3 files changed, 51 insertions, 0 deletions

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 431da21cb488..ac93d874578a 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -1597,6 +1597,27 @@ void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector, bool force)
 }
 EXPORT_SYMBOL(bitmap_cond_end_sync);
 
+void bitmap_sync_with_cluster(struct mddev *mddev,
+                              sector_t old_lo, sector_t old_hi,
+                              sector_t new_lo, sector_t new_hi)
+{
+        struct bitmap *bitmap = mddev->bitmap;
+        sector_t sector, blocks = 0;
+
+        for (sector = old_lo; sector < new_lo; ) {
+                bitmap_end_sync(bitmap, sector, &blocks, 0);
+                sector += blocks;
+        }
+        WARN((blocks > new_lo) && old_lo, "alignment is not correct for lo\n");
+
+        for (sector = old_hi; sector < new_hi; ) {
+                bitmap_start_sync(bitmap, sector, &blocks, 0);
+                sector += blocks;
+        }
+        WARN((blocks > new_hi) && old_hi, "alignment is not correct for hi\n");
+}
+EXPORT_SYMBOL(bitmap_sync_with_cluster);
+
 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
 {
         /* For each chunk covered by any of these sectors, set the
diff --git a/drivers/md/bitmap.h b/drivers/md/bitmap.h
index 5e3fcd6ecf77..5b6dd63dda91 100644
--- a/drivers/md/bitmap.h
+++ b/drivers/md/bitmap.h
@@ -258,6 +258,9 @@ int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
 void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted);
 void bitmap_close_sync(struct bitmap *bitmap);
 void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector, bool force);
+void bitmap_sync_with_cluster(struct mddev *mddev,
+                              sector_t old_lo, sector_t old_hi,
+                              sector_t new_lo, sector_t new_hi);
 
 void bitmap_unplug(struct bitmap *bitmap);
 void bitmap_daemon_work(struct mddev *mddev);
diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
index 30f1160142c1..a55b5f4d0dbe 100644
--- a/drivers/md/md-cluster.c
+++ b/drivers/md/md-cluster.c
@@ -85,6 +85,9 @@ struct md_cluster_info {
         struct completion newdisk_completion;
         wait_queue_head_t wait;
         unsigned long state;
+        /* record the region in RESYNCING message */
+        sector_t sync_low;
+        sector_t sync_hi;
 };
 
 enum msg_type {
@@ -411,6 +414,30 @@ static void process_suspend_info(struct mddev *mddev,
                 md_wakeup_thread(mddev->thread);
                 return;
         }
+
+        /*
+         * The bitmaps are not same for different nodes
+         * if RESYNCING is happening in one node, then
+         * the node which received the RESYNCING message
+         * probably will perform resync with the region
+         * [lo, hi] again, so we could reduce resync time
+         * a lot if we can ensure that the bitmaps among
+         * different nodes are match up well.
+         *
+         * sync_low/hi is used to record the region which
+         * arrived in the previous RESYNCING message,
+         *
+         * Call bitmap_sync_with_cluster to clear
+         * NEEDED_MASK and set RESYNC_MASK since
+         * resync thread is running in another node,
+         * so we don't need to do the resync again
+         * with the same section */
+        bitmap_sync_with_cluster(mddev, cinfo->sync_low,
+                                        cinfo->sync_hi,
+                                        lo, hi);
+        cinfo->sync_low = lo;
+        cinfo->sync_hi = hi;
+
         s = kzalloc(sizeof(struct suspend_info), GFP_KERNEL);
         if (!s)
                 return;