| Message ID | 1493196046-5607-1-git-send-email-den@openvz.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 04/26/2017 03:40 AM, Denis V. Lunev wrote: > 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 <den@openvz.org> > CC: Stefan Hajnoczi <stefanha@redhat.com> > CC: Fam Zheng <famz@redhat.com> > --- > block/io.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Reviewed-by: Eric Blake <eblake@redhat.com>
Am 26.04.2017 um 10:40 hat Denis V. Lunev geschrieben: > 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 <den@openvz.org> > CC: Stefan Hajnoczi <stefanha@redhat.com> > CC: Fam Zheng <famz@redhat.com> Thanks, applied to block-next. Kevin
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);
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 <den@openvz.org> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Fam Zheng <famz@redhat.com> --- block/io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)