freebsd-dev/sys/geom/multipath/g_multipath.h
Alexander Motin e6afd72b93 Implement automatic live resize support for GEOM MULTIPATH class.
In "manual" mode just automatically resize provider in any direction.
In "automatic" mode allow only growth (with new metadata write); in case
of shrinking destroy the multipath device same as before since it may be
undesirable to write new metadata within old user area.

MFC after:	1 month
2013-11-16 14:31:49 +00:00

111 lines
3.7 KiB
C

/*-
* Copyright (c) 2006-2007 Matthew Jacob <mjacob@FreeBSD.org>
* All rights reserved.
*
* 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.
*
* $FreeBSD$
*/
/*
* Based upon work by Pawel Jakub Dawidek <pjd@FreeBSD.org> for all of the
* fine geom examples, and by Poul Henning Kamp <phk@FreeBSD.org> for GEOM
* itself, all of which is most gratefully acknowledged.
*/
#ifndef _G_MULTIPATH_H_
#define _G_MULTIPATH_H_
#define G_MULTIPATH_CLASS_NAME "MULTIPATH"
#define G_MULTIPATH_VERSION 1
#define G_MULTIPATH_MAGIC "GEOM::MULTIPATH"
#include <sys/endian.h>
#ifdef _KERNEL
struct g_multipath_softc {
struct g_provider * sc_pp;
struct g_consumer * sc_active;
struct mtx sc_mtx;
char sc_name[16];
char sc_uuid[40];
off_t sc_size;
int sc_opened;
int sc_stopping;
int sc_ndisks;
int sc_active_active; /* Active/Active mode */
};
#endif /* _KERNEL */
struct g_multipath_metadata {
char md_magic[16]; /* Magic Value */
char md_uuid[40]; /* more magic */
char md_name[16]; /* a friendly name */
uint32_t md_version; /* version */
uint32_t md_sectorsize; /* sectorsize of provider */
uint64_t md_size; /* absolute size of provider */
uint8_t md_active_active; /* Active/Active mode */
};
static __inline void
multipath_metadata_encode(const struct g_multipath_metadata *, u_char *);
static __inline void
multipath_metadata_decode(u_char *, struct g_multipath_metadata *);
static __inline void
multipath_metadata_encode(const struct g_multipath_metadata *md, u_char *data)
{
bcopy(md->md_magic, data, sizeof(md->md_magic));
data += sizeof(md->md_magic);
bcopy(md->md_uuid, data, sizeof(md->md_uuid));
data += sizeof(md->md_uuid);
bcopy(md->md_name, data, sizeof(md->md_name));
data += sizeof(md->md_name);
le32enc(data, md->md_version);
data += sizeof(md->md_version);
le32enc(data, md->md_sectorsize);
data += sizeof(md->md_sectorsize);
le64enc(data, md->md_size);
data += sizeof(md->md_size);
*data = md->md_active_active;
}
static __inline void
multipath_metadata_decode(u_char *data, struct g_multipath_metadata *md)
{
bcopy(data, md->md_magic, sizeof(md->md_magic));
data += sizeof(md->md_magic);
bcopy(data, md->md_uuid, sizeof(md->md_uuid));
data += sizeof(md->md_uuid);
bcopy(data, md->md_name, sizeof(md->md_name));
data += sizeof(md->md_name);
md->md_version = le32dec(data);
data += sizeof(md->md_version);
md->md_sectorsize = le32dec(data);
data += sizeof(md->md_sectorsize);
md->md_size = le64dec(data);
data += sizeof(md->md_size);
md->md_active_active = *data;
}
#endif /* _G_MULTIPATH_H_ */