File System Extended Attributes in NFSv4
RFC 8276
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Type |
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RFC - Proposed Standard
(December 2017; Errata)
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Last updated |
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2017-12-05
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IETF
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plain text
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bibtex
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WG state
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Submitted to IESG for Publication
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Document shepherd |
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Spencer Shepler
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Shepherd write-up |
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Show
(last changed 2017-04-14)
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| IESG |
IESG state |
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RFC 8276 (Proposed Standard)
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Consensus Boilerplate |
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Yes
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Responsible AD |
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Spencer Dawkins
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Send notices to |
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"Spencer Shepler" <spencer.shepler@gmail.com>
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| IANA |
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Version Changed - Review Needed
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No IANA Actions
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Internet Engineering Task Force (IETF) M. Naik
Request for Comments: 8276 Nutanix
Category: Standards Track M. Eshel
ISSN: 2070-1721 IBM Almaden
December 2017
File System Extended Attributes in NFSv4
Abstract
This document describes an optional feature extending the NFSv4
protocol. This feature allows extended attributes (hereinafter also
referred to as xattrs) to be interrogated and manipulated using NFSv4
clients. Xattrs are provided by a file system to associate opaque
metadata, not interpreted by the file system, with files and
directories. Such support is present in many modern local file
systems. New file attributes are provided to allow clients to query
the server for xattr support, with that support consisting of new
operations to get and set xattrs on file system objects.
Status of This Memo
This is an Internet Standards Track document.
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 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc8276.
Naik & Eshel Standards Track [Page 1]
RFC 8276 Extended Attributes in NFSv4 December 2017
Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Naik & Eshel Standards Track [Page 2]
RFC 8276 Extended Attributes in NFSv4 December 2017
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5
2. Uses of Extended Attributes . . . . . . . . . . . . . . . . . 5
3. Functional Gaps Due to Lack of NFSv4 Extended Attribute
Support . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. File System Support for Extended Attributes . . . . . . . . . 6
5. Namespaces . . . . . . . . . . . . . . . . . . . . . . . . . 7
6. Relationship with Named Attributes . . . . . . . . . . . . . 7
7. XDR Description . . . . . . . . . . . . . . . . . . . . . . . 8
7.1. Code Components Licensing Notice . . . . . . . . . . . . 9
7.2. XDR for Xattr Extension . . . . . . . . . . . . . . . . . 11
8. Protocol Extensions . . . . . . . . . . . . . . . . . . . . . 11
8.1. New Definitions . . . . . . . . . . . . . . . . . . . . . 11
8.2. New Attribute . . . . . . . . . . . . . . . . . . . . . . 12
8.2.1. xattr_support . . . . . . . . . . . . . . . . . . . . 12
8.3. New Error Definitions . . . . . . . . . . . . . . . . . . 12
8.3.1. NFS4ERR_NOXATTR (Error Code 10095) . . . . . . . . . 12
8.3.2. NFS4ERR_XATTR2BIG (Error Code 10096) . . . . . . . . 13
8.4. New Operations . . . . . . . . . . . . . . . . . . . . . 13
8.4.1. GETXATTR - Get an Extended Attribute of a File . . . 14
8.4.2. SETXATTR - Set an Extended Attribute of a File . . . 15
8.4.3. LISTXATTRS - List Extended Attributes of a File . . . 17
8.4.4. REMOVEXATTR - Remove an Extended Attribute of a File 18
8.4.5. Valid Errors . . . . . . . . . . . . . . . . . . . . 19
8.5. Modifications to Existing Operations . . . . . . . . . . 21
8.6. Numeric Values Assigned to Protocol Extensions . . . . . 22
8.7. Caching . . . . . . . . . . . . . . . . . . . . . . . . . 23
8.8. Xattrs and File Locking . . . . . . . . . . . . . . . . . 25
8.9. pNFS Considerations . . . . . . . . . . . . . . . . . . . 25
9. Security Considerations . . . . . . . . . . . . . . . . . . . 25
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 26
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