From ecc4fb6e1941035e1d9def1f69b779fbea216caf Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Mon, 24 Feb 2020 16:13:07 +0000 Subject: [PATCH 7/9] qcow2: Fix qcow2_alloc_cluster_abort() for external data file RH-Author: Kevin Wolf Message-id: <20200224161307.29783-2-kwolf@redhat.com> Patchwork-id: 94042 O-Subject: [RHEL-AV-8.2.0 qemu-kvm PATCH 1/1] qcow2: Fix qcow2_alloc_cluster_abort() for external data file Bugzilla: 1703907 RH-Acked-by: John Snow RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Max Reitz For external data file, cluster allocations return an offset in the data file and are not refcounted. In this case, there is nothing to do for qcow2_alloc_cluster_abort(). Freeing the same offset in the qcow2 file is wrong and causes crashes in the better case or image corruption in the worse case. Signed-off-by: Kevin Wolf Message-Id: <20200211094900.17315-3-kwolf@redhat.com> Signed-off-by: Kevin Wolf (cherry picked from commit c3b6658c1a5a3fb24d6c27b2594cf86146f75b22) Signed-off-by: Kevin Wolf Signed-off-by: Danilo C. L. de Paula --- block/qcow2-cluster.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 8982b7b..dc3c270 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -1015,8 +1015,11 @@ err: void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m) { BDRVQcow2State *s = bs->opaque; - qcow2_free_clusters(bs, m->alloc_offset, m->nb_clusters << s->cluster_bits, - QCOW2_DISCARD_NEVER); + if (!has_data_file(bs)) { + qcow2_free_clusters(bs, m->alloc_offset, + m->nb_clusters << s->cluster_bits, + QCOW2_DISCARD_NEVER); + } } /* -- 1.8.3.1