afs: Split the directory content defs into a header

Split the directory content definitions into a header file so that they can
be used by multiple .c files.

Signed-off-by: David Howells <dhowells@redhat.com>

fs/afs/xdr_fs.h

@@ -37,4 +37,67 @@ struct afs_xdr_AFSFetchStatus {
 	__be32	abort_code;
 } __packed;
 
+#define AFS_DIR_HASHTBL_SIZE	128
+#define AFS_DIR_DIRENT_SIZE	32
+#define AFS_DIR_SLOTS_PER_BLOCK	64
+#define AFS_DIR_BLOCK_SIZE	2048
+#define AFS_DIR_BLOCKS_PER_PAGE	(PAGE_SIZE / AFS_DIR_BLOCK_SIZE)
+#define AFS_DIR_MAX_SLOTS	65536
+#define AFS_DIR_BLOCKS_WITH_CTR	128
+#define AFS_DIR_MAX_BLOCKS	1023
+#define AFS_DIR_RESV_BLOCKS	1
+#define AFS_DIR_RESV_BLOCKS0	13
+
+/*
+ * Directory entry structure.
+ */
+union afs_dirent {
+	struct {
+		uint8_t		valid;
+		uint8_t		unused[1];
+		__be16		hash_next;
+		__be32		vnode;
+		__be32		unique;
+		uint8_t		name[16];
+		uint8_t		overflow[4];	/* if any char of the name (inc
+						 * NUL) reaches here, consume
+						 * the next dirent too */
+	} u;
+	uint8_t	extended_name[32];
+};
+
+/*
+ * Directory page header (one at the beginning of every 2048-byte chunk).
+ */
+struct afs_dir_pagehdr {
+	__be16		npages;
+	__be16		magic;
+#define AFS_DIR_MAGIC htons(1234)
+	uint8_t		reserved;
+	uint8_t		bitmap[8];
+	uint8_t		pad[19];
+};
+
+/*
+ * Directory block layout
+ */
+union afs_dir_block {
+	struct afs_dir_pagehdr	pagehdr;
+
+	struct {
+		struct afs_dir_pagehdr	pagehdr;
+		uint8_t			alloc_ctrs[AFS_DIR_MAX_BLOCKS];
+		__be16			hashtable[AFS_DIR_HASHTBL_SIZE];
+	} hdr;
+
+	union afs_dirent	dirents[AFS_DIR_SLOTS_PER_BLOCK];
+};
+
+/*
+ * Directory layout on a linux VM page.
+ */
+struct afs_dir_page {
+	union afs_dir_block	blocks[AFS_DIR_BLOCKS_PER_PAGE];
+};
+
 #endif /* XDR_FS_H */