static void external_snapshot_prepare(BlkTransactionState *common, Error **errp) { BlockDriver *drv; int flags, ret; QDict *options = NULL; Error *local_err = NULL; bool has_device = false; const char *device; bool has_node_name = false; const char *node_name; bool has_snapshot_node_name = false; const char *snapshot_node_name; const char *new_image_file; const char *format = "qcow2"; enum NewImageMode mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS; ExternalSnapshotState *state = DO_UPCAST(ExternalSnapshotState, common, common); TransactionAction *action = common->action; /* get parameters */ g_assert(action->kind == TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC); has_device = action->blockdev_snapshot_sync->has_device; device = action->blockdev_snapshot_sync->device; has_node_name = action->blockdev_snapshot_sync->has_node_name; node_name = action->blockdev_snapshot_sync->node_name; has_snapshot_node_name = action->blockdev_snapshot_sync->has_snapshot_node_name; snapshot_node_name = action->blockdev_snapshot_sync->snapshot_node_name; new_image_file = action->blockdev_snapshot_sync->snapshot_file; if (action->blockdev_snapshot_sync->has_format) { format = action->blockdev_snapshot_sync->format; } if (action->blockdev_snapshot_sync->has_mode) { mode = action->blockdev_snapshot_sync->mode; } /* start processing */ drv = bdrv_find_format(format); if (!drv) { error_set(errp, QERR_INVALID_BLOCK_FORMAT, format); return; } state->old_bs = bdrv_lookup_bs(has_device ? device : NULL, has_node_name ? node_name : NULL, &local_err); if (error_is_set(&local_err)) { error_propagate(errp, local_err); return; } if (has_node_name && !has_snapshot_node_name) { error_setg(errp, "New snapshot node name missing"); return; } if (has_snapshot_node_name && bdrv_find_node(snapshot_node_name)) { error_setg(errp, "New snapshot node name already existing"); return; } if (!bdrv_is_inserted(state->old_bs)) { error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device); return; } if (bdrv_in_use(state->old_bs)) { error_set(errp, QERR_DEVICE_IN_USE, device); return; } if (!bdrv_is_read_only(state->old_bs)) { if (bdrv_flush(state->old_bs)) { error_set(errp, QERR_IO_ERROR); return; } } if (!bdrv_is_first_non_filter(state->old_bs)) { error_set(errp, QERR_FEATURE_DISABLED, "snapshot"); return; } flags = state->old_bs->open_flags; /* create new image w/backing file */ if (mode != NEW_IMAGE_MODE_EXISTING) { bdrv_img_create(new_image_file, format, state->old_bs->filename, state->old_bs->drv->format_name, NULL, -1, flags, &local_err, false); if (error_is_set(&local_err)) { error_propagate(errp, local_err); return; } } if (has_snapshot_node_name) { options = qdict_new(); qdict_put(options, "node-name", qstring_from_str(snapshot_node_name)); } /* We will manually add the backing_hd field to the bs later */ state->new_bs = bdrv_new(""); /* TODO Inherit bs->options or only take explicit options with an * extended QMP command? */ ret = bdrv_open(state->new_bs, new_image_file, options, flags | BDRV_O_NO_BACKING, drv, &local_err); if (ret != 0) { error_propagate(errp, local_err); } QDECREF(options); }