Re: [PATCH] nfsd41: check the size of response

[Mi Jinlong <mijinlong@cn.fujitsu.com>]

J. Bruce Fields:
> On Wed, May 18, 2011 at 10:19:23AM +0800, Mi Jinlong wrote:
>> Compare response's size to the session se_fmaxresp_sz and 
>> se_fmaxresp_cached at the same function.
>>
>> And modify function name nfsd4_check_drc_limit to
>> nfsd4_check_response_size.
> 
> Hm.  I guess that's OK.  Note we have a bigger problem, though, which is
> that we're waiting too late to check these limits:
> 
> 	http://wiki.linux-nfs.org/wiki/index.php/Server_4.0_and_4.1_issues#DRC_limit_checking
> 
> Have you looked at that list, by the way?:

  I will have a look, and try to solve this problem.
  Maybe it will take me some times.

-- 
----
thanks
Mi Jinlong

> 
> 	http://wiki.linux-nfs.org/wiki/index.php/Server_4.0_and_4.1_issues#Highest_priority
> 
> Those are the 4.1 spec compliance problems that I think are the most
> important to fix--the ones that I think we have to get done before we
> can really declare the 4.1 server correct.
> 
> --b.
> 
>> Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.com>
>> ---
>>  fs/nfsd/nfs4xdr.c |   20 ++++++++++++--------
>>  1 files changed, 12 insertions(+), 8 deletions(-)
>>
>> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
>> index c6766af..a7cf985 100644
>> --- a/fs/nfsd/nfs4xdr.c
>> +++ b/fs/nfsd/nfs4xdr.c
>> @@ -3224,12 +3224,12 @@ static nfsd4_enc nfsd4_enc_ops[] = {
>>   * pad: add on 8 bytes for the next operation's op_code and status so that
>>   * there is room to cache a failure on the next operation.
>>   *
>> - * Compare this length to the session se_fmaxresp_cached.
>> + * Compare this length to the session se_fmaxresp_sz and se_fmaxresp_cached.
>>   *
>>   * Our se_fmaxresp_cached will always be a multiple of PAGE_SIZE, and so
>>   * will be at least a page and will therefore hold the xdr_buf head.
>>   */
>> -static int nfsd4_check_drc_limit(struct nfsd4_compoundres *resp)
>> +static int nfsd4_check_response_size(struct nfsd4_compoundres *resp)
>>  {
>>  	int status = 0;
>>  	struct xdr_buf *xb = &resp->rqstp->rq_res;
>> @@ -3242,7 +3242,7 @@ static int nfsd4_check_drc_limit(struct nfsd4_compoundres *resp)
>>  		return status;
>>  
>>  	session = resp->cstate.session;
>> -	if (session == NULL || slot->sl_cachethis == 0)
>> +	if (session == NULL)
>>  		return status;
>>  
>>  	if (resp->opcnt >= args->opcnt)
>> @@ -3259,10 +3259,14 @@ static int nfsd4_check_drc_limit(struct nfsd4_compoundres *resp)
>>  	dprintk("%s length %u, xb->page_len %u tlen %u pad %u\n", __func__,
>>  		length, xb->page_len, tlen, pad);
>>  
>> -	if (length <= session->se_fchannel.maxresp_cached)
>> -		return status;
>> -	else
>> +	if (length > session->se_fchannel.maxresp_sz)
>> +		return nfserr_rep_too_big;
>> +
>> +	if (slot->sl_cachethis == 1 &&
>> +	    length > session->se_fchannel.maxresp_cached)
>>  		return nfserr_rep_too_big_to_cache;
>> +
>> +	return status;
>>  }
>>  
>>  void
>> @@ -3282,8 +3286,8 @@ nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
>>  	       !nfsd4_enc_ops[op->opnum]);
>>  	op->status = nfsd4_enc_ops[op->opnum](resp, op->status, &op->u);
>>  	/* nfsd4_check_drc_limit guarantees enough room for error status */
>> -	if (!op->status && nfsd4_check_drc_limit(resp))
>> -		op->status = nfserr_rep_too_big_to_cache;
>> +	if (!op->status)
>> +		op->status = nfsd4_check_response_size(resp);
>>  status:
>>  	/*
>>  	 * Note: We write the status directly, instead of using WRITE32(),
>> -- 
>> 1.7.4.5
>>
>>
> 
>