ceph: define 'end/complete' in readdir reply as bit flags

Set a flag in readdir request, which indicates that client interprets
'end/complete' as bit flags. So that mds can reply additional flags in
readdir reply.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

include/linux/ceph/ceph_fs.h

@@ -347,6 +347,17 @@ extern const char *ceph_mds_op_name(int op);
 #define CEPH_XATTR_REPLACE (1 << 1)
 #define CEPH_XATTR_REMOVE  (1 << 31)
 
+/*
+ * readdir request flags;
+ */
+#define CEPH_READDIR_REPLY_BITFLAGS	(1<<0)
+
+/*
+ * readdir reply flags.
+ */
+#define CEPH_READDIR_FRAG_END		(1<<0)
+#define CEPH_READDIR_FRAG_COMPLETE	(1<<8)
+
 union ceph_mds_request_args {
 	struct {
 		__le32 mask;                 /* CEPH_CAP_* */
@@ -364,6 +375,7 @@ union ceph_mds_request_args {
 		__le32 frag;                 /* which dir fragment */
 		__le32 max_entries;          /* how many dentries to grab */
 		__le32 max_bytes;
+		__le16 flags;
 	} __attribute__ ((packed)) readdir;
 	struct {
 		__le32 mode;