3 files changed, 13 insertions, 1 deletions

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 04e04854a311..9fd051a33c4f 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -1951,7 +1951,6 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
         if (update_sr) {
                 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
                                        segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
-                set_nilfs_sb_dirty(nilfs);
 
                 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
                 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 88c8976c55a9..f2efc8c5be7f 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -47,6 +47,16 @@ void nilfs_set_last_segment(struct the_nilfs *nilfs,
         nilfs->ns_last_pseg = start_blocknr;
         nilfs->ns_last_seq = seq;
         nilfs->ns_last_cno = cno;
+
+        if (!nilfs_sb_dirty(nilfs)) {
+                if (nilfs->ns_prev_seq == nilfs->ns_last_seq)
+                        goto stay_cursor;
+
+                set_nilfs_sb_dirty(nilfs);
+        }
+        nilfs->ns_prev_seq = nilfs->ns_last_seq;
+
+ stay_cursor:
         spin_unlock(&nilfs->ns_last_segment_lock);
 }
 
@@ -267,6 +277,7 @@ static int nilfs_store_log_cursor(struct the_nilfs *nilfs,
         nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno);
         nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq);
 
+        nilfs->ns_prev_seq = nilfs->ns_last_seq;
         nilfs->ns_seg_seq = nilfs->ns_last_seq;
         nilfs->ns_segnum =
                 nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg);
diff --git a/fs/nilfs2/the_nilfs.h b/fs/nilfs2/the_nilfs.h
index 32b4983b7458..f785a7b0ab99 100644
--- a/fs/nilfs2/the_nilfs.h
+++ b/fs/nilfs2/the_nilfs.h
@@ -74,6 +74,7 @@ enum {
  * @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_prev_seq: base sequence number used to decide if advance log cursor
  * @ns_segctor_sem: segment constructor semaphore
  * @ns_dat: DAT file inode
  * @ns_cpfile: checkpoint file inode
@@ -151,6 +152,7 @@ struct the_nilfs {
         u64                     ns_last_seq;
         __u64                   ns_last_cno;
         u64                     ns_prot_seq;
+        u64                     ns_prev_seq;
 
         struct rw_semaphore     ns_segctor_sem;