When we revert to non-leaf snapshot and create new branch or branches the overlay in snapshot metadata is no longer usable as a disk source for deletion of that snapshot. We need to use other places to figure out the correct storage source. Fixes: https://gitlab.com/libvirt/libvirt/-/issues/534 Signed-off-by: Pavel Hrdina <phrdina(a)redhat.com&gt; --- src/qemu/qemu_snapshot.c | 46 ++++++++++++++++++++++++++++++++++++++-- 1 file changed, 44 insertions(+), 2 deletions(-) diff --git a/src/qemu/qemu_snapshot.c b/src/qemu/qemu_snapshot.c index 1962ba4027..ee06e72b11 100644 --- a/src/qemu/qemu_snapshot.c +++ b/src/qemu/qemu_snapshot.c @@ -2748,6 +2748,44 @@ qemuSnapshotGetDisksWithBackingStore(virDomainObj *vm, } +/** + * qemuSnapshotExternalGetSnapDiskSrc: + * @vm: domain object + * @snap: snapshot object + * @snapDisk: disk definition from snapshost + * + * Try to get actual disk source for @snapDisk as the source stored in + * snapshot metadata is not always the correct source we need to work with. + * This happens mainly after reverting to non-leaf snapshot and creating + * new branch with new snapshot. + * + * Returns disk source on success, NULL on error. + */ +static virStorageSource * +qemuSnapshotExternalGetSnapDiskSrc(virDomainObj *vm, + virDomainMomentObj *snap, + virDomainSnapshotDiskDef *snapDisk) +{ + virDomainDiskDef *disk = NULL; + + /* Should never happen when deleting external snapshot as for now we do + * not support this specific case for now. */ + if (snap->nchildren > 1) + return snapDisk->src; + + if (snap->first_child) { + disk = qemuDomainDiskByName(snap->first_child->def->dom, snapDisk->name); + } else if (virDomainSnapshotGetCurrent(vm->snapshots) == snap) { + disk = qemuDomainDiskByName(vm->def, snapDisk->name); + } + + if (disk) + return disk->src; + + return snapDisk->src; +} + + /** * qemuSnapshotDeleteExternalPrepareData: * @vm: domain object @@ -2802,18 +2840,22 @@ qemuSnapshotDeleteExternalPrepareData(virDomainObj *vm, } if (data->merge) { + virStorageSource *snapDiskSrc = NULL; + data->domDisk = qemuDomainDiskByName(vm->def, snapDisk->name); if (!data->domDisk) return -1; + snapDiskSrc = qemuSnapshotExternalGetSnapDiskSrc(vm, snap, data->snapDisk); + if (virDomainObjIsActive(vm)) { data->diskSrc = virStorageSourceChainLookupBySource(data->domDisk->src, - data->snapDisk->src, + snapDiskSrc, &data->prevDiskSrc); if (!data->diskSrc) return -1; - if (!virStorageSourceIsSameLocation(data->diskSrc, data->snapDisk->src)) { + if (!virStorageSourceIsSameLocation(data->diskSrc, snapDiskSrc)) { virReportError(VIR_ERR_OPERATION_FAILED, "%s", _("VM disk source and snapshot disk source are not the same")); return -1; -- 2.41.0