NFSv4: Save a few bytes in the nfs_pgio_args/res

Trond Myklebust · Trond Myklebust · commit 28d52235ee25 · 2018-09-30T15:35:17.000-04:00
Save a few bytes by allowing the read/write specific fields of the
structures to share storage.

Signed-off-by: Trond Myklebust &lt;trond.myklebust@hammerspace.com&gt;
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
@@ -608,20 +608,30 @@ struct nfs_pgio_args {
 	__u32			count;
 	unsigned int		pgbase;
 	struct page **		pages;
-	unsigned int		replen;		/* used by read */
-	const u32 *		bitmask;	/* used by write */
-	enum nfs3_stable_how	stable;		/* used by write */
+	union {
+		unsigned int		replen;			/* used by read */
+		struct {
+			const u32 *		bitmask;	/* used by write */
+			enum nfs3_stable_how	stable;		/* used by write */
+		};
+	};
 };
 
 struct nfs_pgio_res {
 	struct nfs4_sequence_res	seq_res;
 	struct nfs_fattr *	fattr;
 	__u32			count;
 	__u32			op_status;
-	int			eof;		/* used by read */
-	unsigned int		replen;		/* used by read */
-	struct nfs_writeverf *	verf;		/* used by write */
-	const struct nfs_server *server;	/* used by write */
+	union {
+		struct {
+			unsigned int		replen;		/* used by read */
+			int			eof;		/* used by read */
+		};
+		struct {
+			struct nfs_writeverf *	verf;		/* used by write */
+			const struct nfs_server *server;	/* used by write */
+		};
+	};
 };
 
 /*
