/*

 * Copyright (c) 2020 Red Hat, Inc.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 * 

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 * 

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

 * 02110-1301, USA. 

 *

 * $Id: //eng/vdo-releases/aluminum/src/c++/vdo/kernel/kvdoFlush.h#1 $

 */

#ifndef KVDO_FLUSH_H

#define KVDO_FLUSH_H

#include "flush.h"

#include "kernelLayer.h"

/**

 * Create a KVDOFlush.

 *

 * @param flushPtr  A pointer to hold the new flush

 **/

int makeKVDOFlush(KVDOFlush **flushPtr);

/**

 * Answer the question as to whether VDO should be processing REQ_FLUSH

 * requests or not.

 *

 * @param layer    The layer

 *

 * @return true if VDO should process empty flush requests, or false if

 *         they should just be forwarded to our storage device.

 **/

bool shouldProcessFlush(KernelLayer *layer);

/**

 * Function called to start processing a flush request. It is called when we

 * receive an empty flush bio from the block layer, and before acknowledging a

 * non-empty bio with the FUA flag set.

 *

 * @param layer  The physical layer

 * @param bio    The bio containing an empty flush request

 **/

void launchKVDOFlush(KernelLayer *layer, BIO *bio);

/**

 * Function called from base VDO to complete and free a flush request.

 *

 * @param kfp  Pointer to the flush request

 **/

void kvdoCompleteFlush(VDOFlush **kfp);

/**

 * Issue a flush request and wait for it to complete.

 *

 * @param layer The kernel layer

 *

 * @return VDO_SUCCESS or an error

 */

int synchronousFlush(KernelLayer *layer);

#endif /* KVDO_FLUSH_H */