Prior to
1143ec5ebf4 it was OK to qemu_iovec_from_buf() from aligned-up
buffer to original qiov, as qemu_iovec_from_buf() will stop at qiov end
anyway.
But after
1143ec5ebf4 we assume that bdrv_co_do_copy_on_readv works on
part of original qiov, defined by qiov_offset and bytes. So we must not
touch qiov behind qiov_offset+bytes bound. Fix it.
Cc: qemu-stable@nongnu.org # v4.2
Fixes:
1143ec5ebf4
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id:
20200312081949.5350-1-vsementsov@virtuozzo.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
if (!(flags & BDRV_REQ_PREFETCH)) {
qemu_iovec_from_buf(qiov, qiov_offset + progress,
bounce_buffer + skip_bytes,
- pnum - skip_bytes);
+ MIN(pnum - skip_bytes, bytes - progress));
}
} else if (!(flags & BDRV_REQ_PREFETCH)) {
/* Read directly into the destination */