block/dirty-bitmap: add deserialize_ones func

Add bdrv_dirty_bitmap_deserialize_ones() function, which is needed for
qcow2 bitmap loading, to handle unallocated bitmap parts, marked as
all-ones.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20170628120530.31251-7-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>

block/dirty-bitmap.c

@@ -586,6 +586,13 @@ void bdrv_dirty_bitmap_deserialize_zeroes(BdrvDirtyBitmap *bitmap,
     hbitmap_deserialize_zeroes(bitmap->bitmap, start, count, finish);
 }
 
+void bdrv_dirty_bitmap_deserialize_ones(BdrvDirtyBitmap *bitmap,
+                                        uint64_t start, uint64_t count,
+                                        bool finish)
+{
+    hbitmap_deserialize_ones(bitmap->bitmap, start, count, finish);
+}
+
 void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap)
 {
     hbitmap_deserialize_finish(bitmap->bitmap);

include/block/dirty-bitmap.h

@@ -66,6 +66,9 @@ void bdrv_dirty_bitmap_deserialize_part(BdrvDirtyBitmap *bitmap,
 void bdrv_dirty_bitmap_deserialize_zeroes(BdrvDirtyBitmap *bitmap,
                                           uint64_t start, uint64_t count,
                                           bool finish);
+void bdrv_dirty_bitmap_deserialize_ones(BdrvDirtyBitmap *bitmap,
+                                        uint64_t start, uint64_t count,
+                                        bool finish);
 void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap);
 
 /* Functions that require manual locking.  */

include/qemu/hbitmap.h

@@ -228,6 +228,21 @@ void hbitmap_deserialize_part(HBitmap *hb, uint8_t *buf,
 void hbitmap_deserialize_zeroes(HBitmap *hb, uint64_t start, uint64_t count,
                                 bool finish);
 
+/**
+ * hbitmap_deserialize_ones
+ * @hb: HBitmap to operate on.
+ * @start: First bit to restore.
+ * @count: Number of bits to restore.
+ * @finish: Whether to call hbitmap_deserialize_finish automatically.
+ *
+ * Fills the bitmap with ones.
+ *
+ * If @finish is false, caller must call hbitmap_serialize_finish before using
+ * the bitmap.
+ */
+void hbitmap_deserialize_ones(HBitmap *hb, uint64_t start, uint64_t count,
+                              bool finish);
+
 /**
  * hbitmap_deserialize_finish
  * @hb: HBitmap to operate on.

util/hbitmap.c

@@ -551,6 +551,23 @@ void hbitmap_deserialize_zeroes(HBitmap *hb, uint64_t start, uint64_t count,
     }
 }
 
+void hbitmap_deserialize_ones(HBitmap *hb, uint64_t start, uint64_t count,
+                              bool finish)
+{
+    uint64_t el_count;
+    unsigned long *first;
+
+    if (!count) {
+        return;
+    }
+    serialization_chunk(hb, start, count, &first, &el_count);
+
+    memset(first, 0xff, el_count * sizeof(unsigned long));
+    if (finish) {
+        hbitmap_deserialize_finish(hb);
+    }
+}
+
 void hbitmap_deserialize_finish(HBitmap *bitmap)
 {
     int64_t i, size, prev_size;