source: mainline/uspace/srv/bd/hr/var.h

/*
 * Copyright (c) 2025 Miroslav Cimerman
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

/** @addtogroup hr
 * @{
 */
/**
 * @file
 */

#ifndef _HR_VAR_H
#define _HR_VAR_H

#include <adt/list.h>
#include <bd_srv.h>
#include <errno.h>
#include <fibril_synch.h>
#include <hr.h>
#include <stdatomic.h>

#include "fge.h"
#include "superblock.h"

#define NAME "hr"
#define HR_STRIP_SIZE DATA_XFER_LIMIT

#define HR_RAID1_READ_STRATEGY_SPLIT
#define HR_RAID1_READ_STRATEGY_SPLIT_THRESHOLD (1024 * 1)

/* #define HR_RAID1_READ_STRATEGY_CLOSEST */
/* #define HR_RAID1_READ_STRATEGY_ROUND_ROBIN */
/* #define HR_RAID1_READ_STRATEGY_FIRST */

#if !defined(HR_RAID1_READ_STRATEGY_ROUND_ROBIN) && \
    !defined(HR_RAID1_READ_STRATEGY_CLOSEST) && \
    !defined(HR_RAID1_READ_STRATEGY_FIRST) && \
    (!defined(HR_RAID1_READ_STRATEGY_SPLIT) && \
    !defined(HR_RAID1_READ_STRATEGY_SPLIT_THRESHOLD))
#error "Some RAID 1 read strategy must be used"
#endif

/*
 * During a rebuild operation, we save the rebuild
 * position this each many bytes. Currently each
 * 10 MiB.
 */
#define HR_REBUILD_SAVE_BYTES (10U * 1024 * 1024)

struct hr_volume;
typedef struct hr_volume hr_volume_t;
typedef struct hr_stripe hr_stripe_t;
typedef struct hr_metadata hr_metadata_t;
typedef struct hr_superblock_ops hr_superblock_ops_t;

typedef struct hr_ops {
        errno_t (*create)(hr_volume_t *);
        errno_t (*init)(hr_volume_t *);
        void (*vol_state_eval)(hr_volume_t *);
        void (*ext_state_cb)(hr_volume_t *, size_t, errno_t);
} hr_ops_t;

typedef struct hr_volume {
        link_t lvolumes; /* link to all volumes list */
        hr_ops_t hr_ops; /* level init and create fcns */
        bd_srvs_t hr_bds; /* block interface to the vol */
        service_id_t svc_id; /* service id */

        list_t range_lock_list; /* list of range locks */
        fibril_mutex_t range_lock_list_lock; /* range locks list lock */

        hr_fpool_t *fge; /* fibril pool */

        void *in_mem_md;
        fibril_mutex_t md_lock; /* lock protecting in_mem_md */

        hr_superblock_ops_t *meta_ops;

        /* invariants */
        size_t extent_no; /* number of extents */
        size_t bsize; /* block size */
        uint64_t truncated_blkno; /* blkno per extent */
        uint64_t data_blkno; /* no. of user usable blocks */
        uint64_t data_offset; /* user data offset in blocks */
        uint32_t strip_size; /* strip size */
        hr_level_t level; /* volume level */
        hr_layout_t layout; /* RAID Level Qualifier */
        char devname[HR_DEVNAME_LEN];

        hr_extent_t extents[HR_MAX_EXTENTS];
        fibril_rwlock_t extents_lock; /* extent service id lock */

        size_t hotspare_no; /* no. of available hotspares */
        hr_extent_t hotspares[HR_MAX_HOTSPARES];
        fibril_mutex_t hotspare_lock; /* lock protecting hotspares */

        fibril_rwlock_t states_lock; /* states lock */

        _Atomic bool state_dirty; /* dirty state */

        /*
         * used to increment metadata counter on first write,
         * allowing non-destructive read-only access
         */
        _Atomic bool first_write;

        _Atomic uint64_t last_ext_pos_arr[HR_MAX_EXTENTS];
        _Atomic uint64_t last_ext_used;

        _Atomic uint64_t rebuild_blk; /* rebuild position */
        _Atomic int open_cnt; /* open/close() counter */
        hr_vol_state_t state; /* volume state */
        uint8_t vflags;
} hr_volume_t;

typedef enum {
        HR_BD_READ,
        HR_BD_WRITE
} hr_bd_op_type_t;

/* macros for hr_metadata_save() */
#define WITH_STATE_CALLBACK true
#define NO_STATE_CALLBACK false

extern errno_t hr_raid0_create(hr_volume_t *);
extern errno_t hr_raid1_create(hr_volume_t *);
extern errno_t hr_raid5_create(hr_volume_t *);

extern errno_t hr_raid0_init(hr_volume_t *);
extern errno_t hr_raid1_init(hr_volume_t *);
extern errno_t hr_raid5_init(hr_volume_t *);

extern void hr_raid0_vol_state_eval(hr_volume_t *);
extern void hr_raid1_vol_state_eval(hr_volume_t *);
extern void hr_raid5_vol_state_eval(hr_volume_t *);

extern void hr_raid0_ext_state_cb(hr_volume_t *, size_t, errno_t);
extern void hr_raid1_ext_state_cb(hr_volume_t *, size_t, errno_t);
extern void hr_raid5_ext_state_cb(hr_volume_t *, size_t, errno_t);
#endif

/** @}
 */