block: add ability to specify list of blockdevs during snapshot

When running snapshot operations, there are various rules for which
blockdevs are included/excluded. While this provides reasonable default
behaviour, there are scenarios that are not well handled by the default
logic. Some of the conditions do not have a single correct answer.

Thus there needs to be a way for the mgmt app to provide an explicit
list of blockdevs to perform snapshots across. This can be achieved
by passing a list of node names that should be used.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20210204124834.774401-5-berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

1 files changed, 16 insertions, 6 deletions

diff --git a/include/block/snapshot.h b/include/block/snapshot.h
index 5cb2b696ad..2569a903f2 100644
--- a/include/block/snapshot.h
+++ b/include/block/snapshot.h
@@ -25,7 +25,7 @@
 #ifndef SNAPSHOT_H
 #define SNAPSHOT_H
 
-
+#include "qapi/qapi-builtin-types.h"
 
 #define SNAPSHOT_OPT_BASE       "snapshot."
 #define SNAPSHOT_OPT_ID         "snapshot.id"
@@ -77,15 +77,25 @@ int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs,
  * These functions will properly handle dataplane (take aio_context_acquire
  * when appropriate for appropriate block drivers */
 
-bool bdrv_all_can_snapshot(Error **errp);
-int bdrv_all_delete_snapshot(const char *name, Error **errp);
-int bdrv_all_goto_snapshot(const char *name, Error **errp);
-int bdrv_all_find_snapshot(const char *name, Error **errp);
+bool bdrv_all_can_snapshot(bool has_devices, strList *devices,
+                           Error **errp);
+int bdrv_all_delete_snapshot(const char *name,
+                             bool has_devices, strList *devices,
+                             Error **errp);
+int bdrv_all_goto_snapshot(const char *name,
+                           bool has_devices, strList *devices,
+                           Error **errp);
+int bdrv_all_find_snapshot(const char *name,
+                           bool has_devices, strList *devices,
+                           Error **errp);
 int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
                              BlockDriverState *vm_state_bs,
                              uint64_t vm_state_size,
+                             bool has_devices,
+                             strList *devices,
                              Error **errp);
 
-BlockDriverState *bdrv_all_find_vmstate_bs(Error **errp);
+BlockDriverState *bdrv_all_find_vmstate_bs(bool has_devices, strList *devices,
+                                           Error **errp);
 
 #endif