/*-
 * Copyright (c) 2004 Pawel Jakub Dawidek <pjd@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.
 *
 * $FreeBSD$
 */

#ifndef	_G_MIRROR_H_
#define	_G_MIRROR_H_

#include <sys/endian.h>

#define	G_MIRROR_CLASS_NAME	"MIRROR"

#define	G_MIRROR_MAGIC		"GEOM::MIRROR"
#define	G_MIRROR_VERSION	0

#define	G_MIRROR_BALANCE_NONE		0
#define	G_MIRROR_BALANCE_ROUND_ROBIN	1
#define	G_MIRROR_BALANCE_SMART		2
#define	G_MIRROR_BALANCE_MIN		G_MIRROR_BALANCE_NONE
#define	G_MIRROR_BALANCE_MAX		G_MIRROR_BALANCE_SMART

#define	G_MIRROR_DISK_FLAG_SYNCHRONIZING	0x0000000000000001ULL
#define	G_MIRROR_DISK_FLAG_INACTIVE		0x0000000000000002ULL

#define	G_MIRROR_DISK_FLAG_MASK			0x00000000ffffffffULL
#define	G_MIRROR_DEVICE_FLAG_MASK		0xffffffff00000000ULL

#define	G_MIRROR_OPT_BALANCE	0x01
#define	G_MIRROR_OPT_SLICE	0x02
#define	G_MIRROR_OPT_QUARANTINE	0x04
#define	G_MIRROR_OPT_SUSPECTS	0x08

#ifdef _KERNEL
#define	G_MIRROR_TYPE_MANUAL	0
#define	G_MIRROR_TYPE_AUTOMATIC	1

#define	G_MIRROR_DEBUG(lvl, ...)	do {				\
	if (g_mirror_debug >= (lvl)) {					\
		printf("GEOM_MIRROR");					\
		if (g_mirror_debug > 0)					\
			printf("[%u]", lvl);				\
		printf(": ");						\
		printf(__VA_ARGS__);					\
		printf("\n");						\
	}								\
} while (0)
#define	G_MIRROR_LOGREQ(bp, ...)	do {				\
	if (g_mirror_debug >= 2) {					\
		printf("GEOM_MIRROR[2]: ");				\
		printf(__VA_ARGS__);					\
		printf(" ");						\
		g_print_bio(bp);					\
		printf("\n");						\
	}								\
} while (0)

/*
 * Informations needed for synchronization.
 */
struct g_mirror_disk_sync {
	struct g_consumer *ds_consumer;
	off_t		ds_offset;
	off_t		ds_offset_done;
	uint16_t	ds_syncid;
};

/*
 * Informations needed for synchronization.
 */
struct g_mirror_device_sync {
	struct g_geom	*ds_geom;
	size_t		 ds_block;
	int		 ds_bits;
	uma_zone_t	 ds_zone;
};

#define	G_MIRROR_DISK_STATE_NONE		0
#define	G_MIRROR_DISK_STATE_NEW			1
#define	G_MIRROR_DISK_STATE_ACTIVE		2
#define	G_MIRROR_DISK_STATE_SYNCHRONIZING	3
#define	G_MIRROR_DISK_STATE_DISCONNECTED	4
#define	G_MIRROR_DISK_STATE_DESTROY		5
struct g_mirror_disk {
	uint32_t	 d_id;		/* Disk ID. */
	struct g_consumer *d_consumer;	/* Consumer. */
	uint32_t	 d_count;	/* Number of pending requests. */
	struct g_mirror_softc	*d_softc; /* Back-pointer to softc. */
	struct proc	*d_worker;
	int		 d_state;	/* Disk state. */
	uint64_t	 d_flags;	/* Additional flags. */
	struct g_mirror_disk_sync d_sync;/* Sync information. */
	LIST_ENTRY(g_mirror_disk) d_next;
};
#define	d_name	d_consumer->provider->name

#define	G_MIRROR_EVENT_DONTWAIT	0x1
#define	G_MIRROR_EVENT_WAIT	0x2
#define	G_MIRROR_EVENT_DEVICE	0x4
#define	G_MIRROR_EVENT_DONE	0x8
struct g_mirror_event {
	struct g_mirror_disk	*e_disk;
	int			 e_state;
	int			 e_flags;
	int			 e_error;
	TAILQ_ENTRY(g_mirror_event) e_next;
};

#define	G_MIRROR_DEVICE_FLAG_DESTROY		0x0001
#define	G_MIRROR_DEVICE_FLAG_WAIT		0x0002

#define	G_MIRROR_DEVICE_STATE_STARTING		0
#define	G_MIRROR_DEVICE_STATE_RUNNING		1
struct g_mirror_softc {
	u_int		sc_state;	/* Device state. */
	uint32_t	sc_slice;	/* Slice size. */
	uint8_t		sc_balance;	/* Balance algorithm. */
	uint64_t	sc_mediasize;	/* Device size. */
	uint32_t	sc_sectorsize;	/* Sector size. */
	uint64_t	sc_flags;	/* Additional flags. */

	struct g_geom	*sc_geom;
	struct g_provider *sc_provider;

	char		sc_name[16];	/* Mirror name. */
	uint32_t	sc_id;		/* Mirror unique ID. */

	struct bio_queue_head sc_queue;
	struct mtx	 sc_queue_mtx;
	struct proc	*sc_worker;

	LIST_HEAD(, g_mirror_disk) sc_disks;
	u_int		sc_ndisks;	/* Number of disks. */
	struct g_mirror_disk *sc_hint;

	uint16_t	sc_syncid;	/* Synchronization ID. */
	int		sc_bump_syncid;	/* Bump syncid on first write. */
	struct g_mirror_device_sync sc_sync;

	TAILQ_HEAD(, g_mirror_event) sc_events;
	struct mtx	sc_events_mtx;

	struct callout	sc_callout;
};

/* XXX: Temporary. */
extern int g_mirror_stop;

u_int g_mirror_ndisks(struct g_mirror_softc *sc, int state);
int g_mirror_destroy(struct g_mirror_softc *sc, boolean_t force);
int g_mirror_event_send(void *arg, int state, int flags);
struct g_mirror_metadata;
void g_mirror_fill_metadata(struct g_mirror_softc *sc,
    struct g_mirror_disk *disk, struct g_mirror_metadata *md);
void g_mirror_update_metadata(struct g_mirror_disk *disk);

g_ctl_req_t g_mirror_config;
#endif	/* _KERNEL */

struct g_mirror_metadata {
	char		md_magic[16];	/* Magic value. */
	uint32_t	md_version;	/* Version number. */
	char		md_name[16];	/* Mirror name. */
	uint32_t	md_mid;		/* Mirror unique ID. */
	uint32_t	md_did;		/* Disk unique ID. */
	uint16_t	md_all;		/* Number of disks in mirror. */
	uint16_t	md_syncid;	/* Synchronization ID. */
	uint32_t	md_slice;	/* Slice size. */
	uint8_t		md_balance;	/* Balance type. */
	uint64_t	md_mediasize;	/* Size of the smallest
					   disk in mirror. */
	uint32_t	md_sectorsize;	/* Sector size. */
	uint64_t	md_sync_offset;	/* Synchronized offset. */
	uint64_t	md_flags;	/* Additional flags. */
};
static __inline void
mirror_metadata_encode(const struct g_mirror_metadata *md, u_char *data)
{

	bcopy(md->md_magic, data, 16);
	le32enc(data + 16, md->md_version);
	bcopy(md->md_name, data + 20, 16);
	le32enc(data + 36, md->md_mid);
	le32enc(data + 40, md->md_did);
	le16enc(data + 44, md->md_all);
	le16enc(data + 46, md->md_syncid);
	le32enc(data + 48, md->md_slice);
	*(data + 52) = md->md_balance;
	le64enc(data + 53, md->md_mediasize);
	le32enc(data + 61, md->md_sectorsize);
	le64enc(data + 65, md->md_sync_offset);
	le64enc(data + 73, md->md_flags);
}
static __inline void
mirror_metadata_decode(const u_char *data, struct g_mirror_metadata *md)
{

	bcopy(data, md->md_magic, 16);
	md->md_version = le32dec(data + 16);
	bcopy(data + 20, md->md_name, 16);
	md->md_mid = le32dec(data + 36);
	md->md_did = le32dec(data + 40);
	md->md_all = le16dec(data + 44);
	md->md_syncid = le16dec(data + 46);
	md->md_slice = le32dec(data + 48);
	md->md_balance = *(data + 52);
	md->md_mediasize = le64dec(data + 53);
	md->md_sectorsize = le64dec(data + 61);
	md->md_sync_offset = le64dec(data + 65);
	md->md_flags = le64dec(data + 73);
}

static __inline const char *
balance_name(u_int balance)
{
	static const char *algorithms[] = {
		[G_MIRROR_BALANCE_NONE] = "none",
		[G_MIRROR_BALANCE_ROUND_ROBIN] = "round-robin",
		[G_MIRROR_BALANCE_SMART] = "smart",
		[G_MIRROR_BALANCE_MAX + 1] = "unknown"
	};

	if (balance > G_MIRROR_BALANCE_MAX)
		balance = G_MIRROR_BALANCE_MAX + 1;

	return (algorithms[balance]);
}

static __inline int
balance_id(const char *name)
{
	static const char *algorithms[] = {
		[G_MIRROR_BALANCE_NONE] = "none",
		[G_MIRROR_BALANCE_ROUND_ROBIN] = "round-robin",
		[G_MIRROR_BALANCE_SMART] = "smart"
	};
	int n;

	for (n = G_MIRROR_BALANCE_MIN; n <= G_MIRROR_BALANCE_MAX; n++) {
		if (strcmp(name, algorithms[n]) == 0)
			return (n);
	}
	return (-1);
}
#endif	/* !_G_MIRROR_H_ */