tree b3e2be4c49d43cd621a579de7865c3687b7b59e9
parent 2115f2a1d8c77c2a735add1ed02ae0c1feae0d9a
author Fam Zheng <famz@redhat.com> 1427160229 +0800
committer Stefan Hajnoczi <stefanha@redhat.com> 1427450472 +0000

block: Fix unaligned zero write

If the zero write is not aligned, bdrv_co_do_pwritev will segfault
because of accessing to the NULL qiov passed in by bdrv_co_write_zeroes.
Fix this by allocating a local qiov in bdrv_co_do_pwritev if the request
is not aligned. (In this case the padding iovs are necessary anyway, so
it doesn't hurt.)

Also add a check at the end of bdrv_co_do_pwritev to clear the zero flag
if padding is involved.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 1427160230-4489-2-git-send-email-famz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>