[v9,09/11] migration: introduce a delete_snapshot wrapper

Commit Message

Daniel P. Berrangé Jan. 20, 2021, 10:44 a.m. UTC

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 <[e-mail]>
---
 include/migration/snapshot.h | 13 +++++++++++++
 migration/savevm.c           | 14 ++++++++++++++
 monitor/hmp-cmds.c           |  2 +-
 3 files changed, 28 insertions(+), 1 deletion(-)

Comments

Eric Blake Jan. 20, 2021, 5:32 p.m. UTC | #1

On 1/20/21 4:44 AM, Daniel P. Berrangé wrote:
> 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 <[e-mail]>
> ---
>  include/migration/snapshot.h | 13 +++++++++++++
>  migration/savevm.c           | 14 ++++++++++++++
>  monitor/hmp-cmds.c           |  2 +-
>  3 files changed, 28 insertions(+), 1 deletion(-)
> 

Reviewed-by: Eric Blake <[e-mail]>

Patch

diff --git a/include/migration/snapshot.h b/include/migration/snapshot.h
index 3bdbef435b..e72083b117 100644
--- a/include/migration/snapshot.h
+++ b/include/migration/snapshot.h
@@ -48,4 +48,17 @@  bool load_snapshot(const char *name,
                    bool has_devices, strList *devices,
                    Error **errp);
 
+/**
+ * delete_snapshot: Delete a snapshot.
+ * @name: path to snapshot
+ * @has_devices: whether to use explicit device list
+ * @devices: explicit device list to snapshot
+ * @errp: pointer to error object
+ * On success, return %true.
+ * On failure, store an error through @errp and return %false.
+ */
+bool delete_snapshot(const char *name,
+                    bool has_devices, strList *devices,
+                    Error **errp);
+
 #endif
diff --git a/migration/savevm.c b/migration/savevm.c
index add7712bdf..3828fa2c8d 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -3036,6 +3036,20 @@  err_drain:
     return false;
 }
 
+bool delete_snapshot(const char *name, bool has_devices,
+                     strList *devices, Error **errp)
+{
+    if (!bdrv_all_can_snapshot(has_devices, devices, errp)) {
+        return false;
+    }
+
+    if (bdrv_all_delete_snapshot(name, has_devices, devices, errp) < 0) {
+        return false;
+    }
+
+    return true;
+}
+
 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 04fa57585a..06054021ab 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -1150,7 +1150,7 @@  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);
 }