[PATCH 3/6] qemu-img: rebase: use backing files' BlockBackend for buffer alignment

[Andrey Drobyshev]

Since commit bb1c05973cf ("qemu-img: Use qemu_blockalign"), buffers for
the data read from the old and new backing files are aligned using
BlockDriverState (or BlockBackend later on) referring to the target image.
However, this isn't quite right, because target image is only being
written to and has nothing to do with those buffers.  Let's fix that.

Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
---
 qemu-img.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/qemu-img.c b/qemu-img.c
index 78433f3746..60f4c06487 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -3746,8 +3746,8 @@ static int img_rebase(int argc, char **argv)
         int64_t n;
         float local_progress = 0;
 
-        buf_old = blk_blockalign(blk, IO_BUF_SIZE);
-        buf_new = blk_blockalign(blk, IO_BUF_SIZE);
+        buf_old = blk_blockalign(blk_old_backing, IO_BUF_SIZE);
+        buf_new = blk_blockalign(blk_new_backing, IO_BUF_SIZE);
 
         size = blk_getlength(blk);
         if (size < 0) {
-- 
2.31.1