1 /* 2 * copy-before-write filter driver 3 * 4 * The driver performs Copy-Before-Write (CBW) operation: it is injected above 5 * some node, and before each write it copies _old_ data to the target node. 6 * 7 * Copyright (c) 2018-2021 Virtuozzo International GmbH. 8 * 9 * Author: 10 * Sementsov-Ogievskiy Vladimir <vsementsov@virtuozzo.com> 11 * 12 * This program is free software; you can redistribute it and/or modify 13 * it under the terms of the GNU General Public License as published by 14 * the Free Software Foundation; either version 2 of the License, or 15 * (at your option) any later version. 16 * 17 * This program is distributed in the hope that it will be useful, 18 * but WITHOUT ANY WARRANTY; without even the implied warranty of 19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 20 * GNU General Public License for more details. 21 * 22 * You should have received a copy of the GNU General Public License 23 * along with this program. If not, see <http://www.gnu.org/licenses/>. 24 */ 25 26 #ifndef COPY_BEFORE_WRITE_H 27 #define COPY_BEFORE_WRITE_H 28 29 #include "block/block_int.h" 30 #include "block/block-copy.h" 31 32 /* 33 * Global state (GS) API. These functions run under the BQL. 34 * 35 * See include/block/block-global-state.h for more information about 36 * the GS API. 37 */ 38 39 BlockDriverState *bdrv_cbw_append(BlockDriverState *source, 40 BlockDriverState *target, 41 const char *filter_node_name, 42 bool discard_source, 43 BlockCopyState **bcs, 44 Error **errp); 45 void bdrv_cbw_drop(BlockDriverState *bs); 46 47 #endif /* COPY_BEFORE_WRITE_H */ 48