tail_padding_bytes is calculated wrong. F.e. for
offset = 0
bytes = 2048
align = 512
we will have tail_padding_bytes = 512 which is definitely wrong. The patch
fixes that arithmetics.
Fortunately this problem is harmless, we will have 1 extra allocation and
free thus there is no need to put this into stable. The problem is here
from the very beginning.
Signed-off-by: Denis V. Lunev <[email protected]>
CC: Stefan Hajnoczi <[email protected]>
CC: Fam Zheng <[email protected]>
---
block/io.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/io.c b/block/io.c
index a7142e0..1e1523b 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1452,7 +1452,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild
*child,
int ret = 0;
head_padding_bytes = offset & (align - 1);
- tail_padding_bytes = align - ((offset + bytes) & (align - 1));
+ tail_padding_bytes = (align - (offset + bytes)) & (align - 1);
assert(flags & BDRV_REQ_ZERO_WRITE);
--
2.7.4
