NFSv4: Fix the alignment of page data in the getdeviceinfo reply

We can fit the device_addr4 opaque data padding in the pages.

Fixes: cf500ba ("SUNRPC: Introduce rpc_prepare_reply_pages()")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/nfs4xdr.c

@@ -3009,15 +3009,19 @@ static void nfs4_xdr_enc_getdeviceinfo(struct rpc_rqst *req,
 	struct compound_hdr hdr = {
 		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
 	};
+	uint32_t replen;
 
 	encode_compound_hdr(xdr, req, &hdr);
 	encode_sequence(xdr, &args->seq_args, &hdr);
+
+	replen = hdr.replen + op_decode_hdr_maxsz;
+
 	encode_getdeviceinfo(xdr, args, &hdr);
 
-	/* set up reply kvec. Subtract notification bitmap max size (2)
-	 * so that notification bitmap is put in xdr_buf tail */
+	/* set up reply kvec. device_addr4 opaque data is read into the
+	 * pages */
 	rpc_prepare_reply_pages(req, args->pdev->pages, args->pdev->pgbase,
-				args->pdev->pglen, hdr.replen - 2);
+				args->pdev->pglen, replen + 2 + 1);
 	encode_nops(&hdr);
 }