static void external_snapshot_prepare(BlkTransactionStates *common, Error **errp) { BlockDriver *proto_drv; BlockDriver *drv; int flags, ret; Error *local_err = NULL; const char *device; const char *new_image_file; const char *format = "qcow2"; enum NewImageMode mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS; ExternalSnapshotStates *states = DO_UPCAST(ExternalSnapshotStates, common, common); TransactionAction *action = common->action; /* get parameters */ g_assert(action->kind == TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC); device = action->blockdev_snapshot_sync->device; 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; } states->old_bs = bdrv_find(device); if (!states->old_bs) { error_set(errp, QERR_DEVICE_NOT_FOUND, device); return; } if (!bdrv_is_inserted(states->old_bs)) { error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device); return; } if (bdrv_in_use(states->old_bs)) { error_set(errp, QERR_DEVICE_IN_USE, device); return; } if (!bdrv_is_read_only(states->old_bs)) { if (bdrv_flush(states->old_bs)) { error_set(errp, QERR_IO_ERROR); return; } } flags = states->old_bs->open_flags; proto_drv = bdrv_find_protocol(new_image_file); if (!proto_drv) { error_set(errp, QERR_INVALID_BLOCK_FORMAT, format); return; } /* create new image w/backing file */ if (mode != NEW_IMAGE_MODE_EXISTING) { bdrv_img_create(new_image_file, format, states->old_bs->filename, states->old_bs->drv->format_name, NULL, -1, flags, &local_err, false); if (error_is_set(&local_err)) { error_propagate(errp, local_err); return; } } /* We will manually add the backing_hd field to the bs later */ states->new_bs = bdrv_new(""); /* TODO Inherit bs->options or only take explicit options with an * extended QMP command? */ ret = bdrv_open(states->new_bs, new_image_file, NULL, flags | BDRV_O_NO_BACKING, drv); if (ret != 0) { error_setg_file_open(errp, -ret, new_image_file); } }