[Qemu-block] [PATCH 14/29] qcow2-bitmap: add qcow2_bitmap_load_check()

[Vladimir Sementsov-Ogievskiy]

The function checks the existance of the bitmap without loading it.
Will be used in future patches.

Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
 block/dirty-bitmap.c         | 15 +++++++++++++++
 block/qcow2-bitmap.c         |  5 +++++
 block/qcow2.c                |  1 +
 block/qcow2.h                |  1 +
 include/block/block_int.h    |  2 ++
 include/block/dirty-bitmap.h |  2 ++
 6 files changed, 26 insertions(+)

diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 90af372..83415e1 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -540,3 +540,18 @@ int64_t bdrv_get_meta_dirty_count(BdrvDirtyBitmap *bitmap)
 {
     return hbitmap_count(bitmap->meta);
 }
+
+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-bitmap.c b/block/qcow2-bitmap.c
index a34cfe8..32f1a50 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -252,6 +252,11 @@ static QCow2BitmapHeader 
*find_bitmap_by_name(BlockDriverState *bs,
     return NULL;
 }
 
+bool qcow2_bitmap_load_check(BlockDriverState *file, const char *name)
+{
+    return find_bitmap_by_name(file, name) != NULL;
+}
+
 static void clear_bitmap_table(BlockDriverState *bs, uint64_t *bitmap_table,
                                uint32_t bitmap_table_size)
 {
diff --git a/block/qcow2.c b/block/qcow2.c
index 3e9b47e..60b0acb 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3517,6 +3517,7 @@ 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 0ec0b31..d4515fb 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -608,6 +608,7 @@ 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, BdrvDirtyBitmap *bitmap,
diff --git a/include/block/block_int.h b/include/block/block_int.h
index ba002f3..da1f843 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -224,6 +224,8 @@ 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 1e17729..6007c64 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -75,4 +75,6 @@ void bdrv_dirty_bitmap_deserialize_ones(BdrvDirtyBitmap 
*bitmap,
                                         bool finish);
 void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap);
 
+bool bdrv_load_check_dirty_bitmap(BlockDriverState *file, const char *name);
+
 #endif
-- 
1.8.3.1