Subject: [nfsv4] CB_COPY list of errors (WAS: server-side copy offload I-D)

From: "Erasani, Pranoop" <[email-masked]>
Date: Sun, 5 Apr 2009 03:21:20 -0700

Currently, I see CB_COPY return only the following error:

   The CB_COPY operation may fail for the following reasons:

   NFS4ERR_NOSUPP:  The copy offload operation is not supported by the
      NFS client receiving this request.

This operation is a key piece of the protocol and I don't see why only
one error code is applicable here? What is the story around actual
errors codes that we get back from the server-to-server copy operations
in the backend? Meaning, if let's say server-to-server protocol is FTP,
would a FTP specific error code make sense for the NFSv4.x client that
is initiatint the s2s copy?
 
Assuming the actual s2s protocol is NFSv4.x, I do see many more errors
to be represented here to make sense of the communication between
client-destination, destination-source. At the minimum, I see the
CB_COPY sending the same set of errors (and many many more) as
CB_STATUS.
 
I think CB_COPY errors section needs a major clarification.
 
- Pranoop

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From: anshul <[email-masked]>
Date: Mon, 06 Apr 2009 12:22:35 +0530

> I think CB_COPY errors section needs a major clarification.

The error codes were not addressed comprehensively in this draft. This
was discussed before also, we are planning to add a complete list of
errors in a latter revision.

Regards,
Anshul

>  
> - Pranoop
> _______________________________________________
> nfsv4 mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/nfsv4

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From: "Erasani, Pranoop" <[email-masked]>
Date: Mon, 6 Apr 2009 00:03:02 -0700

> -----Original Message-----
> From: Madan, Anshul 
> Sent: Sunday, April 05, 2009 11:53 PM
> To: Erasani, Pranoop
> Cc: [email-masked]
> Subject: Re: [nfsv4] CB_COPY list of errors (WAS: server-side 
> copy offloadI-D)
> 
> 
> > 
> >  
> The error codes were not addressed comprehensively in this 
> draft. This was discussed before also, we are planning to add 
> a complete list of errors in a latter revision.

I will paste my entire question (which had meat), given that you picked

to be represented here to make sense of the communication between
client-destination,destination-source. At the minimum, I see the CB_COPY
sending the same set of errors (and many many more) as CB_STATUS.

I started with error codes. But, ended with the question that, there
could be some s2s protocol error codes that the clients need to know.
What do you want to do with them? I took an example of a case were s2s
protocol isnot NFSv4.x. What would be the error code that is returned
back, to the client, let's say, if source does not accept the
destination FTP requests.

- Pranoop

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From: anshul <[email-masked]>
Date: Mon, 06 Apr 2009 12:42:03 +0530

> destination FTP requests.

If the source does not accept any copy offload requests from the
destination, then we have an error defined for COPY - 
"NFS4ERR_PARTNER_NOTSUPP:  The remote server does not support the
      server-to-server copy offload protocol"

But even before that, when the client issues the COPY_NOTIFY to source, it should return NFS4ERR_NOSUPP  - 
"NFS4ERR_NOSUPP:  The copy offload operation is not supported by the
      NFS server receiving this request."

Regards,
Anshul

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From: "Erasani, Pranoop" <[email-masked]>
Date: Mon, 6 Apr 2009 00:28:23 -0700

> > client-destination,destination-source. At the minimum, I see the 
> > CB_COPY sending the same set of errors (and many many more) 
> as CB_STATUS.
> > 
> If the source does not accept any copy offload requests from 
> the destination, then we have an error defined for COPY -
> But even before that, when the client issues the COPY_NOTIFY 
> to source, it should return NFS4ERR_NOSUPP  -

Okay. One more try. I'm not talking about the beginning's of the
workings of the protocol. Yes, I know COPY_NOTIFY, COPY can reject such
requests.

I'm talking about the actual srouce-destination transfer protocol. What
happens if say FTP (mid-way through the transfer) gets an error from the
source? It could be any of the FTP specific errors as described in
RFC765. How does the current protocol propose dealing with the actual
copy protocol errors and how would it enlighten the client about the
same? What sorta of abstract error codes (as defined by this spec) would
the actual copy protocol errors need to be mapped to, so that clients
get a meaningful errors back for an admin to make sense of?

- Pranoop

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From: anshul <[email-masked]>
Date: Mon, 06 Apr 2009 13:13:40 +0530

> get a meaningful errors back for an admin to make sense of?

The actual error would have to be mapped to a valid NFSv4.1 error code
or any new error code that would be defined in this Spec. For the
example you describe i.e. if say FTP (mid-way through the transfer) gets
an error, - let us say the destination is out of space(I do not know the
corresponding FTP error), then the NFS client could be returned
NFS4ERR_NOSPC. 

Regards,
Anshul

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From: "Erasani, Pranoop" <[email-masked]>
Date: Mon, 6 Apr 2009 00:50:58 -0700

> Sent: Monday, April 06, 2009 12:44 AM
> To: Erasani, Pranoop
> Cc: [email-masked]
> Subject: RE: [nfsv4] CB_COPY list of errors (WAS: 
> server-sidecopyoffloadI-D)

> The actual error would have to be mapped to a valid NFSv4.1 
> error code or any new error code that would be defined in 
> this Spec. For the example you describe i.e. if say FTP 
> (mid-way through the transfer) gets an error, - let us say 
> the destination is out of space(I do not know the 
> corresponding FTP error), then the NFS client could be 
> returned NFS4ERR_NOSPC. 

Ok. At last, I feel that you got my question. Now, so the blanket
statement that I expect to see in the specification is:

    CB_COPY could get back any one of the error codes in NFSv4.1
specification.

(OR)

Do you plan to sift through the error codes and publish the ones that
makes sense to most server-to-server protocols?

- Pranoop

---

From: anshul <[email-masked]>
Date: Mon, 06 Apr 2009 13:26:04 +0530

> makes sense to most server-to-server protocols?

When we specify a comprehensive list of errors in a latter draft, then
we would sift through valid NFSv4.1 errors, filter them and specify
which are applicable for CB_COPY. Also, we plan to do the same for the
other new operations that are being defined in this proposal.

Regards,
Anshul

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From: "Iyer, Rahul" <[email-masked]>
Date: Mon, 6 Apr 2009 17:00:38 -0700

The error codes to CB_COPY are meant to imply the errors the client
would send back to the server as a result of CB_COPY. Any errors the
server encountered would be in cca_status and would be one of the many
errors outlined in the COPY rpc.
Thanks,
Rahul

-----Original Message-----
From: Erasani, Pranoop 
Sent: Monday, April 06, 2009 12:03 AM
To: Madan, Anshul
Cc: [email-masked]
Subject: Re: [nfsv4] CB_COPY list of errors (WAS: server-side
copyoffloadI-D)

> Subject: Re: [nfsv4] CB_COPY list of errors (WAS: server-side copy 
> offloadI-D)
> 
> 
> > 
> >  

 

- Pranoop