[pve-devel] [PATCH v8 qemu 10/10] PVE backup: backup-access-api: explicit bitmap-mode parameter

[Wolfgang Bumiller]

This allows to explicitly request to re-create a bitmap under the same
name.

Signed-off-by: Wolfgang Bumiller <w.bumiller at proxmox.com>
---
New in v8

 pve-backup.c         | 17 ++++++++++++++++-
 qapi/block-core.json | 20 +++++++++++++++++++-
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/pve-backup.c b/pve-backup.c
index 8909842292..18bcf29533 100644
--- a/pve-backup.c
+++ b/pve-backup.c
@@ -1043,7 +1043,16 @@ BackupAccessInfoList *coroutine_fn qmp_backup_access_setup(
             error_propagate(errp, local_err);
             goto err;
         }
-        di->requested_bitmap_name = g_strdup(it->value->bitmap_name);
+        if (it->value->bitmap_mode == BACKUP_ACCESS_SETUP_BITMAP_MODE_NONE) {
+            di->bitmap_action = PBS_BITMAP_ACTION_NOT_USED;
+        } else {
+            di->requested_bitmap_name = g_strdup(it->value->bitmap_name);
+            if (it->value->bitmap_mode == BACKUP_ACCESS_SETUP_BITMAP_MODE_NEW) {
+                di->bitmap_action = PBS_BITMAP_ACTION_NEW;
+            } else if (it->value->bitmap_mode == BACKUP_ACCESS_SETUP_BITMAP_MODE_USE) {
+                di->bitmap_action = PBS_BITMAP_ACTION_USED;
+            }
+        }
         di_list = g_list_append(di_list, di);
     }
     bdrv_graph_co_rdunlock();
@@ -1096,6 +1105,12 @@ BackupAccessInfoList *coroutine_fn qmp_backup_access_setup(
             && di->requested_bitmap_name
             && strcmp(di->requested_bitmap_name, old_bitmap_name) == 0;
 
+        /* special case: if we explicitly requested a *new* bitmap, treat an
+         * existing bitmap as having a different name */
+        if (di->bitmap_action == PBS_BITMAP_ACTION_NEW) {
+            same_bitmap_name = false;
+        }
+
         if (old_bitmap_name && !same_bitmap_name) {
             BdrvDirtyBitmap *old_bitmap = bdrv_find_dirty_bitmap(di->bs, old_bitmap_name);
             if (!old_bitmap) {
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 58586170d9..e1c79649fb 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1145,9 +1145,27 @@
 #     in the result to see if you can actually re-use the bitmap or if it had to
 #     be newly created.
 #
+# @bitmap-mode: used to control whether the bitmap should be reused or
+#     recreated.
+#
 ##
 { 'struct': 'BackupAccessSourceDevice',
-  'data': { 'device': 'str', '*bitmap-name': 'str' } }
+  'data': { 'device': 'str', '*bitmap-name': 'str',
+            '*bitmap-mode': 'BackupAccessSetupBitmapMode' } }
+
+##
+# @BackupAccessSetupBitmapMode:
+#
+# How to setup a bitmap for a device for @backup-access-setup.
+# 
+# @none: do not use a bitmap. Removes an existing bitmap if present.
+#
+# @new: create and use a new bitmap.
+#
+# @use: try to re-use an existing bitmap. Create a new one if it doesn't exist.
+##
+{ 'enum': 'BackupAccessSetupBitmapMode',
+  'data': ['none', 'new', 'use' ] }
 
 ##
 # @backup-access-setup:
-- 
2.39.5