[Qemu-devel] [PATCH 12/22] qcow2-dirty-bitmap: add qcow2_bitmap_load_check()

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

The function checks existing of the bitmap without loading it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block/dirty-bitmap.c         | 15 +++++++++++++++
 block/qcow2-dirty-bitmap.c   |  5 +++++
 block/qcow2.c                |  1 +
 block/qcow2.h                |  1 +
 include/block/block_int.h    |  2 ++
 include/block/dirty-bitmap.h |  1 +
 6 files changed, 25 insertions(+)

diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 816c6ee..7a44722 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -419,3 +419,18 @@ int bdrv_dirty_bitmap_store(const BdrvDirtyBitmap *bitmap, BlockDriverState *bs,
 {
     return hbitmap_store(bitmap->bitmap, bs, table, table_size, cluster_size);
 }
+
+bool bdrv_load_check_dirty_bitmap(BlockDriverState *file, const char *name)
+{
+    BlockDriver *drv = file->drv;
+    if (!drv) {
+        return false;
+    }
+    if (drv->bdrv_dirty_bitmap_load_check) {
+        return drv->bdrv_dirty_bitmap_load_check(file, name);
+    }
+    if (file->file)  {
+        return bdrv_load_check_dirty_bitmap(file->file->bs, name);
+    }
+    return false;
+}
diff --git a/block/qcow2-dirty-bitmap.c b/block/qcow2-dirty-bitmap.c
index 28ed309..24415df 100644
--- a/block/qcow2-dirty-bitmap.c
+++ b/block/qcow2-dirty-bitmap.c
@@ -276,6 +276,11 @@ static int load_bitmap_data(BlockDriverState *bs, const uint64_t *bitmap_table,
     return ret;
 }
 
+bool qcow2_bitmap_load_check(BlockDriverState *file, const char *name)
+{
+    return find_bitmap_by_name(file, name) != NULL;
+}
+
 static BdrvDirtyBitmap *load_bitmap(BlockDriverState *bs, QCow2Bitmap *bm,
                                     Error **errp)
 {
diff --git a/block/qcow2.c b/block/qcow2.c
index bda3026..7a342c2 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3442,6 +3442,7 @@ BlockDriver bdrv_qcow2 = {
     .bdrv_get_specific_info = qcow2_get_specific_info,
 
     .bdrv_dirty_bitmap_load = qcow2_bitmap_load,
+    .bdrv_dirty_bitmap_load_check = qcow2_bitmap_load_check,
     .bdrv_dirty_bitmap_store = qcow2_bitmap_store,
 
     .bdrv_save_vmstate    = qcow2_save_vmstate,
diff --git a/block/qcow2.h b/block/qcow2.h
index e4a517c..423c279 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -620,6 +620,7 @@ int qcow2_read_snapshots(BlockDriverState *bs);
 void qcow2_free_bitmaps(BlockDriverState *bs);
 int qcow2_read_bitmaps(BlockDriverState *bs, Error **errp);
 
+bool qcow2_bitmap_load_check(BlockDriverState *file, const char *name);
 BdrvDirtyBitmap *qcow2_bitmap_load(BlockDriverState *bs, const char *name,
                                    Error **errp);
 void qcow2_bitmap_store(BlockDriverState *bs, const BdrvDirtyBitmap *bitmap,
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 7cd05e1..66a388a 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -215,6 +215,8 @@ struct BlockDriver {
     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
     ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);
 
+    bool (*bdrv_dirty_bitmap_load_check)(BlockDriverState *file,
+                                         const char *name);
     BdrvDirtyBitmap *(*bdrv_dirty_bitmap_load)(BlockDriverState *bs,
                                                const char *name,
                                                Error **errp);
diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index 20cb540..f3cedaa 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -53,5 +53,6 @@ int bdrv_dirty_bitmap_prepare_store(const BdrvDirtyBitmap *bitmap,
 int bdrv_dirty_bitmap_store(const BdrvDirtyBitmap *bitmap, BlockDriverState *bs,
                             const uint64_t *table, uint32_t table_size,
                             uint32_t cluster_size);
+bool bdrv_load_check_dirty_bitmap(BlockDriverState *file, const char *name);
 
 #endif
-- 
1.8.3.1