2 and 3 Auxiliary Protocols
Storage administrators typically deploy NFS versions 2 and 3 with Storage administrators typically deploy NFS versions 2 and 3 with
several other protocols, sometimes referred to as "NFS auxiliary several other protocols, sometimes referred to as the "NFS auxiliary
protocols." These are distinct RPC programs that define procedures protocols." These are distinct RPC programs that define procedures
that are not part of the NFS RPC program (100003). The Upper-Layer that are not part of the NFS RPC program (100003). The Upper-Layer
Bindings in this section apply to: Bindings in this section apply to:
* Versions 2 and 3 of the MOUNT RPC program (100005) [RFC1813] * Versions 2 and 3 of the MOUNT RPC program (100005) [RFC1813]
* Versions 1, 3, and 4 of the NLM RPC program (100021) [RFC1813] * Versions 1, 3, and 4 of the NLM RPC program (100021) [RFC1813]
* Version 1 of the NSM RPC program (100024), described in Chapter 11 * Version 1 of the NSM RPC program (100024), described in Chapter 11
of [XNFS] of [XNFS]
* Version 1 of the NFSACL RPC program (100227), which does not have * Versions 2 and 3 of the NFSACL RPC program (100227). The NFSACL
a public definition. NFSACL is treated in this document as a de program does not have a public definition. In this document it is
facto standard, as there are several interoperating treated as a de facto standard, as there are several
implementations. interoperating implementations.
5.1. MOUNT, NLM, and NSM Protocols 4.1. MOUNT, NLM, and NSM Protocols
Historically, NFS/RDMA implementations have chosen to convey the Historically, NFS/RDMA implementations have chosen to convey the
MOUNT, NLM, and NSM protocols via TCP. A legacy NFS server MOUNT, NLM, and NSM protocols via TCP. A legacy NFS server
implementation MUST provide support for these protocols via TCP to implementation MUST provide support for these protocols via TCP to
enable interoperation of these protocols when NFS/RDMA is in use. enable interoperation of these protocols when NFS/RDMA is in use.
5.2. NFSACL Protocol 4.2. NFSACL Protocol
Often legacy clients and servers that support the NFSACL RPC program Often legacy clients and servers that support the NFSACL RPC program
convey NFSACL procedures on the same connection as the NFS RPC convey NFSACL procedures on the same transport connection and port as
program (100003). Utilizing the same connection obviates the need the NFS RPC program (100003). Utilizing the same port obviates the
for separate rpcbind queries to discover server support for this RPC need for separate a rpcbind query to discover server support for this
program. RPC program.
ACLs are typically small, but even large ACLs must be encoded and ACLs are typically small, but even large ACLs must be encoded and
decoded to some degree before being made available to users. Thus no decoded to some degree before being made available to users. Thus no
data item in this Upper-Layer Protocol is DDP-eligible. data item in this Upper-Layer Protocol is DDP-eligible.
For procedures whose replies do not include an ACL object, the size For procedures whose replies do not include an ACL object, the size
of a reply is determined directly from the NFSACL RPC program's XDR of a reply is determined directly from the NFSACL RPC program's XDR
definition. Legacy client implementations should choose a maximum definition. However, legacy client implementations should choose a
size for ACLs based on internal limits. maximum size for ACLs based on internal limits, and can rely on
message continuation to handle the a priori unknown size of large ACL
objects in Replies.
6. Upper-Layer Binding For NFS Version 4 5. Upper-Layer Binding For NFS Version 4
The Upper-Layer Binding specification in this section applies to The Upper-Layer Binding specification in this section applies to
versions of the NFS RPC program defined in NFS version 4.0 [RFC7530] versions of the NFS RPC program defined in NFS version 4.0 [RFC7530]
NFS version 4.1 [RFC5661] and NFS version 4.2 [RFC7862]. NFS version 4.1 [RFC8881] and NFS version 4.2 [RFC7862].
6.1. DDP-Eligibility 5.1. DDP-Eligibility
Only the following XDR data items in the COMPOUND procedure of all Only the following XDR data items in the COMPOUND procedure of all
NFS version 4 minor versions are DDP-eligible: NFS version 4 minor versions are DDP-eligible:
* The opaque data field in the WRITE4args structure * The opaque data field in the WRITE4args structure
* The linkdata field of the NF4LNK arm in the createtype4 union * The linkdata field of the NF4LNK arm in the createtype4 union
* The opaque data field in the READ4resok structure * The opaque data field in the READ4resok structure
* The linkdata field in the READLINK4resok structure * The linkdata field in the READLINK4resok structure
6.1.1. The NFSv4.2 READ_PLUS operation 5.1.1. The NFSv4.2 READ_PLUS operation
NFS version 4.2 introduces an enhanced READ operation called NFS version 4.2 introduces an enhanced READ operation called
READ_PLUS [RFC7862]. READ_PLUS enables an NFS server to perform READ_PLUS [RFC7862]. READ_PLUS enables an NFS server to perform data
inline data reduction of READ results so that the returned READ data reduction of READ results so that the returned READ data is more
is more compact. compact.
In a READ_PLUS result, returned file content appears as a list of one In a READ_PLUS result, returned file content appears as a list of one
or more of the following items: or more of the following items:
* Regular data content: the same as the result of a traditional READ * Regular data content: the same as the result of a traditional READ
operation. operation.
* Unallocated space in a file: where no data has yet been written or * Unallocated space in a file: where no data has yet been written or
previously-written data has been removed via a hole-punch previously-written data has been removed via a hole-punch
operation. operation.
* A counted pattern. * A counted pattern.
Upon receipt of a READ_PLUS result, an NFSv4.2 client expands the Upon receipt of a READ_PLUS result, an NFSv4.2 client expands the
returned list into a preferred local representation of the original returned list into the preferred local representation of the original
file content. file content.
Before receiving that result, an NFSv4.2 client typically does not Before receiving that result, an NFSv4.2 client typically does not
know how the file's content is organized on the NFS server. Thus it know how the file's content is organized on the NFS server. Thus it
is not possible to predict the size or structure of a READ_PLUS Reply is not possible to predict the size or structure of a READ_PLUS Reply
in advance. The use of direct data placement is therefore in advance. The use of direct data placement is therefore
challenging. challenging.
A READ_PLUS content list containing more than one segment of regular A READ_PLUS content list containing more than one segment of regular
file data could be conveyed using multiple Write chunks, but only if file data could be conveyed using multiple Write chunks, but only if
the client knows in advance where those chunks appear in the Reply the client knows in advance where those chunks appear in the Reply
Payload stream. Moreover, the usual benefits of hardware-assisted Payload stream. Moreover, the usual benefits of hardware-assisted
data placement are entirely waived if the client-side transport must data placement are entirely waived if the client-side transport must
parse the result of each read I/O. parse the result of each read I/O.
Therefore this Upper Layer Binding does not make any element of an Therefore this Upper Layer Binding does not make any element of an
NFSv4.2 READ_PLUS Reply DDP-eligible. Further, this Upper Layer NFSv4.2 READ_PLUS Reply DDP-eligible. Further, this Upper Layer
Binding recommends that implementers disable the use of the READ_PLUS Binding recommends that implementations avoid the use of the
operation on NFS/RDMA mount points. READ_PLUS operation on NFS/RDMA mount points.
6.2. Reply Size Estimation 5.2. Reply Size Estimation
Within NFS version 4, there are certain variable-length result data Within NFS version 4, there are certain variable-length result data
items whose maximum size cannot be estimated by clients reliably items whose maximum size cannot be estimated by clients reliably
because there is no protocol-specified size limit on these result because there is no protocol-specified size limit on these result
arrays. These include: arrays. These include:
* The attrlist4 field * The attrlist4 field
* Fields containing ACLs such as fattr4_acl, fattr4_dacl, and * Fields containing ACLs such as fattr4_acl, fattr4_dacl, and
fattr4_sacl fattr4_sacl
* Fields in the fs_locations4 and fs_locations_info4 data structures * Fields in the fs_locations4 and fs_locations_info4 data structures
* Fields which pertain to pNFS layout metadata, such as loc_body, * Fields which pertain to pNFS layout metadata, such as loc_body,
loh_body, da_addr_body, lou_body, lrf_body, fattr_layout_types, loh_body, da_addr_body, lou_body, lrf_body, fattr_layout_types,
and fs_layout_types and fs_layout_types
6.2.1. Reply Size Estimation for Minor Version 0 5.2.1. Reply Size Estimation for Minor Version 0
The NFS version 4.0 protocol itself does not impose any bound on the The NFS version 4.0 protocol itself does not impose any bound on the
size of NFS calls or replies. size of NFS calls or replies.
Some of the data items enumerated in Section 6.2 (in particular, the Some of the data items enumerated in Section 5.2 (in particular, the
items related to ACLs and fs_locations) make it difficult to predict items related to ACLs and fs_locations) make it difficult to predict
the maximum size of NFS version 4.0 replies that interrogate the maximum size of NFS version 4.0 replies that interrogate
variable-length fattr4 attributes. Client implementations might rely variable-length fattr4 attributes. Client implementations might rely
upon internal architectural limits to constrain the reply size, but upon internal architectural limits to constrain the reply size, but
such limits are not always guaranteed to be reliable. such limits are not always guaranteed to be reliable.
When an NFS version 4.0 client expects an especially sizeable fattr4 When an NFS version 4.0 client expects an especially sizeable fattr4
result, it can provide a Reply chunk to enable that server to return result, it can rely on message continuation or provision a Reply
that result via explicit RDMA. An NFS version 4.0 client can use chunk to enable that server to return that result via explicit RDMA.
short Reply chunk retry when an NFS COMPOUND containing a GETATTR
operation encounters a transport error.
6.2.2. Reply Size Estimation for Minor Version 1 and Newer 5.2.2. Reply Size Estimation for Minor Version 1 and Newer
In NFS version 4.1 and newer minor versions, the csa_fore_chan_attrs In NFS version 4.1 and newer minor versions, the csa_fore_chan_attrs
argument of the CREATE_SESSION operation contains a argument of the CREATE_SESSION operation contains a
ca_maxresponsesize field. The value in this field can be taken as ca_maxresponsesize field. The value in this field can be taken as
the absolute maximum size of replies generated by an NFS version 4.1 the absolute maximum size of replies generated by an NFS version 4.1
server. server.
An NFS version 4 client can use this value in cases where it is not An NFS version 4 client can use this value in cases where it is not
possible to estimate a reply size upper bound precisely. In possible to estimate a reply size upper bound precisely. In
practice, objects such as ACLs, named attributes, layout bodies, and practice, objects such as ACLs, named attributes, layout bodies, and
security labels are much smaller than this maximum. security labels are much smaller than this maximum.
6.3. RPC Binding Considerations 5.3. RPC Binding Considerations
NFS version 4 servers are required to listen on TCP port 2049, and NFS version 4 servers are required to listen on TCP port 2049, and
they are not required to register with a rpcbind service [RFC7530]. are not required to register with an rpcbind service [RFC7530].
Therefore, an NFS version 4 server supporting RPC-over-RDMA version 2 Therefore, an NFS version 4 server supporting RPC-over-RDMA version 2
MUST use the alternative well-known port number for its RPC-over-RDMA MUST use the alternative well-known port number for its RPC-over-RDMA
service (see Section 9 Clients SHOULD connect to this well-known port service (see Section 8 Clients SHOULD connect to this well-known port
without consulting the RPC portmapper (as for NFS version 4 on TCP without consulting the RPC portmapper (as for NFS version 4 on TCP
transports). transports).
6.4. NFS COMPOUND Requests 5.4. NFS COMPOUND Requests
6.4.1. Multiple DDP-eligible Data Items
5.4.1. Multiple DDP-eligible Data Items
An NFS version 4 COMPOUND procedure can contain more than one An NFS version 4 COMPOUND procedure can contain more than one
operation that carries a DDP-eligible data item. An NFS version 4 operation that carries a DDP-eligible data item. An NFS version 4
client provides XDR Position values in each Read chunk to client provides XDR Position values in each Read chunk to
disambiguate which chunk is associated with which argument data item. disambiguate which chunk is associated with which argument data item.
However, NFS version 4 server and client implementations must agree However, NFS version 4 server and client implementations must agree
in advance on how to pair Write chunks with returned result data in advance on how to pair Write chunks with returned result data
items. items.
In the following lists, a "READ operation" refers to any NFS version In the following lists, a "READ operation" refers to any NFS version
4 operation that has a DDP-eligible result data item. An NFS version 4 operation that has a DDP-eligible result data item. An NFS version
4 client applies the mechanism specified in Section 4.3.2 of 4 client applies the mechanism specified in Section 4.3.2 of
[I-D.ietf-nfsv4-rpcrdma-version-two] is applied to this class of [I-D.ietf-nfsv4-rpcrdma-version-two] to this class of operations as
operations as follows: follows:
* If an NFS version 4 client wishes all DDP-eligible items in an NFS * If an NFS version 4 client wishes all DDP-eligible items in an NFS
reply to be conveyed inline, it leaves the Write list empty. reply to be conveyed inline, it leaves the Write list empty.
An NFS version 4 server applies that mechanism as follows: An NFS version 4 server acts as follows:
* The first chunk in the Write list MUST be used by the first READ * The first chunk in the Write list MUST be used by the first READ
operation in an NFS version 4 COMPOUND procedure. The next Write operation in an NFS version 4 COMPOUND procedure. The next Write
chunk is used by the next READ operation, and so on. chunk is used by the next READ operation, and so on.
* If an NFS version 4 client has provided a matching non-empty Write * If an NFS version 4 client has provided a matching non-empty Write
chunk, then the corresponding READ operation MUST return its DDP- chunk, then the corresponding READ operation MUST return its DDP-
eligible data item using that chunk. eligible data item using that chunk.
* If an NFS version 4 client has provided an empty matching Write * If an NFS version 4 client has provided an empty matching Write
skipping to change at page 11, line 5 skipping to change at page 11, line 14
* If a READ operation returns a union arm which does not contain a * If a READ operation returns a union arm which does not contain a
DDP-eligible result, and the NFS version 4 client has provided a DDP-eligible result, and the NFS version 4 client has provided a
matching non-empty Write chunk, an NFS version 4 server MUST matching non-empty Write chunk, an NFS version 4 server MUST
return an empty Write chunk in that Write list position. return an empty Write chunk in that Write list position.
* If there are more READ operations than Write chunks, then * If there are more READ operations than Write chunks, then
remaining NFS Read operations in an NFS version 4 COMPOUND that remaining NFS Read operations in an NFS version 4 COMPOUND that
have no matching Write chunk MUST return their results inline. have no matching Write chunk MUST return their results inline.
6.4.2. Chunk List Complexity 5.4.2. Chunk List Complexity
The RPC-over-RDMA version 2 protocol does not place any limit on the By default, the RPC-over-RDMA version 2 protocol places limits on the
number of chunks or segments that may appear in Read or Write lists. number of chunks or segments that may appear in Read or Write lists
However, for various reasons, NFS version 4 server implementations (see Section 5.2 of [I-D.ietf-nfsv4-rpcrdma-version-two]).
often have practical limits on the number of chunks or segments they
can process in a single RPC transaction conveyed via RPC-over-RDMA
version 2.
These implementation limits are especially important when Kerberos These implementation limits are especially important when Kerberos
integrity or privacy is in use [RFC7861]. GSS services increase the integrity or privacy is in use [RFC7861]. GSS services increase the
size of credential material in RPC headers, potentially requiring the size of credential material in RPC headers, potentially requiring the
use of a Long message, which increases the complexity of chunk lists use of a Long message, which increases the complexity of chunk lists
independent of the particular NFS version 4 COMPOUND being conveyed. independent of the particular NFS version 4 COMPOUND being conveyed.
In the absence of explicit knowledge of the server's limits, NFS In the absence of an explicit transport property exchange that alters
version 4 clients SHOULD follow the prescriptions listed below when these limits, NFS version 4 clients SHOULD follow the prescriptions
constructing RPC-over-RDMA version 2 messages. NFS version 4 servers listed below when constructing RPC-over-RDMA version 2 messages. NFS
MUST accept and process all such requests. version 4 servers MUST accept and process all such requests.
* The Read list can contain either a Position-Zero Read chunk, one * The Read list can contain either a Position-Zero Read chunk, one
Read chunk with a non-zero Position, or both. Read chunk with a non-zero Position, or both.
* The Write list can contain no more than one Write chunk. * The Write list can contain no more than one Write chunk.
* Any chunk can contain up to sixteen RDMA segments.
NFS version 4 clients wishing to send more complex chunk lists can NFS version 4 clients wishing to send more complex chunk lists can
provide configuration interfaces to bound the complexity of NFS provide configuration interfaces to bound the complexity of NFS
version 4 COMPOUNDs, limit the number of elements in scatter-gather version 4 COMPOUNDs, limit the number of elements in scatter-gather
operations, and avoid other sources of chunk overruns at the operations, and avoid other sources of chunk overruns at the
receiving peer. receiving peer.
If an NFS version 4 server receives an RPC request via RPC-over-RDMA If an NFS version 4 server receives an RPC request via RPC-over-RDMA
version 2 that it cannot process due to chunk list complexity limits, version 2 that it cannot process due to chunk list complexity limits,
it SHOULD return one of the following responses to the client: it SHOULD return one of the following responses to the client:
skipping to change at page 12, line 7 skipping to change at page 12, line 12
transport header in an RPC Call message. The server responds with transport header in an RPC Call message. The server responds with
an RDMA2_ERROR message with the err field set to ERR_CHUNK. an RDMA2_ERROR message with the err field set to ERR_CHUNK.
* A problem is detected during XDR decoding of the RPC Call message * A problem is detected during XDR decoding of the RPC Call message
while the RPC layer reassembles the call's XDR stream. The server while the RPC layer reassembles the call's XDR stream. The server
responds with an RPC reply with its "reply_stat" field set to responds with an RPC reply with its "reply_stat" field set to
MSG_ACCEPTED and its "accept_stat" field set to GARBAGE_ARGS. MSG_ACCEPTED and its "accept_stat" field set to GARBAGE_ARGS.
After receiving one of these errors, an NFS version 4 client SHOULD After receiving one of these errors, an NFS version 4 client SHOULD
NOT retransmit the failing request, as the result would be the same NOT retransmit the failing request, as the result would be the same
error. It SHOULD immediately terminate the RPC transaction error. It SHOULD terminate the RPC transaction associated with the
associated with the XID in the reply. XID in the reply without further processing, and report an error to
the RPC consumer.
6.4.3. NFS Version 4 COMPOUND Example 5.4.3. NFS Version 4 COMPOUND Example
The following example shows a Write list with three Write chunks, A, The following example shows a Write list with three Write chunks, A,
B, and C. The NFS version 4 server consumes the provided Write B, and C. The NFS version 4 server consumes the provided Write
chunks by writing the results of the designated operations in the chunks by writing the results of the designated operations in the
compound request (READ and READLINK) back to each chunk. compound request (READ and READLINK) back to each chunk.
Write list: Write list:
A --> B --> C A --> B --> C
skipping to change at page 12, line 32 skipping to change at page 12, line 38
PUTFH LOOKUP READ PUTFH LOOKUP READLINK PUTFH LOOKUP READ PUTFH LOOKUP READ PUTFH LOOKUP READLINK PUTFH LOOKUP READ
| | | | | |
v v v v v v
A B C A B C
If the NFS version 4 client does not want to have the READLINK result If the NFS version 4 client does not want to have the READLINK result
returned via RDMA, it provides an empty Write chunk for buffer B to returned via RDMA, it provides an empty Write chunk for buffer B to
indicate that the READLINK result must be returned inline. indicate that the READLINK result must be returned inline.
6.5. NFS Callback Requests 5.5. NFS Callback Requests
The NFS version 4 family of protocols support server-initiated The NFS version 4 family of protocols support server-initiated
callbacks to notify NFS version 4 clients of events such as recalled callbacks to notify NFS version 4 clients of events such as recalled
delegations. delegations.
6.5.1. NFS Version 4.0 Callback 5.5.1. NFS Version 4.0 Callback
NFS version 4.0 implementations typically employ a separate TCP
connection to handle callback operations, even when the forward
channel uses an RPC-over-RDMA version 2 transport.
No operation in the NFS version 4.0 callback RPC program conveys a
data payload of significant size. Therefore, no XDR data items in
this RPC program is DDP-eligible.
A CB_RECALL reply is small and fixed in size. The CB_GETATTR reply An NFS version 4.0 client uses the SETCLIENTID operation to advertise
contains a variable-length fattr4 data item. See Section 6.2.1 for a the IP address, port, and netid of its NFS version 4.0 callback
discussion of reply size prediction for this data item. service. When an NFS version 4.0 server provides a backchannel
service to an NFS version 4.0 client that uses RPC-over-RDMA version
2 for its forward channel, the server MUST advertise the backchannel
service using either the "tcp" or "tcp6" netid.
An NFS version 4.0 client advertises netids and ad hoc port addresses Because the backchannel does not operate on RPC-over-RDMA, no XDR
for contacting its NFS version 4.0 callback service using the data item in the NFS version 4.0 callback RPC program is DDP-
SETCLIENTID operation. eligible.
6.5.2. NFS Version 4.1 Callback 5.5.2. NFS Version 4.1 Callback
In NFS version 4.1 and newer minor versions, callback operations may In NFS version 4.1 and newer minor versions, callback operations may
appear on the same connection as is used for NFS version 4 forward appear on the same connection that is in use for NFS version 4
channel client requests. NFS version 4 clients and servers MUST use forward channel client requests. NFS version 4 clients and servers
the approach described in [RFC8167] to convey backchannel operations MUST use the mechanisms described in Section 4.5 of
[I-D.ietf-nfsv4-rpcrdma-version-two] to convey backchannel operations
on an RPC-over-RDMA version 2 transport. on an RPC-over-RDMA version 2 transport.
The csa_back_chan_attrs argument of the CREATE_SESSION operation The csa_back_chan_attrs argument of the CREATE_SESSION operation
contains a ca_maxresponsesize field. The value in this field is the contains a ca_maxresponsesize field. The value in this field is the
absolute maximum size of backchannel replies generated by a replying absolute maximum size of backchannel replies generated by a replying
NFS version 4 client. NFS version 4 client.
There are no DDP-eligible data items in callback procedures defined There are no DDP-eligible data items in callback procedures defined
in NFS version 4.1 or NFS version 4.2. However, some callback in NFS version 4.1 or NFS version 4.2. However, some callback
operations, such as messages that convey device ID information, can operations, such as messages that convey device ID information, can
be sizeable. A sender can use Message Continuation or a Long message be sizeable. A sender can use Message Continuation or a Long message
in this situation. in this situation.
When an NFS version 4.1 client can support Long Calls in its When an NFS version 4.1 client can support Long Calls in its
backchannel, it reports a backchannel ca_maxrequestsize that is backchannel, it reports a backchannel ca_maxrequestsize that is
larger than the connection's inline thresholds. Otherwise, an NFS larger than the connection's inline thresholds. Otherwise, an NFS
version 4 server MUST use only Short messages to convey backchannel version 4 server MUST use only Short messages to convey backchannel
operations. operations.
6.6. Session-Related Considerations 5.6. Session-Related Considerations
The presence of an NFS version 4 session (as defined in [RFC5661]) The presence of an NFS version 4 session (as defined in [RFC8881])
does not effect the operation of RPC-over-RDMA version 2. None of does not effect the operation of RPC-over-RDMA version 2. None of
the operations introduced to support NFS sessions (e.g., the SEQUENCE the operations introduced to support NFS sessions (e.g., the SEQUENCE
operation) contain DDP-eligible data items. There is no need to operation) contain DDP-eligible data items. There is no need to
match the number of session slots with the number of available RPC- match the number of session slots with the number of available RPC-
over-RDMA version 2 credits. over-RDMA version 2 credits.
However, there are a few new cases where an RPC transaction can fail. However, there are a few new cases where an RPC transaction can fail.
For example, a Requester might receive, in response to an RPC For example, a Requester might receive, in response to an RPC
request, an RDMA2_ERROR message with a rdma_err value of ERR_CHUNK. request, an RDMA2_ERROR message with a rdma_err value of ERR_CHUNK.
These situations are not different from existing RPC errors, which an These situations are not different from existing RPC errors, which an
skipping to change at page 14, line 19 skipping to change at page 14, line 19
Requester's session implementation then determines the session ID and Requester's session implementation then determines the session ID and
slot for the failed request and performs slot recovery to make that slot for the failed request and performs slot recovery to make that
slot usable again. Otherwise, that slot could be rendered slot usable again. Otherwise, that slot could be rendered
permanently unavailable. permanently unavailable.
When an NFS session is not present (for example, when NFS version 4.0 When an NFS session is not present (for example, when NFS version 4.0
is in use), a transport error does not indicate whether the server is in use), a transport error does not indicate whether the server
has processed the arguments of the RPC Call, or whether the server has processed the arguments of the RPC Call, or whether the server
has accessed or modified client memory associated with that RPC. has accessed or modified client memory associated with that RPC.
6.7. Transport Considerations 5.7. Transport Considerations
6.7.1. Congestion Avoidance 5.7.1. Congestion Avoidance
Section 3.1 of [RFC7530] states: Section 3.1 of [RFC7530] states:
Where an NFS version 4 implementation supports operation over the Where an NFS version 4 implementation supports operation over the
IP network protocol, the supported transport layer between NFS and IP network protocol, the supported transport layer between NFS and
IP MUST be an IETF standardized transport protocol that is IP MUST be an IETF standardized transport protocol that is
specified to avoid network congestion; such transports include TCP specified to avoid network congestion; such transports include TCP
and the Stream Control Transmission Protocol (SCTP). and the Stream Control Transmission Protocol (SCTP).
Section 2.9.1 of [RFC5661] further states: Section 2.9.1 of [RFC8881] further states:
Even if NFS version 4.1 is used over a non-IP network protocol, it Even if NFS version 4.1 is used over a non-IP network protocol, it
is RECOMMENDED that the transport support congestion control. is RECOMMENDED that the transport support congestion control.
It is permissible for a connectionless transport to be used under It is permissible for a connectionless transport to be used under
NFS version 4.1; however, reliable and in-order delivery of data NFS version 4.1; however, reliable and in-order delivery of data
combined with congestion control by the connectionless transport combined with congestion control by the connectionless transport
is REQUIRED. As a consequence, UDP by itself MUST NOT be used as is REQUIRED. As a consequence, UDP by itself MUST NOT be used as
an NFS version 4.1 transport. an NFS version 4.1 transport.
RPC-over-RDMA version 2 utilizes only RDMA Reliable Connected QP type RPC-over-RDMA version 2 utilizes only reliable, connection-oriented
connections [I-D.ietf-nfsv4-rpcrdma-version-two]. RDMA Reliable transports that guarantee in-order delivery, meeting all the above
Connected QPs are reliable, connection-oriented transports that requirements for NFS version 4.0 and 4.1. See Section 4.2.1 of
guarantee in-order delivery, meeting all the above requirements. [I-D.ietf-nfsv4-rpcrdma-version-two] for more details.
6.7.2. Retransmission and Keep-alive 5.7.2. Retransmission and Keep-alive
NFS version 4 client implementations often rely on a transport-layer NFS version 4 client implementations often rely on a transport-layer
keep-alive mechanism to detect when an NFS version 4 server has keep-alive mechanism to detect when an NFS version 4 server has
become unresponsive. When an NFS server is no longer responsive, become unresponsive. When an NFS server is no longer responsive,
client-side keep-alive terminates the connection, which in turn client-side keep-alive terminates the connection, which in turn
triggers reconnection and RPC retransmission. triggers reconnection and RPC retransmission.
Some RDMA transports (such as the Reliable Connected QP type on Some RDMA transports (such as the Reliable Connected QP type on
InfiniBand) have no keep-alive mechanism. Without a disconnect or InfiniBand) have no keep-alive mechanism. Without a disconnect or
new RPC traffic, such connections can remain alive long after an NFS new RPC traffic, such connections can remain alive long after an NFS
skipping to change at page 15, line 43 skipping to change at page 15, line 43
* If a transport error occurs (e.g., an RDMA2_ERROR type message is * If a transport error occurs (e.g., an RDMA2_ERROR type message is
received) before the disconnect or instead of a disconnect, the received) before the disconnect or instead of a disconnect, the
Requester MUST respond to that error as prescribed by the Requester MUST respond to that error as prescribed by the
specification of the RPC transport. Then the NFS version 4 rules specification of the RPC transport. Then the NFS version 4 rules
for handling retransmission apply. for handling retransmission apply.
* If there is a transport disconnect and the Responder has provided * If there is a transport disconnect and the Responder has provided
no other response for a request, then only the NFS version 4 rules no other response for a request, then only the NFS version 4 rules
for handling retransmission apply. for handling retransmission apply.
7. Extending NFS Upper-Layer Bindings 6. Extending NFS Upper-Layer Bindings
RPC programs such as NFS are required to have an Upper-Layer Binding RPC programs such as NFS are required to have an Upper-Layer Binding
specification to interoperate on RPC-over-RDMA version 2 transports specification to interoperate on RPC-over-RDMA version 2 transports
[I-D.ietf-nfsv4-rpcrdma-version-two]. Via standards action, the [I-D.ietf-nfsv4-rpcrdma-version-two]. Via standards action, the
Upper-Layer Binding specified in this document can be extended to Upper-Layer Binding specified in this document can be extended to
cover versions of the NFS version 4 protocol specified after NFS cover versions of the NFS version 4 protocol specified after NFS
version 4 minor version 2, or to cover separately published version 4 minor version 2, or to cover separately published
extensions to an existing NFS version 4 minor version, as described extensions to an existing NFS version 4 minor version, as described
in [RFC8178]. in [RFC8178].
8. Security Considerations 7. Security Considerations
RPC-over-RDMA version 2 supports all RPC security models, including RPC-over-RDMA version 2 supports all RPC security models, including
RPCSEC_GSS security and transport-level security [RFC7861]. The RPCSEC_GSS security and transport-level security [RFC7861]. The
choice of what Direct Data Placement mechanism to convey RPC argument choice of what Direct Data Placement mechanism to convey RPC argument
and results does not affect this since it changes only the method of and results does not affect this since it changes only the method of
data transfer. Because the current document defines only the binding data transfer. Because the current document defines only the binding
of the NFS protocols atop [I-D.ietf-nfsv4-rpcrdma-version-two], all of the NFS protocols atop RPC-over-RDMA version 2
relevant security considerations are, therefore, described at that [I-D.ietf-nfsv4-rpcrdma-version-two], all relevant security
layer. considerations are, therefore, described at that layer.
9. IANA Considerations 8. IANA Considerations
The use of direct data placement in NFS introduces a need for an The use of direct data placement in NFS introduces a need for an
additional port number assignment for networks that share traditional additional port number assignment for networks that share traditional
UDP and TCP port spaces with RDMA services. The iWARP protocol is UDP and TCP port spaces with RDMA services. The iWARP protocol is
such an example [RFC5040] [RFC5041]. such an example [RFC5040] [RFC5041].
For this purpose, the current document specifies a set of transport For this purpose, the current document specifies a set of transport
protocol port number assignments. IANA has assigned the following protocol port number assignments. IANA has assigned the following
ports for NFS/RDMA in the IANA port registry, according to the ports for NFS/RDMA in the IANA port registry, according to the
guidelines described in [RFC6335]. guidelines described in [RFC6335].
nfsrdma 20049/tcp Network File System (NFS) over RDMA nfsrdma 20049/tcp Network File System (NFS) over RDMA
nfsrdma 20049/udp Network File System (NFS) over RDMA nfsrdma 20049/udp Network File System (NFS) over RDMA
nfsrdma 20049/sctp Network File System (NFS) over RDMA nfsrdma 20049/sctp Network File System (NFS) over RDMA
The current document should be added as a reference for the nfsrdma The current document should be added as a reference for the nfsrdma
port assignments. The current document does not alter these port assignments. The current document does not alter these
assignments. assignments.
10. References 9. References
10.1. Normative References 9.1. Normative References
[I-D.ietf-nfsv4-rpcrdma-version-two] [I-D.ietf-nfsv4-rpcrdma-version-two]
Lever, C. and D. Noveck, "RPC-over-RDMA Version 2 Lever, C. and D. Noveck, "RPC-over-RDMA Version 2
Protocol", Work in Progress, Internet-Draft, draft-ietf- Protocol", Work in Progress, Internet-Draft, draft-ietf-
nfsv4-rpcrdma-version-two-02, 3 July 2020, nfsv4-rpcrdma-version-two-03, 10 August 2020,
<https://tools.ietf.org/html/draft-ietf-nfsv4-rpcrdma- <https://tools.ietf.org/html/draft-ietf-nfsv4-rpcrdma-
version-two-02>. version-two-03>.
[RFC1833] Srinivasan, R., "Binding Protocols for ONC RPC Version 2", [RFC1833] Srinivasan, R., "Binding Protocols for ONC RPC Version 2",
RFC 1833, DOI 10.17487/RFC1833, August 1995, RFC 1833, DOI 10.17487/RFC1833, August 1995,
<https://www.rfc-editor.org/info/rfc1833>. <https://www.rfc-editor.org/info/rfc1833>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC5661] Shepler, S., Ed., Eisler, M., Ed., and D. Noveck, Ed.,
"Network File System (NFS) Version 4 Minor Version 1
Protocol", RFC 5661, DOI 10.17487/RFC5661, January 2010,
<https://www.rfc-editor.org/info/rfc5661>.
[RFC6335] Cotton, M., Eggert, L., Touch, J., Westerlund, M., and S. [RFC6335] Cotton, M., Eggert, L., Touch, J., Westerlund, M., and S.
Cheshire, "Internet Assigned Numbers Authority (IANA) Cheshire, "Internet Assigned Numbers Authority (IANA)
Procedures for the Management of the Service Name and Procedures for the Management of the Service Name and
Transport Protocol Port Number Registry", BCP 165, Transport Protocol Port Number Registry", BCP 165,
RFC 6335, DOI 10.17487/RFC6335, August 2011, RFC 6335, DOI 10.17487/RFC6335, August 2011,
<https://www.rfc-editor.org/info/rfc6335>. <https://www.rfc-editor.org/info/rfc6335>.
[RFC7530] Haynes, T., Ed. and D. Noveck, Ed., "Network File System [RFC7530] Haynes, T., Ed. and D. Noveck, Ed., "Network File System
(NFS) Version 4 Protocol", RFC 7530, DOI 10.17487/RFC7530, (NFS) Version 4 Protocol", RFC 7530, DOI 10.17487/RFC7530,
March 2015, <https://www.rfc-editor.org/info/rfc7530>. March 2015, <https://www.rfc-editor.org/info/rfc7530>.
[RFC7861] Adamson, A. and N. Williams, "Remote Procedure Call (RPC) [RFC7861] Adamson, A. and N. Williams, "Remote Procedure Call (RPC)
Security Version 3", RFC 7861, DOI 10.17487/RFC7861, Security Version 3", RFC 7861, DOI 10.17487/RFC7861,
November 2016, <https://www.rfc-editor.org/info/rfc7861>. November 2016, <https://www.rfc-editor.org/info/rfc7861>.
[RFC7862] Haynes, T., "Network File System (NFS) Version 4 Minor [RFC7862] Haynes, T., "Network File System (NFS) Version 4 Minor
Version 2 Protocol", RFC 7862, DOI 10.17487/RFC7862, Version 2 Protocol", RFC 7862, DOI 10.17487/RFC7862,
November 2016, <https://www.rfc-editor.org/info/rfc7862>. November 2016, <https://www.rfc-editor.org/info/rfc7862>.
[RFC8167] Lever, C., "Bidirectional Remote Procedure Call on RPC-
over-RDMA Transports", RFC 8167, DOI 10.17487/RFC8167,
June 2017, <https://www.rfc-editor.org/info/rfc8167>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
10.2. Informative References [RFC8881] Noveck, D., Ed. and C. Lever, "Network File System (NFS)
Version 4 Minor Version 1 Protocol", RFC 8881,
DOI 10.17487/RFC8881, August 2020,
<https://www.rfc-editor.org/info/rfc8881>.
9.2. Informative References
[RFC1094] Nowicki, B., "NFS: Network File System Protocol [RFC1094] Nowicki, B., "NFS: Network File System Protocol
specification", RFC 1094, DOI 10.17487/RFC1094, March specification", RFC 1094, DOI 10.17487/RFC1094, March
1989, <https://www.rfc-editor.org/info/rfc1094>. 1989, <https://www.rfc-editor.org/info/rfc1094>.
[RFC1813] Callaghan, B., Pawlowski, B., and P. Staubach, "NFS [RFC1813] Callaghan, B., Pawlowski, B., and P. Staubach, "NFS
Version 3 Protocol Specification", RFC 1813, Version 3 Protocol Specification", RFC 1813,
DOI 10.17487/RFC1813, June 1995, DOI 10.17487/RFC1813, June 1995,
<https://www.rfc-editor.org/info/rfc1813>. <https://www.rfc-editor.org/info/rfc1813>.
skipping to change at page 18, line 24 skipping to change at page 18, line 19
[RFC8178] Noveck, D., "Rules for NFSv4 Extensions and Minor [RFC8178] Noveck, D., "Rules for NFSv4 Extensions and Minor
Versions", RFC 8178, DOI 10.17487/RFC8178, July 2017, Versions", RFC 8178, DOI 10.17487/RFC8178, July 2017,
<https://www.rfc-editor.org/info/rfc8178>. <https://www.rfc-editor.org/info/rfc8178>.
[XNFS] The Open Group, "Protocols for Interworking: XNFS, Version [XNFS] The Open Group, "Protocols for Interworking: XNFS, Version
3W", February 1998. 3W", February 1998.
Acknowledgments Acknowledgments
Thanks to Tom Talpey, who contributed the text of Section 6.4.2. Thanks to Tom Talpey, who contributed the text of Section 5.4.2.
David Noveck contributed the text of Section 6.6 and Section 7. The David Noveck contributed the text of Section 5.6 and Section 6. The
author also wishes to thank Bill Baker and Greg Marsden for their author also wishes to thank Bill Baker and Greg Marsden for their
support of this work. support of this work.
Special thanks go to Transport Area Director Magnus Westerlund, NFSV4 Special thanks go to Transport Area Director Magnus Westerlund, NFSV4
Working Group Chairs Spencer Shepler, Brian Pawlowski, and David Working Group Chairs Brian Pawlowski, and David Noveck, and NFSV4
Noveck, and NFSV4 Working Group Secretary Thomas Haynes for their Working Group Secretary Thomas Haynes for their support.
support.
Author's Address Author's Address
Charles Lever Charles Lever
Oracle Corporation Oracle Corporation
United States of America United States of America
Email: chuck.lever@oracle.com Email: chuck.lever@oracle.com
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