[libvirt PATCH] qemu: snapshot: delete disk image only if parent snapshot is external
When we are deleting external snapshot that is not active we only need
to delete overlay disk image of the parent snapshot. This works
correctly even if parent snapshot is external and active as it will have
another overlay created when user reverted to that snapshot.
In case the parent snapshot is internal there are no overlay disk images
created as everything is stored internally within the disk image. In
this case we would delete the actual disk image storing internal
snapshots and most likely the original disk image as well resulting in
data loss once the VM is shutoff.
Fixes: https://gitlab.com/libvirt/libvirt/-/issues/734
Signed-off-by: Pavel Hrdina <phrdina(a)redhat.com>
---
src/qemu/qemu_snapshot.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/src/qemu/qemu_snapshot.c b/src/qemu/qemu_snapshot.c
index 18b2e478f6..80cd54bf33 100644
--- a/src/qemu/qemu_snapshot.c
+++ b/src/qemu/qemu_snapshot.c
@@ -3144,6 +3144,8 @@ qemuSnapshotDeleteExternalPrepareData(virDomainObj *vm,
return -1;
}
+ data->parentSnap = qemuSnapshotFindParentSnapForDisk(snap,
data->snapDisk);
+
if (data->merge) {
virStorageSource *snapDiskSrc = NULL;
@@ -3185,8 +3187,6 @@ qemuSnapshotDeleteExternalPrepareData(virDomainObj *vm,
qemuSnapshotGetDisksWithBackingStore(vm, snap, data);
}
- data->parentSnap = qemuSnapshotFindParentSnapForDisk(snap,
data->snapDisk);
-
if (data->parentSnap &&
!virDomainSnapshotIsExternal(data->parentSnap)) {
virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
_("deleting external snapshot that has internal
snapshot as parent not supported"));
@@ -3642,10 +3642,12 @@ qemuSnapshotDiscardExternal(virDomainObj *vm,
if (!data->job)
goto error;
} else {
- if (virStorageSourceInit(data->parentDomDisk->src) < 0 ||
- virStorageSourceUnlink(data->parentDomDisk->src) < 0) {
- VIR_WARN("Failed to remove snapshot image '%s'",
- data->snapDisk->name);
+ if (data->parentSnap &&
virDomainSnapshotIsExternal(data->parentSnap)) {
+ if (virStorageSourceInit(data->parentDomDisk->src) < 0 ||
+ virStorageSourceUnlink(data->parentDomDisk->src) < 0) {
+ VIR_WARN("Failed to remove snapshot image '%s'",
+ data->snapDisk->name);
+ }
}
}
}
--
2.47.1