squashfs: add xattr id support

This patch adds support for mapping xattr ids (stored in inodes)
into the on-disk location of the xattrs themselves.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
diff --git a/fs/squashfs/squashfs_fs_sb.h b/fs/squashfs/squashfs_fs_sb.h
index 2e77dc5..d9037a5 100644
--- a/fs/squashfs/squashfs_fs_sb.h
+++ b/fs/squashfs/squashfs_fs_sb.h
@@ -61,6 +61,7 @@
 	int					next_meta_index;
 	__le64					*id_table;
 	__le64					*fragment_index;
+	__le64					*xattr_id_table;
 	struct mutex				read_data_mutex;
 	struct mutex				meta_index_mutex;
 	struct meta_index			*meta_index;
@@ -68,9 +69,11 @@
 	__le64					*inode_lookup_table;
 	u64					inode_table;
 	u64					directory_table;
+	u64					xattr_table;
 	unsigned int				block_size;
 	unsigned short				block_log;
 	long long				bytes_used;
 	unsigned int				inodes;
+	int					xattr_ids;
 };
 #endif