source: mainline/uspace/srv/bd/hr/raid1.c@ 6aafb48

/*
 * 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
 */

#include <abi/ipc/ipc.h>
#include <bd_srv.h>
#include <block.h>
#include <errno.h>
#include <hr.h>
#include <inttypes.h>
#include <io/log.h>
#include <ipc/hr.h>
#include <ipc/services.h>
#include <loc.h>
#include <task.h>
#include <stdatomic.h>
#include <stdio.h>
#include <stdlib.h>
#include <str_error.h>

#include "fge.h"
#include "io.h"
#include "superblock.h"
#include "util.h"
#include "var.h"

static void hr_raid1_vol_state_eval_forced(hr_volume_t *);
static size_t hr_raid1_count_good_extents(hr_volume_t *, uint64_t, size_t,
    uint64_t);
static errno_t hr_raid1_bd_op(hr_bd_op_type_t, hr_volume_t *, aoff64_t, size_t,
    void *, const void *, size_t);
static errno_t hr_raid1_rebuild(void *);

/* bdops */
static errno_t hr_raid1_bd_open(bd_srvs_t *, bd_srv_t *);
static errno_t hr_raid1_bd_close(bd_srv_t *);
static errno_t hr_raid1_bd_read_blocks(bd_srv_t *, aoff64_t, size_t, void *,
    size_t);
static errno_t hr_raid1_bd_sync_cache(bd_srv_t *, aoff64_t, size_t);
static errno_t hr_raid1_bd_write_blocks(bd_srv_t *, aoff64_t, size_t,
    const void *, size_t);
static errno_t hr_raid1_bd_get_block_size(bd_srv_t *, size_t *);
static errno_t hr_raid1_bd_get_num_blocks(bd_srv_t *, aoff64_t *);

static bd_ops_t hr_raid1_bd_ops = {
        .open = hr_raid1_bd_open,
        .close = hr_raid1_bd_close,
        .sync_cache = hr_raid1_bd_sync_cache,
        .read_blocks = hr_raid1_bd_read_blocks,
        .write_blocks = hr_raid1_bd_write_blocks,
        .get_block_size = hr_raid1_bd_get_block_size,
        .get_num_blocks = hr_raid1_bd_get_num_blocks
};

extern loc_srv_t *hr_srv;

errno_t hr_raid1_create(hr_volume_t *new_volume)
{
        HR_DEBUG("%s()", __func__);

        if (new_volume->level != HR_LVL_1)
                return EINVAL;

        if (new_volume->extent_no < 2) {
                HR_ERROR("RAID 1 volume needs at least 2 devices\n");
                return EINVAL;
        }

        bd_srvs_init(&new_volume->hr_bds);
        new_volume->hr_bds.ops = &hr_raid1_bd_ops;
        new_volume->hr_bds.sarg = new_volume;

        hr_raid1_vol_state_eval_forced(new_volume);

        fibril_rwlock_read_lock(&new_volume->states_lock);
        hr_vol_state_t state = new_volume->state;
        fibril_rwlock_read_unlock(&new_volume->states_lock);
        if (state == HR_VOL_FAULTY || state == HR_VOL_NONE) {
                HR_NOTE("\"%s\": unusable state, not creating\n",
                    new_volume->devname);
                return EINVAL;
        }

        return EOK;
}

/*
 * Called only once in volume's lifetime.
 */
errno_t hr_raid1_init(hr_volume_t *vol)
{
        HR_DEBUG("%s()", __func__);

        if (vol->level != HR_LVL_1)
                return EINVAL;

        vol->data_offset = vol->meta_ops->get_data_offset();
        vol->data_blkno = vol->truncated_blkno - vol->meta_ops->get_size();
        vol->strip_size = 0;

        return EOK;
}

void hr_raid1_vol_state_eval(hr_volume_t *vol)
{
        HR_DEBUG("%s()", __func__);

        bool exp = true;
        if (!atomic_compare_exchange_strong(&vol->state_dirty, &exp, false))
                return;

        vol->meta_ops->inc_counter(vol);
        vol->meta_ops->save(vol, WITH_STATE_CALLBACK);

        hr_raid1_vol_state_eval_forced(vol);
}

void hr_raid1_ext_state_cb(hr_volume_t *vol, size_t extent, errno_t rc)
{
        HR_DEBUG("%s()", __func__);

        assert(fibril_rwlock_is_locked(&vol->extents_lock));

        if (rc == EOK)
                return;

        fibril_rwlock_write_lock(&vol->states_lock);

        switch (rc) {
        case ENOENT:
                hr_update_ext_state(vol, extent, HR_EXT_MISSING);
                break;
        default:
                hr_update_ext_state(vol, extent, HR_EXT_FAILED);
        }

        hr_mark_vol_state_dirty(vol);

        fibril_rwlock_write_unlock(&vol->states_lock);
}

static void hr_raid1_vol_state_eval_forced(hr_volume_t *vol)
{
        HR_DEBUG("%s()", __func__);

        fibril_rwlock_read_lock(&vol->extents_lock);
        fibril_rwlock_read_lock(&vol->states_lock);

        hr_vol_state_t old_state = vol->state;
        size_t healthy = hr_count_extents(vol, HR_EXT_ONLINE);

        size_t invalid_no = hr_count_extents(vol, HR_EXT_INVALID);

        size_t rebuild_no = hr_count_extents(vol, HR_EXT_REBUILD);

        fibril_rwlock_read_unlock(&vol->states_lock);
        fibril_rwlock_read_unlock(&vol->extents_lock);

        fibril_mutex_lock(&vol->hotspare_lock);
        size_t hs_no = vol->hotspare_no;
        fibril_mutex_unlock(&vol->hotspare_lock);

        if (healthy == 0) {
                if (old_state != HR_VOL_FAULTY) {
                        fibril_rwlock_write_lock(&vol->states_lock);
                        hr_update_vol_state(vol, HR_VOL_FAULTY);
                        fibril_rwlock_write_unlock(&vol->states_lock);
                }
        } else if (healthy < vol->extent_no) {
                if (old_state != HR_VOL_REBUILD &&
                    old_state != HR_VOL_DEGRADED) {
                        fibril_rwlock_write_lock(&vol->states_lock);
                        hr_update_vol_state(vol, HR_VOL_DEGRADED);
                        fibril_rwlock_write_unlock(&vol->states_lock);
                }

                if (hs_no > 0 || invalid_no > 0 || rebuild_no > 0) {
                        fid_t fib = fibril_create(hr_raid1_rebuild, vol);
                        if (fib == 0)
                                return;
                        fibril_start(fib);
                        fibril_detach(fib);
                }
        } else {
                if (old_state != HR_VOL_OPTIMAL) {
                        fibril_rwlock_write_lock(&vol->states_lock);
                        hr_update_vol_state(vol, HR_VOL_OPTIMAL);
                        fibril_rwlock_write_unlock(&vol->states_lock);
                }
        }
}

static errno_t hr_raid1_bd_open(bd_srvs_t *bds, bd_srv_t *bd)
{
        HR_DEBUG("%s()", __func__);

        hr_volume_t *vol = bd->srvs->sarg;

        atomic_fetch_add_explicit(&vol->open_cnt, 1, memory_order_relaxed);

        return EOK;
}

static errno_t hr_raid1_bd_close(bd_srv_t *bd)
{
        HR_DEBUG("%s()", __func__);

        hr_volume_t *vol = bd->srvs->sarg;

        atomic_fetch_sub_explicit(&vol->open_cnt, 1, memory_order_relaxed);

        return EOK;
}

static errno_t hr_raid1_bd_sync_cache(bd_srv_t *bd, aoff64_t ba, size_t cnt)
{
        hr_volume_t *vol = bd->srvs->sarg;

        return hr_sync_extents(vol);
}

static errno_t hr_raid1_bd_read_blocks(bd_srv_t *bd, aoff64_t ba, size_t cnt,
    void *buf, size_t size)
{
        hr_volume_t *vol = bd->srvs->sarg;

        return hr_raid1_bd_op(HR_BD_READ, vol, ba, cnt, buf, NULL, size);
}

static errno_t hr_raid1_bd_write_blocks(bd_srv_t *bd, aoff64_t ba, size_t cnt,
    const void *data, size_t size)
{
        hr_volume_t *vol = bd->srvs->sarg;

        if (vol->vflags & HR_VOL_FLAG_READ_ONLY)
                return ENOTSUP;

        return hr_raid1_bd_op(HR_BD_WRITE, vol, ba, cnt, NULL, data, size);
}

static errno_t hr_raid1_bd_get_block_size(bd_srv_t *bd, size_t *rsize)
{
        hr_volume_t *vol = bd->srvs->sarg;

        *rsize = vol->bsize;
        return EOK;
}

static errno_t hr_raid1_bd_get_num_blocks(bd_srv_t *bd, aoff64_t *rnb)
{
        hr_volume_t *vol = bd->srvs->sarg;

        *rnb = vol->data_blkno;
        return EOK;
}

static size_t hr_raid1_count_good_extents(hr_volume_t *vol, uint64_t ba,
    size_t cnt, uint64_t rebuild_blk)
{
        assert(fibril_rwlock_is_locked(&vol->extents_lock));
        assert(fibril_rwlock_is_locked(&vol->states_lock));

        size_t count = 0;
        for (size_t i = 0; i < vol->extent_no; i++) {
                if (vol->extents[i].state == HR_EXT_ONLINE ||
                    (vol->extents[i].state == HR_EXT_REBUILD &&
                    rebuild_blk >= ba)) {
                        count++;
                }
        }

        return count;
}

static errno_t hr_raid1_bd_op(hr_bd_op_type_t type, hr_volume_t *vol,
    aoff64_t ba, size_t cnt, void *data_read, const void *data_write,
    size_t size)
{
        HR_DEBUG("%s()", __func__);

        hr_range_lock_t *rl = NULL;
        errno_t rc;
        size_t i;
        uint64_t rebuild_blk;

        if (size < cnt * vol->bsize)
                return EINVAL;

        fibril_rwlock_read_lock(&vol->states_lock);
        hr_vol_state_t vol_state = vol->state;
        fibril_rwlock_read_unlock(&vol->states_lock);

        if (vol_state == HR_VOL_FAULTY || vol_state == HR_VOL_NONE)
                return EIO;

        /* increment metadata counter only on first write */
        bool exp = false;
        if (type == HR_BD_WRITE &&
            atomic_compare_exchange_strong(&vol->first_write, &exp, true)) {
                vol->meta_ops->inc_counter(vol);
                vol->meta_ops->save(vol, WITH_STATE_CALLBACK);
        }

        rc = hr_check_ba_range(vol, cnt, ba);
        if (rc != EOK)
                return rc;

        hr_add_data_offset(vol, &ba);

        /*
         * extent order has to be locked for the whole IO duration,
         * so that workers have consistent targets
         */
        fibril_rwlock_read_lock(&vol->extents_lock);

        size_t successful = 0;
        switch (type) {
        case HR_BD_READ:
                rebuild_blk = atomic_load_explicit(&vol->rebuild_blk,
                    memory_order_relaxed);

                for (i = 0; i < vol->extent_no; i++) {
                        fibril_rwlock_read_lock(&vol->states_lock);
                        hr_ext_state_t state = vol->extents[i].state;
                        fibril_rwlock_read_unlock(&vol->states_lock);

                        if (state != HR_EXT_ONLINE &&
                            (state != HR_EXT_REBUILD ||
                            ba + cnt - 1 >= rebuild_blk)) {
                                continue;
                        }

                        rc = hr_read_direct(vol->extents[i].svc_id, ba, cnt,
                            data_read);
                        if (rc != EOK) {
                                hr_raid1_ext_state_cb(vol, i, rc);
                        } else {
                                successful++;
                                break;
                        }
                }
                break;
        case HR_BD_WRITE:
                rl = hr_range_lock_acquire(vol, ba, cnt);

                fibril_rwlock_read_lock(&vol->states_lock);

                rebuild_blk = atomic_load_explicit(&vol->rebuild_blk,
                    memory_order_relaxed);

                size_t good = hr_raid1_count_good_extents(vol, ba, cnt,
                    rebuild_blk);

                hr_fgroup_t *group = hr_fgroup_create(vol->fge, good);

                for (i = 0; i < vol->extent_no; i++) {
                        if (vol->extents[i].state != HR_EXT_ONLINE &&
                            (vol->extents[i].state != HR_EXT_REBUILD ||
                            ba > rebuild_blk)) {
                                /*
                                 * When the extent is being rebuilt,
                                 * we only write to the part that is already
                                 * rebuilt. If IO starts after vol->rebuild_blk
                                 * we do not proceed, the write is going to
                                 * be replicated later in the rebuild.
                                 */
                                continue;
                        }

                        hr_io_t *io = hr_fgroup_alloc(group);
                        io->extent = i;
                        io->data_write = data_write;
                        io->data_read = data_read;
                        io->ba = ba;
                        io->cnt = cnt;
                        io->type = type;
                        io->vol = vol;

                        hr_fgroup_submit(group, hr_io_worker, io);
                }

                fibril_rwlock_read_unlock(&vol->states_lock);

                (void)hr_fgroup_wait(group, &successful, NULL);

                hr_range_lock_release(rl);

                break;
        default:
                assert(0);
        }

        if (successful > 0)
                rc = EOK;
        else
                rc = EIO;

        fibril_rwlock_read_unlock(&vol->extents_lock);

        hr_raid1_vol_state_eval(vol);

        return rc;
}

static errno_t hr_raid1_rebuild(void *arg)
{
        HR_DEBUG("%s()", __func__);

        hr_volume_t *vol = arg;
        void *buf = NULL;
        size_t rebuild_idx;
        hr_extent_t *rebuild_ext = NULL;
        errno_t rc;

        if (vol->vflags & HR_VOL_FLAG_READ_ONLY)
                return ENOTSUP;
        if (!(vol->meta_ops->get_flags() & HR_METADATA_ALLOW_REBUILD))
                return ENOTSUP;

        rc = hr_init_rebuild(vol, &rebuild_idx);
        if (rc != EOK)
                return rc;

        rebuild_ext = &vol->extents[rebuild_idx];

        size_t left = vol->data_blkno - vol->rebuild_blk;
        size_t max_blks = DATA_XFER_LIMIT / vol->bsize;
        buf = hr_malloc_waitok(max_blks * vol->bsize);

        size_t cnt;
        uint64_t ba = vol->rebuild_blk;
        hr_add_data_offset(vol, &ba);

        /*
         * this is not necessary because a rebuild is
         * protected by itself, i.e. there can be only
         * one REBUILD at a time
         */
        fibril_rwlock_read_lock(&vol->extents_lock);

        /* increment metadata counter only on first write */
        bool exp = false;
        if (atomic_compare_exchange_strong(&vol->first_write, &exp, true)) {
                vol->meta_ops->inc_counter(vol);
                vol->meta_ops->save(vol, WITH_STATE_CALLBACK);
        }

        hr_range_lock_t *rl = NULL;

        HR_NOTE("\"%s\": REBUILD started on extent no. %zu at block %lu.\n",
            vol->devname, rebuild_idx, ba);

        uint64_t written = 0;
        unsigned int percent, old_percent = 100;
        while (left != 0) {
                cnt = min(max_blks, left);

                rl = hr_range_lock_acquire(vol, ba, cnt);

                atomic_store_explicit(&vol->rebuild_blk, ba,
                    memory_order_relaxed);

                rc = hr_raid1_bd_op(HR_BD_READ, vol, ba, cnt, buf, NULL,
                    cnt * vol->bsize);
                if (rc != EOK) {
                        hr_range_lock_release(rl);
                        goto end;
                }

                rc = hr_write_direct(rebuild_ext->svc_id, ba, cnt, buf);
                if (rc != EOK) {
                        hr_raid1_ext_state_cb(vol, rebuild_idx, rc);
                        hr_range_lock_release(rl);
                        goto end;
                }

                percent = ((ba + cnt) * 100) / vol->data_blkno;
                if (percent != old_percent) {
                        if (percent % 5 == 0)
                                HR_DEBUG("\"%s\" REBUILD progress: %u%%\n",
                                    vol->devname, percent);
                }

                if (written * vol->bsize > HR_REBUILD_SAVE_BYTES) {
                        vol->meta_ops->save_ext(vol, rebuild_idx,
                            WITH_STATE_CALLBACK);
                        written = 0;
                }

                hr_range_lock_release(rl);

                written += cnt;
                ba += cnt;
                left -= cnt;
                old_percent = percent;
        }

        HR_DEBUG("hr_raid1_rebuild(): rebuild finished on \"%s\" (%" PRIun "), "
            "extent no. %zu\n", vol->devname, vol->svc_id, rebuild_idx);

        fibril_rwlock_write_lock(&vol->states_lock);

        hr_update_ext_state(vol, rebuild_idx, HR_EXT_ONLINE);

        atomic_store_explicit(&vol->rebuild_blk, 0, memory_order_relaxed);

        hr_mark_vol_state_dirty(vol);

        hr_update_vol_state(vol, HR_VOL_DEGRADED);

        fibril_rwlock_write_unlock(&vol->states_lock);
end:
        fibril_rwlock_read_unlock(&vol->extents_lock);

        hr_raid1_vol_state_eval(vol);

        free(buf);

        return rc;
}

/** @}
 */