+THE_NILFS_FNS(GC_RUNNING, gc_running)
+
+/* Minimum interval of periodical update of superblocks (in seconds) */
+#define NILFS_SB_FREQ 10
+#define NILFS_ALTSB_FREQ 60 /* spare superblock */
+
+static inline int nilfs_sb_need_update(struct the_nilfs *nilfs)
+{
+ u64 t = get_seconds();
+ return t < nilfs->ns_sbwtime[0] ||
+ t > nilfs->ns_sbwtime[0] + NILFS_SB_FREQ;
+}
+
+static inline int nilfs_altsb_need_update(struct the_nilfs *nilfs)
+{
+ u64 t = get_seconds();
+ struct nilfs_super_block **sbp = nilfs->ns_sbp;
+ return sbp[1] && t > nilfs->ns_sbwtime[1] + NILFS_ALTSB_FREQ;
+}