Re: [PATCH 3/3] nfsd41: implement NFS4_SHARE_WANT_NO_DELEG, NFS4_OPEN_DELEGATE_NONE_EXT, why_no_deleg

[Benny Halevy <bhalevy@tonian.com>]

On 2012-02-18 06:41, J. Bruce Fields wrote:
> On Sat, Feb 18, 2012 at 10:02:56AM +0200, Benny Halevy wrote:
>> On 2012-02-18 00:14, J. Bruce Fields wrote:
>>> On Thu, Feb 16, 2012 at 08:57:17PM +0200, Benny Halevy wrote:
>>>> Respect client request for not getting a delegation in NFSv4.1
>>>> Appropriately return delegation "type" NFS4_OPEN_DELEGATE_NONE_EXT
>>>> and WND4_NOT_WANTED reason.
>>>
>>> These all look fine, just two nits:
>>>
>>>> @@ -2903,11 +2903,32 @@ static int nfs4_set_delegation(struct nfs4_delegation *dp, int flag)
>>>>  	dprintk("NFSD: delegation stateid=" STATEID_FMT "\n",
>>>>  		STATEID_VAL(&dp->dl_stid.sc_stateid));
>>>>  out:
>>>> -	if (open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS
>>>> -			&& flag == NFS4_OPEN_DELEGATE_NONE
>>>> -			&& open->op_delegate_type != NFS4_OPEN_DELEGATE_NONE)
>>>> -		dprintk("NFSD: WARNING: refusing delegation reclaim\n");
>>>>  	open->op_delegate_type = flag;
>>>> +	if (flag == NFS4_OPEN_DELEGATE_NONE) {
>>>> +		if (open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS &&
>>>> +		    open->op_delegate_type != NFS4_OPEN_DELEGATE_NONE)
>>>> +			dprintk("NFSD: WARNING: refusing delegation reclaim\n");
>>>> +
>>>> +		if (open->op_deleg_want) {
>>>> +			open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE_EXT;
>>>> +			if (status == -EAGAIN)
>>>> +				open->op_why_no_deleg = WND4_CONTENTION;
>>>> +			else {
>>>> +				open->op_why_no_deleg = WND4_RESOURCE;
>>>> +				switch (open->op_deleg_want) {
>>>> +				case NFS4_SHARE_WANT_READ_DELEG:
>>>> +				case NFS4_SHARE_WANT_WRITE_DELEG:
>>>> +				case NFS4_SHARE_WANT_ANY_DELEG:
>>>> +					break;
>>>> +				case NFS4_SHARE_WANT_CANCEL:
>>>> +					open->op_why_no_deleg = WND4_CANCELLED;
>>>> +					break;
>>>> +				case NFS4_SHARE_WANT_NO_DELEG:
>>>> +					BUG();	/* not supposed to get here */
>>>> +				}
>>>> +			}
>>>> +		}
>>>> +	}
>>>
>>> This looks like a reasonably well-encapsulated bit of code--could you
>>> move it into a helper function?
>>>
>>>>  out:
>>>> +	/* 4.1 client trying to upgrade/downgrade delegation? */
>>>> +	if (open->op_delegate_type == NFS4_OPEN_DELEGATE_NONE && dp &&
>>>> +	    open->op_deleg_want) {
>>>> +		if (open->op_deleg_want == NFS4_SHARE_WANT_READ_DELEG &&
>>>> +		    dp->dl_type == NFS4_OPEN_DELEGATE_WRITE) {
>>>> +			open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE_EXT;
>>>> +			open->op_why_no_deleg = WND4_NOT_SUPP_DOWNGRADE;
>>>> +		} else if (open->op_deleg_want == NFS4_SHARE_WANT_WRITE_DELEG &&
>>>> +			   dp->dl_type == NFS4_OPEN_DELEGATE_WRITE) {
>>>> +			open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE_EXT;
>>>> +			open->op_why_no_deleg = WND4_NOT_SUPP_UPGRADE;
>>>> +		}
>>>> +		/* Otherwise the client must be confused wanting a delegation
>>>> +		 * it already has, therefore we don't return
>>>> +		 * NFS4_OPEN_DELEGATE_NONE_EXT and reason.
>>>> +		 */
>>>> +	}
>>>
>>> Ditto for this.
>>>
>>> I'll go ahead and apply the previous two patches pending some regression
>>> tests.
>>
>> Thanks!
>> I'm sending two additional patches that refactor these two helpers and add
>> some documentation to the commit message.
>>
>> I think it might be helpful to keep them separated but let me know otherwise
>> and I'll send a squashed patch instead.
> 
> Either way's fine.  What I've got so far is pushed out to
> 
> 	git://linux-nfs.org/~bfields/linux.git for-3.4

Good. So the missing patches are:
http://marc.info/?l=linux-nfs&m=132941866004294&w=2
http://marc.info/?l=linux-nfs&m=132955306211255&w=2
http://marc.info/?l=linux-nfs&m=132955306211256&w=2

Benny

> 
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