https://tools.ietf.org/rfc/rfc7530.txt
Internet Engineering Task Force (IETF) T. Haynes, Ed.
Request for Comments: 7530 Primary Data
Obsoletes: 3530 D. Noveck, Ed.
Category: Standards Track Dell
ISSN: 2070-1721 March 2015
Network File System (NFS) Version 4 Protocol
Abstract
The Network File System (NFS) version 4 protocol is a distributed
file system protocol that builds on the heritage of NFS protocol
version 2 (RFC 1094) and version 3 (RFC 1813). Unlike earlier
versions, the NFS version 4 protocol supports traditional file access
while integrating support for file locking and the MOUNT protocol.
In addition, support for strong security (and its negotiation),
COMPOUND operations, client caching, and internationalization has
been added. Of course, attention has been applied to making NFS
version 4 operate well in an Internet environment.
NFSv4はNFSv2 (RFC 1094)、NFSv3(RFC 1813)をもとに作成された分散ファイルシステムプロトコルである。以前のバージョンと異なりNFSv4では、ファイルのロックとマウントプロトコルのサポートを統合しながら従来のファイルアクセスもサポートしている。加えて、強固なセキュリティとネゴシエーション、COMPOUNDオペレーション、クライアントのキャッシュ、多言語もサポートする。NFSv4はインターネット環境でも動作する。
This document, together with the companion External Data
Representation (XDR) description document, RFC 7531, obsoletes RFC
3530 as the definition of the NFS version 4 protocol.
このドキュメントは付録のXDRであるRFC7531とともにNFSv4を定義し、RFC3530を廃止している。
Status of This Memo
This is an Internet Standards Track document.
インターネット標準文章である。
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7530.
Copyright Notice
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Table of Contents
1. Introduction ....................................................8
1.1. Requirements Language ......................................8
1.2. NFS Version 4 Goals ........................................8
1.3. Definitions in the Companion Document RFC 7531 Are
Authoritative ..............................................9
1.4. Overview of NFSv4 Features .................................9
1.4.1. RPC and Security ....................................9
1.4.2. Procedure and Operation Structure ..................10
1.4.3. File System Model ..................................10
1.4.4. OPEN and CLOSE .....................................12
1.4.5. File Locking .......................................12
1.4.6. Client Caching and Delegation ......................13
1.5. General Definitions .......................................14
1.6. Changes since RFC 3530 ....................................16
1.7. Changes between RFC 3010 and RFC 3530 .....................16
2. Protocol Data Types ............................................18
2.1. Basic Data Types ..........................................18
2.2. Structured Data Types .....................................21
3. RPC and Security Flavor ........................................25
3.1. Ports and Transports ......................................25
3.1.1. Client Retransmission Behavior .....................26
3.2. Security Flavors ..........................................27
3.2.1. Security Mechanisms for NFSv4 ......................27
3.3. Security Negotiation ......................................28
3.3.1. SECINFO ............................................29
3.3.2. Security Error .....................................29
3.3.3. Callback RPC Authentication ........................29
4. Filehandles ....................................................30
4.1. Obtaining the First Filehandle ............................30
4.1.1. Root Filehandle ....................................31
4.1.2. Public Filehandle ..................................31
4.2. Filehandle Types ..........................................31
4.2.1. General Properties of a Filehandle .................32
4.2.2. Persistent Filehandle ..............................32
4.2.3. Volatile Filehandle ................................33
4.2.4. One Method of Constructing a Volatile Filehandle ...34
4.3. Client Recovery from Filehandle Expiration ................35
5. Attributes .....................................................35
5.1. REQUIRED Attributes .......................................37
5.2. RECOMMENDED Attributes ....................................37
5.3. Named Attributes ..........................................37
5.4. Classification of Attributes ..............................39
5.5. Set-Only and Get-Only Attributes ..........................40
5.6. REQUIRED Attributes - List and Definition References ......40
5.7. RECOMMENDED Attributes - List and Definition References ...41
5.8. Attribute Definitions .....................................42
5.8.1. Definitions of REQUIRED Attributes .................42
5.8.2. Definitions of Uncategorized RECOMMENDED
Attributes .........................................45
5.9. Interpreting owner and owner_group ........................51
5.10. Character Case Attributes ................................53
6. Access Control Attributes ......................................54
6.1. Goals .....................................................54
6.2. File Attributes Discussion ................................55
6.2.1. Attribute 12: acl ..................................55
6.2.2. Attribute 33: mode .................................70
6.3. Common Methods ............................................71
6.3.1. Interpreting an ACL ................................71
6.3.2. Computing a mode Attribute from an ACL .............72
6.4. Requirements ..............................................73
6.4.1. Setting the mode and/or ACL Attributes .............74
6.4.2. Retrieving the mode and/or ACL Attributes ..........75
6.4.3. Creating New Objects ...............................75
7. NFS Server Namespace ...........................................77
7.1. Server Exports ............................................77
7.2. Browsing Exports ..........................................77
7.3. Server Pseudo-File System .................................78
7.4. Multiple Roots ............................................79
7.5. Filehandle Volatility .....................................79
7.6. Exported Root .............................................79
7.7. Mount Point Crossing ......................................79
7.8. Security Policy and Namespace Presentation ................80
8. Multi-Server Namespace .........................................81
8.1. Location Attributes .......................................81
8.2. File System Presence or Absence ...........................81
8.3. Getting Attributes for an Absent File System ..............83
8.3.1. GETATTR within an Absent File System ...............83
8.3.2. READDIR and Absent File Systems ....................84
8.4. Uses of Location Information ..............................84
8.4.1. File System Replication ............................85
8.4.2. File System Migration ..............................86
8.4.3. Referrals ..........................................86
8.5. Location Entries and Server Identity ......................87
8.6. Additional Client-Side Considerations .....................88
8.7. Effecting File System Referrals ...........................89
8.7.1. Referral Example (LOOKUP) ..........................89
8.7.2. Referral Example (READDIR) .........................93
8.8. The Attribute fs_locations ................................96
9. File Locking and Share Reservations ............................98
9.1. Opens and Byte-Range Locks ................................99
9.1.1. Client ID ..........................................99
9.1.2. Server Release of Client ID .......................102
9.1.3. Use of Seqids .....................................103
9.1.4. Stateid Definition ................................104
9.1.5. Lock-Owner ........................................110
9.1.6. Use of the Stateid and Locking ....................110
9.1.7. Sequencing of Lock Requests .......................113
9.1.8. Recovery from Replayed Requests ...................114
9.1.9. Interactions of Multiple Sequence Values ..........114
9.1.10. Releasing State-Owner State ......................115
9.1.11. Use of Open Confirmation .........................116
9.2. Lock Ranges ..............................................117
9.3. Upgrading and Downgrading Locks ..........................117
9.4. Blocking Locks ...........................................118
9.5. Lease Renewal ............................................119
9.6. Crash Recovery ...........................................120
9.6.1. Client Failure and Recovery .......................120
9.6.2. Server Failure and Recovery .......................120
9.6.3. Network Partitions and Recovery ...................122
9.7. Recovery from a Lock Request Timeout or Abort ............130
9.8. Server Revocation of Locks ...............................130
9.9. Share Reservations .......................................132
9.10. OPEN/CLOSE Operations ...................................132
9.10.1. Close and Retention of State Information .........133
9.11. Open Upgrade and Downgrade ..............................134
9.12. Short and Long Leases ...................................135
9.13. Clocks, Propagation Delay, and Calculating Lease
Expiration ..............................................135
9.14. Migration, Replication, and State .......................136
9.14.1. Migration and State ..............................136
9.14.2. Replication and State ............................137
9.14.3. Notification of Migrated Lease ...................137
9.14.4. Migration and the lease_time Attribute ...........138
10. Client-Side Caching ..........................................139
10.1. Performance Challenges for Client-Side Caching ..........139
10.2. Delegation and Callbacks ................................140
10.2.1. Delegation Recovery ..............................142
10.3. Data Caching ............................................147
10.3.1. Data Caching and OPENs ...........................147
10.3.2. Data Caching and File Locking ....................148
10.3.3. Data Caching and Mandatory File Locking ..........150
10.3.4. Data Caching and File Identity ...................150
10.4. Open Delegation .........................................151
10.4.1. Open Delegation and Data Caching .................154
10.4.2. Open Delegation and File Locks ...................155
10.4.3. Handling of CB_GETATTR ...........................155
10.4.4. Recall of Open Delegation ........................158
10.4.5. OPEN Delegation Race with CB_RECALL ..............160
10.4.6. Clients That Fail to Honor Delegation Recalls ....161
10.4.7. Delegation Revocation ............................162
10.5. Data Caching and Revocation .............................162
10.5.1. Revocation Recovery for Write Open Delegation ....163
10.6. Attribute Caching .......................................164
10.7. Data and Metadata Caching and Memory-Mapped Files .......166
10.8. Name Caching ............................................168
10.9. Directory Caching .......................................169
11. Minor Versioning .............................................170
12. Internationalization .........................................170
12.1. Introduction ............................................170
12.2. Limitations on Internationalization-Related
Processing in the NFSv4 Context .........................172
12.3. Summary of Server Behavior Types ........................173
12.4. String Encoding .........................................173
12.5. Normalization ...........................................174
12.6. Types with Processing Defined by Other Internet Areas ...175
12.7. Errors Related to UTF-8 .................................177
12.8. Servers That Accept File Component Names That
Are Not Valid UTF-8 Strings .............................177
13. Error Values .................................................178
13.1. Error Definitions .......................................179
13.1.1. General Errors ...................................180
13.1.2. Filehandle Errors ................................181
13.1.3. Compound Structure Errors ........................183
13.1.4. File System Errors ...............................184
13.1.5. State Management Errors ..........................186
13.1.6. Security Errors ..................................187
13.1.7. Name Errors ......................................187
13.1.8. Locking Errors ...................................188
13.1.9. Reclaim Errors ...................................190
13.1.10. Client Management Errors ........................191
13.1.11. Attribute Handling Errors .......................191
13.1.12. Miscellaneous Errors ............................191
13.2. Operations and Their Valid Errors .......................192
13.3. Callback Operations and Their Valid Errors ..............200
13.4. Errors and the Operations That Use Them .................201
14. NFSv4 Requests ...............................................206
14.1. COMPOUND Procedure ......................................207
14.2. Evaluation of a COMPOUND Request ........................207
14.3. Synchronous Modifying Operations ........................208
14.4. Operation Values ........................................208
15. NFSv4 Procedures .............................................209
15.1. Procedure 0: NULL - No Operation ........................209
15.2. Procedure 1: COMPOUND - COMPOUND Operations .............210
16. NFSv4 Operations .............................................214
16.1. Operation 3: ACCESS - Check Access Rights ...............214
16.2. Operation 4: CLOSE - Close File .........................217
16.3. Operation 5: COMMIT - Commit Cached Data ................218
16.4. Operation 6: CREATE - Create a Non-regular File Object ..221
16.5. Operation 7: DELEGPURGE - Purge Delegations
Awaiting Recovery .......................................224
16.6. Operation 8: DELEGRETURN - Return Delegation ............226
16.7. Operation 9: GETATTR - Get Attributes ...................227
16.8. Operation 10: GETFH - Get Current Filehandle ............229
16.9. Operation 11: LINK - Create Link to a File ..............230
16.10. Operation 12: LOCK - Create Lock .......................232
16.11. Operation 13: LOCKT - Test for Lock ....................236
16.12. Operation 14: LOCKU - Unlock File ......................238
16.13. Operation 15: LOOKUP - Look Up Filename ................240
16.14. Operation 16: LOOKUPP - Look Up Parent Directory .......242
16.15. Operation 17: NVERIFY - Verify Difference in
Attributes .............................................243
16.16. Operation 18: OPEN - Open a Regular File ...............245
16.17. Operation 19: OPENATTR - Open Named Attribute
Directory ..............................................256
16.18. Operation 20: OPEN_CONFIRM - Confirm Open ..............257
16.19. Operation 21: OPEN_DOWNGRADE - Reduce Open File
Access .................................................260
16.20. Operation 22: PUTFH - Set Current Filehandle ...........262
16.21. Operation 23: PUTPUBFH - Set Public Filehandle .........263
16.22. Operation 24: PUTROOTFH - Set Root Filehandle ..........265
16.23. Operation 25: READ - Read from File ....................266
16.24. Operation 26: READDIR - Read Directory .................269
16.25. Operation 27: READLINK - Read Symbolic Link ............273
16.26. Operation 28: REMOVE - Remove File System Object .......274
16.27. Operation 29: RENAME - Rename Directory Entry ..........276
16.28. Operation 30: RENEW - Renew a Lease ....................278
16.29. Operation 31: RESTOREFH - Restore Saved Filehandle .....280
16.30. Operation 32: SAVEFH - Save Current Filehandle .........281
16.31. Operation 33: SECINFO - Obtain Available Security ......282
16.32. Operation 34: SETATTR - Set Attributes .................286
16.33. Operation 35: SETCLIENTID - Negotiate Client ID ........289
16.34. Operation 36: SETCLIENTID_CONFIRM - Confirm Client ID ..293
16.35. Operation 37: VERIFY - Verify Same Attributes ..........297
16.36. Operation 38: WRITE - Write to File ....................299
16.37. Operation 39: RELEASE_LOCKOWNER - Release
Lock-Owner State .......................................304
16.38. Operation 10044: ILLEGAL - Illegal Operation ...........305
17. NFSv4 Callback Procedures ....................................306
17.1. Procedure 0: CB_NULL - No Operation .....................306
17.2. Procedure 1: CB_COMPOUND - COMPOUND Operations ..........307
18. NFSv4 Callback Operations ....................................309
18.1. Operation 3: CB_GETATTR - Get Attributes ................309
18.2. Operation 4: CB_RECALL - Recall an Open Delegation ......310
18.3. Operation 10044: CB_ILLEGAL - Illegal Callback
Operation ...............................................311
19. Security Considerations ......................................312
20. IANA Considerations ..........................................314
20.1. Named Attribute Definitions .............................314
20.1.1. Initial Registry .................................315
20.1.2. Updating Registrations ...........................315
20.2. Updates to Existing IANA Registries .....................315
21. References ...................................................316
21.1. Normative References ....................................316
21.2. Informative References ..................................318
Acknowledgments ..................................................322
Authors' Addresses ...............................................323
Haynes & Noveck Standards Track [Page 7]
RFC 7530 NFSv4 March 2015
1. Introduction
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119],
except where "REQUIRED" and "RECOMMENDED" are used as qualifiers to
distinguish classes of attributes as described in Sections 1.4.3.2
and 5 of this document.
各用語はRFC 2119参照。1.4.3.2章、5章で説明されるように、attributeのclassを区別するために"REQUIRED" and "RECOMMENDED" が使用される。
1.2. NFS Version 4 Goals
The Network File System version 4 (NFSv4) protocol is a further
revision of the NFS protocol defined already by versions 2 [RFC1094]
and 3 [RFC1813]. It retains the essential characteristics of
previous versions: design for easy recovery; independent of transport
protocols, operating systems, and file systems; simplicity; and good
performance. The NFSv4 revision has the following goals:
NFSv4はNFSv2、NFSv3の改良版である。前のバージョンのエッセンスは保持している。すなわち、容易な復旧が可能な設計・トランスポートプロトコル、OSファイスシステムからの独立・シンプル、パフォーマンスである。
NFSv4には次の目的がある。
o Improved access and good performance on the Internet.
インターネットでのアクセスおよびパフォーマンスの向上
The protocol is designed to transit firewalls easily, perform well
where latency is high and bandwidth is low, and scale to very
large numbers of clients per server.
このプロトコルはファイアーウォールの通過が容易であり、レイテンシが高くてスループットの出ない場所でも動作し、大量のクライアントに対してもスケールするように設計されている。
o Strong security with negotiation built into the protocol.
プロトコル内に組み込まれたネゴシエーションによる強力なセキュリティ。
The protocol builds on the work of the Open Network Computing
(ONC) Remote Procedure Call (RPC) working group in supporting the
RPCSEC_GSS protocol (see both [RFC2203] and [RFC5403]).
Additionally, the NFSv4 protocol provides a mechanism to allow
clients and servers the ability to negotiate security and require
clients and servers to support a minimal set of security schemes.
Open Network Computing (ONC) Remote Procedure Call (RPC) working groupのRPCに基いている。
さらにNFSv4はクライアントとサーバーがセキュリティをネゴシエーションするメカニズムを提供し、クライアントとサーバーへの最低限のセキュリティをサポートする要求をする。
o Good cross-platform interoperability.
クロス環境での相互運用性
The protocol features a file system model that provides a useful,
common set of features that does not unduly favor one file system
or operating system over another.
ファイルシステム、オペレーティングシステムに依存しない、ファイルシステムモデルを提供する。
o Designed for protocol extensions.
拡張性のあるプロトコル
The protocol is designed to accept standard extensions that do not
compromise backward compatibility.
このプロトコルは後方互換を損なわない拡張を許容する設計がされている。
This document, together with the companion External Data
Representation (XDR) description document [RFC7531], obsoletes
[RFC3530] as the authoritative document describing NFSv4. It does
not introduce any over-the-wire protocol changes, in the sense that
previously valid requests remain valid.
本ドキュメントはXDRのRFC7351とともにRFC3530を廃止している。
最終更新：2018年01月02日 23:53
