1 files changed, 21 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