nilfs2: stop using periodic write_super callback

This removes nilfs_write_super and commit super block in nilfs
internal thread, instead of periodic write_super callback.

VFS layer calls ->write_super callback periodically.  However,
it looks like that calling back is ommited when disk I/O is busy.
And when cleanerd (nilfs GC) is runnig, disk I/O tend to be busy thus
nilfs superblock is not synchronized as nilfs designed.

To avoid it, syncing superblock by nilfs thread instead of pdflush.

Signed-off-by: Jiro SEKIBA <jir@unicus.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

1 files changed, 6 insertions, 1 deletions

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 51ff3d0a4ee2..683df89dbae5 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -2501,7 +2501,8 @@ static int nilfs_segctor_construct(struct nilfs_sc_info *sci,
                 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
                     nilfs_discontinued(nilfs)) {
                         down_write(&nilfs->ns_sem);
-                        req->sb_err = nilfs_commit_super(sbi, 0);
+                        req->sb_err = nilfs_commit_super(sbi,
+                                        nilfs_altsb_need_update(nilfs));
                         up_write(&nilfs->ns_sem);
                 }
         }
@@ -2689,6 +2690,7 @@ static int nilfs_segctor_thread(void *arg)
         } else {
                 DEFINE_WAIT(wait);
                 int should_sleep = 1;
+                struct the_nilfs *nilfs;
 
                 prepare_to_wait(&sci->sc_wait_daemon, &wait,
                                 TASK_INTERRUPTIBLE);
@@ -2709,6 +2711,9 @@ static int nilfs_segctor_thread(void *arg)
                 finish_wait(&sci->sc_wait_daemon, &wait);
                 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
                            time_after_eq(jiffies, sci->sc_timer->expires));
+                nilfs = sci->sc_sbi->s_nilfs;
+                if (sci->sc_super->s_dirt && nilfs_sb_need_update(nilfs))
+                        set_nilfs_discontinued(nilfs);
         }
         goto loop;