UBIFS: slightly optimize write-buffer timer usage

This patch adds the following minor optimization:

1. If write-buffer does not use the timer, indicate it with the
   wbuf->no_timer variable, instead of using the wbuf->softlimit
   variable. This is better because wbuf->softlimit is of ktime_t
   type, and the ktime_to_ns function contains 64-bit multiplication.

2. Do not call the 'hrtimer_cancel()' function for write-buffers
   which do not use timers.

3. Do not cancel the timer in 'ubifs_put_super()' because the
   synchronization function does this.

This patch also removes a confusing comment.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

1 files changed, 2 insertions, 4 deletions

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 79fad43f3c57..5bb272c56a9b 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -797,7 +797,7 @@ static int alloc_wbufs(struct ubifs_info *c)
          * does not need to be synchronized by timer.
          */
         c->jheads[GCHD].wbuf.dtype = UBI_LONGTERM;
-        c->jheads[GCHD].wbuf.softlimit = ktime_set(0, 0);
+        c->jheads[GCHD].wbuf.no_timer = 1;
 
         return 0;
 }
@@ -1754,10 +1754,8 @@ static void ubifs_put_super(struct super_block *sb)
 
                 /* Synchronize write-buffers */
                 if (c->jheads)
-                        for (i = 0; i < c->jhead_cnt; i++) {
+                        for (i = 0; i < c->jhead_cnt; i++)
                                 ubifs_wbuf_sync(&c->jheads[i].wbuf);
-                                hrtimer_cancel(&c->jheads[i].wbuf.timer);
-                        }
 
                 /*
                  * On fatal errors c->ro_media is set to 1, in which case we do