freebsd-src/sbin/hastd/activemap.h
Pawel Jakub Dawidek 32115b105a Please welcome HAST - Highly Avalable Storage.
HAST allows to transparently store data on two physically separated machines
connected over the TCP/IP network. HAST works in Primary-Secondary
(Master-Backup, Master-Slave) configuration, which means that only one of the
cluster nodes can be active at any given time. Only Primary node is able to
handle I/O requests to HAST-managed devices. Currently HAST is limited to two
cluster nodes in total.

HAST operates on block level - it provides disk-like devices in /dev/hast/
directory for use by file systems and/or applications. Working on block level
makes it transparent for file systems and applications. There in no difference
between using HAST-provided device and raw disk, partition, etc. All of them
are just regular GEOM providers in FreeBSD.

For more information please consult hastd(8), hastctl(8) and hast.conf(5)
manual pages, as well as http://wiki.FreeBSD.org/HAST.

Sponsored by:	FreeBSD Foundation
Sponsored by:	OMCnet Internet Service GmbH
Sponsored by:	TransIP BV
2010-02-18 23:16:19 +00:00

70 lines
2.8 KiB
C

/*-
* Copyright (c) 2009-2010 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Pawel Jakub Dawidek under sponsorship from
* the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _ACTIVEMAP_H_
#define _ACTIVEMAP_H_
#include <stdbool.h>
#include <stdint.h>
struct activemap;
int activemap_init(struct activemap **ampp, uint64_t mediasize,
uint32_t extentsize, uint32_t sectorsize, uint32_t keepdirty);
void activemap_free(struct activemap *amp);
bool activemap_write_start(struct activemap *amp, off_t offset, off_t length);
bool activemap_write_complete(struct activemap *amp, off_t offset,
off_t length);
bool activemap_extent_complete(struct activemap *amp, int extent);
uint64_t activemap_ndirty(const struct activemap *amp);
bool activemap_differ(const struct activemap *amp);
size_t activemap_size(const struct activemap *amp);
size_t activemap_ondisk_size(const struct activemap *amp);
void activemap_copyin(struct activemap *amp, const unsigned char *buf,
size_t size);
void activemap_merge(struct activemap *amp, const unsigned char *buf,
size_t size);
const unsigned char *activemap_bitmap(struct activemap *amp, size_t *sizep);
size_t activemap_calc_ondisk_size(uint64_t mediasize, uint32_t extentsize,
uint32_t sectorsize);
void activemap_sync_rewind(struct activemap *amp);
off_t activemap_sync_offset(struct activemap *amp, off_t *lengthp,
int *syncextp);
bool activemap_need_sync(struct activemap *amp, off_t offset, off_t length);
void activemap_dump(const struct activemap *amp);
#endif /* !_ACTIVEMAP_H_ */