Setting the QCOW_OFLAG_ZERO bit of the L2 entry is forbidden if an image has subclusters. Instead, the individual 'all zeroes' bits must be used.
Signed-off-by: Alberto Garcia <be...@igalia.com> --- block/qcow2-cluster.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 70b0aaa00a..207f670c94 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -1790,7 +1790,11 @@ static int discard_in_l2_slice(BlockDriverState *bs, uint64_t offset, /* First remove L2 entries */ qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice); - if (!full_discard && s->qcow_version >= 3) { + if (has_subclusters(s)) { + set_l2_entry(s, l2_slice, l2_index + i, 0); + set_l2_bitmap(s, l2_slice, l2_index + i, + full_discard ? 0 : QCOW_L2_BITMAP_ALL_ZEROES); + } else if (!full_discard && s->qcow_version >= 3) { set_l2_entry(s, l2_slice, l2_index + i, QCOW_OFLAG_ZERO); } else { set_l2_entry(s, l2_slice, l2_index + i, 0); -- 2.20.1