Last Call Review of draft-ietf-nfsv4-rfc3530-migration-update-07
review-ietf-nfsv4-rfc3530-migration-update-07-genart-lc-davies-2016-01-22-00
| Request | Review of | draft-ietf-nfsv4-rfc3530-migration-update |
|---|---|---|
| Requested revision | No specific revision (document currently at 08) | |
| Type | Last Call Review | |
| Team | General Area Review Team (Gen-ART) (genart) | |
| Deadline | 2016-01-19 | |
| Requested | 2016-01-14 | |
| Authors | David Noveck , Piyush Shivam , Chuck Lever , Bill Baker | |
| Draft last updated | 2016-01-22 | |
| Completed reviews |
Genart Last Call review of -07
by
Elwyn B. Davies
(diff)
Genart Last Call review of -07 by Elwyn B. Davies (diff) Opsdir Telechat review of -07 by Victor Kuarsingh (diff) |
|
| Assignment | Reviewer | Elwyn B. Davies |
| State | Completed | |
| Review |
review-ietf-nfsv4-rfc3530-migration-update-07-genart-lc-davies-2016-01-22
|
|
| Reviewed revision | 07 (document currently at 08) | |
| Result | Ready with Nits | |
| Completed | 2016-01-22 |
review-ietf-nfsv4-rfc3530-migration-update-07-genart-lc-davies-2016-01-22-00
Hi, David.
Thanks for the rapid response!
The majority of suggested mods look sensible. If you have a draft
version, please send it along and I'll do a quick comparison if that
would help. I'll not push any further on the 'boot verifier'
stuff. The only one that I am still a bit dubious about is the
server judging that a change of auth flavor is bona fide - I
understand that this should be a rare occurrence but attackers are
good at exploiting rare occurrences if it could be misused! I am
not sufficient of a security geek to know if this is an exploitable
hole.
As regards the fs-location issue, I think it would be worth putting
in a brief note on the retention of fs information while we remember
that there is something to consider. I guess that the advice is to
retain some limited history about fs's that were managed
previously. A pointer to s8.3.1 of RFC 7530 would be helpful. One
suggestion would be to modify the checking process so that it
suggests using the root filehandle of the moved fs rather than
allowing for a enquiry on any old fh that used to be in the moved
fs.. Then the server would only have to remember the root fh that
it handed out and the known locations of the now-absent file system
that has moved and the client would be bound to have (or at least
have had) the root fh. However, this is way above my pay grade!
Apologies for missing the moved open-owner/lock-owner descriptions.
Cheers,
Elwyn
On 20/01/2016 17:57, David Noveck
wrote:
I think I've addressed everything that I can at
this point. In what follows, one should assume that anything
from the review that is not mentioned has been dealt with as
suggested.
First, let me mention a few items where it is unclear how
we would proceed.
> With respect to s4:
> In s9.1.1, para 1 of RFC 7530 there is:
...
> There is nothing in the update about servers that
don't support the CLAIM_DELEGATE_PREV claim type. Should
something be said about this?
I think so. It
looks like this paragraph was lost in the general
re-organization. I've moved it back into the new draft,
edited to reflect the new context.
There's one
potential issue that we may or may not want to address
now. While the paragraph as written is correct, it is
unclear about the case of servers which do support the
CLAIM_DELEGATE_PREV type. It should be made clearer that all delegation state
not associated with requests of this type, independent of server support for
this request type, is released
I'm not sure whether it is best to deal with this issue now, or later, via the
errata process.
> s5.1.3: When a file system is migrated, the source
server is queried about the new location of the file system
> using GETATTR(fs_locations). Since the file system
involved has migrated, the server no longer has a connection
> with the relevant file system but still needs to
respond to the GETATTR appropriately. Does there need to be
some
> discussion of how long the server needs to hang onto
information that will allow it to respond to these requests,
> particularly since the suggested means of discovery
uses an arbitrary file from the file system. It is possible
that I
> have missed something or my understanding/memory of
how fs_locations works is faulty.
Let me me give you some background here:
This document was done to deal with issues related to
the handling related to locking state and migration.
in the case in which a client haas locking state on
the migrated fs, there is a mechanism described for him
to find out pretty quickly (i.e within lease time) about
the migration, since it is necessary for him to find out
about the change so he can renew the lease on
the destination server.
In the other case, i.e., the one in which there is no
locking state, there is no urgency about notifying the
client ofthe change and
implementation should probably hold on to
this information for a long time, although I don't think
RFC7530 says much about this.
Regarding "the suggested means of discovery uses an
arbitrary file from the file system", I don't think you
should conclude that a lot of information needs to be
kept. I think implementation will look at the fsid
field an return NFS4ERR_MOVED based on the fsid field of
the handle. Since the fs has moved they have no way
of checking that the other file handle fields are valid
anyway. I don't think RFC7530 addresses this either.
There are two possible ways of dealing with this set of
issues:
deciding that this set of issues is basically
out-of-scope for this document since the focus is to be
on state management and leave these other migration
issues for another day.
I could write a new short section 6.x, entitled
"Retention of fs-location information"
----------------------------------------------------------------------------------------------------------------------------------
From here on, I've dealt with the suggestion in some
way, although not necessarily the way suggested in the
review.
> s3 , para 6/s4.1, para 7: The terms 'client boot
instance' and (subsequently) 'boot verifier' are not used in
> RFC 7530. s9.1.1 uses the term 'client incarnation
verifier' (and this term is actually used in s4.1 , para 10
> (second bullet after nfs_client_id4 data structure
definition). I personally think is a more descriptive
term.
> I would be inclined to replace 'boot verifier' with
'incarnation verifier' throughout, and provide a definition
in
> a terminology section (see above).
I disagree. The way that a new incarnation of an nfs
client is created is generally referred to as 'booting"
which would be clearer to those implementing clients.
> This could also cover the case where the incarnation
verifier is changed because the structure is destroyed
> rather then the client host (as noted in s4.6)
although the intention is that it should only change on a
reboot.
I think the case you are referring to is describing broken
clients who used a different verifier on the same boot for a
new instance of mount. I think using the terms boot
instance and boot verifier were intended to make it clearer
that that is not the idea behind these fields.
What I wound up doing here is saying that a "boot
instance id" (defined in the new Terminology section) is to
be used as the appropriate value to be placed in the verfer
field of the nfs_clirnt_id structure. The definition of
verifier in the Terminology section is generalized so that
it covers all the many verifier4's in NFSv4.0 but states
that it most often used to indicate the verifier field in
the nfs_client_id structure.
> The general description of the distinction between open
owners and lock owners in para 2, 3 and 4 of s9.1.1 is lost
if the new text is taken as a
> true replacement of s9.1.1. This is undesirable.
I verified that the corresponding paragraphs are there.
They are now the third, fourth and fifth
complete paragraphs on page 7
> s7.4.5.1: It would be helpful to indicate the if-then
structure of the bullets by making current bullets 3 and 4
sub-bullets of bullet 2. Indeed, on second thoughts, it is
not clear which 'if' (either that in bullet 2 or bullet 3)
> the 'otherwise' in bullet 4 applies to. Please make
the logic clearer.
I reworded to make things clearer.
> General: Lack of terminology section. There are a
number of terms that might be advantageously
> incorporated into a terminology section - lock
types, client id, stateid, incarnation verifier (and its
relation
> to reboots/'boot verifier'), server (address)
trunking, open owners, lock owners spring to mind.
A Terminology section was created, based on the General
Definitions section of RFC7530.
> s4.1, last para: The concept of 'server trunking'
needs to be defined. NFSv4.0 per RFC 7530 does
> not have this concept - it is introduced in NFSv4.1,
thus somebody looking from the PoV of a 4.0 implementer
> need not know anything about trunking.
Defined in Terminology section.
> Should 'clientid causes the clientid4' be 'client ID
causes the clientid4'?
Yes.
>There are 10 other instances of clientid (rather than
clientid4) where the same question applies.
most instances of "clientid" have become "clientid4".
> s4.2, para after last bullet on p9:
...
>
Which error is
meant? There isn't one mentioned in this para - I guess
_STALE_CLIENTID but could be 'any of the above errors'.
It now says "In cases of server or client error resulting
in a clientid4 becoming unusable"
> s4.2, para last but two:
> In the last two cases, different recovery procedures are required.
> See Section 5.1.1 for details.
>
It isn't clear
which cases you are referring to here... the last two
bullets two paras before or the last two cases referred to
in the previous para out of
> In the event of a server reboot, loss of lease state due to lease
> expiration, or administrative revocation of a clientid4, the client
> Please make this more explicit.
It now says "In cases in which loss of server knowledge of a clientid4 is the
result of migration"
>
Which of the three
events in the previous para is being referred to?
Presumably the deliberate change of the primcipal since the
other two are not really recognizable in a controlled way.
;-)
It now says "In situations in which there is an apparent
change of principal"
> s4.8, last para on page 17:
...
>I am unclear why (and, indeed, how) the target IP
address needs to be incorporated in the callback
parameters.
> AFAICS, the process described in this section does
not examine a callback (by this I mean the results of one
of
> the CB_xxx operations) as part of the process of
trunking determination. The choice of callback_ident
(which
> appears to be the only relevant parameter) seems
more likely to be appropriately selected in line with the
statement
> later in the process (on page 19):
...
>but chosen so that they would be appropriate if the
server doesn't end up trunked with any other existing client
ID.
The intention was that it was to be appropriate, as a
default in the untrunked case. That's been made clearer.
...
> Clearly the IP address would be a convenient
semi-random value which would work to identify the callback
uniquely
> eventually but the selected value doesn't seem to
have any effect on the algorithm.
The selected value is not intended to have an effect on
the algorithm. Instead, you want the appropriate value
to be be assigned as a result of the algorithm.
>
s4.8, para 1 on
page 18:
...
> I am not clear how this interacts with the variation of
the definition of NFS4ERR_CLID_INUSE given in s7.2.
It doesn't at all.
> Would I expect the server to accept authentication
flavors other than the one already used for another address
leading
> to the same server? s7.2 says that the server MAY
accept a different flavor if it thinks the request is bona
fide. I
> don't understand what might or might not lead the
server to think an alternative flavor was bona fide - and
would it
> be likely to apply in this case?
Note that this error is very unlikely to occur. The only
way is through administrative confusion in which a client
supports multiple flavors/principals to connect to
different servers and gets confused about which is which,
and
find that two servers that it thought required different
principals were really the same server. This is only in
the algorithm because one cannot prove that it won't
happen.
> s4.9, last set of bullets: Should the draft also advise
applying a one way function to the MAC address for privacy
reasons?
added. I hope this will also address the issues mentioned
in Alissa's DISCUSS.
> s4.8, page 18:
...
> I suspect that the second para in the section quoted
here is not intended to be part of the bullet, and should be
unindented.
The largest part of it has been. There is still a brief
second paragraph in the bullet to link this material to the
bullet since it only is prompted by the case on that vullet.
> s5.1, para 2: It would be desirable to mention that the
change from big endian in [RFC7530] to network byte order is
purely terminological.
Yes. I just say "in network byte order (i.e., in a
big-endian format)"
> s5.1.1.2, para 5: How does the server know that the
client has been implemented to isolate owners to a
particular filesystem? Looking at the next para, I suspect
that the server doesn't know - it merely observes that
owners don't sprerad across multiple file systems at the
time of migration but there is no guarantee - and it doesn't
matter - that the client might not have owners that spread
across filesystems some time.
Right. Rewritten to make this clearer.
> s
5.1.1.2, para 7 on
page 29
> I can't parse the last line of this sentence.
I've rewritten this to be clearer.
>
s6.2, para 7 on
page 37:
...
> I don't understand what this criterion is driving
at. The second sentence appears to be aimed at identifying
the time associated with some action that is associated with
the earliest-started request but doesn't actually say what
it is AFAICS.
Hope this is clearer now.
On Mon, Jan 18, 2016 at 2:04 PM, David
Noveck
<
davenoveck at gmail.com
>
wrote:
Thanks for the review.
With regard to the minor issues:
> With respect to s4:
> In s9.1.1, para 1 of
RFC 7530 there is:
...
> There is nothing in the update about servers
that don't support the CLAIM_DELEGATE_PREV claim
type. Should something be said about this?
I think so. It looks like this paragraph was lost
in the general re-organization. I'll figure out where
this makes sense to put.
There's one potential issue that we may or may want
to address now. While the paragraph as written is
correct, it is unclear about the case of server which
do support the
CLAIM_DELEGATE_PREV type. It should be made clearer that all delegation state
not associated with requests of this type, independent of server support for
this request type, is released
I'm not sure whether it is best to deal with this issue now, or later, via the
errata process.
> The general
description of the distinction between open owners
and lock owners in para 2, 3 and 4 of s9.1.1 is
lost if the new text is taken as a true
replacement of s9.1.1. This is undesirable.
Actually the
corresponing paragraphs are there. They are now the
third, fourth and fifth complete paragraphs on page
7.
On Mon, Jan 18, 2016 at 9:02
AM, Elwyn Davies
<
elwynd at folly.org.uk
>
wrote:
I am the
assigned Gen-ART reviewer for this draft. The
General Area
Review Team (Gen-ART) reviews all IETF documents
being processed
by the IESG for the IETF Chair. Please wait for
direction from your
document shepherd or AD before posting a new
version of the draft.
For more information, please see the FAQ at
<http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq>
.
Document:
draft-ietf-nfsv4-rfc3530-migration-update-07.tx
Reviewer: Elwyn Davies
Review Date: 2016/01/16
IETF LC End Date: 2016/01/18
IESG Telechat date: 2016/01/18
Summary: Almost ready. There are a few minor
issues and a considerable number of nits that
need attention. The text is extremely complex
and in some places the logic is not entirely
clear. I would encourage the authors to revisit
the various usages of RFC 2119 language; a
number of the instances, especially several of
the 'SHOULDs', appear to refer to operational or
administrative decisions rather than matters
that affect the protocol - and are therefore not
actionable by the receiving implementation. If
appropriate the language should be modified.
Major issues:
------------------
None
Minor issues:
------------------
Bits possibly not covered from RFC 7530:
---------------------------------------------------------
With respect to s4:
In s9.1.1, para 1 of RFC 7530 there is:
Breaking
the lease state amounts to the server removing all lock, share
reservation, and, where the server is not supporting the
CLAIM_DELEGATE_PREV claim type, all delegation state associated with
the same client with the same identity. For a discussion of
delegation state recovery, see
Section 10.2.1
.
There is nothing in the update about servers
that don't support the CLAIM_DELEGATE_PREV claim
type. Should something be said about this?
The general description of the distinction
between open owners and lock owners in para 2, 3
and 4 of s9.1.1 is lost if the new text is taken
as a true replacement of s9.1.1. This is
undesirable.
------------------------------------------
Items in the text of this draft:
-----------------------------------------
s5.1.3: When a file system is migrated, the
source server is queried about the new location
of the file system using GETATTR(fs_locations).
Since the file system involved has migrated, the
server no longer has a connection with the
relevant file system but still needs to respond
to the GETATTR appropriately. Does there need
to be some discussion of how long the server
needs to hang onto information that will allow
it to respond to these requests, particularly
since the suggested means of discovery uses an
arbitrary file from the file system. It is
possible that I have missed something or my
understanding/memory of how fs_locations works
is faulty.
s7.4.5.1: It would be helpful to indicate the
if-then structure of the bullets by making
current bullets 3 and 4 sub-bullets of bullet
2. Indeed, on second thoughts, it is not clear
which 'if' (either that in bullet 2 or bullet 3)
the 'otherwise' in bullet 4 applies to. Please
make the logic clearer.
s7.5, bullet 1: Surely the decision as to
whether privacy is needed is an
administrative/operational deployment decision?
Transfer integrity is vital and provision should
be made for transfer privacy to be possible if
the installation requires it, but I can't see
that privacy needs to be ensured in all possible
circumstances.
=======================
Nits/editorial comments:
-----------------------------------
General: s/e.g. /e.g., /g (5 instances); s/i.e.
/i.e., /g (5 instances).
General (in s5): s/openowner/open-owner/g;
s/lockowner/lock-owner/g
General: s/filesystem/file system/g (In line
with usage in RFC 7530).
General: Lack of terminology section. There are
a number of terms that might be advantageously
incorporated into a terminology section - lock
types, client id, stateid, incarnation verifier
(and its relation to reboots/'boot verifier'),
server (address) trunking, open owners, lock
owners spring to mind.
s3 , para 6/s4.1, para 7: The terms 'client boot
instance' and (subsequently) 'boot verifier' are
not used in RFC 7530. s9.1.1 uses the term
'client incarnation verifier' (and this term is
actually used in s4.1 , para 10 (second bullet
after nfs_client_id4 data structure
definition). I personally think is a more
descriptive term. I would be inclined to
replace 'boot verifier' with 'incarnation
verifier' throughout, and provide a definition
in a terminology section (see above). This
could also cover the case where the incarnation
verifier is changed because the structure is
destroyed rather then the client host rebooting
(as noted in s4.6) although the intention is
that it should only change on a reboot.
s3, 2nd set of bullets, bullets 2 and 3; Also
s4.9, para 1: s/client id/client id string/
s3, last bullet: It would be worth pointing out
that there is a complete revision of the
definition of the SETCLIENTID operation. This
is relevant because there is a pointer to the
definition of SETCLIENTID in s4.
s4: Correct section names from RFC 7530..
OLD:
The replaced sections are named "client ID" and
"Server Release of Clientid."
NEW:
The replaced sections are named "Client ID" and
"Server Release of Client ID."
END
s4.1, bullet 1: s/client IP address/the client
IP address/
s4.1,bullet 2: I would replace 'save' by
'maintain a non-volatile record across reboots
of' to make it clear what is intended.
s4.1, last para: The concept of 'server
trunking' needs to be defined. NFSv4.0 per RFC
7530 does not have this concept - it is
introduced in NFSv4.1, thus somebody looking
from the PoV of a 4.0 implementer need not know
anything about trunking.
s4.2: Section references to relevant parts of
RFC 7530 that provide definitions of structures
and operations would be helpful here.
s4.2, bullet 1 of second set of bullets (under
struct nfs_client_id):
The id field is a variable-length string which uniquely identifies
a specific client. Although, we describe it as a string and it is
often referred to as a "client string," it should be understood
that the protocol defines this as opaque data.
Later on s5.1 recommends that opaque data such
as this should be encoded in network byte
order. It would be helpful to repeat or
introduce this recommendation (make it a
MUST???) here to ensure that the id will be
identical on servers of whatever endianess.
Also the term 'network byte order' is primarily
relevant to data for which the internal
representation is a (binary) number. A better
way of saying this might be 'the encoding and
decoding processes (e.g., using network byte
order for the external representation) for the
opaque data result in the same internal
representation whatever the endianness of the
originating and receiving machines' even if it
is somewhat more long winded.
s4.2, para 20 (across the boundary between p7
and p8):
This shorthand client identifier (a client ID) is
assigned by the server and should be chosen so that it will not
conflict with a client ID previously assigned by same server. This
applies across server restarts or reboots.
Would there be any advantage to recommending
that servers should try to generate clientid4's
that are unique to the server as far as possible
as well as different across reboots, etc.? It
would appear to minimise the risk of clashes
during migrations but this may be unnecessarily
complicated and the client has to cope with the
remote possibility anyway. I note that there is
a statement in s4.8, para 4 on page 19
Given that it is already highly unlikely that the clientid XC is
duplicated by distinct servers, the probability that SCn is
duplicated as well has to be considered vanishingly small.
Adding the recommendation would support this
statement.
s4.2, para 7 on page 8:
s/of administrative action,/of administrative
action./ (swap comma for period/full stop)
s4.2, last bullet:
o Merger of state under the associated lease with another lease
under a different clientid causes the clientid4 serving as the
source of the merge to cease being recognized on its server.
(Always returns NFS4ERR_STALE_CLIENTID)
Should 'clientid causes the clientid4' be
'client ID causes the clientid4'?
There are 10 other instances of clientid (rather
than clientid4) where the same question applies.
s4.2, para after last bullet on p9:
In
cases of server or client error resulting in this error, use of
SETCLIENTID to establish a new lease is desirable as well.
Which error is meant? There isn't one mentioned
in this para - I guess _STALE_CLIENTID but could
be 'any of the above errors'.
s4.2, page 9.
(See the section entitled "Server Failure and Recovery")
and
(see the section entitled "lock-owner" for
details)
I take these are intended to be sections in
RFC 7530 (respectively 9.6.2 and 9.1.5) -
adding these section numbers and the RFC ref
would be helpful.
s4.2, para last but two:
In the last two cases, different recovery procedures are required.
See Section 5.1.1 for details.
It isn't clear which cases you are referring to
here... the last two bullets two paras before or
the last two cases referred to in the previous
para out of
In the event of a server reboot, loss of lease state due to lease
expiration, or administrative revocation of a clientid4, the client
Please make this more explicit.
s4.2, last para:
See the detailed descriptions of SETCLIENTID and SETCLIENTID_CONFIRM
for a complete specification of these operations.
Section references would help, plus a note that
the definition of SETCLIENTID is now in this
document (s7.4) rather than Section 16.33 of
[RFC7530]. SETCLIENTID_CONFIRM is at Section
16.34 of [RFC7530].
s4.3, last para:
In that event, when the server gets a SETCLIENTID specifying a client
id string for which the server has a clientid4
Which of the three events in the previous para
is being referred to? Presumably the deliberate
change of the primcipal since the other two are
not really recognizable in a controlled way. ;-)
s4.4, 2nd bullet on page 11 (para 7):
the client to be
aware when two server IP addresses are connected to the same
server (they return the same server name in responding to an
EXCHANGE_ID).
The comment about 'return[ing] the same server
name' in NFSv4.1 is not the real reason the
client is sure they are the same server. Would
suggest changing this to '(Section 2.10.5.1 of
[RFC5661] explains how the client is able to
assure itself that the connections are to the
same logical server.)'
s4.4, 3rd bullet on page 11 (para 9): Suggest
adding a reference to the fs_locations
discussions in RFC 7530 - Perhaps '(see Sections
8.1 and 8.42 of [RFC7530])'.
s4.4. 4th bullet on page 11 (para 10):
in that the two different
client id strings sent to different IP addresses may wind up on
the same IP address, adding confusion.
The phrase 'same IP address' doesn't really
express what is going on IMO. Perhaps 'same
(logical) server'.
s4.5, para 3: s/per server network
addresses./per server network address./
s4.5, last para:
Therefore, client implementations
that support migration with transparent state migration SHOULD NOT
use the non-uniform client id string approach, except where it is
necessary for compatibility with existing server implementations
Arguably, this is an operational decision rather
than something that affects the protocol...
possibly s/SHOULD NOT/should not/.
s4.6, para 10: s/typically the reboot
time./typically at reboot time./
s4.7, para 6: s/the spec/this specification/
s4.7, para 8: Spurious double quote (") at end
of para:
enable transparent state migration."
s4.7, para 9: Missing period/full stop at end of
para.
s4.8, para 3: s/blind-sided/surprised/
(blind-sided is rather too idiomatic).
s4.8, para 7: s/Servers MUST NOT do
that./Servers MUST NOT behave in this way./
s4.8, last para on page 17:
In this algorithm, when SETCLIENTID is done it will use the common
nfs_client_id4 and specify the current target IP address as part of
the callback parameters.
I am unclear why (and, indeed, how) the target
IP address needs to be incorporated in the
callback parameters. AFAICS, the process
described in this section does not examine a
callback (by this I mean the results of one of
the CB_xxx operations) as part of the process of
trunking determination. The choice of
callback_ident (which appears to be the only
relevant parameter) seems more likely to be
appropriately selected in line with the
statement later in the process (on page 19):
The specific callback
parameters chosen, in terms of cb_client4 and callback_ident, are
up to the client and should reflect its preferences as to callback
handling for the common clientid, in the event that X and IPn are
trunked together.
but chosen so that they would be appropriate if
the server doesn't end up trunked with any other
existing client ID. Clearly the IP address
would be a convenient semi-random value which
would work to identify the callback uniquely
eventually but the selected value doesn't seem
to have any effect on the algorithm.
s4.8, para 1 on page 18:
Note that when the client has done previous SETCLIENTID's, to any IP
addresses, with more than one principal or authentication flavor, we
have the possibility of receiving NFS4ERR_CLID_INUSE, since we do not
yet know which of our connections with existing IP addresses might be
trunked with our current one. In the event that the SETCLIENTID
fails with NFS4ERR_CLID_INUSE, one must try all other combinations of
principals and authentication flavors currently in use and eventually
one will be correct and not return NFS4ERR_CLID_INUSE.
I am not clear how this interacts with the
variation of the definition of
NFS4ERR_CLID_INUSE given in s7.2. Would I
expect the server to accept authentication
flavors other than the one already used for
another address leading to the same server?
s7.2 says that the server MAY accept a different
flavor if it thinks the request is bona fide. I
don't understand what might or might not lead
the server to think an alternative flavor was
bona fide - and would it be likely to apply in
this case?
s4.9, last set of bullets: Should the draft also
advise applying a one way function to the MAC
address for privacy reasons?
s4.8, page 18:
o If one or more matching clientid4's is found, none of which is
marked unresolved, the new IP address X is entered and marked
unresolved. A SETCLIENTID_CONFIRM is done to X using XC and XV.
After applying the steps below to each of the lead IP addresses
with a matching clientid4, the address will have been resolved: It
may have been determined to be part of an already known server as
a new IP address to be added to an existing set of IP addresses
for that server. Otherwise, it will be recognized as a new
server. At the point at which this determination is made, the
unresolved indication is cleared and any suspended SETCLIENTID
processing is restarted
I suspect that the second para in the section
quoted here is not intended to be part of the
bullet, and should be unindented.
-----------------
s5.1, para 2: It would be desirable to mention
that the change from big endian in [RFC7530] to
network byte order is purely terminological.
s5.1.1, para 1:
In the case of migration, the servers involved in the migration of a
filesystem SHOULD transfer all server state associated with the
migrating filesystem from source to the destination server.
Arguably this SHOULD is an operational
decision. It does not affect the protocol or
the format of the bits on the wire. Accordingly
I suggest s/SHOULD/should/. This corresponds
with the discussion in [RFC7530]. On the other
hand:
This
must be done in a way that is transparent to the client.
is probably a MUST: s/This must be done/If state
is transferred it MUST be done/
s5.1.1, para 7: s/NFS version 4.0 protocol/NFS
version 4.0 protocol (either in [RFC7530] or
this update)/
s5.1.1, para 12:
When a
server implements migration and it does not transfer state
information, it SHOULD provide a filesystem-specific grace period, to
allow clients to reclaim locks associated with files in the migrated
filesystem.
I believe this is a MUST rather than a SHOULD.
The alternative of not doing it doesn't look
good! If so the last sentence of s5..1.1 needs
adapting to match.
s5.1.1.1: The {v, X, c} notation needs to be
defined (presumably as used in s7.4 and Section
16.33 of [RFC7530]). Section references in this
doc or [RFC7530] ought to be provided for
SETCLIENTID (**s7.4 in this doc**) and
SETCLIENTID_CONFIRM (s16.34 of [RFC7530]).
s5.1.1.2, para 5: How does the server know that
the client has been implemented to isolate
owners to a particular filesystem? Looking at
the next para, I suspect that the server doesn't
know - it merely observes that owners don't
sprerad across multiple file systems at the time
of migration but there is no guarantee - and it
doesn't matter - that the client might not have
owners that spread across filesystems some time.
s5.1.1.2, para 7 on page 29:
Such support only needs to be
provided for requests issued before the migration event whose status
as the last by sequence is invalidated by the migration event.
I can't parse the last line of this sentence.
s5.1.1.2, 1st and 2nd bullets on page 30: s/the
last request for the owner in effect/the
sequence number for the last request for the
owner in effect/; s/longer one less the next
sequence to be received./longer one less than
the next sequence to be received./
------------------------
s6.2, para 4:
o Some operations which modify locking state are not allowed to
return NFS4ERR_DELAY.
I think it be worth mentioning which operations
these are in this para. Inspection of Table 7
in RFC7530 indicates to me that the relevant
operations are OPEN_CONFIRM and
RELEASE_LOCKOWNER plus possibly RENEW. GETFH,
RESTOREFH, SAVEFH and ILLEGAL don't return
NFS4ERR_DELAY but don't appear to affect the
locking state. I observe that all of these are
mentioned explicitly except for OPEN_CONFIRM:
Does anything need to be said about this extra
case?
s6.2, para 6 on page 37: s/cannot change target
filesystem locking state,/cannot change the
target file system locking state,/
s6.2, para 7 on page 37:
o Keeping track of the earliest request started which is still in
execution (for example, by keeping a list of active requests
ordered by request start time). The server can then define T' to
be the first time at which the earliest-started active request
started after time T.
I don't understand what this criterion is
driving at. The second sentence appears to be
aimed at identifying the time associated with
some action that is associated with the
earliest-started request but doesn't actually
say what it is AFAICS.
s7.1: It would be helpful to identify the
sections of RFC 7530 that are affected by the
changes summarized here, identifying
replacements and modifications. It would also
be worth reordering the summary to match with
the order of subsections of s7.1.
s7.1, bullets 1 and 2:
s/CLID_INUSE/NFS4ERR_CLID_INUSE/
s7.2: See the comment on s4.8, para 1 on page 18
above.
s7.3, para 7: s/Thus, a client that is prepared
to receive NFS4ERR_MOVED/Thus, if a client is
prepared to receive NFS4ERR_MOVED
s7.4.5.1: A pointer to Section 9.1.7 of
[RFC7530] where the DRC is introduced would be
helpful. BTW I am not sure that a server is
*allowed* to be without a DRC - s9.1.7 says it
is critical to have something that looks like a
DRC.
s7.6, para 1: Please reference Section 19 of
[RFC7530]. The affected para is the penultimate
rather than the ultimate para of Section 19 of
[RFC7530] judging from the initial words.
s7.6, para 2:
See the section "Client Identity
Definition" for further discussion.
Please add a section reference (Section 4 of
this document)
s8: Suggest
OLD:
Is to be modified as specified in Section 7.6.
NEW:
The security considerations of [RFC7530] remain
appropriate with the exception of the
modification to the penultimate paragraph
specified in Section 7.6 of this document and
the addition of the material in Section 7.5.
END