2 files changed, 25 insertions, 5 deletions

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index b26927ce889..dedba16d42f 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -454,8 +454,11 @@ void bitmap_update_sb(struct bitmap *bitmap)
         spin_unlock_irqrestore(&bitmap->lock, flags);
         sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
         sb->events = cpu_to_le64(bitmap->mddev->events);
-        if (!bitmap->mddev->degraded)
-                sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
+        if (bitmap->mddev->events < bitmap->events_cleared) {
+                /* rocking back to read-only */
+                bitmap->events_cleared = bitmap->mddev->events;
+                sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
+        }
         kunmap_atomic(sb, KM_USER0);
         write_page(bitmap, bitmap->sb_page, 1);
 }
@@ -1085,9 +1088,19 @@ void bitmap_daemon_work(struct bitmap *bitmap)
                         } else
                                 spin_unlock_irqrestore(&bitmap->lock, flags);
                         lastpage = page;
-/*
-                        printk("bitmap clean at page %lu\n", j);
-*/
+
+                        /* We are possibly going to clear some bits, so make
+                         * sure that events_cleared is up-to-date.
+                         */
+                        if (bitmap->need_sync) {
+                                bitmap_super_t *sb;
+                                bitmap->need_sync = 0;
+                                sb = kmap_atomic(bitmap->sb_page, KM_USER0);
+                                sb->events_cleared =
+                                        cpu_to_le64(bitmap->events_cleared);
+                                kunmap_atomic(sb, KM_USER0);
+                                write_page(bitmap, bitmap->sb_page, 1);
+                        }
                         spin_lock_irqsave(&bitmap->lock, flags);
                         clear_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
                 }
@@ -1257,6 +1270,12 @@ void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long secto
                         return;
                 }
 
+                if (success &&
+                    bitmap->events_cleared < bitmap->mddev->events) {
+                        bitmap->events_cleared = bitmap->mddev->events;
+                        bitmap->need_sync = 1;
+                }
+
                 if (!success && ! (*bmc & NEEDED_MASK))
                         *bmc |= NEEDED_MASK;
 
diff --git a/include/linux/raid/bitmap.h b/include/linux/raid/bitmap.h
index 78bfdea24a8..e98900671ca 100644
--- a/include/linux/raid/bitmap.h
+++ b/include/linux/raid/bitmap.h
@@ -221,6 +221,7 @@ struct bitmap {
         unsigned long syncchunk;
 
         __u64   events_cleared;
+        int need_sync;
 
         /* bitmap spinlock */
         spinlock_t lock;