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>

fs/ceph/dir.c

@@ -365,6 +365,8 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
 		req->r_readdir_cache_idx = fi->readdir_cache_idx;
 		req->r_readdir_offset = fi->next_offset;
 		req->r_args.readdir.frag = cpu_to_le32(frag);
+		req->r_args.readdir.flags =
+				cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS);
 
 		req->r_inode = inode;
 		ihold(inode);

fs/ceph/mds_client.c

@@ -181,8 +181,11 @@ static int parse_reply_info_dir(void **p, void *end,
 
 	ceph_decode_need(p, end, sizeof(num) + 2, bad);
 	num = ceph_decode_32(p);
-	info->dir_end = ceph_decode_8(p);
-	info->dir_complete = ceph_decode_8(p);
+	{
+		u16 flags = ceph_decode_16(p);
+		info->dir_end = !!(flags & CEPH_READDIR_FRAG_END);
+		info->dir_complete = !!(flags & CEPH_READDIR_FRAG_COMPLETE);
+	}
 	if (num == 0)
 		goto done;
 

fs/ceph/mds_client.h

@@ -80,7 +80,7 @@ struct ceph_mds_reply_info_parsed {
 			struct ceph_mds_reply_dirfrag *dir_dir;
 			size_t			      dir_buf_size;
 			int                           dir_nr;
-			u8                            dir_complete, dir_end;
+			bool			      dir_complete, dir_end;
 			struct ceph_mds_reply_dir_entry  *dir_entries;
 		};
 

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;