rfc9754.original.xml		rfc9754.xml
	<?xml version='1.0' encoding='utf-8'?>		<?xml version='1.0' encoding='utf-8'?>
	<!DOCTYPE rfc SYSTEM "rfc2629-xhtml.ent">
	<?xml-stylesheet type="text/xsl" href="rfc2629.xslt"?>
	<rfc		<!DOCTYPE rfc [
	category="std"		<!ENTITY nbsp "&#160;">
	docName="draft-ietf-nfsv4-delstid-08"		<!ENTITY zwsp "&#8203;">
	ipr="trust200902"		<!ENTITY nbhy "&#8209;">
	obsoletes=""		<!ENTITY wj "&#8288;">
	scripts="Common,Latin"		]>
	sortRefs="true"		<rfc xmlns:xi="http://www.w3.org/2001/XInclude" category="std" docName="draft-ie
	submissionType="IETF"		tf-nfsv4-delstid-08" number="9754" ipr="trust200902" obsoletes="" updates="" sor
	symRefs="true"		tRefs="true" submissionType="IETF" consensus="true" symRefs="true" tocDepth="3"
	tocDepth="3"		tocInclude="true" version="3" xml:lang="en">
	tocInclude="true"
	version="3"		<!-- [rfced] Please review the following questions regarding this
	xml:lang="en">		document's title:
			a) May we update "Extending" to "Extensions for"? Also, the abstract notes
			that this document presents extensions for both opening and delegating files,
			but the title only mentions opening of files. Should "Opening of Files" be
			updated to "Opening and Delegating Files"?
			Original:
			Extending the Opening of Files in NFSv4.2
			Perhaps:
			Extensions for Opening and Delegating Files in NFSv4.2
			b) How may we update the document's short title (which appears in the running
			header of the PDF output) for consistency with the document title?
			Original:
			Deleg Stateid
			Perhaps:
			NFSv4.2 Extensions
			Or:
			Extending NFSv4.2
			-->
	<front>		<front>
	<title abbrev="Deleg Stateid">		<title abbrev="Deleg Stateid">Extending the Opening of Files in NFSv4.2</title
	Extending the Opening of Files in NFSv4.2		>
	</title>		<seriesInfo name="RFC" value="9754"/>
	<seriesInfo name="Internet-Draft" value="draft-ietf-nfsv4-delstid-08"/>
	<author fullname="Thomas Haynes" initials="T." surname="Haynes">		<author fullname="Thomas Haynes" initials="T." surname="Haynes">
	<organization abbrev="Hammerspace">Hammerspace</organization>		<organization abbrev="Hammerspace">Hammerspace</organization>
	<address>		<address>
	<email>loghyr@hammerspace.com</email>		<email>loghyr@hammerspace.com</email>
	</address>		</address>
	</author>		</author>
	<author fullname="Trond Myklebust" initials="T." surname="Myklebust">		<author fullname="Trond Myklebust" initials="T." surname="Myklebust">
	<organization abbrev="Hammerspace">Hammerspace</organization>		<organization abbrev="Hammerspace">Hammerspace</organization>
	<address>		<address>
	<email>trondmy@hammerspace.com</email>		<email>trondmy@hammerspace.com</email>
	</address>		</address>
	</author>		</author>
	<date year="2024" month="October" day="02"/>		<date year="2025" month="March"/>
	<area>Transport</area>		<area>WIT</area>
	<workgroup>Network File System Version 4</workgroup>		<workgroup>nfsv4</workgroup>
	<keyword>NFSv4</keyword>		<keyword>NFSv4</keyword>
			<!-- [rfced] FYI - We updated "for both the opening and delegating of the file
			to the client" as follows. Let us know any concerns.
			Original:
			This document presents several extensions for both
			the opening and delegating of the file to the client.
			Updated:
			This document presents several extensions for both
			opening the file and delegating it to the client.
			-->
	<abstract>		<abstract>
	<t>		<t>
	The Network File System v4 (NFSv4) allows a client to both open a		The Network File System v4 (NFSv4) allows a client to both open a
	file and be granted a delegation of that file. This delegation		file and be granted a delegation of that file. This delegation
	provides the client the right to authoritatively cache metadata		provides the client the right to authoritatively cache metadata
	on the file locally. This document presents several extensions		on the file locally. This document presents several extensions
	for both the opening and delegating of the file to		for both opening the file and delegating it to
	the client. This document extends NFSv4.2 (see RFC7863).		the client. This document extends NFSv4.2 (see RFC 7863).
	</t>		</t>
	</abstract>		</abstract>
	<note removeInRFC="true">
	<t>
	Discussion of this draft takes place
	on the NFSv4 working group mailing list (nfsv4@ietf.org),
	which is archived at
	<eref target="https://mailarchive.ietf.org/arch/browse/nfsv4/"/>.
	Working Group information can be found at
	<eref target="https://datatracker.ietf.org/wg/nfsv4/about/"/>.
	</t>
	</note>
	</front>		</front>
	<middle>		<middle>
	<section anchor="sec_intro" numbered="true" removeInRFC="false" toc="default">		<section anchor="sec_intro" numbered="true" toc="default">
	<name>Introduction</name>		<name>Introduction</name>
			<!-- [rfced] This document contains some sentences that are difficult to
			follow because they contain many parentheticals. Below are two examples
			(but the document contains more):
			Original:
			A compound (see Section 2.3 of [RFC8881]) with a GETATTR (see
			Section 18.7 of [RFC8881]) or READDIR (see Section 18.23 of
			[RFC8881]) can report the file's attributes without bringing the file
			online. However, either an OPEN or a LAYOUTGET (see Section 18.43 of
			[RFC8881]) might cause the file server to retrieve the archived data
			contents, bringing the file online.
			...
			Either type of
			stateid is sufficient to enable the server to treat the file as if it
			were open, which allows READ (See Section 18.25 of [RFC8881]), WRITE
			(See Section 18.38 of [RFC8881]), LOCK (See Section 18.12 of
			[RFC8881]), and LAYOUTGET (see Section 18.50 of [RFC8881]) operations
			to proceed.
			Many of these sentences include operations (e.g., GETATTR and READ), and the
			parentheticals point to sections in RFC 8881 that define those operations. To
			improve readability of sentences like this, we recommend adding the operations
			to the Definitions section (i.e, Section 1.1) and then omitting the
			parentheticals from the sentences.
			You may also consider doing the same for other terminology from [RFC8881],
			e.g., delegation, stateid, compound, parallel NFS (pNFS), change attribute,
			time_metadata attribute, time_access attribute, time_modify attribute, and
			NFS4ERR_DELAY.
			Let us know your thoughts.
			Perhaps (add to Section 1.1; sentence form with no section pointers):
			The following operations are used in this document as defined in [RFC8881]:
			CB_GETATTR, CLOSE, DELEGRETURN, GETATTR, LAYOUTGET, LOCK, OPEN,
			READ, READDIR, SETATTR, and WRITE.
			Or (add to Section 1.1; <dl> with section pointers):
			The following operations are used in this document as defined in [RFC8881]:
			CB_GETATTR: Section 20.1 of [RFC8881]
			CLOSE: Section 18.2 of [RFC8881]
			DELEGRETURN: Section 18.6 of [RFC8881]
			GETATTR: Section 18.7 of [RFC8881]
			LAYOUTGET: Section 18.43 of [RFC8881]
			LOCK: Section 18.10 of [RFC8881]
			OPEN: Section 18.16.1 of [RFC8881]
			READ: Section 18.22 of [RFC8881]
			READDIR: Section 18.23 of [RFC8881]
			SETATTR: Section 18.30 of [RFC8881]
			WRITE: Section 18.32 of [RFC8881]
			-->
	<t>		<t>
	In the Network File System version4 (NFSv4), a client may be granted		In the Network File System version 4 (NFSv4), a client may be granted a
	a delegation for a file (see Section 1.8.4 of <xref target="RFC8881"		delegation for a file (see <xref target="RFC8881" section="1.8.4"
	format="default" sectionFormat="of"/>). This allows the client to act as the		sectionFormat="of"/>). This allows the client to act as the authority for
	authority for the file's metadata and data. This document presents		the file's data and metadata. This document presents a number of
	a number of extensions which enhance the functionality of opens and		extensions that enhance the functionality of opens and delegations. These
	delegations. These allow the client to:		allow the client to:
	</t>		</t>
			<!-- [rfced] We moved the parenthetical to appear after "delegation stateid"
			in this sentence. Section 8.2 of RFC 8881 defines stateids and mentions
			both "delegation stateid" and "OPEN stateid". Let us know any concerns.
			Original:
			* during the OPEN procedure, retrieve either the open stateid (see
			Section 8.2 of [RFC8881]) or delegation stateid, but not both
			simultaneously.
			Updated:
			* retrieve either the open or delegation stateid (see
			Section 8.2 of [RFC8881]), but not both simultaneously, during the OPEN
			procedure; and
			-->
	<ul spacing="normal">		<ul spacing="normal">
	<li>		<li>detect an offline file, which may require significant effort to obtain;<
	detect an offline file, which may require significant effort to obtain.		/li>
	</li>
	<li>		<li>determine which extensions of OPEN flags (see <xref target="RFC8881"
	determine which extensions of OPEN (see Section 18.16 of <xref		section="18.16" sectionFormat="of"/>) are supported by the server;</li>
	target="RFC8881" format="default" sectionFormat="of"/>) flags are
	supported by the server.		<li>retrieve either the open or delegation stateid (see <xref target="RFC888
	</li>		1"
	<li>		section="8.2" sectionFormat="of"/>), but not
	during the OPEN procedure, retrieve either the open stateid		both simultaneously, during the OPEN procedure; and</li>
	(see Section 8.2 of <xref target="RFC8881"
	format="default" sectionFormat="of"/>) or		<li>cache both the access and modify timestamps, thereby reducing the
	delegation stateid, but not both simultaneously.		frequency with which the client must query the server for this
	</li>		information.
	<li>
	cache both the access and modify timestamps, thereby reducing
	the frequency with which the client must query the server for
	this information.
	</li>		</li>
	</ul>		</ul>
	<t>		<t>
	Using the process detailed in <xref target="RFC8178" format="default"		Using the process detailed in <xref target="RFC8178" format="default"
	sectionFormat="of"/>, the revisions in this document become an		sectionFormat="of"/>, the revisions in this document become an extension
	extension of NFSv4.2 <xref target="RFC7862" format="default"		of NFSv4.2 <xref target="RFC7862" format="default"
	sectionFormat="of"/>. They are built on top of the external data		sectionFormat="of"/>. They are built on top of the External Data
	representation (XDR) <xref target="RFC4506" format="default"		Representation (XDR) <xref target="RFC4506" format="default"
	sectionFormat="of"/> generated from <xref target="RFC7863"		sectionFormat="of"/> generated from <xref target="RFC7863"
	format="default" sectionFormat="of"/>.		format="default" sectionFormat="of"/>.
	</t>		</t>
	<section anchor="sec_defs" numbered="true" removeInRFC="false" toc="default">		<section anchor="sec_defs" numbered="true" toc="default">
	<name>Definitions</name>		<name>Definitions</name>
			<t>This document uses the following terminology:</t>
	<dl newline="false" spacing="normal">		<dl newline="false" spacing="normal">
	<dt>offline file:</dt>		<dt>offline file:</dt>
	<dd>		<dd>
	A file which exists on a device which is not connected to the		A file that exists on a device that is not connected to the
	server. There is typically a cost associated with bringing the		server. There is typically a cost associated with bringing the
	file to an online status. Historically this would be a file on		file to an online status. Historically, this would be a file on
	tape media and the cost would have been finding and loading the		tape media, and the cost would have been finding and loading the
	tape. A more modern interpretation is that the file is in the		tape. A more modern interpretation is that the file is in the
	cloud and the cost is a monetary one in downloading the file.		cloud, and the cost is a monetary one in downloading the file.
	</dd>		</dd>
	<dt>proxy:</dt>		<dt>proxy:</dt>
	<dd>		<dd>
	Proxying of attributes occurs when a client has the authority, as		The proxying of attributes occurs when a client has the authority, as
	granted by the appropriate delegation, to represent the attributes		granted by the appropriate delegation, to represent the attributes
	normally maintained by the server. For read attributes, this		normally maintained by the server. For read attributes, this
	occurs when the client has either a read or write delegations		occurs when the client has either a read or write delegation
	for the file. For write attributes, this occurs when the client		for the file. For write attributes, this occurs when the client
	has a write delegation for the file. The client having this		has a write delegation for the file. The client having this
	authority is the "proxy" for those attributes.		authority is the "proxy" for those attributes.
	</dd>		</dd>
	</dl>		</dl>
	</section>		</section>
	<section numbered="true" removeInRFC="false" toc="default">		<section numbered="true" toc="default">
	<name>Requirements Language</name>		<name>Requirements Language</name>
	<t>		<t>
	The key words "<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>",		The key words "<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>",
	"<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL		"<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL NOT</bcp14>
	NOT</bcp14>", "<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>",		",
	"<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>",		"<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>",
	"<bcp14>MAY</bcp14>", and "<bcp14>OPTIONAL</bcp14>" in this		"<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>",
	document are to be interpreted as described in BCP&nbsp;14 <xref		"<bcp14>MAY</bcp14>", and "<bcp14>OPTIONAL</bcp14>" in this document are to
	target="RFC2119" format="default" sectionFormat="of"/> <xref		be
	target="RFC8174" format="default" sectionFormat="of"/> when,		interpreted as described in BCP&nbsp;14 <xref target="RFC2119"/> <xref
	and only when, they appear in all capitals, as shown here.		target="RFC8174"/> when, and only when, they appear in all capitals, as
	</t>		shown here.
			</t>
	</section>		</section>
	</section>		</section>
	<section anchor="sec_offline" numbered="true" removeInRFC="false" toc="default">		<section anchor="sec_offline" numbered="true" toc="default">
	<name>Offline Files</name>		<name>Offline Files</name>
	<t>		<t>
	If a file is offline, then the server has immediate high-performance		If a file is offline, then the server has immediate high-performance
	access to the file's attributes, but not to the file's content.		access to the file's attributes, but not to the file's content.
	The action of retrieving the data content is expensive, to the extent		The action of retrieving the data content is expensive, to the extent
	that the content should only be retrieved if it is going to be used.		that the content should only be retrieved if it is going to be used.
	For example, a graphical file manager (such as OSX's Finder) may		For example, a graphical file manager (such as Finder in Mac OS X) may
	want to access the beginning of the file to preview it for an user		want to access the beginning of the file to preview it for a user
	who is hovering their pointer over the file name and not accessing		who is hovering their pointer over the file name and not accessing
	it otherwise. If the file is retrieved, it will most likely either		it otherwise. If the file is retrieved, it will most likely be either
	be immediately thrown away or returned.		immediately thrown away or returned.
	</t>		</t>
			<!-- [rfced] We updated the section numbers below for accuracy with RFC 8881.
			Please review and confirm that these changes are correct.
			Original:
			Either type of stateid is sufficient to enable the server to treat the file
			as if it were open, which allows READ (See Section 18.25 of [RFC8881]),
			WRITE (See Section 18.38 of [RFC8881]), LOCK (See Section 18.12 of
			[RFC8881]), and LAYOUTGET (see Section 18.50 of [RFC8881]) operations to
			proceed.
			Updated:
			Either type of stateid is sufficient to enable the server to treat the file
			as if it were open, which allows READ (see Section 18.22 of [RFC8881]), WRITE
			(see Section 18.32 of [RFC8881]), LOCK (see Section 18.10 of
			[RFC8881]), and LAYOUTGET (see Section 18.43 of [RFC8881]) operations
			to proceed.
			-->
			<!-- [rfced] Is a word missing in "filehandle to the data content"?
			Original:
			For non-parallel NFS (pNFS)
			systems (see Section 12 of [RFC8881]) , the OPEN operation requires a
			filehandle to the data content.
			Perhaps:
			For non-parallel NFS
			systems (see Section 12 of [RFC8881]), the OPEN operation requires a
			filehandle to retrieve the data content.
			-->
	<t>		<t>
	A compound (see Section 2.3 of <xref target="RFC8881" format="default"		A compound (see <xref target="RFC8881" section="2.3" sectionFormat="of"/>)
	sectionFormat="of"/>) with a GETATTR (see Section 18.7 of <xref		with a GETATTR (see <xref target="RFC8881" section="18.7"
	target="RFC8881" format="default" sectionFormat="of"/>) or READDIR		sectionFormat="of"/>) or READDIR (see <xref target="RFC8881"
	(see Section 18.23 of <xref target="RFC8881" format="default"		section="18.23" sectionFormat="of"/>) can report the file's attributes
	sectionFormat="of"/>) can report the file's attributes without		without bringing the file online. However, either an OPEN or a LAYOUTGET
	bringing the file online. However, either an OPEN or a LAYOUTGET		(see <xref target="RFC8881" section="18.43" sectionFormat="of"/>) might
	(see Section 18.43 of <xref target="RFC8881" format="default"		cause the file server to retrieve the archived data contents, bringing the
	sectionFormat="of"/>) might cause the file server to retrieve the		file online. For non-parallel NFS systems (see <xref
	archived data contents, bringing the file online. For non-parallel		target="RFC8881" section="12" sectionFormat="of"/>), the OPEN operation
	NFS (pNFS) systems (see Section 12 of <xref target="RFC8881"		requires a filehandle to the data content. For parallel NFS (pNFS) systems,
	format="default" sectionFormat="of"/>) , the OPEN operation		the
	requires a filehandle to the data content. For pNFS systems, the		filehandle retrieved from an OPEN need not cause the data content to be
	filehandle retrieved from an OPEN need not cause the data content		retrieved. However, when the LAYOUTGET operation is processed, a layout-type
	to be retrieved. But when the LAYOUTGET operation is processed,		-specific mapping
	a layout type specific mapping will cause the data content to be		will cause the data content to be retrieved from offline
	retrieved from offline storage.		storage.
	</t>		</t>
	<t>		<t>
	If the client is not aware that the file is offline, it might		If the client is not aware that the file is offline, it might
	inadvertently open the file to determine what type of file it		inadvertently open the file to determine what type of file it
	is accessing. By interrogating the new attribute fattr4_offline,		is accessing. By interrogating the new attribute fattr4_offline,
	a client can predetermine the availability of the file, avoiding the		a client can predetermine the availability of the file, avoiding the
	need to open it at all. Being offline might also involve situations		need to open it at all. Being offline might also involve situations
	in which the file is archived in the cloud, i.e., there can be an		in which the file is archived in the cloud, i.e., there can be an
	expense in both retrieving the file to bring online and in sending		expense in both retrieving the file to bring it online and in sending
	the file back to offline status.		the file back to offline status.
	</t>		</t>
	<section anchor="ssec_offline_attr" numbered="true" removeInRFC="false" toc="d		<section anchor="ssec_offline_attr" numbered="true" toc="default">
	efault">		<name>XDR for the Offline Attribute</name>
	<name>XDR for Offline Attribute</name>
	<sourcecode name="" type="" markers="true"><![CDATA[		<sourcecode name="" type="xdr" markers="true"><![CDATA[
	///		///
	/// typedef bool fattr4_offline;		/// typedef bool fattr4_offline;
	///		///
	///		///
	/// const FATTR4_OFFLINE = 83;		/// const FATTR4_OFFLINE = 83;
	///		///
	]]>		]]></sourcecode>
	</sourcecode>
	</section>		</section>
	</section>		</section>
	<section anchor="ssec_open_xor_xdr" numbered="true" removeInRFC="false" toc="def ault">		<section anchor="ssec_open_xor_xdr" numbered="true" toc="default">
	<name>Determining OPEN Feature Support</name>		<name>Determining OPEN Feature Support</name>
			<!-- [rfced] May we update "[RFC8178] (see Section 4.4.2)" as follows? Or do
			you prefer the original?
			Original:
			[RFC8178] (see Section 4.4.2) allows for extending a particular minor
			version of the NFSv4 protocol without requiring the definition of a
			new minor version.
			Perhaps:
			Section 4.4.2 of [RFC8178] allows for extending a particular minor
			version of the NFSv4 protocol without requiring the definition of a
			new minor version.
			-->
	<t>		<t>
	<xref target="RFC8178" format="default" sectionFormat="of"/>		<xref target="RFC8178" format="default" sectionFormat="of"/> (see Section <x
	(see Section 4.4.2) allows for extending a particular minor		ref
	version of the NFSv4 protocol without requiring the definition		target="RFC8178" section="4.4.2" sectionFormat="bare"/>) allows for
	of a new minor version. The client can probe the capabilities of		extending a particular minor version of the NFSv4 protocol without
	the server and based on the result, determine if both it and the		requiring the definition of a new minor version. The client can
	server support optional features not previously specified as part		probe the capabilities of the server and, based on the result, determine if
	of the minor version.		both it and the server support optional features not previously specified
			as part of the minor version.
	</t>		</t>
	<t>		<t>
	The fattr4_open_arguments attribute is a new XDR extension which		The fattr4_open_arguments attribute is a new XDR extension that
	provides helpful support when the OPEN procedure is extended in		provides helpful support when the OPEN procedure is extended in
	such a fashion. It models all of the parameters via bitmap4 data		such a fashion. It models all of the parameters via bitmap4 data
	structures, which allows for the addition of a new flag to any of		structures, which allows for the addition of a new flag to any of
	the OPEN arguments (see Section 18.16.1 of <xref target="RFC8881"		the OPEN arguments (see <xref target="RFC8881" section="18.16.1" sectionForm
	format="default" sectionFormat="of"/>). The scope of this attribute		at="of"/>). The scope of this attribute
	applies to all objects with a matching fsid.		applies to all objects with a matching fsid.
	</t>		</t>
	<t>		<t>
	Two new flags are provided:		Two new flags are provided:
	</t>		</t>
	<ul spacing="normal">		<ul spacing="normal">
	<li>		<li>
	OPEN4_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION		OPEN4_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION
	(see <xref target="sec_open_xor" format="default" sectionFormat="of"/>)		(see <xref target="sec_open_xor" format="default" sectionFormat="of"/>)
	</li>		</li>
	<li>		<li>
	OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS		OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS
	(see <xref target="sec_proxy" format="default" sectionFormat="of"/>)		(see <xref target="sec_proxy" format="default" sectionFormat="of"/>)
	</li>		</li>
	</ul>		</ul>
	<t>		<t>
	Subsequent extensions can use this framework when introducing new		Subsequent extensions can use this framework when introducing new
	<bcp14>OPTIONAL</bcp14> functionality to OPEN, by creating a new		<bcp14>OPTIONAL</bcp14> functionality to OPEN by creating a new
	flag for each <bcp14>OPTIONAL</bcp14> parameter.		flag for each <bcp14>OPTIONAL</bcp14> parameter.
	</t>		</t>
	<t>		<t>
	Since fattr4_open_arguments is a <bcp14>RECOMMENDED</bcp14> attribute, if th e		Since fattr4_open_arguments is a <bcp14>RECOMMENDED</bcp14> attribute, if th e
	server informs the client via NFS4ERR_ATTRNOTSUPP that it does not support t his new		server informs the client via NFS4ERR_ATTRNOTSUPP that it does not support t his new
	attribute, the client <bcp14>MUST</bcp14> take this to mean that		attribute, the client <bcp14>MUST</bcp14> take this to mean that
	the additional new <bcp14>OPTIONAL</bcp14> functionality to OPEN		the additional new <bcp14>OPTIONAL</bcp14> functionality to OPEN
	is also not supported.		is also not supported.
	</t>		</t>
	<t>		<t>
	Some other concerns are how to process both currently		Some other concerns are how to process both currently
	<bcp14>REQUIRED</bcp14> flags and <bcp14>OPTIONAL</bcp14> flags		<bcp14>REQUIRED</bcp14> flags and <bcp14>OPTIONAL</bcp14> flags that
	which become <bcp14>REQUIRED</bcp14> in the future. The server		become <bcp14>REQUIRED</bcp14> in the future. The server
	<bcp14>MUST</bcp14> mark <bcp14>REQUIRED</bcp14> flags as being supported.		<bcp14>MUST</bcp14> mark <bcp14>REQUIRED</bcp14> flags as being supported.
	Note that these flags <bcp14>MUST</bcp14> only change from		Note that these flags <bcp14>MUST</bcp14> only change from
	<bcp14>OPTIONAL</bcp14> to <bcp14>REQUIRED</bcp14> when the NFSv4		<bcp14>OPTIONAL</bcp14> to <bcp14>REQUIRED</bcp14> when the NFSv4 minor
	minor version is incremented.		version is incremented.
	</t>		</t>
	<section anchor="ssec_open_xdr" numbered="true" removeInRFC="false" toc="defau lt">		<section anchor="ssec_open_xdr" numbered="true" toc="default">
	<name>XDR for Open Arguments</name>		<name>XDR for Open Arguments</name>
	<sourcecode name="" type="" markers="true"><![CDATA[
			<sourcecode name="" type="xdr" markers="true"><![CDATA[
	///		///
	/// struct open_arguments4 {		/// struct open_arguments4 {
	/// bitmap4 oa_share_access;		/// bitmap4 oa_share_access;
	/// bitmap4 oa_share_deny;		/// bitmap4 oa_share_deny;
	/// bitmap4 oa_share_access_want;		/// bitmap4 oa_share_access_want;
	/// bitmap4 oa_open_claim;		/// bitmap4 oa_open_claim;
	/// bitmap4 oa_create_mode;		/// bitmap4 oa_create_mode;
	/// };		/// };
	///		///
	///		///
	skipping to change at line 332 ¶		skipping to change at line 473 ¶
	/// % * Determine what OPEN supports.		/// % * Determine what OPEN supports.
	/// % */		/// % */
	/// const FATTR4_OPEN_ARGUMENTS = 86;		/// const FATTR4_OPEN_ARGUMENTS = 86;
	///		///
	///		///
	/// const OPEN4_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION = 0x200000;		/// const OPEN4_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION = 0x200000;
	///		///
	///		///
	/// const OPEN4_RESULT_NO_OPEN_STATEID = 0x00000010;		/// const OPEN4_RESULT_NO_OPEN_STATEID = 0x00000010;
	///		///
	]]>		]]></sourcecode>
	</sourcecode>
	</section>		</section>
	</section>		</section>
	<section anchor="sec_open_xor" numbered="true" removeInRFC="false" toc="default"		<section anchor="sec_open_xor" numbered="true" toc="default">
	>		<name>OPEN Grants Only One of Open or Delegation Stateid</name>
	<name>OPEN grants only one of Open or Delegation Stateid</name>
	<t>		<!-- [rfced] May we update "only one of" in the title of Section 4 as follows?
	The OPEN (See Section 18.16 of <xref target="RFC8881" format="default"
	sectionFormat="of"/>) procedure returns an open stateid to the		Original:
	client to reference the state of the file. The client could also		4. OPEN grants only one of Open or Delegation Stateid
	request a delegation stateid in the OPEN arguments. The file can
	be considered open for the client as long as the count of open		Perhaps:
	and delegated stateids is greater than 0. Either type of stateid		4. OPEN Grants Either an Open or a Delegation Stateid
	is sufficient to enable the server to treat the file as if it were		-->
	open, which allows READ (See Section 18.25 of <xref target="RFC8881"
	format="default" sectionFormat="of"/>), WRITE (See Section 18.38		<t>
	of <xref target="RFC8881" format="default" sectionFormat="of"/>),		The OPEN (see <xref target="RFC8881" section="18.16" sectionFormat="of"/>)
	LOCK (See Section 18.12 of <xref target="RFC8881" format="default"		procedure returns an open stateid to the client to reference the state of
	sectionFormat="of"/>), and LAYOUTGET (see Section 18.50 of <xref		the file. The client could also request a delegation stateid in the OPEN
	target="RFC8881" format="default" sectionFormat="of"/>) operations		arguments. The file can be considered open for the client as long as the
	to proceed. If the client gets both an open and a delegation stateid		count of open and delegated stateids is greater than 0. Either type of
	as part of the OPEN, then it has to return them both to the server. A furth		stateid is sufficient to enable the server to treat the file as if it were
	er		open, which allows READ (see <xref target="RFC8881" section="18.22"
	consideration is that during each operation, the client can send		sectionFormat="of"/>), WRITE (see <xref target="RFC8881" section="18.32"
	a costly GETATTR (See Section 18.7 of <xref target="RFC8881"		sectionFormat="of"/>), LOCK (see <xref target="RFC8881" section="18.10"
	format="default" sectionFormat="of"/>).		sectionFormat="of"/>), and LAYOUTGET (see <xref target="RFC8881"
			section="18.43" sectionFormat="of"/>) operations to proceed. If the client
			gets both an open and a delegation stateid as part of the OPEN, then it
			has to return them both to the server. A further consideration is that
			during each operation, the client can send a costly GETATTR (see <xref
			target="RFC8881" section="18.7" sectionFormat="of"/>).
	</t>		</t>
	<t>		<t>
	If the client knows that the server supports the		If the client knows that the server supports the
	OPEN4_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION flag (as determined by an		OPEN4_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION flag (as determined by an
	earlier GETATTR operation which queried for the fattr4_open_arguments		earlier GETATTR operation that queried for the fattr4_open_arguments
	attribute), then the client can supply that flag during the OPEN		attribute), then the client can supply that flag during the OPEN and
	and only get either an open or delegation stateid.		get either an open or a delegation stateid.
	</t>		</t>
			<!-- [rfced] We do not see "OPEN4resok.stateid" in Section 18.16.2 of RFC 8811.
			Should this be updated to "OPEN4resok"?
			Original:
			The open stateid field,
			OPEN4resok.stateid (see Section 18.16.2 of [RFC8881]), MUST be set to
			the special all zero stateid in this case.
			Perhaps:
			The open stateid field,
			OPEN4resok (see Section 18.16.2 of [RFC8881]), MUST be set to
			the special all-zero stateid in this case.
			-->
	<t>		<t>
	The client is already prepared to not get a delegation		The client is already prepared to not get a delegation
	stateid even if requested. In order to not send an open		stateid, even if requested. In order to not send an open
	stateid, the server <bcp14>MUST</bcp14> indicate that fact with the result		stateid, the server <bcp14>MUST</bcp14> indicate that fact with the result
	flag of OPEN4_RESULT_NO_OPEN_STATEID. The open stateid field,		flag of OPEN4_RESULT_NO_OPEN_STATEID. The open stateid field,
	OPEN4resok.stateid (see Section 18.16.2 of <xref target="RFC8881"		OPEN4resok.stateid (see <xref target="RFC8881" section="18.16.2" sectionForm
	format="default" sectionFormat="of"/>), <bcp14>MUST</bcp14> be set to the		at="of"/>), <bcp14>MUST</bcp14> be set to the
	special all zero stateid in this case.		special all-zero stateid in this case.
	</t>		</t>
	<t>
	Note that the OPEN4_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION flag		<!-- [rfced] Would it be helpful to update "then the server has three options"
	is a hint. The server might return both stateids. Consider		in one of the following ways?
	the scenario in which the client opens a file read-only (with
	OPEN4_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION set) and gets only		Original:
	an open stateid. If the client then opens the file for read-write		If the client then opens the file for read-write (with
	(with OPEN4_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION set), then		OPEN4_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION set), then the server has
	the server has three options:		three options:
			1. Only an open stateid with the correct seqid.
			2. Only a delegation stateid with the open stateid now having an
			incorrect seqid as it needs to be upgraded.
			3. Both an open (which will be upgraded) and a delegation stateid.
			Perhaps:
			If the client then opens the file for read-write (with
			OPEN4_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION set), the server
			can return one of the following three options:
			1. Only an open stateid with the correct seqid.
			2. Only a delegation stateid with the open stateid now having an
			incorrect seqid as it needs to be upgraded.
			3. Both an open stateid (which will be upgraded) and a delegation stateid.
			Or:
			If the client then opens the file for read-write (with
			OPEN4_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION set), then the server has
			three options. The server can return:
			1. only an open stateid with the correct seqid,
			2. only a delegation stateid (with the open stateid now having an
			incorrect seqid as it needs to be upgraded), or
			3. both an open stateid (which will be upgraded) and a delegation
			stateid.
			-->
			<t>
			Note that the OPEN4_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION flag is a
			hint. The server might return both stateids. Consider the scenario in
			which the client opens a file for read-only (with
			OPEN4_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION set) and only gets an open
			stateid. If the client then opens the file for read-write (with
			OPEN4_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION set), then the server has
			three options:
	</t>		</t>
	<ol>		<ol>
	<li>Only an open stateid with the correct seqid.</li>		<li>Only an open stateid with the correct seqid.</li>
	<li>Only a delegation stateid with the open stateid now having an incorrect seqid as it needs to be upgraded.</li>		<li>Only a delegation stateid with the open stateid now having an incorrect seqid as it needs to be upgraded.</li>
	<li>Both an open (which will be upgraded) and a delegation stateid.</li>		<li>Both an open stateid (which will be upgraded) and a delegation stateid.< /li>
	</ol>		</ol>
	<t>		<t>
	In this scenario, returning just a delegation stateid would hide information		In this scenario, returning just a delegation stateid would hide
	from the client. If the client already has an open stateid, then the		information from the client. If the client already has an open stateid,
	server <bcp14>SHOULD</bcp14> ignore the OPEN4_SHARE_ACCESS_WANT_OPEN_XOR_DEL		then the server <bcp14>SHOULD</bcp14> ignore the
	EGATION		OPEN4_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION flag and return both the open
	flag and return both the open and delegation stateids.		and delegation stateids.
	</t>		</t>
	<section anchor="delstid_analysis" numbered="true" removeInRFC="false" toc="de
	fault">		<section anchor="delstid_analysis" numbered="true" toc="default">
	<name>Implementation Experience</name>		<name>Implementation Experience</name>
	<t>		<t>
	The CLOSE operation (see Section		The CLOSE operation (see <xref target="RFC8881" section="18.2" sectionForm
	18.2 of <xref target="RFC8881" format="default" sectionFormat="of"/>)		at="of"/>)
	neither explicitly nor implicitly releases any		neither explicitly nor implicitly releases any
	delegation stateids. This is not symmetrical with the OPEN operation,		delegation stateids. This is not symmetrical with the OPEN operation,
	which can grant both an open and a delegation stateid. This specification		which can grant both an open and a delegation stateid. This specification
	could have tried to extend the CLOSE operation to release both		could have tried to extend the CLOSE operation to release both
	stateids, but implementation experience shows that is more costly		stateids, but implementation experience shows that is more costly
	than the approach which has been proposed.		than the approach that has been proposed.
	</t>		</t>
			<!-- [rfced] Please review "That takes" in the second sentence below. Would
			updating to "This involves" be an improvement? Also, would it be helpful
			to update the long third sentence to be a bulleted list?
			Original:
			Consider a small workload of creating a file with content. That
			takes 3 synchronous and 1 asynchronous operations with existing
			implementations. The first synchronous one has to OPEN the file, the
			second synchronous one performs the WRITE to the file, the third
			synchronous one has to CLOSE the file, and the fourth asynchronous
			one uses DELEGRETURN (see Section 18.6 of [RFC8881]) to return the
			delegation stateid.
			Perhaps:
			Consider a small workload of creating a file with content. This
			involves three synchronous operations and one asynchronous operation with exi
			sting
			implementations:
			* The first synchronous operation has to OPEN the file.
			* The second synchronous operation performs the WRITE to the file.
			* The third synchronous operation has to CLOSE the file.
			* The asynchronous operation uses DELEGRETURN (see Section 18.6 of [RFC8881])
			to return
			the delegation stateid.
			-->
	<t>		<t>
	Consider a small workload of creating a file with content. That		Consider a small workload of creating a file with content. That takes thre
	takes 3 synchronous and 1 asynchronous operations with existing		e
	implementations. The first synchronous one has to OPEN the file,		synchronous operations and one asynchronous operation with existing
	the second synchronous one performs the WRITE to the file, the third		implementations.
	synchronous one has to CLOSE the file, and the fourth asynchronous		The first synchronous operation has to OPEN the file;
	one uses DELEGRETURN (see Section		the second synchronous one performs the WRITE to the file;
	18.6 of <xref target="RFC8881" format="default" sectionFormat="of"/>)		the third synchronous one has to CLOSE the file; and
	to return the delegation stateid.		the asynchronous one uses DELEGRETURN (see <xref target="RFC8881"
			section="18.6" sectionFormat="of"/>) to return the delegation stateid.
	</t>		</t>
	<sourcecode name="" type="" markers="true"><![CDATA[		<sourcecode name="" type="" markers="true"><![CDATA[
	SEQ PUTFH OPEN GETFH GETATTR		SEQ PUTFH OPEN GETFH GETATTR
	SEQ PUTFH WRITE GETATTR		SEQ PUTFH WRITE GETATTR
	SEQ PUTFH CLOSE		SEQ PUTFH CLOSE
	...		...
	SEQ PUTFH DELEGRETURN		SEQ PUTFH DELEGRETURN
	]]>		]]></sourcecode>
	</sourcecode>
	<t>		<t>
	With the proposed approach of setting the		With the proposed approach of setting the
	OPEN_ARGS_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION flag during		OPEN_ARGS_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION flag during
	the OPEN, the number of operations is always 3. The first two		the OPEN, the number of operations is always three. The first two
	compounds are still synchronous, but the last is asynchronous. I.e.,		compounds are still synchronous, but the last is asynchronous. That is,
	since the client no longer has to send a CLOSE operation, it can		since the client no longer has to send a CLOSE operation, it can
	delay the DELEGRETURN until either the server requests it back		delay the DELEGRETURN until either the server requests it back
	via delegation recall or garbage collection causes the client to		via delegation recall or garbage collection causes the client to
	return the stateid.		return the stateid.
	</t>		</t>
	<sourcecode name="" type="" markers="true"><![CDATA[		<sourcecode name="" type="" markers="true"><![CDATA[
	SEQ PUTFH OPEN(OPEN_ARGS_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION)		SEQ PUTFH OPEN(OPEN_ARGS_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION)
	GETFH GETATTR		GETFH GETATTR
	SEQ PUTFH WRITE GETATTR		SEQ PUTFH WRITE GETATTR
	...		...
	SEQ PUTFH DELEGRETURN		SEQ PUTFH DELEGRETURN
	]]>		]]></sourcecode>
	</sourcecode>
	<t>		<t>
	This approach reduces the cost of synchronous operations by 33%		This approach reduces the cost of synchronous operations by 33%
	and the total number of operations by 25%. Contrast that against		and the total number of operations by 25%. Contrast that with
	the alternative proposal of having CLOSE return both stateids,		the alternative proposal of having CLOSE return both stateids,
	which would not reduce the number of synchronous operations.		which would not reduce the number of synchronous operations.
	</t>		</t>
	</section>		</section>
	</section>		</section>
	<section anchor="sec_proxy" numbered="true" removeInRFC="false" toc="default">		<section anchor="sec_proxy" numbered="true" toc="default">
	<name>Proxying of Times</name>		<name>Proxying of Times</name>
	<t>
			<!-- [rfced] For readability, may we adjust the text below as follows? In the
			suggested text below, we moved the phrase "to notify...values" to the
			beginning of the sentence and used a semicolon to split up the long
			sentence.
			Original:
			While the client could send a compound of the form: SEQ, PUTFH,
			SETATTR (time_modify | time_access), DELEGRETURN, to notify the
			server of the proxied values, that SETATTR (see Section 18.30 of
			[RFC8881]) operation would cause either or both of change (see
			Section 5.8.1.4 of [RFC8881]) or time_metadata (see Section 5.8.2.42
			of [RFC8881]) to be modified to the current time on the server.
			Perhaps:
			To notify the server of the proxied values, the client could send a
			compound of the form SEQ, PUTFH, SETATTR (time_modify |
			time_access), DELEGRETURN; however, the SETATTR operation (see
			Section 18.30 of [RFC8881]) would cause either or both of the change
			attribute (see Section 5.8.1.4 of [RFC8881]) or time_metadata
			attribute (see Section 5.8.2.42 of [RFC8881]) to be modified to the
			current time on the server.
			-->
			<!-- [rfced] Is "pass these times up" correct, or should this be updated to
			"pass on these times"?
			Original:
			As a result, it can not pass
			these times up to an application expecting POSIX compliance, as is
			often necessary for correct operation.
			Perhaps:
			As a result, it cannot pass on
			these times to an application expecting POSIX compliance, as is
			often necessary for correct operation.
			-->
			<t>
	When a client is granted a write delegation on a file, it becomes the		When a client is granted a write delegation on a file, it becomes the
	authority for the file contents and associated attributes. If the		authority for the file contents and associated attributes. If the server
	server queries the client as to the state of the file via a CB_GETATTR		queries the client as to the state of the file via a CB_GETATTR (see <xref
	(see Section 20.1 of <xref target="RFC8881" format="default"		target="RFC8881" section="20.1" sectionFormat="of"/>), then according to
	sectionFormat="of"/>), then, according to the unextended NFSv4		the unextended NFSv4 protocol, it can only determine the size of the file
	protocol, it can only determine the size of the file and the change		and the change attribute. In the case of the client holding the
	attribute. In the case of the client holding the delegation, it has		delegation, it has the current values of the access and modify times.
	the current values of the access and modify times. There is no way		There is no way that other clients can have access to these values. To
	that other clients can have access to these values. While the		notify the server of the proxied values, the client could send a compound
	client could send a compound of the form: SEQ, PUTFH,		of the form SEQ, PUTFH, SETATTR (time_modify | time_access), DELEGRETURN;
	SETATTR (time_modify | time_access), DELEGRETURN, to notify		however, the SETATTR operation (see <xref target="RFC8881" section="18.30"
	the server of the proxied values, that SETATTR (see Section 18.30 of <xref t		sectionFormat="of"/>) would cause either or both of the change attribute
	arget="RFC8881" format="default"		(see <xref target="RFC8881" sectionFormat="of" section="5.8.1.4"/>) or
	sectionFormat="of"/>) operation would		time_metadata attribute (see <xref target="RFC8881" section="5.8.2.42"
	cause either or both of change (see Section 5.8.1.4 of <xref target="RFC8881		sectionFormat="of"/>) to be modified to the current time on the server.
	" format="default"
	sectionFormat="of"/>) or time_metadata (see Section 5.8.2.42 of <xref target		There is no current provision to obtain these values before
	="RFC8881" format="default"		delegation return using CB_GETATTR. As a result, it cannot pass these
	sectionFormat="of"/>) to		times up to an application expecting POSIX compliance, as is often
	be modified to the current time on the server.		necessary for correct operation.
	There is no current provision to obtain these values before delegation
	return using CB_GETATTR. As a result, it can not pass these times up
	to an application expecting POSIX compliance, as is often necessary
	for correct operation.
	</t>		</t>
	<t>		<t>
	With the addition of the new flag:		With the addition of the new
	OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS, the client and server can		OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS flag, the client and server can
	negotiate that the client will be the authority for these values and		negotiate that the client will be the authority for these values, and upon
	upon return of the delegation stateid via a DELEGRETURN (see section		return of the delegation stateid via a DELEGRETURN (see <xref
	18.6 of <xref target="RFC8881" format="default" sectionFormat="of"/>),		target="RFC8881" section="18.6" sectionFormat="of"/>), the times will be
	the times will be passed back to the server. If the server is queried		passed back to the server. If the server is queried by another client for
	by another client for either the size or the times, it will need to		either the size or the times, it will need to use a CB_GETATTR to query
	use a CB_GETATTR to query the client which holds the delegation		the client that holds the delegation (see <xref target="RFC8881"
	(see Section 20.1 of <xref target="RFC8881" format="default"		section="20.1" sectionFormat="of"/>).
	sectionFormat="of"/>).
	</t>		</t>
			<!-- [rfced] May we update this sentence as follows to improve clarity? Note
			that the suggested text a) clarifies what "it" refers to, b) revises
			"fattr4_time_deleg_access attribute and fattr4_time_deleg_modify
			attribute changes", and c) updates "or reject" to ", or it MUST reject".
			Original:
			Further, when it gets a SETATTR with those attributes being set, then
			it MUST accept those fattr4_time_deleg_access attribute and
			fattr4_time_deleg_modify attribute changes and derive the change time
			or reject the changes with NFS4ERR_DELAY (see Section 15.1.1.3 of
			[RFC8881]).
			Perhaps:
			Further, when a server gets a SETATTR with those attributes set, then
			it MUST accept those changes in the fattr4_time_deleg_access and
			fattr4_time_deleg_modify attributes and derive the change time,
			or it MUST reject the changes with NFS4ERR_DELAY (see Section 15.1.1.3 of
			[RFC8881]).
			-->
	<t>		<t>
	If a server informs the client via the fattr4_open_arguments attribute		If a server informs the client via the fattr4_open_arguments attribute
	that it supports OPEN_ARGS_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS and		that it supports OPEN_ARGS_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS and it
	it returns a valid delegation stateid for an OPEN operation which		returns a valid delegation stateid for an OPEN operation that sets the
	sets the OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS flag, then it		OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS flag, then it <bcp14>MUST</bcp14>
	<bcp14>MUST</bcp14> query the client via a CB_GETATTR for the		query the client via a CB_GETATTR for the fattr4_time_deleg_access
	fattr4_time_deleg_access (see <xref target="ssec_proxy_xdr"/>)		attribute (see <xref target="ssec_proxy_xdr"/>) and the
	attribute and fattr4_time_deleg_modify attribute (see <xref		fattr4_time_deleg_modify attribute (see <xref
	target="ssec_proxy_xdr"/>). (The change time can be derived from		target="ssec_proxy_xdr"/>). (Note that the change time can be derived from
	the modify time.) Further, when it gets a SETATTR with those		the modify time.) Further, when it gets a SETATTR with those attributes
	attributes being set, then it <bcp14>MUST</bcp14> accept those		set, then it <bcp14>MUST</bcp14> accept those
	fattr4_time_deleg_access attribute and fattr4_time_deleg_modify		fattr4_time_deleg_access attribute and fattr4_time_deleg_modify
	attribute changes and derive the change time or reject the changes		attribute changes and derive the change time or reject the changes with
	with NFS4ERR_DELAY (see Section 15.1.1.3 of <xref target="RFC8881"		NFS4ERR_DELAY (see <xref target="RFC8881" section="15.1.1.3"
	format="default" sectionFormat="of"/>).		sectionFormat="of"/>).
	</t>		</t>
			<!-- [rfced] We are having trouble parsing the text after "either". Please
			clarify.
			Original:
			The SETATTR SHOULD either be in a
			separate compound before the one containing the DELEGRETURN or when
			in the same compound, as an operation before the DELEGRETURN.
			Perhaps:
			The SETATTR SHOULD be either 1) in a
			separate compound before the one containing the DELEGRETURN or 2)
			in the same compound as an operation before the DELEGRETURN.
			-->
	<t>		<t>
	These new attributes are invalid to be used with GETATTR, VERIFY, and NVERIF Y and		These new attributes are invalid to be used with GETATTR, VERIFY, and NVERIF Y, and they
	can only be used with CB_GETATTR and SETATTR by a client holding an		can only be used with CB_GETATTR and SETATTR by a client holding an
	appropriate delegation. The SETATTR <bcp14>SHOULD</bcp14> either be		appropriate delegation. The SETATTR <bcp14>SHOULD</bcp14> either be
	in a separate compound before the one containing the DELEGRETURN or		in a separate compound before the one containing the DELEGRETURN or
	when in the same compound, as an operation before the DELEGRETURN.		when in the same compound, as an operation before the DELEGRETURN.
	Failure to properly sequence the operations may lead to race conditions.		Failure to properly sequence the operations may lead to race conditions.
	</t>		</t>
	<t>		<t>
	A key prerequisite of this approach is that the server and client are		A key prerequisite of this approach is that the server and client are in
	in time synchronization with each other. Note that while the base		time synchronization with each other. Note that while the base NFSv4.2
	NFSv4.2 does not require such synchronization, the use of RPCSEC_GSS		does not require such synchronization, the use of RPCSEC_GSS typically
	typically makes such a requirement. When the client presents either		makes such a requirement. When the client presents either the
	fattr4_time_deleg_access or fattr4_time_deleg_modify attributes		fattr4_time_deleg_access or the fattr4_time_deleg_modify attribute to the
	to the server, the server <bcp14>MUST</bcp14> decide for both of		server, the server <bcp14>MUST</bcp14> decide for both of them whether the t
	them whether the time presented is before the corresponding		ime presented is:</t>
	time_access (see Section 5.8.2.37 of <xref target="RFC8881" format="default"
	sectionFormat="of"/>) or time_modify (see Section 5.8.2.43 of <xref target="		<!-- [rfced] FYI - We have reworked the text below to be a bulleted list for
	RFC8881" format="default"		ease of the reader. Please review.
	sectionFormat="of"/>) attribute
	on the file or past the current server time.		Original:
	When the time presented is before the original time, then the update		When the client presents either
	is ignored. When the time presented is in the future, the server		fattr4_time_deleg_access or fattr4_time_deleg_modify attributes to
	can either clamp the new time to the current time, or it may return		the server, the server MUST decide for both of them whether the time
	NFS4ERR_DELAY to the client, allowing it to retry. Note that if the		presented is before the corresponding time_access (see
	clock skew is large, the delay approach would result in access to		Section 5.8.2.37 of [RFC8881]) or time_modify (see Section 5.8.2.43
	the file being denied until the clock skew is exceeded.		of [RFC8881]) attribute on the file or past the current server time.
			Current:
			When the client presents either
			the fattr4_time_deleg_access or the fattr4_time_deleg_modify
			attributes to the server, the server MUST decide for both of them
			whether the time presented is:
			* before the corresponding time_access attribute (see Section 5.8.2.37 of
			[RFC8881]) or time_modify attribute (see Section 5.8.2.43 of [RFC8881])
			on the file, or
			* past the current server time.
			-->
			<ul>
			<li>before the corresponding time_access attribute (see <xref target="RFC8
			881" section="5.8.2.37" sectionFormat="of"/>) or time_modify attribute
			(see <xref target="RFC8881" section="5.8.2.43" sectionFormat="of"/>) on th
			e file, or</li>
			<li>past the current server time.</li>
			</ul>
			<t>When the time
			presented is before the original time, then the update is ignored. When
			the time presented is in the future, the server can either clamp the new
			time to the current time or return NFS4ERR_DELAY to the client,
			allowing it to retry. Note that if the clock skew is large, the delay
			approach would result in access to the file being denied until the clock
			skew is exceeded.
	</t>		</t>
	<t>		<t>
	A change in the access time <bcp14>MUST NOT</bcp14> advance the change time,		A change in the access time <bcp14>MUST NOT</bcp14> advance the change
	also known as the time_metadata attribute (see Section 5.8.2.42 of		time, also known as the time_metadata attribute (see <xref
	<xref target="RFC8881" format="default" sectionFormat="of"/>), but a		target="RFC8881" section="5.8.2.42" sectionFormat="of"/>). However, a
	change in the modify time might advance the change time (and in turn		change in the modify time might advance the change time (and in turn, the
	the change attribute (See Section 5.8.1.4 of <xref target="RFC8881"		change attribute; see <xref target="RFC8881" section="5.8.1.4"
	format="default" sectionFormat="of"/>). If the modify time is greater		sectionFormat="of"/>). If the modify time is greater than the change time
	than the change time and before the current time, then the change time		and before the current time, then the change time is adjusted to the
	is adjusted to the modify time and not the current time (as is most		modify time and not the current time (as is most likely done on most
	likely done on most SETATTR calls that change the metadata). If the		SETATTR calls that change the metadata). If the modify time is in the
	modify time is in the future, it will be clamped to the current time.		future, it will be clamped to the current time.
	</t>		</t>
	<t>		<t>
	Note that each of the possible times, access, modify, and change, are		Note that each of the possible times (access, modify, and change) are
	compared to the current time. They should all be compared against		compared to the current time. They should all be compared against
	the same time value for the current time. I.e., do not retrieve		the same time value for the current time (i.e., they do not retrieve
	a different value of the current time for each calculation.		a different value of the current time for each calculation).
	</t>		</t>
	<t>		<t>
	If the client sets the OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS		If the client sets the OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS
	flag in an OPEN operation, then it <bcp14>MUST</bcp14> support		flag in an OPEN operation, then it <bcp14>MUST</bcp14> support
	the fattr4_time_deleg_access		the fattr4_time_deleg_access
	and fattr4_time_deleg_modify attributes both in the CB_GETATTR		and fattr4_time_deleg_modify attributes in both the CB_GETATTR
	and SETATTR operations.		and SETATTR operations.
	</t>		</t>
	<section anchor="ssec_proxy_use" numbered="true" removeInRFC="false" toc="defa		<section anchor="ssec_proxy_use" numbered="true" toc="default">
	ult">		<name>Use Case for NFSv3 Client Proxy</name>
	<name>Use case: NFSv3 client proxy</name>
	<t>		<t>
	Consider a NFSv3 client which wants to access data on a server		Consider an NFSv3 client that wants to access data on a server
	which only supports NFSv4.2. An implementation may introduce an		that only supports NFSv4.2. An implementation may introduce an
	NFSv3 server that functions as an NFSv4.2 client, serving as a		NFSv3 server that functions as an NFSv4.2 client, serving as a
	gateway between the two otherwise incompatible systems. As NFSv3		gateway between the two otherwise incompatible systems. As NFSv3
	is a stateless protocol, the state is not kept on the client, but		is a stateless protocol, the state is not kept on the client, but rather
	rather the NFSv3 server. As the NFSv3 server is already managing the		on the NFSv3 server. As the NFSv3 server is already managing the
	state, it can proxy file delegations to avoid spurious GETATTRs.		state, it can proxy file delegations to avoid spurious GETATTRs. That is,
	I.e., as the client queries the NFSv3 server for the attributes,		as the client queries the NFSv3 server for the attributes,
	they can be served without the NFSv3 server sending a GETATTR to		they can be served without the NFSv3 server sending a GETATTR to
	the NFSv4.2 server.		the NFSv4.2 server.
	</t>		</t>
	</section>		</section>
	<section anchor="ssec_proxy_xdr" numbered="true" removeInRFC="false" toc="defa ult">		<section anchor="ssec_proxy_xdr" numbered="true" toc="default">
	<name>XDR for Proxying of Times</name>		<name>XDR for Proxying of Times</name>
	<sourcecode name="" type="" markers="true"><![CDATA[		<sourcecode name="" type="xdr" markers="true"><![CDATA[
	///		///
	/// /*		/// /*
	/// * attributes for the delegation times being		/// * attributes for the delegation times being
	/// * cached and served by the "client"		/// * cached and served by the "client"
	/// */		/// */
	/// typedef nfstime4 fattr4_time_deleg_access;		/// typedef nfstime4 fattr4_time_deleg_access;
	/// typedef nfstime4 fattr4_time_deleg_modify;		/// typedef nfstime4 fattr4_time_deleg_modify;
	///		///
	///		///
	/// %/*		/// %/*
	/// % * New RECOMMENDED Attribute for		/// % * New RECOMMENDED Attribute for
	/// % * delegation caching of times		/// % * delegation caching of times
	/// % */		/// % */
	/// const FATTR4_TIME_DELEG_ACCESS = 84;		/// const FATTR4_TIME_DELEG_ACCESS = 84;
	/// const FATTR4_TIME_DELEG_MODIFY = 85;		/// const FATTR4_TIME_DELEG_MODIFY = 85;
	///		///
	///		///
	/// const OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS = 0x100000;		/// const OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS = 0x100000;
	///		///
	]]>		]]></sourcecode>
	</sourcecode>
	</section>		</section>
	</section>		</section>
	<section anchor="xdr_desc" numbered="true" removeInRFC="false" toc="default">		<section anchor="xdr_desc" numbered="true" toc="default">
	<name>Extraction of XDR</name>		<name>Extraction of XDR</name>
	<t>		<t>
	This document contains the external data representation (XDR)		This document contains the XDR <xref
	<xref target="RFC4506" format="default" sectionFormat="of"/> description of		target="RFC4506" format="default" sectionFormat="of"/> description of the
	the new open		new open flags for delegating the file to the client. The XDR description
	flags for delegating the file to the client.		is embedded in this document in a way that makes it simple for the reader
	The XDR description is embedded in this		to extract into a ready-to-compile form. The reader can feed this
	document in a way that makes it simple for the reader to extract		document into the following shell script to produce the machine-readable
	into a ready-to-compile form. The reader can feed this document
	into the following shell script to produce the machine readable
	XDR description of the new flags:		XDR description of the new flags:
	</t>		</t>
	<sourcecode name="" type="" markers="true"><![CDATA[		<sourcecode name="" type="" markers="true"><![CDATA[
	#!/bin/sh		#!/bin/sh
	grep '^ *///' $* | sed 's?^ */// ??' | sed 's?^ *///$??'		grep '^ *///' $* | sed 's?^ */// ??' | sed 's?^ *///$??'
	]]>		]]></sourcecode>
	</sourcecode>
	<t>		<t>
	That is, if the above script is stored in a file called "extract.sh", and		That is, if the above script is stored in a file called "extract.sh" and
	this document is in a file called "spec.txt", then the reader can do:		this document is in a file called "spec.txt", then the reader can do the
			following:
	</t>		</t>
	<sourcecode name="" type="" markers="true"><![CDATA[		<sourcecode name="" type="" markers="true"><![CDATA[
	sh extract.sh < spec.txt > delstid_prot.x		sh extract.sh < spec.txt > delstid_prot.x
	]]>		]]></sourcecode>
	</sourcecode>
	<t>		<t>
	The effect of the script is to remove leading white space from each		The effect of the script is to remove leading white space from each
	line, plus a sentinel sequence of "///". XDR descriptions with the		line, plus a sentinel sequence of "///". XDR descriptions with the
	sentinel sequence are embedded throughout the document.		sentinel sequence are embedded throughout the document.
	</t>		</t>
	<t>		<t>
	Note that the XDR code contained in this document depends on types		Note that the XDR code contained in this document depends on types
	from the NFSv4.2 nfs4_prot.x file (generated from		from the NFSv4.2 nfs4_prot.x file (generated from <xref target="RFC7863"
	<xref target="RFC7863" format="default" sectionFormat="of"/>).		format="default" sectionFormat="of"/>). This includes both nfs types that
	This includes both nfs types that end with a 4, such as offset4,		end with a 4 (such as offset4 and length4) as well as more generic
	length4, etc., as well as more generic types such as uint32_t and		types (such as uint32_t and uint64_t).
	uint64_t.
	</t>		</t>
	<t>		<t>
	While the XDR can be appended to that from		While the XDR can be appended to that from
	<xref target="RFC7863" format="default" sectionFormat="of"/>,		<xref target="RFC7863" format="default" sectionFormat="of"/>,
	the various code snippets belong in their respective areas of		the various code snippets belong in their respective areas of
	that XDR.		that XDR.
	</t>		</t>
	</section>		</section>
	<section anchor="sec_security" numbered="true" removeInRFC="false" toc="default" >		<section anchor="sec_security" numbered="true" toc="default">
	<name>Security Considerations</name>		<name>Security Considerations</name>
	<t>		<t>
	While we are extending some capabilities for client delegation, there are no		While this document extends some capabilities for client delegation, there a
	new security concerns. The client cannot be queried by other clients as to		re
	the cached attributes. The client could report false data for the cached		no new security concerns. The client cannot be queried by other clients
	attributes, but it already has this ability via a SETATTR operation (see Sec		as to the cached attributes. The client could report false data for the
	tion		cached attributes, but it already has this ability via a SETATTR operation
	18.30 of <xref target="RFC8881" format="default" sectionFormat="of"/>).		(see <xref target="RFC8881" section="18.30" sectionFormat="of"/>).
	</t>		</t>
	</section>		</section>
	<section anchor="sec_iana" numbered="true" removeInRFC="false" toc="default">		<section anchor="sec_iana" numbered="true" toc="default">
	<name>IANA Considerations</name>		<name>IANA Considerations</name>
	<t>		<t>This document has no IANA actions.</t>
	There are no IANA considerations.
	</t>
	</section>		</section>
	</middle>		</middle>
	<back>		<back>
	<references>		<references>
	<name>References</name>
	<references>
	<name>Normative References</name>		<name>Normative References</name>
	<xi:include xmlns:xi="http://www.w3.org/2001/XInclude"		<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.2119.
	href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.2119		xml"/>
	.xml"/>		<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.4506.
	<xi:include xmlns:xi="http://www.w3.org/2001/XInclude"		xml"/>
	href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.4506		<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7862.
	.xml"/>		xml"/>
	<xi:include xmlns:xi="http://www.w3.org/2001/XInclude"		<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7863.
	href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.7862		xml"/>
	.xml"/>		<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8174.
	<xi:include xmlns:xi="http://www.w3.org/2001/XInclude"		xml"/>
	href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.7863		<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8178.
	.xml"/>		xml"/>
	<xi:include xmlns:xi="http://www.w3.org/2001/XInclude"		<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8881.
	href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8174		xml"/>
	.xml"/>
	<xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
	href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8178
	.xml"/>
	<xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
	href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8881
	.xml"/>
	</references>
	</references>		</references>
	<section numbered="true" removeInRFC="false" toc="default">		<section numbered="false" toc="default">
	<name>Acknowledgments</name>		<name>Acknowledgments</name>
	<t>		<t><contact fullname="Trond Myklebust"/>, <contact fullname="Tom
	Trond Myklebust, Tom Haynes, and David Flynn		Haynes"/>, and <contact fullname="David Flynn"/> all worked on the
	all worked on the prototype at Hammerspace.		prototype at Hammerspace.</t>
	</t>		<t><contact fullname="Dave Noveck"/>, <contact fullname="Chuck Lever"/>,
	<t>		<contact fullname="Rick Macklem"/>, and <contact fullname="Zaheduzzaman
	Dave Noveck, Chuck Lever, Rick Macklem, and Zaheduzzaman Sarker		Sarker"/> provided reviews of the document.</t>
	provided reviews of the document.		<t><contact fullname="Jeff Layton"/> provided experience from an
	</t>		implementation he authored.</t>
	<t>
	Jeff Layton provided experience from an implementation he authored.
	</t>
	</section>		</section>
	</back>		</back>
			<!-- [rfced] We updated the sourcecode type in Sections 2.1, 3.1, and 5.2 to
			"xdr". Please confirm that this is correct.
			Should the sourcecode type be set for the sourcecode in Sections 4.1 and 6?
			Note that the current list of preferred values for "type" is available at
			<https://www.rfc-editor.org/rpc/wiki/doku.php?id=sourcecode-types>.
			If the current list does not contain an applicable type, feel free to
			suggest additions for consideration. Note that it is also acceptable
			to leave the "type" attribute not set.
			-->
			<!-- [rfced] Please review the "Inclusive Language" portion of the online
			Style Guide <https://www.rfc-editor.org/styleguide/part2/#inclusive_language>
			and let us know if any changes are needed. Updates of this nature typically
			result in more precise language, which is helpful for readers.
			For example, please consider whether "white space" should be updated in the
			text below:
			Original:
			The effect of the script is to remove leading white space from each
			line, plus a sentinel sequence of "///".
			-->
	</rfc>		</rfc>
End of changes. 101 change blocks.
	356 lines changed or deleted		708 lines changed or added
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