NFS: Optimise inode attribute cache updates

Allow nfs_refresh_inode() also to update attributes on the inode if the
 RPC call was sent after the last call to nfs_update_inode().

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

include/linux/nfs_fs.h

@@ -141,6 +141,7 @@ struct nfs_inode {
 	unsigned long		attrtimeo_timestamp;
 	__u64			change_attr;		/* v4 only */
 
+	unsigned long		last_updated;
 	/* "Generation counter" for the attribute cache. This is
 	 * bumped whenever we update the metadata on the
 	 * server.
@@ -319,6 +320,7 @@ extern u32 root_nfs_parse_addr(char *name); /*__init*/
 static inline void nfs_fattr_init(struct nfs_fattr *fattr)
 {
 	fattr->valid = 0;
+	fattr->time_start = jiffies;
 }
 
 /*

include/linux/nfs_xdr.h

@@ -41,7 +41,7 @@ struct nfs_fattr {
 	__u32			bitmap[2];	/* NFSv4 returned attribute bitmap */
 	__u64			change_attr;	/* NFSv4 change attribute */
 	__u64			pre_change_attr;/* pre-op NFSv4 change attribute */
-	unsigned long		timestamp;
+	unsigned long		time_start;
 };
 
 #define NFS_ATTR_WCC		0x0001		/* pre-op WCC data    */