/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2004-2006 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.
 */

#ifndef _G_MIRROR_H_
#define _G_MIRROR_H_

#include <sys/endian.h>
#include <sys/md5.h>

#define G_MIRROR_CLASS_NAME     "MIRROR"

#define G_MIRROR_MAGIC          "GEOM::MIRROR"
/*
 * Version history:
 * 0 - Initial version number.
 * 1 - Added 'prefer' balance algorithm.
 * 2 - Added md_genid field to metadata.
 * 3 - Added md_provsize field to metadata.
 * 4 - Added 'no failure synchronization' flag.
 */
#define G_MIRROR_VERSION        4

#define G_MIRROR_BALANCE_NONE           0
#define G_MIRROR_BALANCE_ROUND_ROBIN    1
#define G_MIRROR_BALANCE_LOAD           2
#define G_MIRROR_BALANCE_SPLIT          3
#define G_MIRROR_BALANCE_PREFER         4
#define G_MIRROR_BALANCE_MIN            G_MIRROR_BALANCE_NONE
#define G_MIRROR_BALANCE_MAX            G_MIRROR_BALANCE_PREFER

#define G_MIRROR_DISK_FLAG_DIRTY                0x0000000000000001ULL
#define G_MIRROR_DISK_FLAG_SYNCHRONIZING        0x0000000000000002ULL
#define G_MIRROR_DISK_FLAG_FORCE_SYNC           0x0000000000000004ULL
#define G_MIRROR_DISK_FLAG_INACTIVE             0x0000000000000008ULL
#define G_MIRROR_DISK_FLAG_HARDCODED            0x0000000000000010ULL
#define G_MIRROR_DISK_FLAG_BROKEN               0x0000000000000020ULL
#define G_MIRROR_DISK_FLAG_CANDELETE            0x0000000000000040ULL

/* Per-disk flags which are recorded in on-disk metadata. */
#define G_MIRROR_DISK_FLAG_MASK         (G_MIRROR_DISK_FLAG_DIRTY |     \
                                         G_MIRROR_DISK_FLAG_SYNCHRONIZING | \
                                         G_MIRROR_DISK_FLAG_FORCE_SYNC | \
                                         G_MIRROR_DISK_FLAG_INACTIVE | \
                                         G_MIRROR_DISK_FLAG_CANDELETE)

#define G_MIRROR_DEVICE_FLAG_NOAUTOSYNC 0x0000000000000001ULL
#define G_MIRROR_DEVICE_FLAG_NOFAILSYNC 0x0000000000000002ULL

/* Mirror flags which are recorded in on-disk metadata. */
#define G_MIRROR_DEVICE_FLAG_MASK       (G_MIRROR_DEVICE_FLAG_NOAUTOSYNC | \
                                         G_MIRROR_DEVICE_FLAG_NOFAILSYNC)

#ifdef _KERNEL
#define G_MIRROR_DEVICE_FLAG_DESTROY    0x0100000000000000ULL
#define G_MIRROR_DEVICE_FLAG_DRAIN      0x0200000000000000ULL
#define G_MIRROR_DEVICE_FLAG_CLOSEWAIT  0x0400000000000000ULL
#define G_MIRROR_DEVICE_FLAG_TASTING    0x0800000000000000ULL
#define G_MIRROR_DEVICE_FLAG_WIPE       0x1000000000000000ULL

extern int g_mirror_debug;

#define G_MIRROR_DEBUG(lvl, ...) \
    _GEOM_DEBUG("GEOM_MIRROR", g_mirror_debug, (lvl), NULL, __VA_ARGS__)
#define G_MIRROR_LOGREQ(lvl, bp, ...) \
    _GEOM_DEBUG("GEOM_MIRROR", g_mirror_debug, (lvl), (bp), __VA_ARGS__)

#define G_MIRROR_BIO_FLAG_REGULAR       0x01
#define G_MIRROR_BIO_FLAG_SYNC          0x02

/*
 * Informations needed for synchronization.
 */
struct g_mirror_disk_sync {
        struct g_consumer *ds_consumer; /* Consumer connected to our mirror. */
        off_t             ds_offset;    /* Offset of next request to send. */
        off_t             ds_offset_done; /* Offset of already synchronized
                                           region. */
        time_t            ds_update_ts; /* Time of last metadata update. */
        u_int             ds_syncid;    /* Disk's synchronization ID. */
        u_int             ds_inflight;  /* Number of in-flight sync requests. */
        struct bio      **ds_bios;      /* BIOs for synchronization I/O. */
};

/*
 * Informations needed for synchronization.
 */
struct g_mirror_device_sync {
        struct g_geom   *ds_geom;       /* Synchronization geom. */
        u_int            ds_ndisks;     /* Number of disks in SYNCHRONIZING
                                           state. */
};

#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_STALE               3
#define G_MIRROR_DISK_STATE_SYNCHRONIZING       4
#define G_MIRROR_DISK_STATE_DISCONNECTED        5
#define G_MIRROR_DISK_STATE_DESTROY             6
struct g_mirror_disk {
        uint32_t         d_id;          /* Disk ID. */
        struct g_consumer *d_consumer;  /* Consumer. */
        struct g_mirror_softc   *d_softc; /* Back-pointer to softc. */
        int              d_state;       /* Disk state. */
        u_int            d_priority;    /* Disk priority. */
        u_int            load;          /* Averaged queue length */
        off_t            d_last_offset; /* Last read offset */
        uint64_t         d_flags;       /* Additional flags. */
        u_int            d_genid;       /* Disk's generation ID. */
        struct g_mirror_disk_sync d_sync;/* Sync information. */
        LIST_ENTRY(g_mirror_disk) d_next;
        u_int            d_init_ndisks; /* Initial number of mirror components */
        uint32_t         d_init_slice;  /* Initial slice size */
        uint8_t          d_init_balance;/* Initial balance */
        uint16_t         d_rotation_rate;/* Disk's rotation rate */
        uint64_t         d_init_mediasize;/* Initial mediasize */
};
#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_STATE_STARTING          0
#define G_MIRROR_DEVICE_STATE_RUNNING           1

#define G_MIRROR_TYPE_MANUAL    0
#define G_MIRROR_TYPE_AUTOMATIC 1

/* Bump syncid on first write. */
#define G_MIRROR_BUMP_SYNCID            0x1
/* Bump genid immediately. */
#define G_MIRROR_BUMP_GENID             0x2
/* Bump syncid immediately. */
#define G_MIRROR_BUMP_SYNCID_NOW        0x4
struct g_mirror_softc {
        u_int           sc_type;        /* Device type (manual/automatic). */
        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;
        int             sc_provider_open;

        uint32_t        sc_id;          /* Mirror unique ID. */

        struct sx        sc_lock;
        struct bio_queue sc_queue;
        struct mtx       sc_queue_mtx;
        struct proc     *sc_worker;
        struct bio_queue sc_inflight; /* In-flight regular write requests. */
        struct bio_queue sc_regular_delayed; /* Delayed I/O requests due to
                                                collision with sync requests. */
        struct bio_queue sc_sync_delayed; /* Delayed sync requests due to
                                             collision with regular requests. */

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

        u_int           sc_genid;       /* Generation ID. */
        u_int           sc_syncid;      /* Synchronization ID. */
        int             sc_bump_id;
        struct g_mirror_device_sync sc_sync;
        int             sc_idle;        /* DIRTY flags removed. */
        time_t          sc_last_write;
        u_int           sc_writes;
        u_int           sc_refcnt;      /* Number of softc references */

        TAILQ_HEAD(, g_mirror_event) sc_events;
        struct mtx      sc_events_mtx;
        struct g_mirror_event *sc_timeout_event;

        struct callout  sc_callout;

        struct root_hold_token *sc_rootmount;

        struct mtx       sc_done_mtx;
};
#define sc_name sc_geom->name

struct g_mirror_metadata;

u_int g_mirror_ndisks(struct g_mirror_softc *sc, int state);
struct g_geom * g_mirror_create(struct g_class *mp,
    const struct g_mirror_metadata *md, u_int type);
#define G_MIRROR_DESTROY_SOFT           0
#define G_MIRROR_DESTROY_DELAYED        1
#define G_MIRROR_DESTROY_HARD           2
int g_mirror_destroy(struct g_mirror_softc *sc, int how);
int g_mirror_event_send(void *arg, int state, int flags);
struct g_mirror_metadata;
int g_mirror_add_disk(struct g_mirror_softc *sc, struct g_provider *pp,
    struct g_mirror_metadata *md);
int g_mirror_read_metadata(struct g_consumer *cp, struct g_mirror_metadata *md);
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. */
        uint8_t         md_all;         /* Number of disks in mirror. */
        uint32_t        md_genid;       /* Generation ID. */
        uint32_t        md_syncid;      /* Synchronization ID. */
        uint8_t         md_priority;    /* Disk priority. */
        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_mflags;      /* Additional mirror flags. */
        uint64_t        md_dflags;      /* Additional disk flags. */
        char            md_provider[16]; /* Hardcoded provider. */
        uint64_t        md_provsize;    /* Provider's size. */
        u_char          md_hash[16];    /* MD5 hash. */
};
static __inline void
mirror_metadata_encode(struct g_mirror_metadata *md, u_char *data)
{
        MD5_CTX ctx;

        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);
        *(data + 44) = md->md_all;
        le32enc(data + 45, md->md_genid);
        le32enc(data + 49, md->md_syncid);
        *(data + 53) = md->md_priority;
        le32enc(data + 54, md->md_slice);
        *(data + 58) = md->md_balance;
        le64enc(data + 59, md->md_mediasize);
        le32enc(data + 67, md->md_sectorsize);
        le64enc(data + 71, md->md_sync_offset);
        le64enc(data + 79, md->md_mflags);
        le64enc(data + 87, md->md_dflags);
        bcopy(md->md_provider, data + 95, 16);
        le64enc(data + 111, md->md_provsize);
        MD5Init(&ctx);
        MD5Update(&ctx, data, 119);
        MD5Final(md->md_hash, &ctx);
        bcopy(md->md_hash, data + 119, 16);
}
static __inline int
mirror_metadata_decode_v0v1(const u_char *data, struct g_mirror_metadata *md)
{
        MD5_CTX ctx;

        bcopy(data + 20, md->md_name, 16);
        md->md_mid = le32dec(data + 36);
        md->md_did = le32dec(data + 40);
        md->md_all = *(data + 44);
        md->md_syncid = le32dec(data + 45);
        md->md_priority = *(data + 49);
        md->md_slice = le32dec(data + 50);
        md->md_balance = *(data + 54);
        md->md_mediasize = le64dec(data + 55);
        md->md_sectorsize = le32dec(data + 63);
        md->md_sync_offset = le64dec(data + 67);
        md->md_mflags = le64dec(data + 75);
        md->md_dflags = le64dec(data + 83);
        bcopy(data + 91, md->md_provider, 16);
        bcopy(data + 107, md->md_hash, 16);
        MD5Init(&ctx);
        MD5Update(&ctx, data, 107);
        MD5Final(md->md_hash, &ctx);
        if (bcmp(md->md_hash, data + 107, 16) != 0)
                return (EINVAL);

        /* New fields. */
        md->md_genid = 0;
        md->md_provsize = 0;

        return (0);
}
static __inline int
mirror_metadata_decode_v2(const u_char *data, struct g_mirror_metadata *md)
{
        MD5_CTX ctx;

        bcopy(data + 20, md->md_name, 16);
        md->md_mid = le32dec(data + 36);
        md->md_did = le32dec(data + 40);
        md->md_all = *(data + 44);
        md->md_genid = le32dec(data + 45);
        md->md_syncid = le32dec(data + 49);
        md->md_priority = *(data + 53);
        md->md_slice = le32dec(data + 54);
        md->md_balance = *(data + 58);
        md->md_mediasize = le64dec(data + 59);
        md->md_sectorsize = le32dec(data + 67);
        md->md_sync_offset = le64dec(data + 71);
        md->md_mflags = le64dec(data + 79);
        md->md_dflags = le64dec(data + 87);
        bcopy(data + 95, md->md_provider, 16);
        bcopy(data + 111, md->md_hash, 16);
        MD5Init(&ctx);
        MD5Update(&ctx, data, 111);
        MD5Final(md->md_hash, &ctx);
        if (bcmp(md->md_hash, data + 111, 16) != 0)
                return (EINVAL);

        /* New fields. */
        md->md_provsize = 0;

        return (0);
}
static __inline int
mirror_metadata_decode_v3v4(const u_char *data, struct g_mirror_metadata *md)
{
        MD5_CTX ctx;

        bcopy(data + 20, md->md_name, 16);
        md->md_mid = le32dec(data + 36);
        md->md_did = le32dec(data + 40);
        md->md_all = *(data + 44);
        md->md_genid = le32dec(data + 45);
        md->md_syncid = le32dec(data + 49);
        md->md_priority = *(data + 53);
        md->md_slice = le32dec(data + 54);
        md->md_balance = *(data + 58);
        md->md_mediasize = le64dec(data + 59);
        md->md_sectorsize = le32dec(data + 67);
        md->md_sync_offset = le64dec(data + 71);
        md->md_mflags = le64dec(data + 79);
        md->md_dflags = le64dec(data + 87);
        bcopy(data + 95, md->md_provider, 16);
        md->md_provsize = le64dec(data + 111);
        bcopy(data + 119, md->md_hash, 16);
        MD5Init(&ctx);
        MD5Update(&ctx, data, 119);
        MD5Final(md->md_hash, &ctx);
        if (bcmp(md->md_hash, data + 119, 16) != 0)
                return (EINVAL);
        return (0);
}
static __inline int
mirror_metadata_decode(const u_char *data, struct g_mirror_metadata *md)
{
        int error;

        bcopy(data, md->md_magic, 16);
        md->md_version = le32dec(data + 16);
        switch (md->md_version) {
        case 0:
        case 1:
                error = mirror_metadata_decode_v0v1(data, md);
                break;
        case 2:
                error = mirror_metadata_decode_v2(data, md);
                break;
        case 3:
        case 4:
                error = mirror_metadata_decode_v3v4(data, md);
                break;
        default:
                error = EINVAL;
                break;
        }
        return (error);
}

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_LOAD] = "load",
                [G_MIRROR_BALANCE_SPLIT] = "split",
                [G_MIRROR_BALANCE_PREFER] = "prefer",
                [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_LOAD] = "load",
                [G_MIRROR_BALANCE_SPLIT] = "split",
                [G_MIRROR_BALANCE_PREFER] = "prefer"
        };
        int n;

        for (n = G_MIRROR_BALANCE_MIN; n <= G_MIRROR_BALANCE_MAX; n++) {
                if (strcmp(name, algorithms[n]) == 0)
                        return (n);
        }
        return (-1);
}

static __inline void
mirror_metadata_dump(const struct g_mirror_metadata *md)
{
        static const char hex[] = "0123456789abcdef";
        char hash[16 * 2 + 1];
        u_int i;

        printf("     magic: %s\n", md->md_magic);
        printf("   version: %u\n", (u_int)md->md_version);
        printf("      name: %s\n", md->md_name);
        printf("       mid: %u\n", (u_int)md->md_mid);
        printf("       did: %u\n", (u_int)md->md_did);
        printf("       all: %u\n", (u_int)md->md_all);
        printf("     genid: %u\n", (u_int)md->md_genid);
        printf("    syncid: %u\n", (u_int)md->md_syncid);
        printf("  priority: %u\n", (u_int)md->md_priority);
        printf("     slice: %u\n", (u_int)md->md_slice);
        printf("   balance: %s\n", balance_name((u_int)md->md_balance));
        printf(" mediasize: %jd\n", (intmax_t)md->md_mediasize);
        printf("sectorsize: %u\n", (u_int)md->md_sectorsize);
        printf("syncoffset: %jd\n", (intmax_t)md->md_sync_offset);
        printf("    mflags:");
        if (md->md_mflags == 0)
                printf(" NONE");
        else {
                if ((md->md_mflags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
                        printf(" NOFAILSYNC");
                if ((md->md_mflags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) != 0)
                        printf(" NOAUTOSYNC");
        }
        printf("\n");
        printf("    dflags:");
        if (md->md_dflags == 0)
                printf(" NONE");
        else {
                if ((md->md_dflags & G_MIRROR_DISK_FLAG_DIRTY) != 0)
                        printf(" DIRTY");
                if ((md->md_dflags & G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0)
                        printf(" SYNCHRONIZING");
                if ((md->md_dflags & G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0)
                        printf(" FORCE_SYNC");
                if ((md->md_dflags & G_MIRROR_DISK_FLAG_INACTIVE) != 0)
                        printf(" INACTIVE");
        }
        printf("\n");
        printf("hcprovider: %s\n", md->md_provider);
        printf("  provsize: %ju\n", (uintmax_t)md->md_provsize);
        bzero(hash, sizeof(hash));
        for (i = 0; i < 16; i++) {
                hash[i * 2] = hex[md->md_hash[i] >> 4];
                hash[i * 2 + 1] = hex[md->md_hash[i] & 0x0f];
        }
        printf("  MD5 hash: %s\n", hash);
}
#endif  /* !_G_MIRROR_H_ */