[Qemu-devel] [PATCH 1/2] block/raw-format: switch to BDRV_BLOCK_DATA with BDRV_BLOCK_RECURSE

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

BDRV_BLOCK_RAW makes generic bdrv_co_block_status to fallthrough to
returned file. But is it correct behavior at all? If returned file
itself has a backing file, we may report as totally unallocated and
area which actually has data in bottom backing file.

So, mirroring of qcow2 under raw-format is broken. Which is illustrated
by following commit with a test. Let's make raw-format behave more
correctly returning BDRV_BLOCK_DATA.

Suggested-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block/raw-format.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/raw-format.c b/block/raw-format.c
index bffd424dd0..a273ee2387 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -275,7 +275,7 @@ static int coroutine_fn raw_co_block_status(BlockDriverState *bs,
     *pnum = bytes;
     *file = bs->file->bs;
     *map = offset + s->offset;
-    return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID;
+    return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | BDRV_BLOCK_RECURSE;
 }
 
 static int coroutine_fn raw_co_pwrite_zeroes(BlockDriverState *bs,
-- 
2.18.0