Re: [PATCH v2 2/4] NFSD: Add READ_PLUS support for data segments

[Anna Schumaker <Anna.Schumaker@netapp.com>]

On 02/05/2015 09:13 AM, Christoph Hellwig wrote:
>> +	p = xdr_reserve_space(xdr, 4 + 8 + 4); /* content type, offset, maxcount */
>> +	if (!p)
>> +		return nfserr_resource;
>> +	xdr_commit_encode(xdr);
>> +
>> +	maxcount = svc_max_payload(resp->rqstp);
>> +	maxcount = min_t(unsigned long, maxcount, (xdr->buf->buflen - xdr->buf->len));
>> +	maxcount = min_t(unsigned long, maxcount, read->rd_length);
>> +
>> +	err = nfsd4_encode_readv(resp, read, file, &maxcount);
> 
> If the READ_PLUS implementation can't use the splice read path it's
> probably a loss for most workloads.
> 

I'll play around with the splice path, but I don't think it was designed for encoding multiple read segments.