NFSD: Shrink size of struct nfsd4_copy

struct nfsd4_copy is part of struct nfsd4_op, which resides in an
8-element array.

sizeof(struct nfsd4_op):
Before: /* size: 1696, cachelines: 27, members: 5 */
After:  /* size: 672, cachelines: 11, members: 5 */

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/nfs4proc.c

@@ -1289,6 +1289,7 @@ void nfs4_put_copy(struct nfsd4_copy *copy)
 {
 	if (!refcount_dec_and_test(&copy->refcount))
 		return;
+	kfree(copy->cp_src);
 	kfree(copy);
 }
 
@@ -1549,7 +1550,7 @@ nfsd4_setup_inter_ssc(struct svc_rqst *rqstp,
 	if (status)
 		goto out;
 
-	status = nfsd4_interssc_connect(&copy->cp_src, rqstp, mount);
+	status = nfsd4_interssc_connect(copy->cp_src, rqstp, mount);
 	if (status)
 		goto out;
 
@@ -1761,7 +1762,7 @@ static void dup_copy_fields(struct nfsd4_copy *src, struct nfsd4_copy *dst)
 		dst->nf_src = nfsd_file_get(src->nf_src);
 
 	memcpy(&dst->cp_stateid, &src->cp_stateid, sizeof(src->cp_stateid));
-	memcpy(&dst->cp_src, &src->cp_src, sizeof(struct nl4_server));
+	memcpy(dst->cp_src, src->cp_src, sizeof(struct nl4_server));
 	memcpy(&dst->stateid, &src->stateid, sizeof(src->stateid));
 	memcpy(&dst->c_fh, &src->c_fh, sizeof(src->c_fh));
 	dst->ss_mnt = src->ss_mnt;
@@ -1855,6 +1856,9 @@ nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 		async_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL);
 		if (!async_copy)
 			goto out_err;
+		async_copy->cp_src = kmalloc(sizeof(*async_copy->cp_src), GFP_KERNEL);
+		if (!async_copy->cp_src)
+			goto out_err;
 		if (!nfs4_init_copy_state(nn, copy))
 			goto out_err;
 		refcount_set(&async_copy->refcount, 1);

fs/nfsd/nfs4xdr.c

@@ -1920,6 +1920,9 @@ nfsd4_decode_copy(struct nfsd4_compoundargs *argp, struct nfsd4_copy *copy)
 
 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
 		return nfserr_bad_xdr;
+	copy->cp_src = svcxdr_tmpalloc(argp, sizeof(*copy->cp_src));
+	if (copy->cp_src == NULL)
+		return nfserr_jukebox;
 	copy->cp_intra = false;
 	if (count == 0) { /* intra-server copy */
 		copy->cp_intra = true;
@@ -1927,7 +1930,7 @@ nfsd4_decode_copy(struct nfsd4_compoundargs *argp, struct nfsd4_copy *copy)
 	}
 
 	/* decode all the supplied server addresses but use only the first */
-	status = nfsd4_decode_nl4_server(argp, &copy->cp_src);
+	status = nfsd4_decode_nl4_server(argp, copy->cp_src);
 	if (status)
 		return status;
 

fs/nfsd/xdr4.h

@@ -540,7 +540,7 @@ struct nfsd4_copy {
 	u64			cp_src_pos;
 	u64			cp_dst_pos;
 	u64			cp_count;
-	struct nl4_server	cp_src;
+	struct nl4_server	*cp_src;
 	bool			cp_intra;
 
 	/* both */