From: Trond Myklebust <trond.myklebust@hammerspace.com>
Date: Mon, 24 Sep 2018 17:15:37 +0000 (-0400)
Subject: NFSv4: Save a few bytes in the nfs_pgio_args/res
X-Git-Tag: v4.20-rc1~2^2~17
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=28d52235ee25ba7d843242b4cb3c3f27a8828b5a;p=linux.git

NFSv4: Save a few bytes in the nfs_pgio_args/res

Save a few bytes by allowing the read/write specific fields of the
structures to share storage.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---

diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 7f5535e5e852..343e44166346 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -608,9 +608,13 @@ 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 {
@@ -618,10 +622,16 @@ struct nfs_pgio_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 */
+		};
+	};
 };
 
 /*