diff --git a/fs/nilfs2/recovery.c b/fs/nilfs2/recovery.c
index 877dc1ba23f3..a4253f34e138 100644
--- a/fs/nilfs2/recovery.c
+++ b/fs/nilfs2/recovery.c
@@ -416,6 +416,7 @@ static int nilfs_prepare_segment_for_recovery(struct the_nilfs *nilfs,
 	struct nilfs_segment_entry *ent, *n;
 	struct inode *sufile = nilfs->ns_sufile;
 	__u64 segnum[4];
+	time_t mtime;
 	int err;
 	int i;
 
@@ -442,9 +443,9 @@ static int nilfs_prepare_segment_for_recovery(struct the_nilfs *nilfs,
 
 	/*
 	 * Collecting segments written after the latest super root.
-	 * These are marked volatile active, and won't be reallocated in
-	 * the next construction.
+	 * These are marked dirty to avoid being reallocated in the next write.
 	 */
+	mtime = get_seconds();
 	list_for_each_entry_safe(ent, n, head, list) {
 		if (ent->segnum == segnum[0]) {
 			list_del(&ent->list);
@@ -454,17 +455,16 @@ static int nilfs_prepare_segment_for_recovery(struct the_nilfs *nilfs,
 		err = nilfs_open_segment_entry(ent, sufile);
 		if (unlikely(err))
 			goto failed;
-		if (nilfs_segment_usage_clean(ent->raw_su)) {
-			nilfs_segment_usage_set_volatile_active(ent->raw_su);
-			/* Keep it open */
-		} else {
-			/* Removing duplicated entries */
-			list_del(&ent->list);
-			nilfs_close_segment_entry(ent, sufile);
-			nilfs_free_segment_entry(ent);
+		if (!nilfs_segment_usage_dirty(ent->raw_su)) {
+			/* make the segment garbage */
+			ent->raw_su->su_nblocks = cpu_to_le32(0);
+			ent->raw_su->su_lastmod = cpu_to_le32(mtime);
+			nilfs_segment_usage_set_dirty(ent->raw_su);
 		}
+		list_del(&ent->list);
+		nilfs_close_segment_entry(ent, sufile);
+		nilfs_free_segment_entry(ent);
 	}
-	list_splice_init(head, nilfs->ns_used_segments.prev);
 
 	/*
 	 * The segment having the latest super root is active, and
@@ -882,10 +882,12 @@ int nilfs_search_super_root(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi,
 
 		if (scan_newer)
 			ri->ri_need_recovery = NILFS_RECOVERY_SR_UPDATED;
-		else if (nilfs->ns_mount_state & NILFS_VALID_FS)
-			goto super_root_found;
-
-		scan_newer = 1;
+		else {
+			nilfs->ns_prot_seq = ssi.seg_seq;
+			if (nilfs->ns_mount_state & NILFS_VALID_FS)
+				goto super_root_found;
+			scan_newer = 1;
+		}
 
 		/* reset region for roll-forward */
 		pseg_start += ssi.nblocks;
diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 5db12d774a03..24d0fbd4271c 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -2229,13 +2229,6 @@ static void nilfs_segctor_reactivate_segments(struct nilfs_sc_info *sci,
 		nilfs_segment_usage_set_active(ent->raw_su);
 		nilfs_close_segment_entry(ent, sufile);
 	}
-
-	down_write(&nilfs->ns_sem);
-	head = &nilfs->ns_used_segments;
-	list_for_each_entry(ent, head, list) {
-		nilfs_segment_usage_set_volatile_active(ent->raw_su);
-	}
-	up_write(&nilfs->ns_sem);
 }
 
 static int nilfs_segctor_deactivate_segments(struct nilfs_sc_info *sci,
@@ -2244,7 +2237,6 @@ static int nilfs_segctor_deactivate_segments(struct nilfs_sc_info *sci,
 	struct nilfs_segment_buffer *segbuf, *last;
 	struct nilfs_segment_entry *ent;
 	struct inode *sufile = nilfs->ns_sufile;
-	struct list_head *head;
 	int err;
 
 	last = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
@@ -2265,22 +2257,13 @@ static int nilfs_segctor_deactivate_segments(struct nilfs_sc_info *sci,
 		BUG_ON(!buffer_dirty(ent->bh_su));
 	}
 
-	head = &sci->sc_active_segments;
-	list_for_each_entry(ent, head, list) {
+	list_for_each_entry(ent, &sci->sc_active_segments, list) {
 		err = nilfs_open_segment_entry(ent, sufile);
 		if (unlikely(err))
 			goto failed;
 		nilfs_segment_usage_clear_active(ent->raw_su);
 		BUG_ON(!buffer_dirty(ent->bh_su));
 	}
-
-	down_write(&nilfs->ns_sem);
-	head = &nilfs->ns_used_segments;
-	list_for_each_entry(ent, head, list) {
-		/* clear volatile active for segments of older generations */
-		nilfs_segment_usage_clear_volatile_active(ent->raw_su);
-	}
-	up_write(&nilfs->ns_sem);
 	return 0;
 
  failed:
@@ -2304,19 +2287,15 @@ static void nilfs_segctor_bead_completed_segments(struct nilfs_sc_info *sci)
 	}
 }
 
-static void
-__nilfs_segctor_commit_deactivate_segments(struct nilfs_sc_info *sci,
-					   struct the_nilfs *nilfs)
-
+static void nilfs_segctor_commit_deactivate_segments(struct nilfs_sc_info *sci,
+						     struct the_nilfs *nilfs)
 {
-	struct nilfs_segment_entry *ent;
+	struct nilfs_segment_entry *ent, *n;
 
-	list_splice_init(&sci->sc_active_segments,
-			 nilfs->ns_used_segments.prev);
-
-	list_for_each_entry(ent, &nilfs->ns_used_segments, list) {
-		nilfs_segment_usage_set_volatile_active(ent->raw_su);
-		/* These segments are kept open */
+	list_for_each_entry_safe(ent, n, &sci->sc_active_segments, list) {
+		list_del(&ent->list);
+		nilfs_close_segment_entry(ent, nilfs->ns_sufile);
+		nilfs_free_segment_entry(ent);
 	}
 }
 
@@ -2405,8 +2384,8 @@ static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
 		if (has_sr) {
 			down_write(&nilfs->ns_sem);
 			nilfs_update_last_segment(sbi, 1);
-			__nilfs_segctor_commit_deactivate_segments(sci, nilfs);
 			up_write(&nilfs->ns_sem);
+			nilfs_segctor_commit_deactivate_segments(sci, nilfs);
 			nilfs_segctor_commit_free_segments(sci);
 			nilfs_segctor_clear_metadata_dirty(sci);
 		}
diff --git a/fs/nilfs2/sufile.c b/fs/nilfs2/sufile.c
index b3674a8162a1..cc714c72b138 100644
--- a/fs/nilfs2/sufile.c
+++ b/fs/nilfs2/sufile.c
@@ -446,6 +446,7 @@ int nilfs_sufile_get_stat(struct inode *sufile, struct nilfs_sustat *sustat)
 {
 	struct buffer_head *header_bh;
 	struct nilfs_sufile_header *header;
+	struct the_nilfs *nilfs = NILFS_MDT(sufile)->mi_nilfs;
 	void *kaddr;
 	int ret;
 
@@ -460,8 +461,11 @@ int nilfs_sufile_get_stat(struct inode *sufile, struct nilfs_sustat *sustat)
 	sustat->ss_nsegs = nilfs_sufile_get_nsegments(sufile);
 	sustat->ss_ncleansegs = le64_to_cpu(header->sh_ncleansegs);
 	sustat->ss_ndirtysegs = le64_to_cpu(header->sh_ndirtysegs);
-	sustat->ss_ctime = NILFS_MDT(sufile)->mi_nilfs->ns_ctime;
-	sustat->ss_nongc_ctime = NILFS_MDT(sufile)->mi_nilfs->ns_nongc_ctime;
+	sustat->ss_ctime = nilfs->ns_ctime;
+	sustat->ss_nongc_ctime = nilfs->ns_nongc_ctime;
+	spin_lock(&nilfs->ns_last_segment_lock);
+	sustat->ss_prot_seq = nilfs->ns_prot_seq;
+	spin_unlock(&nilfs->ns_last_segment_lock);
 	kunmap_atomic(kaddr, KM_USER0);
 	brelse(header_bh);
 
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 268b563d215a..2f0e9f7bf152 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -262,8 +262,10 @@ static int nilfs_sync_super(struct nilfs_sb_info *sbi)
 		printk(KERN_ERR
 		       "NILFS: unable to write superblock (err=%d)\n", err);
 	else {
-		nilfs_dispose_used_segments(nilfs);
 		clear_nilfs_discontinued(nilfs);
+		spin_lock(&nilfs->ns_last_segment_lock);
+		nilfs->ns_prot_seq = le64_to_cpu(nilfs->ns_sbp->s_last_seq);
+		spin_unlock(&nilfs->ns_last_segment_lock);
 	}
 
 	return err;
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 69b625586226..661ab762d765 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -71,7 +71,6 @@ struct the_nilfs *alloc_nilfs(struct block_device *bdev)
 	INIT_LIST_HEAD(&nilfs->ns_supers);
 	spin_lock_init(&nilfs->ns_last_segment_lock);
 	nilfs->ns_gc_inodes_h = NULL;
-	INIT_LIST_HEAD(&nilfs->ns_used_segments);
 	init_rwsem(&nilfs->ns_segctor_sem);
 
 	return nilfs;
@@ -95,7 +94,6 @@ void put_nilfs(struct the_nilfs *nilfs)
 	 */
 	might_sleep();
 	if (nilfs_loaded(nilfs)) {
-		nilfs_dispose_used_segments(nilfs);
 		nilfs_mdt_clear(nilfs->ns_sufile);
 		nilfs_mdt_destroy(nilfs->ns_sufile);
 		nilfs_mdt_clear(nilfs->ns_cpfile);
@@ -463,22 +461,6 @@ int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
 	return err;
 }
 
-void nilfs_dispose_used_segments(struct the_nilfs *nilfs)
-{
-	struct nilfs_segment_entry *ent, *n;
-
-	/* nilfs->sem must be locked by the caller. */
-	if (!nilfs_loaded(nilfs))
-		return;
-
-	list_for_each_entry_safe(ent, n, &nilfs->ns_used_segments, list) {
-		list_del_init(&ent->list);
-		nilfs_segment_usage_clear_volatile_active(ent->raw_su);
-		nilfs_close_segment_entry(ent, nilfs->ns_sufile);
-		nilfs_free_segment_entry(ent);
-	}
-}
-
 int nilfs_near_disk_full(struct the_nilfs *nilfs)
 {
 	struct inode *sufile = nilfs->ns_sufile;
diff --git a/fs/nilfs2/the_nilfs.h b/fs/nilfs2/the_nilfs.h
index 75da37306964..af566e78f7af 100644
--- a/fs/nilfs2/the_nilfs.h
+++ b/fs/nilfs2/the_nilfs.h
@@ -51,7 +51,6 @@ enum {
  * @ns_writer_refcount: number of referrers on ns_writer
  * @ns_sbh: buffer head of the on-disk super block
  * @ns_sbp: pointer to the super block data
- * @ns_used_segments: list of full segments in volatile active state
  * @ns_supers: list of nilfs super block structs
  * @ns_seg_seq: segment sequence counter
  * @ns_segnum: index number of the latest full segment.
@@ -65,6 +64,7 @@ enum {
  * @ns_last_pseg: start block number of the latest segment
  * @ns_last_seq: sequence value of the latest segment
  * @ns_last_cno: checkpoint number of the latest segment
+ * @ns_prot_seq: least sequence number of segments which must not be reclaimed
  * @ns_free_segments_count: counter of free segments
  * @ns_segctor_sem: segment constructor semaphore
  * @ns_dat: DAT file inode
@@ -103,7 +103,6 @@ struct the_nilfs {
 	 */
 	struct buffer_head     *ns_sbh;
 	struct nilfs_super_block *ns_sbp;
-	struct list_head	ns_used_segments;
 	unsigned		ns_mount_state;
 	struct list_head	ns_supers;
 
@@ -132,6 +131,7 @@ struct the_nilfs {
 	sector_t		ns_last_pseg;
 	u64			ns_last_seq;
 	__u64			ns_last_cno;
+	u64			ns_prot_seq;
 	unsigned long		ns_free_segments_count;
 
 	struct rw_semaphore	ns_segctor_sem;
@@ -188,7 +188,6 @@ void put_nilfs(struct the_nilfs *);
 int init_nilfs(struct the_nilfs *, struct nilfs_sb_info *, char *);
 int load_nilfs(struct the_nilfs *, struct nilfs_sb_info *);
 int nilfs_count_free_blocks(struct the_nilfs *, sector_t *);
-void nilfs_dispose_used_segments(struct the_nilfs *);
 int nilfs_checkpoint_is_mounted(struct the_nilfs *, __u64, int);
 int nilfs_near_disk_full(struct the_nilfs *);
 
diff --git a/include/linux/nilfs2_fs.h b/include/linux/nilfs2_fs.h
index 306c446e694e..aa93f0ee29d4 100644
--- a/include/linux/nilfs2_fs.h
+++ b/include/linux/nilfs2_fs.h
@@ -565,8 +565,6 @@ enum {
 	NILFS_SEGMENT_USAGE_DIRTY,
 	NILFS_SEGMENT_USAGE_ERROR,
 
-	/* on-memory only */
-	NILFS_SEGMENT_USAGE_VOLATILE_ACTIVE,
 	/* ... */
 };
 
@@ -594,7 +592,6 @@ nilfs_segment_usage_##name(const struct nilfs_segment_usage *su)	\
 NILFS_SEGMENT_USAGE_FNS(ACTIVE, active)
 NILFS_SEGMENT_USAGE_FNS(DIRTY, dirty)
 NILFS_SEGMENT_USAGE_FNS(ERROR, error)
-NILFS_SEGMENT_USAGE_FNS(VOLATILE_ACTIVE, volatile_active)
 
 static inline void
 nilfs_segment_usage_set_clean(struct nilfs_segment_usage *su)
@@ -650,7 +647,6 @@ nilfs_suinfo_##name(const struct nilfs_suinfo *si)			\
 NILFS_SUINFO_FNS(ACTIVE, active)
 NILFS_SUINFO_FNS(DIRTY, dirty)
 NILFS_SUINFO_FNS(ERROR, error)
-NILFS_SUINFO_FNS(VOLATILE_ACTIVE, volatile_active)
 
 static inline int nilfs_suinfo_clean(const struct nilfs_suinfo *si)
 {
@@ -717,8 +713,9 @@ struct nilfs_cpstat {
  * @ss_nsegs: number of segments
  * @ss_ncleansegs: number of clean segments
  * @ss_ndirtysegs: number of dirty segments
- * @ss_ctime:
- * @ss_nongc_ctime:
+ * @ss_ctime: creation time of the last segment
+ * @ss_nongc_ctime: creation time of the last segment not for GC
+ * @ss_prot_seq: least sequence number of segments which must not be reclaimed
  */
 struct nilfs_sustat {
 	__u64 ss_nsegs;
@@ -726,6 +723,7 @@ struct nilfs_sustat {
 	__u64 ss_ndirtysegs;
 	__u64 ss_ctime;
 	__u64 ss_nongc_ctime;
+	__u64 ss_prot_seq;
 };
 
 /**