[Qemu-block] [PATCH v15 23/25] qcow2: add .bdrv_remove_persistent_dirty_bitmap

[Vladimir Sementsov-Ogievskiy]

Realize .bdrv_remove_persistent_dirty_bitmap interface.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Reviewed-by: Max Reitz <mre...@redhat.com>
Reviewed-by: John Snow <js...@redhat.com>
---
 block/qcow2-bitmap.c | 41 +++++++++++++++++++++++++++++++++++++++++
 block/qcow2.c        |  1 +
 block/qcow2.h        |  3 +++
 3 files changed, 45 insertions(+)

diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index 05d3f28..9177c56 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -1055,6 +1055,47 @@ static Qcow2Bitmap *find_bitmap_by_name(Qcow2BitmapList 
*bm_list,
     return NULL;
 }
 
+void qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
+                                          const char *name,
+                                          Error **errp)
+{
+    int ret;
+    BDRVQcow2State *s = bs->opaque;
+    Qcow2Bitmap *bm;
+    Qcow2BitmapList *bm_list;
+
+    if (s->nb_bitmaps == 0) {
+        /* Absence of the bitmap is not an error: see explanation above
+         * bdrv_remove_persistent_dirty_bitmap() definition. */
+        return;
+    }
+
+    bm_list = bitmap_list_load(bs, s->bitmap_directory_offset,
+                               s->bitmap_directory_size, errp);
+    if (bm_list == NULL) {
+        return;
+    }
+
+    bm = find_bitmap_by_name(bm_list, name);
+    if (bm == NULL) {
+        goto fail;
+    }
+
+    QSIMPLEQ_REMOVE(bm_list, bm, Qcow2Bitmap, entry);
+
+    ret = update_ext_header_and_dir(bs, bm_list);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Failed to update bitmap extension");
+        goto fail;
+    }
+
+    free_bitmap_clusters(bs, &bm->table);
+
+fail:
+    bitmap_free(bm);
+    bitmap_list_free(bm_list);
+}
+
 void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp)
 {
     BdrvDirtyBitmap *bitmap;
diff --git a/block/qcow2.c b/block/qcow2.c
index 6e1fe53..653ba78 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3542,6 +3542,7 @@ BlockDriver bdrv_qcow2 = {
     .bdrv_load_autoloading_dirty_bitmaps = 
qcow2_load_autoloading_dirty_bitmaps,
     .bdrv_store_persistent_dirty_bitmaps = 
qcow2_store_persistent_dirty_bitmaps,
     .bdrv_can_store_new_dirty_bitmap = qcow2_can_store_new_dirty_bitmap,
+    .bdrv_remove_persistent_dirty_bitmap = 
qcow2_remove_persistent_dirty_bitmap,
 };
 
 static void bdrv_qcow2_init(void)
diff --git a/block/qcow2.h b/block/qcow2.h
index eaad34a..a009827 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -627,5 +627,8 @@ bool qcow2_can_store_new_dirty_bitmap(BlockDriverState *bs,
 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
                                   void **refcount_table,
                                   int64_t *refcount_table_size);
+void qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
+                                          const char *name,
+                                          Error **errp);
 
 #endif
-- 
1.8.3.1