xref: /openbmc/qemu/block/copy-before-write.h (revision 30b6852c)
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 BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
33                                   BlockDriverState *target,
34                                   const char *filter_node_name,
35                                   BlockCopyState **bcs,
36                                   Error **errp);
37 void bdrv_cbw_drop(BlockDriverState *bs);
38 
39 #endif /* COPY_BEFORE_WRITE_H */
40