m_data must be contain valid data even for zero clusters when no cluster was allocated in the image file. Without this, zero writes segfault with images that have zeroed_grain=on.
For zero writes, we don't want to allocate a cluster in the image file even in compressed files. Fixes: 524089bce43fd1cd3daaca979872451efa2cf7c6 Signed-off-by: Kevin Wolf <kw...@redhat.com> --- block/vmdk.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/block/vmdk.c b/block/vmdk.c index 5b09275578..bdd7d2dcf1 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -1572,6 +1572,12 @@ static int get_cluster_offset(BlockDriverState *bs, extent->l2_cache_counts[min_index] = 1; found: l2_index = ((offset >> 9) / extent->cluster_sectors) % extent->l2_size; + if (m_data) { + m_data->l1_index = l1_index; + m_data->l2_index = l2_index; + m_data->l2_offset = l2_offset; + m_data->l2_cache_entry = ((uint32_t *)l2_table) + l2_index; + } if (extent->sesparse) { cluster_sector = le64_to_cpu(((uint64_t *)l2_table)[l2_index]); @@ -1631,10 +1637,6 @@ static int get_cluster_offset(BlockDriverState *bs, } if (m_data) { m_data->new_allocation = true; - m_data->l1_index = l1_index; - m_data->l2_index = l2_index; - m_data->l2_offset = l2_offset; - m_data->l2_cache_entry = ((uint32_t *)l2_table) + l2_index; } } *cluster_offset = cluster_sector << BDRV_SECTOR_BITS; @@ -1990,7 +1992,7 @@ static int vmdk_pwritev(BlockDriverState *bs, uint64_t offset, error_report("Could not write to allocated cluster" " for streamOptimized"); return -EIO; - } else { + } else if (!zeroed) { /* allocate */ ret = get_cluster_offset(bs, extent, &m_data, offset, true, &cluster_offset, 0, 0); -- 2.25.3