[Qemu-block] [PATCH 12/29] qcow2: add qcow2_delete_bitmaps

[Vladimir Sementsov-Ogievskiy]

Add function to delete dirty bitmaps from image. It will be used in
truncate.

Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
Signed-off-by: Denis V. Lunev <address@hidden>
---
 block/qcow2-bitmap.c | 34 ++++++++++++++++++++++++++++++++++
 block/qcow2.h        |  1 +
 2 files changed, 35 insertions(+)

diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index 0c0cb7c..92d95c5 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -273,6 +273,24 @@ static void do_free_bitmap_clusters(BlockDriverState *bs,
                         QCOW2_DISCARD_ALWAYS);
 }
 
+static int bitmap_table_load(BlockDriverState *bs, QCow2BitmapHeader *bmh,
+                             uint64_t **table);
+static int free_bitmap_clusters(BlockDriverState *bs, QCow2BitmapHeader *bmh)
+{
+    int ret;
+    uint64_t *bitmap_table;
+
+    ret = bitmap_table_load(bs, bmh, &bitmap_table);
+    if (ret < 0 || bitmap_table == NULL) {
+        return ret;
+    }
+
+    do_free_bitmap_clusters(bs, bmh->bitmap_table_offset,
+                            bmh->bitmap_table_size, bitmap_table);
+
+    return 0;
+}
+
 /* dirty sectors in cluster is a number of sectors in the image, corresponding
  * to one cluster of bitmap data */
 static uint64_t dirty_sectors_in_cluster(const BDRVQcow2State *s,
@@ -588,6 +606,22 @@ BdrvDirtyBitmap *qcow2_bitmap_load(BlockDriverState *bs, 
const char *name,
     return load_bitmap(bs, h, errp);
 }
 
+int qcow2_delete_bitmaps(BlockDriverState *bs)
+{
+    BDRVQcow2State *s = bs->opaque;
+    QCow2BitmapHeader *h;
+
+    if (s->nb_bitmaps == 0) {
+        return 0;
+    }
+
+    for_each_bitmap_header(h, s) {
+        free_bitmap_clusters(bs, h);
+    }
+
+    return directory_update(bs, NULL, 0, 0);
+}
+
 /* store_bitmap_data()
  * Store bitmap to image, filling bitamp table accordingly.
  */
diff --git a/block/qcow2.h b/block/qcow2.h
index 87b0a32..0ec0b31 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -612,6 +612,7 @@ BdrvDirtyBitmap *qcow2_bitmap_load(BlockDriverState *bs, 
const char *name,
                                    Error **errp);
 void qcow2_bitmap_store(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
                         Error **errp);
+int qcow2_delete_bitmaps(BlockDriverState *bs);
 
 /* qcow2-cache.c functions */
 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables);
-- 
1.8.3.1