[PATCH v4 7/9] migration: introduce a delete_snapshot wrapper

["Daniel P. Berrangé" <berrange@redhat.com>]

Make snapshot deletion consistent with the snapshot save
and load commands by using a wrapper around the blockdev
layer. The main difference is that we get upfront validation
of the passed in device list (if any).

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 include/migration/snapshot.h |  4 +++-
 migration/savevm.c           | 13 +++++++++++++
 monitor/hmp-cmds.c           |  2 +-
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/include/migration/snapshot.h b/include/migration/snapshot.h
index b2c72e0a1b..f46f28745d 100644
--- a/include/migration/snapshot.h
+++ b/include/migration/snapshot.h
@@ -25,5 +25,7 @@ int load_snapshot(const char *name,
                   const char *vmstate,
                   bool has_devices, strList *devices,
                   Error **errp);
-
+int delete_snapshot(const char *name,
+                    bool has_devices, strList *devices,
+                    Error **errp);
 #endif
diff --git a/migration/savevm.c b/migration/savevm.c
index b3d2ce7045..56f85be250 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2940,6 +2940,19 @@ err_drain:
     return -1;
 }
 
+int delete_snapshot(const char *name, bool has_devices, strList *devices, Error **errp)
+{
+    if (!bdrv_all_can_snapshot(has_devices, devices, errp)) {
+        return -1;
+    }
+
+    if (bdrv_all_delete_snapshot(name, has_devices, devices, errp) < 0) {
+        return -1;
+    }
+
+    return 0;
+}
+
 void vmstate_register_ram(MemoryRegion *mr, DeviceState *dev)
 {
     qemu_ram_set_idstr(mr->ram_block,
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index 1191aac3ae..278dca59b0 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -1140,7 +1140,7 @@ void hmp_delvm(Monitor *mon, const QDict *qdict)
     Error *err = NULL;
     const char *name = qdict_get_str(qdict, "name");
 
-    bdrv_all_delete_snapshot(name, false, NULL, &err);
+    delete_snapshot(name, false, NULL, &err);
     hmp_handle_error(mon, err);
 }
 
-- 
2.26.2