From: Max Reitz Date: Thu, 19 Sep 2013 10:29:15 +0000 (+0200) Subject: qcow2: Correct snapshots size for overlap check X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=0f39ac9a07cc10278e37d87076b143008f28aa3b;p=qmiga%2Fqemu.git qcow2: Correct snapshots size for overlap check Using s->snapshots_size instead of snapshots_size for the metadata overlap check in qcow2_write_snapshots leads to the detection of an overlap with the main qcow2 image header when deleting the last snapshot, since s->snapshots_size has not yet been updated and is therefore non-zero. However, the offset returned by qcow2_alloc_clusters will be zero since snapshots_size is zero. Therefore, an overlap is detected albeit no such will occur. This patch fixes this by replacing s->snapshots_size by snapshots_size when calling qcow2_pre_write_overlap_check. Signed-off-by: Max Reitz Signed-off-by: Stefan Hajnoczi --- diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c index 7d144205c3..5e8a7794f4 100644 --- a/block/qcow2-snapshot.c +++ b/block/qcow2-snapshot.c @@ -192,7 +192,7 @@ static int qcow2_write_snapshots(BlockDriverState *bs) /* The snapshot list position has not yet been updated, so these clusters * must indeed be completely free */ ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, offset, - s->snapshots_size); + snapshots_size); if (ret < 0) { return ret; }