NFSD: Remove NFSSVC_MAXBLKSIZE_V2 macro

The 8192-byte maximum is a protocol-defined limit, and we already
have a symbolic constant defined whose name matches the name of
the limit defined in the protocol. Replace the duplicate.

No change in behavior is expected.

Reviewed-by: NeilBrown <[e-mail]>
Reviewed-by: Christoph Hellwig <[e-mail]>
Signed-off-by: Chuck Lever <[e-mail]>

fs/nfsd/nfsd.h

···
  * Maximum blocksizes supported by daemon under various circumstances.
  */
 #define NFSSVC_MAXBLKSIZE       RPCSVC_MAXPAYLOAD
-/* NFSv2 is limited by the protocol specification, see RFC 1094 */
-#define NFSSVC_MAXBLKSIZE_V2    (8*1024)
 
 struct readdir_cd {
 	__be32			err;	/* 0, nfserr, or nfserr_eof */

fs/nfsd/nfsproc.c

···
 		SVCFH_fmt(&argp->fh),
 		argp->count, argp->offset);
 
-	argp->count = min_t(u32, argp->count, NFSSVC_MAXBLKSIZE_V2);
+	argp->count = min_t(u32, argp->count, NFS_MAXDATA);
 	argp->count = min_t(u32, argp->count, rqstp->rq_res.buflen);
 
 	resp->pages = rqstp->rq_next_page;
···
 		.pc_argzero = sizeof(struct nfsd_readargs),
 		.pc_ressize = sizeof(struct nfsd_readres),
 		.pc_cachetype = RC_NOCACHE,
-		.pc_xdrressize = ST+AT+1+NFSSVC_MAXBLKSIZE_V2/4,
+		.pc_xdrressize = ST+AT+1+NFS_MAXDATA/4,
 		.pc_name = "READ",
 	},
 	[NFSPROC_WRITECACHE] = {

fs/nfsd/nfsxdr.c

···
 	/* opaque data */
 	if (xdr_stream_decode_u32(xdr, &args->len) < 0)
 		return false;
-	if (args->len > NFSSVC_MAXBLKSIZE_V2)
+	if (args->len > NFS_MAXDATA)
 		return false;
 
 	return xdr_stream_subsegment(xdr, &args->payload, args->len);
···
 		p = xdr_reserve_space(xdr, XDR_UNIT * 5);
 		if (!p)
 			return false;
-		*p++ = cpu_to_be32(NFSSVC_MAXBLKSIZE_V2);
+		*p++ = cpu_to_be32(NFS_MAXDATA);
 		*p++ = cpu_to_be32(stat->f_bsize);
 		*p++ = cpu_to_be32(stat->f_blocks);
 		*p++ = cpu_to_be32(stat->f_bfree);