ddt: split internal DDT API into separate header

[mirror_zfs.git] / module / zfs / spa_stats.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or https://opensource.org/licenses/CDDL-1.0.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

#include <sys/zfs_context.h>
#include <sys/spa_impl.h>
#include <sys/vdev_impl.h>
#include <sys/spa.h>
#include <zfs_comutil.h>

/*
 * Keeps stats on last N reads per spa_t, disabled by default.
 */
static uint_t zfs_read_history = B_FALSE;

/*
 * Include cache hits in history, disabled by default.
 */
static int zfs_read_history_hits = B_FALSE;

/*
 * Keeps stats on the last 100 txgs by default.
 */
static uint_t zfs_txg_history = 100;

/*
 * Keeps stats on the last N MMP updates, disabled by default.
 */
static uint_t zfs_multihost_history = B_FALSE;

/*
 * ==========================================================================
 * SPA Read History Routines
 * ==========================================================================
 */

/*
 * Read statistics - Information exported regarding each arc_read call
 */
typedef struct spa_read_history {
        hrtime_t        start;          /* time read completed */
        uint64_t        objset;         /* read from this objset */
        uint64_t        object;         /* read of this object number */
        uint64_t        level;          /* block's indirection level */
        uint64_t        blkid;          /* read of this block id */
        char            origin[24];     /* read originated from here */
        uint32_t        aflags;         /* ARC flags (cached, prefetch, etc.) */
        pid_t           pid;            /* PID of task doing read */
        char            comm[16];       /* process name of task doing read */
        procfs_list_node_t      srh_node;
} spa_read_history_t;

static int
spa_read_history_show_header(struct seq_file *f)
{
        seq_printf(f, "%-8s %-16s %-8s %-8s %-8s %-8s %-8s "
            "%-24s %-8s %-16s\n", "UID", "start", "objset", "object",
            "level", "blkid", "aflags", "origin", "pid", "process");

        return (0);
}

static int
spa_read_history_show(struct seq_file *f, void *data)
{
        spa_read_history_t *srh = (spa_read_history_t *)data;

        seq_printf(f, "%-8llu %-16llu 0x%-6llx "
            "%-8lli %-8lli %-8lli 0x%-6x %-24s %-8i %-16s\n",
            (u_longlong_t)srh->srh_node.pln_id, srh->start,
            (longlong_t)srh->objset, (longlong_t)srh->object,
            (longlong_t)srh->level, (longlong_t)srh->blkid,
            srh->aflags, srh->origin, srh->pid, srh->comm);

        return (0);
}

/* Remove oldest elements from list until there are no more than 'size' left */
static void
spa_read_history_truncate(spa_history_list_t *shl, unsigned int size)
{
        spa_read_history_t *srh;
        while (shl->size > size) {
                srh = list_remove_head(&shl->procfs_list.pl_list);
                ASSERT3P(srh, !=, NULL);
                kmem_free(srh, sizeof (spa_read_history_t));
                shl->size--;
        }

        if (size == 0)
                ASSERT(list_is_empty(&shl->procfs_list.pl_list));
}

static int
spa_read_history_clear(procfs_list_t *procfs_list)
{
        spa_history_list_t *shl = procfs_list->pl_private;
        mutex_enter(&procfs_list->pl_lock);
        spa_read_history_truncate(shl, 0);
        mutex_exit(&procfs_list->pl_lock);
        return (0);
}

static void
spa_read_history_init(spa_t *spa)
{
        spa_history_list_t *shl = &spa->spa_stats.read_history;

        shl->size = 0;
        shl->procfs_list.pl_private = shl;
        procfs_list_install("zfs",
            spa_name(spa),
            "reads",
            0600,
            &shl->procfs_list,
            spa_read_history_show,
            spa_read_history_show_header,
            spa_read_history_clear,
            offsetof(spa_read_history_t, srh_node));
}

static void
spa_read_history_destroy(spa_t *spa)
{
        spa_history_list_t *shl = &spa->spa_stats.read_history;
        procfs_list_uninstall(&shl->procfs_list);
        spa_read_history_truncate(shl, 0);
        procfs_list_destroy(&shl->procfs_list);
}

void
spa_read_history_add(spa_t *spa, const zbookmark_phys_t *zb, uint32_t aflags)
{
        spa_history_list_t *shl = &spa->spa_stats.read_history;
        spa_read_history_t *srh;

        ASSERT3P(spa, !=, NULL);
        ASSERT3P(zb,  !=, NULL);

        if (zfs_read_history == 0 && shl->size == 0)
                return;

        if (zfs_read_history_hits == 0 && (aflags & ARC_FLAG_CACHED))
                return;

        srh = kmem_zalloc(sizeof (spa_read_history_t), KM_SLEEP);
        strlcpy(srh->comm, getcomm(), sizeof (srh->comm));
        srh->start  = gethrtime();
        srh->objset = zb->zb_objset;
        srh->object = zb->zb_object;
        srh->level  = zb->zb_level;
        srh->blkid  = zb->zb_blkid;
        srh->aflags = aflags;
        srh->pid    = getpid();

        mutex_enter(&shl->procfs_list.pl_lock);

        procfs_list_add(&shl->procfs_list, srh);
        shl->size++;

        spa_read_history_truncate(shl, zfs_read_history);

        mutex_exit(&shl->procfs_list.pl_lock);
}

/*
 * ==========================================================================
 * SPA TXG History Routines
 * ==========================================================================
 */

/*
 * Txg statistics - Information exported regarding each txg sync
 */

typedef struct spa_txg_history {
        uint64_t        txg;            /* txg id */
        txg_state_t     state;          /* active txg state */
        uint64_t        nread;          /* number of bytes read */
        uint64_t        nwritten;       /* number of bytes written */
        uint64_t        reads;          /* number of read operations */
        uint64_t        writes;         /* number of write operations */
        uint64_t        ndirty;         /* number of dirty bytes */
        hrtime_t        times[TXG_STATE_COMMITTED]; /* completion times */
        procfs_list_node_t      sth_node;
} spa_txg_history_t;

static int
spa_txg_history_show_header(struct seq_file *f)
{
        seq_printf(f, "%-8s %-16s %-5s %-12s %-12s %-12s "
            "%-8s %-8s %-12s %-12s %-12s %-12s\n", "txg", "birth", "state",
            "ndirty", "nread", "nwritten", "reads", "writes",
            "otime", "qtime", "wtime", "stime");
        return (0);
}

static int
spa_txg_history_show(struct seq_file *f, void *data)
{
        spa_txg_history_t *sth = (spa_txg_history_t *)data;
        uint64_t open = 0, quiesce = 0, wait = 0, sync = 0;
        char state;

        switch (sth->state) {
                case TXG_STATE_BIRTH:           state = 'B';    break;
                case TXG_STATE_OPEN:            state = 'O';    break;
                case TXG_STATE_QUIESCED:        state = 'Q';    break;
                case TXG_STATE_WAIT_FOR_SYNC:   state = 'W';    break;
                case TXG_STATE_SYNCED:          state = 'S';    break;
                case TXG_STATE_COMMITTED:       state = 'C';    break;
                default:                        state = '?';    break;
        }

        if (sth->times[TXG_STATE_OPEN])
                open = sth->times[TXG_STATE_OPEN] -
                    sth->times[TXG_STATE_BIRTH];

        if (sth->times[TXG_STATE_QUIESCED])
                quiesce = sth->times[TXG_STATE_QUIESCED] -
                    sth->times[TXG_STATE_OPEN];

        if (sth->times[TXG_STATE_WAIT_FOR_SYNC])
                wait = sth->times[TXG_STATE_WAIT_FOR_SYNC] -
                    sth->times[TXG_STATE_QUIESCED];

        if (sth->times[TXG_STATE_SYNCED])
                sync = sth->times[TXG_STATE_SYNCED] -
                    sth->times[TXG_STATE_WAIT_FOR_SYNC];

        seq_printf(f, "%-8llu %-16llu %-5c %-12llu "
            "%-12llu %-12llu %-8llu %-8llu %-12llu %-12llu %-12llu %-12llu\n",
            (longlong_t)sth->txg, sth->times[TXG_STATE_BIRTH], state,
            (u_longlong_t)sth->ndirty,
            (u_longlong_t)sth->nread, (u_longlong_t)sth->nwritten,
            (u_longlong_t)sth->reads, (u_longlong_t)sth->writes,
            (u_longlong_t)open, (u_longlong_t)quiesce, (u_longlong_t)wait,
            (u_longlong_t)sync);

        return (0);
}

/* Remove oldest elements from list until there are no more than 'size' left */
static void
spa_txg_history_truncate(spa_history_list_t *shl, unsigned int size)
{
        spa_txg_history_t *sth;
        while (shl->size > size) {
                sth = list_remove_head(&shl->procfs_list.pl_list);
                ASSERT3P(sth, !=, NULL);
                kmem_free(sth, sizeof (spa_txg_history_t));
                shl->size--;
        }

        if (size == 0)
                ASSERT(list_is_empty(&shl->procfs_list.pl_list));

}

static int
spa_txg_history_clear(procfs_list_t *procfs_list)
{
        spa_history_list_t *shl = procfs_list->pl_private;
        mutex_enter(&procfs_list->pl_lock);
        spa_txg_history_truncate(shl, 0);
        mutex_exit(&procfs_list->pl_lock);
        return (0);
}

static void
spa_txg_history_init(spa_t *spa)
{
        spa_history_list_t *shl = &spa->spa_stats.txg_history;

        shl->size = 0;
        shl->procfs_list.pl_private = shl;
        procfs_list_install("zfs",
            spa_name(spa),
            "txgs",
            0644,
            &shl->procfs_list,
            spa_txg_history_show,
            spa_txg_history_show_header,
            spa_txg_history_clear,
            offsetof(spa_txg_history_t, sth_node));
}

static void
spa_txg_history_destroy(spa_t *spa)
{
        spa_history_list_t *shl = &spa->spa_stats.txg_history;
        procfs_list_uninstall(&shl->procfs_list);
        spa_txg_history_truncate(shl, 0);
        procfs_list_destroy(&shl->procfs_list);
}

/*
 * Add a new txg to historical record.
 */
void
spa_txg_history_add(spa_t *spa, uint64_t txg, hrtime_t birth_time)
{
        spa_history_list_t *shl = &spa->spa_stats.txg_history;
        spa_txg_history_t *sth;

        if (zfs_txg_history == 0 && shl->size == 0)
                return;

        sth = kmem_zalloc(sizeof (spa_txg_history_t), KM_SLEEP);
        sth->txg = txg;
        sth->state = TXG_STATE_OPEN;
        sth->times[TXG_STATE_BIRTH] = birth_time;

        mutex_enter(&shl->procfs_list.pl_lock);
        procfs_list_add(&shl->procfs_list, sth);
        shl->size++;
        spa_txg_history_truncate(shl, zfs_txg_history);
        mutex_exit(&shl->procfs_list.pl_lock);
}

/*
 * Set txg state completion time and increment current state.
 */
int
spa_txg_history_set(spa_t *spa, uint64_t txg, txg_state_t completed_state,
    hrtime_t completed_time)
{
        spa_history_list_t *shl = &spa->spa_stats.txg_history;
        spa_txg_history_t *sth;
        int error = ENOENT;

        if (zfs_txg_history == 0)
                return (0);

        mutex_enter(&shl->procfs_list.pl_lock);
        for (sth = list_tail(&shl->procfs_list.pl_list); sth != NULL;
            sth = list_prev(&shl->procfs_list.pl_list, sth)) {
                if (sth->txg == txg) {
                        sth->times[completed_state] = completed_time;
                        sth->state++;
                        error = 0;
                        break;
                }
        }
        mutex_exit(&shl->procfs_list.pl_lock);

        return (error);
}

/*
 * Set txg IO stats.
 */
static int
spa_txg_history_set_io(spa_t *spa, uint64_t txg, uint64_t nread,
    uint64_t nwritten, uint64_t reads, uint64_t writes, uint64_t ndirty)
{
        spa_history_list_t *shl = &spa->spa_stats.txg_history;
        spa_txg_history_t *sth;
        int error = ENOENT;

        if (zfs_txg_history == 0)
                return (0);

        mutex_enter(&shl->procfs_list.pl_lock);
        for (sth = list_tail(&shl->procfs_list.pl_list); sth != NULL;
            sth = list_prev(&shl->procfs_list.pl_list, sth)) {
                if (sth->txg == txg) {
                        sth->nread = nread;
                        sth->nwritten = nwritten;
                        sth->reads = reads;
                        sth->writes = writes;
                        sth->ndirty = ndirty;
                        error = 0;
                        break;
                }
        }
        mutex_exit(&shl->procfs_list.pl_lock);

        return (error);
}

txg_stat_t *
spa_txg_history_init_io(spa_t *spa, uint64_t txg, dsl_pool_t *dp)
{
        txg_stat_t *ts;

        if (zfs_txg_history == 0)
                return (NULL);

        ts = kmem_alloc(sizeof (txg_stat_t), KM_SLEEP);

        spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
        vdev_get_stats(spa->spa_root_vdev, &ts->vs1);
        spa_config_exit(spa, SCL_CONFIG, FTAG);

        ts->txg = txg;
        ts->ndirty = dp->dp_dirty_pertxg[txg & TXG_MASK];

        spa_txg_history_set(spa, txg, TXG_STATE_WAIT_FOR_SYNC, gethrtime());

        return (ts);
}

void
spa_txg_history_fini_io(spa_t *spa, txg_stat_t *ts)
{
        if (ts == NULL)
                return;

        if (zfs_txg_history == 0) {
                kmem_free(ts, sizeof (txg_stat_t));
                return;
        }

        spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
        vdev_get_stats(spa->spa_root_vdev, &ts->vs2);
        spa_config_exit(spa, SCL_CONFIG, FTAG);

        spa_txg_history_set(spa, ts->txg, TXG_STATE_SYNCED, gethrtime());
        spa_txg_history_set_io(spa, ts->txg,
            ts->vs2.vs_bytes[ZIO_TYPE_READ] - ts->vs1.vs_bytes[ZIO_TYPE_READ],
            ts->vs2.vs_bytes[ZIO_TYPE_WRITE] - ts->vs1.vs_bytes[ZIO_TYPE_WRITE],
            ts->vs2.vs_ops[ZIO_TYPE_READ] - ts->vs1.vs_ops[ZIO_TYPE_READ],
            ts->vs2.vs_ops[ZIO_TYPE_WRITE] - ts->vs1.vs_ops[ZIO_TYPE_WRITE],
            ts->ndirty);

        kmem_free(ts, sizeof (txg_stat_t));
}

/*
 * ==========================================================================
 * SPA TX Assign Histogram Routines
 * ==========================================================================
 */

/*
 * Tx statistics - Information exported regarding dmu_tx_assign time.
 */

/*
 * When the kstat is written zero all buckets.  When the kstat is read
 * count the number of trailing buckets set to zero and update ks_ndata
 * such that they are not output.
 */
static int
spa_tx_assign_update(kstat_t *ksp, int rw)
{
        spa_t *spa = ksp->ks_private;
        spa_history_kstat_t *shk = &spa->spa_stats.tx_assign_histogram;
        int i;

        if (rw == KSTAT_WRITE) {
                for (i = 0; i < shk->count; i++)
                        ((kstat_named_t *)shk->priv)[i].value.ui64 = 0;
        }

        for (i = shk->count; i > 0; i--)
                if (((kstat_named_t *)shk->priv)[i-1].value.ui64 != 0)
                        break;

        ksp->ks_ndata = i;
        ksp->ks_data_size = i * sizeof (kstat_named_t);

        return (0);
}

static void
spa_tx_assign_init(spa_t *spa)
{
        spa_history_kstat_t *shk = &spa->spa_stats.tx_assign_histogram;
        char *name;
        kstat_named_t *ks;
        kstat_t *ksp;
        int i;

        mutex_init(&shk->lock, NULL, MUTEX_DEFAULT, NULL);

        shk->count = 42; /* power of two buckets for 1ns to 2,199s */
        shk->size = shk->count * sizeof (kstat_named_t);
        shk->priv = kmem_alloc(shk->size, KM_SLEEP);

        name = kmem_asprintf("zfs/%s", spa_name(spa));

        for (i = 0; i < shk->count; i++) {
                ks = &((kstat_named_t *)shk->priv)[i];
                ks->data_type = KSTAT_DATA_UINT64;
                ks->value.ui64 = 0;
                (void) snprintf(ks->name, KSTAT_STRLEN, "%llu ns",
                    (u_longlong_t)1 << i);
        }

        ksp = kstat_create(name, 0, "dmu_tx_assign", "misc",
            KSTAT_TYPE_NAMED, 0, KSTAT_FLAG_VIRTUAL);
        shk->kstat = ksp;

        if (ksp) {
                ksp->ks_lock = &shk->lock;
                ksp->ks_data = shk->priv;
                ksp->ks_ndata = shk->count;
                ksp->ks_data_size = shk->size;
                ksp->ks_private = spa;
                ksp->ks_update = spa_tx_assign_update;
                kstat_install(ksp);
        }
        kmem_strfree(name);
}

static void
spa_tx_assign_destroy(spa_t *spa)
{
        spa_history_kstat_t *shk = &spa->spa_stats.tx_assign_histogram;
        kstat_t *ksp;

        ksp = shk->kstat;
        if (ksp)
                kstat_delete(ksp);

        kmem_free(shk->priv, shk->size);
        mutex_destroy(&shk->lock);
}

void
spa_tx_assign_add_nsecs(spa_t *spa, uint64_t nsecs)
{
        spa_history_kstat_t *shk = &spa->spa_stats.tx_assign_histogram;
        uint64_t idx = 0;

        while (((1ULL << idx) < nsecs) && (idx < shk->size - 1))
                idx++;

        atomic_inc_64(&((kstat_named_t *)shk->priv)[idx].value.ui64);
}

/*
 * ==========================================================================
 * SPA MMP History Routines
 * ==========================================================================
 */

/*
 * MMP statistics - Information exported regarding attempted MMP writes
 *   For MMP writes issued, fields used as per comments below.
 *   For MMP writes skipped, an entry represents a span of time when
 *      writes were skipped for same reason (error from mmp_random_leaf).
 *      Differences are:
 *      timestamp       time first write skipped, if >1 skipped in a row
 *      mmp_delay       delay value at timestamp
 *      vdev_guid       number of writes skipped
 *      io_error        one of enum mmp_error
 *      duration        time span (ns) of skipped writes
 */

typedef struct spa_mmp_history {
        uint64_t        mmp_node_id;    /* unique # for updates */
        uint64_t        txg;            /* txg of last sync */
        uint64_t        timestamp;      /* UTC time MMP write issued */
        uint64_t        mmp_delay;      /* mmp_thread.mmp_delay at timestamp */
        uint64_t        vdev_guid;      /* unique ID of leaf vdev */
        char            *vdev_path;
        int             vdev_label;     /* vdev label */
        int             io_error;       /* error status of MMP write */
        hrtime_t        error_start;    /* hrtime of start of error period */
        hrtime_t        duration;       /* time from submission to completion */
        procfs_list_node_t      smh_node;
} spa_mmp_history_t;

static int
spa_mmp_history_show_header(struct seq_file *f)
{
        seq_printf(f, "%-10s %-10s %-10s %-6s %-10s %-12s %-24s "
            "%-10s %s\n", "id", "txg", "timestamp", "error", "duration",
            "mmp_delay", "vdev_guid", "vdev_label", "vdev_path");
        return (0);
}

static int
spa_mmp_history_show(struct seq_file *f, void *data)
{
        spa_mmp_history_t *smh = (spa_mmp_history_t *)data;
        char skip_fmt[] = "%-10llu %-10llu %10llu %#6llx %10lld %12llu %-24llu "
            "%-10lld %s\n";
        char write_fmt[] = "%-10llu %-10llu %10llu %6lld %10lld %12llu %-24llu "
            "%-10lld %s\n";

        seq_printf(f, (smh->error_start ? skip_fmt : write_fmt),
            (u_longlong_t)smh->mmp_node_id, (u_longlong_t)smh->txg,
            (u_longlong_t)smh->timestamp, (longlong_t)smh->io_error,
            (longlong_t)smh->duration, (u_longlong_t)smh->mmp_delay,
            (u_longlong_t)smh->vdev_guid, (u_longlong_t)smh->vdev_label,
            (smh->vdev_path ? smh->vdev_path : "-"));

        return (0);
}

/* Remove oldest elements from list until there are no more than 'size' left */
static void
spa_mmp_history_truncate(spa_history_list_t *shl, unsigned int size)
{
        spa_mmp_history_t *smh;
        while (shl->size > size) {
                smh = list_remove_head(&shl->procfs_list.pl_list);
                if (smh->vdev_path)
                        kmem_strfree(smh->vdev_path);
                kmem_free(smh, sizeof (spa_mmp_history_t));
                shl->size--;
        }

        if (size == 0)
                ASSERT(list_is_empty(&shl->procfs_list.pl_list));

}

static int
spa_mmp_history_clear(procfs_list_t *procfs_list)
{
        spa_history_list_t *shl = procfs_list->pl_private;
        mutex_enter(&procfs_list->pl_lock);
        spa_mmp_history_truncate(shl, 0);
        mutex_exit(&procfs_list->pl_lock);
        return (0);
}

static void
spa_mmp_history_init(spa_t *spa)
{
        spa_history_list_t *shl = &spa->spa_stats.mmp_history;

        shl->size = 0;

        shl->procfs_list.pl_private = shl;
        procfs_list_install("zfs",
            spa_name(spa),
            "multihost",
            0644,
            &shl->procfs_list,
            spa_mmp_history_show,
            spa_mmp_history_show_header,
            spa_mmp_history_clear,
            offsetof(spa_mmp_history_t, smh_node));
}

static void
spa_mmp_history_destroy(spa_t *spa)
{
        spa_history_list_t *shl = &spa->spa_stats.mmp_history;
        procfs_list_uninstall(&shl->procfs_list);
        spa_mmp_history_truncate(shl, 0);
        procfs_list_destroy(&shl->procfs_list);
}

/*
 * Set duration in existing "skip" record to how long we have waited for a leaf
 * vdev to become available.
 *
 * Important that we start search at the tail of the list where new
 * records are inserted, so this is normally an O(1) operation.
 */
int
spa_mmp_history_set_skip(spa_t *spa, uint64_t mmp_node_id)
{
        spa_history_list_t *shl = &spa->spa_stats.mmp_history;
        spa_mmp_history_t *smh;
        int error = ENOENT;

        if (zfs_multihost_history == 0 && shl->size == 0)
                return (0);

        mutex_enter(&shl->procfs_list.pl_lock);
        for (smh = list_tail(&shl->procfs_list.pl_list); smh != NULL;
            smh = list_prev(&shl->procfs_list.pl_list, smh)) {
                if (smh->mmp_node_id == mmp_node_id) {
                        ASSERT3U(smh->io_error, !=, 0);
                        smh->duration = gethrtime() - smh->error_start;
                        smh->vdev_guid++;
                        error = 0;
                        break;
                }
        }
        mutex_exit(&shl->procfs_list.pl_lock);

        return (error);
}

/*
 * Set MMP write duration and error status in existing record.
 * See comment re: search order above spa_mmp_history_set_skip().
 */
int
spa_mmp_history_set(spa_t *spa, uint64_t mmp_node_id, int io_error,
    hrtime_t duration)
{
        spa_history_list_t *shl = &spa->spa_stats.mmp_history;
        spa_mmp_history_t *smh;
        int error = ENOENT;

        if (zfs_multihost_history == 0 && shl->size == 0)
                return (0);

        mutex_enter(&shl->procfs_list.pl_lock);
        for (smh = list_tail(&shl->procfs_list.pl_list); smh != NULL;
            smh = list_prev(&shl->procfs_list.pl_list, smh)) {
                if (smh->mmp_node_id == mmp_node_id) {
                        ASSERT(smh->io_error == 0);
                        smh->io_error = io_error;
                        smh->duration = duration;
                        error = 0;
                        break;
                }
        }
        mutex_exit(&shl->procfs_list.pl_lock);

        return (error);
}

/*
 * Add a new MMP historical record.
 * error == 0 : a write was issued.
 * error != 0 : a write was not issued because no leaves were found.
 */
void
spa_mmp_history_add(spa_t *spa, uint64_t txg, uint64_t timestamp,
    uint64_t mmp_delay, vdev_t *vd, int label, uint64_t mmp_node_id,
    int error)
{
        spa_history_list_t *shl = &spa->spa_stats.mmp_history;
        spa_mmp_history_t *smh;

        if (zfs_multihost_history == 0 && shl->size == 0)
                return;

        smh = kmem_zalloc(sizeof (spa_mmp_history_t), KM_SLEEP);
        smh->txg = txg;
        smh->timestamp = timestamp;
        smh->mmp_delay = mmp_delay;
        if (vd) {
                smh->vdev_guid = vd->vdev_guid;
                if (vd->vdev_path)
                        smh->vdev_path = kmem_strdup(vd->vdev_path);
        }
        smh->vdev_label = label;
        smh->mmp_node_id = mmp_node_id;

        if (error) {
                smh->io_error = error;
                smh->error_start = gethrtime();
                smh->vdev_guid = 1;
        }

        mutex_enter(&shl->procfs_list.pl_lock);
        procfs_list_add(&shl->procfs_list, smh);
        shl->size++;
        spa_mmp_history_truncate(shl, zfs_multihost_history);
        mutex_exit(&shl->procfs_list.pl_lock);
}

static void *
spa_state_addr(kstat_t *ksp, loff_t n)
{
        if (n == 0)
                return (ksp->ks_private);       /* return the spa_t */
        return (NULL);
}

static int
spa_state_data(char *buf, size_t size, void *data)
{
        spa_t *spa = (spa_t *)data;
        (void) snprintf(buf, size, "%s\n", spa_state_to_name(spa));
        return (0);
}

/*
 * Return the state of the pool in /proc/spl/kstat/zfs/<pool>/state.
 *
 * This is a lock-less read of the pool's state (unlike using 'zpool', which
 * can potentially block for seconds).  Because it doesn't block, it can useful
 * as a pool heartbeat value.
 */
static void
spa_state_init(spa_t *spa)
{
        spa_history_kstat_t *shk = &spa->spa_stats.state;
        char *name;
        kstat_t *ksp;

        mutex_init(&shk->lock, NULL, MUTEX_DEFAULT, NULL);

        name = kmem_asprintf("zfs/%s", spa_name(spa));
        ksp = kstat_create(name, 0, "state", "misc",
            KSTAT_TYPE_RAW, 0, KSTAT_FLAG_VIRTUAL);

        shk->kstat = ksp;
        if (ksp) {
                ksp->ks_lock = &shk->lock;
                ksp->ks_data = NULL;
                ksp->ks_private = spa;
                ksp->ks_flags |= KSTAT_FLAG_NO_HEADERS;
                kstat_set_raw_ops(ksp, NULL, spa_state_data, spa_state_addr);
                kstat_install(ksp);
        }

        kmem_strfree(name);
}

static int
spa_guid_data(char *buf, size_t size, void *data)
{
        spa_t *spa = (spa_t *)data;
        (void) snprintf(buf, size, "%llu\n", (u_longlong_t)spa_guid(spa));
        return (0);
}

static void
spa_guid_init(spa_t *spa)
{
        spa_history_kstat_t *shk = &spa->spa_stats.guid;
        char *name;
        kstat_t *ksp;

        mutex_init(&shk->lock, NULL, MUTEX_DEFAULT, NULL);

        name = kmem_asprintf("zfs/%s", spa_name(spa));

        ksp = kstat_create(name, 0, "guid", "misc",
            KSTAT_TYPE_RAW, 0, KSTAT_FLAG_VIRTUAL);

        shk->kstat = ksp;
        if (ksp) {
                ksp->ks_lock = &shk->lock;
                ksp->ks_data = NULL;
                ksp->ks_private = spa;
                ksp->ks_flags |= KSTAT_FLAG_NO_HEADERS;
                kstat_set_raw_ops(ksp, NULL, spa_guid_data, spa_state_addr);
                kstat_install(ksp);
        }

        kmem_strfree(name);
}

static void
spa_health_destroy(spa_t *spa)
{
        spa_history_kstat_t *shk = &spa->spa_stats.state;
        kstat_t *ksp = shk->kstat;
        if (ksp)
                kstat_delete(ksp);

        mutex_destroy(&shk->lock);
}

static void
spa_guid_destroy(spa_t *spa)
{
        spa_history_kstat_t *shk = &spa->spa_stats.guid;
        kstat_t *ksp = shk->kstat;
        if (ksp)
                kstat_delete(ksp);

        mutex_destroy(&shk->lock);
}

static const spa_iostats_t spa_iostats_template = {
        { "trim_extents_written",               KSTAT_DATA_UINT64 },
        { "trim_bytes_written",                 KSTAT_DATA_UINT64 },
        { "trim_extents_skipped",               KSTAT_DATA_UINT64 },
        { "trim_bytes_skipped",                 KSTAT_DATA_UINT64 },
        { "trim_extents_failed",                KSTAT_DATA_UINT64 },
        { "trim_bytes_failed",                  KSTAT_DATA_UINT64 },
        { "autotrim_extents_written",           KSTAT_DATA_UINT64 },
        { "autotrim_bytes_written",             KSTAT_DATA_UINT64 },
        { "autotrim_extents_skipped",           KSTAT_DATA_UINT64 },
        { "autotrim_bytes_skipped",             KSTAT_DATA_UINT64 },
        { "autotrim_extents_failed",            KSTAT_DATA_UINT64 },
        { "autotrim_bytes_failed",              KSTAT_DATA_UINT64 },
        { "simple_trim_extents_written",        KSTAT_DATA_UINT64 },
        { "simple_trim_bytes_written",          KSTAT_DATA_UINT64 },
        { "simple_trim_extents_skipped",        KSTAT_DATA_UINT64 },
        { "simple_trim_bytes_skipped",          KSTAT_DATA_UINT64 },
        { "simple_trim_extents_failed",         KSTAT_DATA_UINT64 },
        { "simple_trim_bytes_failed",           KSTAT_DATA_UINT64 },
};

#define SPA_IOSTATS_ADD(stat, val) \
    atomic_add_64(&iostats->stat.value.ui64, (val));

void
spa_iostats_trim_add(spa_t *spa, trim_type_t type,
    uint64_t extents_written, uint64_t bytes_written,
    uint64_t extents_skipped, uint64_t bytes_skipped,
    uint64_t extents_failed, uint64_t bytes_failed)
{
        spa_history_kstat_t *shk = &spa->spa_stats.iostats;
        kstat_t *ksp = shk->kstat;
        spa_iostats_t *iostats;

        if (ksp == NULL)
                return;

        iostats = ksp->ks_data;
        if (type == TRIM_TYPE_MANUAL) {
                SPA_IOSTATS_ADD(trim_extents_written, extents_written);
                SPA_IOSTATS_ADD(trim_bytes_written, bytes_written);
                SPA_IOSTATS_ADD(trim_extents_skipped, extents_skipped);
                SPA_IOSTATS_ADD(trim_bytes_skipped, bytes_skipped);
                SPA_IOSTATS_ADD(trim_extents_failed, extents_failed);
                SPA_IOSTATS_ADD(trim_bytes_failed, bytes_failed);
        } else if (type == TRIM_TYPE_AUTO) {
                SPA_IOSTATS_ADD(autotrim_extents_written, extents_written);
                SPA_IOSTATS_ADD(autotrim_bytes_written, bytes_written);
                SPA_IOSTATS_ADD(autotrim_extents_skipped, extents_skipped);
                SPA_IOSTATS_ADD(autotrim_bytes_skipped, bytes_skipped);
                SPA_IOSTATS_ADD(autotrim_extents_failed, extents_failed);
                SPA_IOSTATS_ADD(autotrim_bytes_failed, bytes_failed);
        } else {
                SPA_IOSTATS_ADD(simple_trim_extents_written, extents_written);
                SPA_IOSTATS_ADD(simple_trim_bytes_written, bytes_written);
                SPA_IOSTATS_ADD(simple_trim_extents_skipped, extents_skipped);
                SPA_IOSTATS_ADD(simple_trim_bytes_skipped, bytes_skipped);
                SPA_IOSTATS_ADD(simple_trim_extents_failed, extents_failed);
                SPA_IOSTATS_ADD(simple_trim_bytes_failed, bytes_failed);
        }
}

static int
spa_iostats_update(kstat_t *ksp, int rw)
{
        if (rw == KSTAT_WRITE) {
                memcpy(ksp->ks_data, &spa_iostats_template,
                    sizeof (spa_iostats_t));
        }

        return (0);
}

static void
spa_iostats_init(spa_t *spa)
{
        spa_history_kstat_t *shk = &spa->spa_stats.iostats;

        mutex_init(&shk->lock, NULL, MUTEX_DEFAULT, NULL);

        char *name = kmem_asprintf("zfs/%s", spa_name(spa));
        kstat_t *ksp = kstat_create(name, 0, "iostats", "misc",
            KSTAT_TYPE_NAMED, sizeof (spa_iostats_t) / sizeof (kstat_named_t),
            KSTAT_FLAG_VIRTUAL);

        shk->kstat = ksp;
        if (ksp) {
                int size = sizeof (spa_iostats_t);
                ksp->ks_lock = &shk->lock;
                ksp->ks_private = spa;
                ksp->ks_update = spa_iostats_update;
                ksp->ks_data = kmem_alloc(size, KM_SLEEP);
                memcpy(ksp->ks_data, &spa_iostats_template, size);
                kstat_install(ksp);
        }

        kmem_strfree(name);
}

static void
spa_iostats_destroy(spa_t *spa)
{
        spa_history_kstat_t *shk = &spa->spa_stats.iostats;
        kstat_t *ksp = shk->kstat;
        if (ksp) {
                kmem_free(ksp->ks_data, sizeof (spa_iostats_t));
                kstat_delete(ksp);
        }

        mutex_destroy(&shk->lock);
}

void
spa_stats_init(spa_t *spa)
{
        spa_read_history_init(spa);
        spa_txg_history_init(spa);
        spa_tx_assign_init(spa);
        spa_mmp_history_init(spa);
        spa_state_init(spa);
        spa_guid_init(spa);
        spa_iostats_init(spa);
}

void
spa_stats_destroy(spa_t *spa)
{
        spa_iostats_destroy(spa);
        spa_health_destroy(spa);
        spa_tx_assign_destroy(spa);
        spa_txg_history_destroy(spa);
        spa_read_history_destroy(spa);
        spa_mmp_history_destroy(spa);
        spa_guid_destroy(spa);
}

ZFS_MODULE_PARAM(zfs, zfs_, read_history, UINT, ZMOD_RW,
        "Historical statistics for the last N reads");

ZFS_MODULE_PARAM(zfs, zfs_, read_history_hits, INT, ZMOD_RW,
        "Include cache hits in read history");

ZFS_MODULE_PARAM(zfs_txg, zfs_txg_, history, UINT, ZMOD_RW,
        "Historical statistics for the last N txgs");

ZFS_MODULE_PARAM(zfs_multihost, zfs_multihost_, history, UINT, ZMOD_RW,
        "Historical statistics for last N multihost writes");