nfsd: hook up nfsd_read to the nfsd_file cache

__be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,

	loff_t offset, struct kvec *vec, int vlen, unsigned long *count)

{

	struct nfsd_file	*nf;

	struct file *file;

	struct raparms	*ra;

	__be32 err;

	trace_nfsd_read_start(rqstp, fhp, offset, *count);

	err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file);

	err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_READ, &nf);

	if (err)

		return err;

	ra = nfsd_init_raparms(file);

	file = nf->nf_file;

	if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags))

		err = nfsd_splice_read(rqstp, fhp, file, offset, count);

	else

		err = nfsd_readv(rqstp, fhp, file, offset, vec, vlen, count);

	if (ra)

		nfsd_put_raparams(file, ra);

	fput(file);

	nfsd_file_put(nf);

	trace_nfsd_read_done(rqstp, fhp, offset, *count);