[fio.git] / zbd.c

/*
 * Copyright (C) 2018 Western Digital Corporation or its affiliates.
 *
 * This file is released under the GPL.
 */

#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <unistd.h>

#include "os/os.h"
#include "file.h"
#include "fio.h"
#include "lib/pow2.h"
#include "log.h"
#include "oslib/asprintf.h"
#include "smalloc.h"
#include "verify.h"
#include "pshared.h"
#include "zbd.h"

/**
 * zbd_get_zoned_model - Get a device zoned model
 * @td: FIO thread data
 * @f: FIO file for which to get model information
 */
int zbd_get_zoned_model(struct thread_data *td, struct fio_file *f,
                        enum zbd_zoned_model *model)
{
        int ret;

        if (f->filetype == FIO_TYPE_PIPE) {
                log_err("zonemode=zbd does not support pipes\n");
                return -EINVAL;
        }

        /* If regular file, always emulate zones inside the file. */
        if (f->filetype == FIO_TYPE_FILE) {
                *model = ZBD_NONE;
                return 0;
        }

        if (td->io_ops && td->io_ops->get_zoned_model)
                ret = td->io_ops->get_zoned_model(td, f, model);
        else
                ret = blkzoned_get_zoned_model(td, f, model);
        if (ret < 0) {
                td_verror(td, errno, "get zoned model failed");
                log_err("%s: get zoned model failed (%d).\n",
                        f->file_name, errno);
        }

        return ret;
}

/**
 * zbd_report_zones - Get zone information
 * @td: FIO thread data.
 * @f: FIO file for which to get zone information
 * @offset: offset from which to report zones
 * @zones: Array of struct zbd_zone
 * @nr_zones: Size of @zones array
 *
 * Get zone information into @zones starting from the zone at offset @offset
 * for the device specified by @f.
 *
 * Returns the number of zones reported upon success and a negative error code
 * upon failure. If the zone report is empty, always assume an error (device
 * problem) and return -EIO.
 */
int zbd_report_zones(struct thread_data *td, struct fio_file *f,
                     uint64_t offset, struct zbd_zone *zones,
                     unsigned int nr_zones)
{
        int ret;

        if (td->io_ops && td->io_ops->report_zones)
                ret = td->io_ops->report_zones(td, f, offset, zones, nr_zones);
        else
                ret = blkzoned_report_zones(td, f, offset, zones, nr_zones);
        if (ret < 0) {
                td_verror(td, errno, "report zones failed");
                log_err("%s: report zones from sector %llu failed (%d).\n",
                        f->file_name, (unsigned long long)offset >> 9, errno);
        } else if (ret == 0) {
                td_verror(td, errno, "Empty zone report");
                log_err("%s: report zones from sector %llu is empty.\n",
                        f->file_name, (unsigned long long)offset >> 9);
                ret = -EIO;
        }

        return ret;
}

/**
 * zbd_reset_wp - reset the write pointer of a range of zones
 * @td: FIO thread data.
 * @f: FIO file for which to reset zones
 * @offset: Starting offset of the first zone to reset
 * @length: Length of the range of zones to reset
 *
 * Reset the write pointer of all zones in the range @offset...@offset+@length.
 * Returns 0 upon success and a negative error code upon failure.
 */
int zbd_reset_wp(struct thread_data *td, struct fio_file *f,
                 uint64_t offset, uint64_t length)
{
        int ret;

        if (td->io_ops && td->io_ops->reset_wp)
                ret = td->io_ops->reset_wp(td, f, offset, length);
        else
                ret = blkzoned_reset_wp(td, f, offset, length);
        if (ret < 0) {
                td_verror(td, errno, "resetting wp failed");
                log_err("%s: resetting wp for %llu sectors at sector %llu failed (%d).\n",
                        f->file_name, (unsigned long long)length >> 9,
                        (unsigned long long)offset >> 9, errno);
        }

        return ret;
}

/**
 * zbd_get_max_open_zones - Get the maximum number of open zones
 * @td: FIO thread data
 * @f: FIO file for which to get max open zones
 * @max_open_zones: Upon success, result will be stored here.
 *
 * A @max_open_zones value set to zero means no limit.
 *
 * Returns 0 upon success and a negative error code upon failure.
 */
int zbd_get_max_open_zones(struct thread_data *td, struct fio_file *f,
                           unsigned int *max_open_zones)
{
        int ret;

        if (td->io_ops && td->io_ops->get_max_open_zones)
                ret = td->io_ops->get_max_open_zones(td, f, max_open_zones);
        else
                ret = blkzoned_get_max_open_zones(td, f, max_open_zones);
        if (ret < 0) {
                td_verror(td, errno, "get max open zones failed");
                log_err("%s: get max open zones failed (%d).\n",
                        f->file_name, errno);
        }

        return ret;
}

/**
 * zbd_zone_idx - convert an offset into a zone number
 * @f: file pointer.
 * @offset: offset in bytes. If this offset is in the first zone_size bytes
 *          past the disk size then the index of the sentinel is returned.
 */
static uint32_t zbd_zone_idx(const struct fio_file *f, uint64_t offset)
{
        uint32_t zone_idx;

        if (f->zbd_info->zone_size_log2 > 0)
                zone_idx = offset >> f->zbd_info->zone_size_log2;
        else
                zone_idx = offset / f->zbd_info->zone_size;

        return min(zone_idx, f->zbd_info->nr_zones);
}

/**
 * zbd_zone_end - Return zone end location
 * @z: zone info pointer.
 */
static inline uint64_t zbd_zone_end(const struct fio_zone_info *z)
{
        return (z+1)->start;
}

/**
 * zbd_zone_capacity_end - Return zone capacity limit end location
 * @z: zone info pointer.
 */
static inline uint64_t zbd_zone_capacity_end(const struct fio_zone_info *z)
{
        return z->start + z->capacity;
}

/**
 * zbd_zone_full - verify whether a minimum number of bytes remain in a zone
 * @f: file pointer.
 * @z: zone info pointer.
 * @required: minimum number of bytes that must remain in a zone.
 *
 * The caller must hold z->mutex.
 */
static bool zbd_zone_full(const struct fio_file *f, struct fio_zone_info *z,
                          uint64_t required)
{
        assert((required & 511) == 0);

        return z->has_wp &&
                z->wp + required > zbd_zone_capacity_end(z);
}

static void zone_lock(struct thread_data *td, const struct fio_file *f,
                      struct fio_zone_info *z)
{
        struct zoned_block_device_info *zbd = f->zbd_info;
        uint32_t nz = z - zbd->zone_info;

        /* A thread should never lock zones outside its working area. */
        assert(f->min_zone <= nz && nz < f->max_zone);

        assert(z->has_wp);

        /*
         * Lock the io_u target zone. The zone will be unlocked if io_u offset
         * is changed or when io_u completes and zbd_put_io() executed.
         * To avoid multiple jobs doing asynchronous I/Os from deadlocking each
         * other waiting for zone locks when building an io_u batch, first
         * only trylock the zone. If the zone is already locked by another job,
         * process the currently queued I/Os so that I/O progress is made and
         * zones unlocked.
         */
        if (pthread_mutex_trylock(&z->mutex) != 0) {
                if (!td_ioengine_flagged(td, FIO_SYNCIO))
                        io_u_quiesce(td);
                pthread_mutex_lock(&z->mutex);
        }
}

static inline void zone_unlock(struct fio_zone_info *z)
{
        int ret;

        assert(z->has_wp);
        ret = pthread_mutex_unlock(&z->mutex);
        assert(!ret);
}

static bool is_valid_offset(const struct fio_file *f, uint64_t offset)
{
        return (uint64_t)(offset - f->file_offset) < f->io_size;
}

static inline struct fio_zone_info *get_zone(const struct fio_file *f,
                                             unsigned int zone_nr)
{
        return &f->zbd_info->zone_info[zone_nr];
}

/* Verify whether direct I/O is used for all host-managed zoned drives. */
static bool zbd_using_direct_io(void)
{
        struct thread_data *td;
        struct fio_file *f;
        int i, j;

        for_each_td(td, i) {
                if (td->o.odirect || !(td->o.td_ddir & TD_DDIR_WRITE))
                        continue;
                for_each_file(td, f, j) {
                        if (f->zbd_info &&
                            f->zbd_info->model == ZBD_HOST_MANAGED)
                                return false;
                }
        }

        return true;
}

/* Whether or not the I/O range for f includes one or more sequential zones */
static bool zbd_is_seq_job(struct fio_file *f)
{
        uint32_t zone_idx, zone_idx_b, zone_idx_e;

        assert(f->zbd_info);
        if (f->io_size == 0)
                return false;
        zone_idx_b = zbd_zone_idx(f, f->file_offset);
        zone_idx_e = zbd_zone_idx(f, f->file_offset + f->io_size - 1);
        for (zone_idx = zone_idx_b; zone_idx <= zone_idx_e; zone_idx++)
                if (get_zone(f, zone_idx)->has_wp)
                        return true;

        return false;
}

/*
 * Verify whether offset and size parameters are aligned with zone boundaries.
 */
static bool zbd_verify_sizes(void)
{
        const struct fio_zone_info *z;
        struct thread_data *td;
        struct fio_file *f;
        uint64_t new_offset, new_end;
        uint32_t zone_idx;
        int i, j;

        for_each_td(td, i) {
                for_each_file(td, f, j) {
                        if (!f->zbd_info)
                                continue;
                        if (f->file_offset >= f->real_file_size)
                                continue;
                        if (!zbd_is_seq_job(f))
                                continue;

                        if (!td->o.zone_size) {
                                td->o.zone_size = f->zbd_info->zone_size;
                                if (!td->o.zone_size) {
                                        log_err("%s: invalid 0 zone size\n",
                                                f->file_name);
                                        return false;
                                }
                        } else if (td->o.zone_size != f->zbd_info->zone_size) {
                                log_err("%s: job parameter zonesize %llu does not match disk zone size %llu.\n",
                                        f->file_name, (unsigned long long) td->o.zone_size,
                                        (unsigned long long) f->zbd_info->zone_size);
                                return false;
                        }

                        if (td->o.zone_skip % td->o.zone_size) {
                                log_err("%s: zoneskip %llu is not a multiple of the device zone size %llu.\n",
                                        f->file_name, (unsigned long long) td->o.zone_skip,
                                        (unsigned long long) td->o.zone_size);
                                return false;
                        }

                        zone_idx = zbd_zone_idx(f, f->file_offset);
                        z = get_zone(f, zone_idx);
                        if ((f->file_offset != z->start) &&
                            (td->o.td_ddir != TD_DDIR_READ)) {
                                new_offset = zbd_zone_end(z);
                                if (new_offset >= f->file_offset + f->io_size) {
                                        log_info("%s: io_size must be at least one zone\n",
                                                 f->file_name);
                                        return false;
                                }
                                log_info("%s: rounded up offset from %llu to %llu\n",
                                         f->file_name, (unsigned long long) f->file_offset,
                                         (unsigned long long) new_offset);
                                f->io_size -= (new_offset - f->file_offset);
                                f->file_offset = new_offset;
                        }
                        zone_idx = zbd_zone_idx(f, f->file_offset + f->io_size);
                        z = get_zone(f, zone_idx);
                        new_end = z->start;
                        if ((td->o.td_ddir != TD_DDIR_READ) &&
                            (f->file_offset + f->io_size != new_end)) {
                                if (new_end <= f->file_offset) {
                                        log_info("%s: io_size must be at least one zone\n",
                                                 f->file_name);
                                        return false;
                                }
                                log_info("%s: rounded down io_size from %llu to %llu\n",
                                         f->file_name, (unsigned long long) f->io_size,
                                         (unsigned long long) new_end - f->file_offset);
                                f->io_size = new_end - f->file_offset;
                        }
                }
        }

        return true;
}

static bool zbd_verify_bs(void)
{
        struct thread_data *td;
        struct fio_file *f;
        int i, j, k;

        for_each_td(td, i) {
                for_each_file(td, f, j) {
                        uint64_t zone_size;

                        if (!f->zbd_info)
                                continue;
                        zone_size = f->zbd_info->zone_size;
                        for (k = 0; k < FIO_ARRAY_SIZE(td->o.bs); k++) {
                                if (td->o.verify != VERIFY_NONE &&
                                    zone_size % td->o.bs[k] != 0) {
                                        log_info("%s: block size %llu is not a divisor of the zone size %llu\n",
                                                 f->file_name, td->o.bs[k],
                                                 (unsigned long long)zone_size);
                                        return false;
                                }
                        }
                }
        }
        return true;
}

static int ilog2(uint64_t i)
{
        int log = -1;

        while (i) {
                i >>= 1;
                log++;
        }
        return log;
}

/*
 * Initialize f->zbd_info for devices that are not zoned block devices. This
 * allows to execute a ZBD workload against a non-ZBD device.
 */
static int init_zone_info(struct thread_data *td, struct fio_file *f)
{
        uint32_t nr_zones;
        struct fio_zone_info *p;
        uint64_t zone_size = td->o.zone_size;
        uint64_t zone_capacity = td->o.zone_capacity;
        struct zoned_block_device_info *zbd_info = NULL;
        int i;

        if (zone_size == 0) {
                log_err("%s: Specifying the zone size is mandatory for regular file/block device with --zonemode=zbd\n\n",
                        f->file_name);
                return 1;
        }

        if (zone_size < 512) {
                log_err("%s: zone size must be at least 512 bytes for --zonemode=zbd\n\n",
                        f->file_name);
                return 1;
        }

        if (zone_capacity == 0)
                zone_capacity = zone_size;

        if (zone_capacity > zone_size) {
                log_err("%s: job parameter zonecapacity %llu is larger than zone size %llu\n",
                        f->file_name, (unsigned long long) td->o.zone_capacity,
                        (unsigned long long) td->o.zone_size);
                return 1;
        }

        if (f->real_file_size < zone_size) {
                log_err("%s: file/device size %"PRIu64" is smaller than zone size %"PRIu64"\n",
                        f->file_name, f->real_file_size, zone_size);
                return -EINVAL;
        }

        nr_zones = (f->real_file_size + zone_size - 1) / zone_size;
        zbd_info = scalloc(1, sizeof(*zbd_info) +
                           (nr_zones + 1) * sizeof(zbd_info->zone_info[0]));
        if (!zbd_info)
                return -ENOMEM;

        mutex_init_pshared(&zbd_info->mutex);
        zbd_info->refcount = 1;
        p = &zbd_info->zone_info[0];
        for (i = 0; i < nr_zones; i++, p++) {
                mutex_init_pshared_with_type(&p->mutex,
                                             PTHREAD_MUTEX_RECURSIVE);
                p->start = i * zone_size;
                p->wp = p->start;
                p->type = ZBD_ZONE_TYPE_SWR;
                p->cond = ZBD_ZONE_COND_EMPTY;
                p->capacity = zone_capacity;
                p->has_wp = 1;
        }
        /* a sentinel */
        p->start = nr_zones * zone_size;

        f->zbd_info = zbd_info;
        f->zbd_info->zone_size = zone_size;
        f->zbd_info->zone_size_log2 = is_power_of_2(zone_size) ?
                ilog2(zone_size) : 0;
        f->zbd_info->nr_zones = nr_zones;
        return 0;
}

/*
 * Maximum number of zones to report in one operation.
 */
#define ZBD_REPORT_MAX_ZONES    8192U

/*
 * Parse the device zone report and store it in f->zbd_info. Must be called
 * only for devices that are zoned, namely those with a model != ZBD_NONE.
 */
static int parse_zone_info(struct thread_data *td, struct fio_file *f)
{
        int nr_zones, nrz;
        struct zbd_zone *zones, *z;
        struct fio_zone_info *p;
        uint64_t zone_size, offset;
        struct zoned_block_device_info *zbd_info = NULL;
        int i, j, ret = -ENOMEM;

        zones = calloc(ZBD_REPORT_MAX_ZONES, sizeof(struct zbd_zone));
        if (!zones)
                goto out;

        nrz = zbd_report_zones(td, f, 0, zones, ZBD_REPORT_MAX_ZONES);
        if (nrz < 0) {
                ret = nrz;
                log_info("fio: report zones (offset 0) failed for %s (%d).\n",
                         f->file_name, -ret);
                goto out;
        }

        zone_size = zones[0].len;
        nr_zones = (f->real_file_size + zone_size - 1) / zone_size;

        if (td->o.zone_size == 0) {
                td->o.zone_size = zone_size;
        } else if (td->o.zone_size != zone_size) {
                log_err("fio: %s job parameter zonesize %llu does not match disk zone size %llu.\n",
                        f->file_name, (unsigned long long) td->o.zone_size,
                        (unsigned long long) zone_size);
                ret = -EINVAL;
                goto out;
        }

        dprint(FD_ZBD, "Device %s has %d zones of size %llu KB\n", f->file_name,
               nr_zones, (unsigned long long) zone_size / 1024);

        zbd_info = scalloc(1, sizeof(*zbd_info) +
                           (nr_zones + 1) * sizeof(zbd_info->zone_info[0]));
        if (!zbd_info)
                goto out;
        mutex_init_pshared(&zbd_info->mutex);
        zbd_info->refcount = 1;
        p = &zbd_info->zone_info[0];
        for (offset = 0, j = 0; j < nr_zones;) {
                z = &zones[0];
                for (i = 0; i < nrz; i++, j++, z++, p++) {
                        mutex_init_pshared_with_type(&p->mutex,
                                                     PTHREAD_MUTEX_RECURSIVE);
                        p->start = z->start;
                        p->capacity = z->capacity;
                        switch (z->cond) {
                        case ZBD_ZONE_COND_NOT_WP:
                        case ZBD_ZONE_COND_FULL:
                                p->wp = p->start + p->capacity;
                                break;
                        default:
                                assert(z->start <= z->wp);
                                assert(z->wp <= z->start + zone_size);
                                p->wp = z->wp;
                                break;
                        }

                        switch (z->type) {
                        case ZBD_ZONE_TYPE_SWR:
                                p->has_wp = 1;
                                break;
                        default:
                                p->has_wp = 0;
                        }
                        p->type = z->type;
                        p->cond = z->cond;

                        if (j > 0 && p->start != p[-1].start + zone_size) {
                                log_info("%s: invalid zone data\n",
                                         f->file_name);
                                ret = -EINVAL;
                                goto out;
                        }
                }
                z--;
                offset = z->start + z->len;
                if (j >= nr_zones)
                        break;
                nrz = zbd_report_zones(td, f, offset, zones,
                                       min((uint32_t)(nr_zones - j),
                                           ZBD_REPORT_MAX_ZONES));
                if (nrz < 0) {
                        ret = nrz;
                        log_info("fio: report zones (offset %llu) failed for %s (%d).\n",
                                 (unsigned long long)offset,
                                 f->file_name, -ret);
                        goto out;
                }
        }

        /* a sentinel */
        zbd_info->zone_info[nr_zones].start = offset;

        f->zbd_info = zbd_info;
        f->zbd_info->zone_size = zone_size;
        f->zbd_info->zone_size_log2 = is_power_of_2(zone_size) ?
                ilog2(zone_size) : 0;
        f->zbd_info->nr_zones = nr_zones;
        zbd_info = NULL;
        ret = 0;

out:
        sfree(zbd_info);
        free(zones);
        return ret;
}

static int zbd_set_max_open_zones(struct thread_data *td, struct fio_file *f)
{
        struct zoned_block_device_info *zbd = f->zbd_info;
        unsigned int max_open_zones;
        int ret;

        if (zbd->model != ZBD_HOST_MANAGED || td->o.ignore_zone_limits) {
                /* Only host-managed devices have a max open limit */
                zbd->max_open_zones = td->o.max_open_zones;
                goto out;
        }

        /* If host-managed, get the max open limit */
        ret = zbd_get_max_open_zones(td, f, &max_open_zones);
        if (ret)
                return ret;

        if (!max_open_zones) {
                /* No device limit */
                zbd->max_open_zones = td->o.max_open_zones;
        } else if (!td->o.max_open_zones) {
                /* No user limit. Set limit to device limit */
                zbd->max_open_zones = max_open_zones;
        } else if (td->o.max_open_zones <= max_open_zones) {
                /* Both user limit and dev limit. User limit not too large */
                zbd->max_open_zones = td->o.max_open_zones;
        } else {
                /* Both user limit and dev limit. User limit too large */
                td_verror(td, EINVAL,
                          "Specified --max_open_zones is too large");
                log_err("Specified --max_open_zones (%d) is larger than max (%u)\n",
                        td->o.max_open_zones, max_open_zones);
                return -EINVAL;
        }

out:
        /* Ensure that the limit is not larger than FIO's internal limit */
        zbd->max_open_zones = min_not_zero(zbd->max_open_zones,
                                           (uint32_t) ZBD_MAX_OPEN_ZONES);
        dprint(FD_ZBD, "%s: using max open zones limit: %"PRIu32"\n",
               f->file_name, zbd->max_open_zones);

        return 0;
}

/*
 * Allocate zone information and store it into f->zbd_info if zonemode=zbd.
 *
 * Returns 0 upon success and a negative error code upon failure.
 */
static int zbd_create_zone_info(struct thread_data *td, struct fio_file *f)
{
        enum zbd_zoned_model zbd_model;
        int ret;

        assert(td->o.zone_mode == ZONE_MODE_ZBD);

        ret = zbd_get_zoned_model(td, f, &zbd_model);
        if (ret)
                return ret;

        switch (zbd_model) {
        case ZBD_HOST_AWARE:
        case ZBD_HOST_MANAGED:
                ret = parse_zone_info(td, f);
                if (ret)
                        return ret;
                break;
        case ZBD_NONE:
                ret = init_zone_info(td, f);
                if (ret)
                        return ret;
                break;
        default:
                td_verror(td, EINVAL, "Unsupported zoned model");
                log_err("Unsupported zoned model\n");
                return -EINVAL;
        }

        assert(f->zbd_info);
        f->zbd_info->model = zbd_model;

        ret = zbd_set_max_open_zones(td, f);
        if (ret) {
                zbd_free_zone_info(f);
                return ret;
        }

        return 0;
}

void zbd_free_zone_info(struct fio_file *f)
{
        uint32_t refcount;

        assert(f->zbd_info);

        pthread_mutex_lock(&f->zbd_info->mutex);
        refcount = --f->zbd_info->refcount;
        pthread_mutex_unlock(&f->zbd_info->mutex);

        assert((int32_t)refcount >= 0);
        if (refcount == 0)
                sfree(f->zbd_info);
        f->zbd_info = NULL;
}

/*
 * Initialize f->zbd_info.
 *
 * Returns 0 upon success and a negative error code upon failure.
 *
 * Note: this function can only work correctly if it is called before the first
 * fio fork() call.
 */
static int zbd_init_zone_info(struct thread_data *td, struct fio_file *file)
{
        struct thread_data *td2;
        struct fio_file *f2;
        int i, j, ret;

        for_each_td(td2, i) {
                for_each_file(td2, f2, j) {
                        if (td2 == td && f2 == file)
                                continue;
                        if (!f2->zbd_info ||
                            strcmp(f2->file_name, file->file_name) != 0)
                                continue;
                        file->zbd_info = f2->zbd_info;
                        file->zbd_info->refcount++;
                        return 0;
                }
        }

        ret = zbd_create_zone_info(td, file);
        if (ret < 0)
                td_verror(td, -ret, "zbd_create_zone_info() failed");
        return ret;
}

static bool zbd_open_zone(struct thread_data *td, const struct fio_file *f,
                          uint32_t zone_idx);
static int zbd_reset_zone(struct thread_data *td, struct fio_file *f,
                          struct fio_zone_info *z);

int zbd_init_files(struct thread_data *td)
{
        struct fio_file *f;
        int i;

        for_each_file(td, f, i) {
                if (zbd_init_zone_info(td, f))
                        return 1;
        }
        return 0;
}

void zbd_recalc_options_with_zone_granularity(struct thread_data *td)
{
        struct fio_file *f;
        int i;

        for_each_file(td, f, i) {
                struct zoned_block_device_info *zbd = f->zbd_info;
                // zonemode=strided doesn't get per-file zone size.
                uint64_t zone_size = zbd ? zbd->zone_size : td->o.zone_size;

                if (zone_size == 0)
                        continue;

                if (td->o.size_nz > 0) {
                        td->o.size = td->o.size_nz * zone_size;
                }
                if (td->o.io_size_nz > 0) {
                        td->o.io_size = td->o.io_size_nz * zone_size;
                }
                if (td->o.start_offset_nz > 0) {
                        td->o.start_offset = td->o.start_offset_nz * zone_size;
                }
                if (td->o.offset_increment_nz > 0) {
                        td->o.offset_increment = td->o.offset_increment_nz * zone_size;
                }
                if (td->o.zone_skip_nz > 0) {
                        td->o.zone_skip = td->o.zone_skip_nz * zone_size;
                }
        }
}

int zbd_setup_files(struct thread_data *td)
{
        struct fio_file *f;
        int i;

        if (!zbd_using_direct_io()) {
                log_err("Using direct I/O is mandatory for writing to ZBD drives\n\n");
                return 1;
        }

        if (!zbd_verify_sizes())
                return 1;

        if (!zbd_verify_bs())
                return 1;

        for_each_file(td, f, i) {
                struct zoned_block_device_info *zbd = f->zbd_info;
                struct fio_zone_info *z;
                int zi;

                if (!zbd)
                        continue;

                f->min_zone = zbd_zone_idx(f, f->file_offset);
                f->max_zone = zbd_zone_idx(f, f->file_offset + f->io_size);

                /*
                 * When all zones in the I/O range are conventional, io_size
                 * can be smaller than zone size, making min_zone the same
                 * as max_zone. This is why the assert below needs to be made
                 * conditional.
                 */
                if (zbd_is_seq_job(f))
                        assert(f->min_zone < f->max_zone);

                if (td->o.max_open_zones > 0 &&
                    zbd->max_open_zones != td->o.max_open_zones) {
                        log_err("Different 'max_open_zones' values\n");
                        return 1;
                }
                if (zbd->max_open_zones > ZBD_MAX_OPEN_ZONES) {
                        log_err("'max_open_zones' value is limited by %u\n", ZBD_MAX_OPEN_ZONES);
                        return 1;
                }

                for (zi = f->min_zone; zi < f->max_zone; zi++) {
                        z = &zbd->zone_info[zi];
                        if (z->cond != ZBD_ZONE_COND_IMP_OPEN &&
                            z->cond != ZBD_ZONE_COND_EXP_OPEN)
                                continue;
                        if (zbd_open_zone(td, f, zi))
                                continue;
                        /*
                         * If the number of open zones exceeds specified limits,
                         * reset all extra open zones.
                         */
                        if (zbd_reset_zone(td, f, z) < 0) {
                                log_err("Failed to reest zone %d\n", zi);
                                return 1;
                        }
                }
        }

        return 0;
}

static inline unsigned int zbd_zone_nr(const struct fio_file *f,
                                       struct fio_zone_info *zone)
{
        return zone - f->zbd_info->zone_info;
}

/**
 * zbd_reset_zone - reset the write pointer of a single zone
 * @td: FIO thread data.
 * @f: FIO file associated with the disk for which to reset a write pointer.
 * @z: Zone to reset.
 *
 * Returns 0 upon success and a negative error code upon failure.
 *
 * The caller must hold z->mutex.
 */
static int zbd_reset_zone(struct thread_data *td, struct fio_file *f,
                          struct fio_zone_info *z)
{
        uint64_t offset = z->start;
        uint64_t length = (z+1)->start - offset;
        uint64_t data_in_zone = z->wp - z->start;
        int ret = 0;

        if (!data_in_zone)
                return 0;

        assert(is_valid_offset(f, offset + length - 1));

        dprint(FD_ZBD, "%s: resetting wp of zone %u.\n", f->file_name,
                zbd_zone_nr(f, z));
        switch (f->zbd_info->model) {
        case ZBD_HOST_AWARE:
        case ZBD_HOST_MANAGED:
                ret = zbd_reset_wp(td, f, offset, length);
                if (ret < 0)
                        return ret;
                break;
        default:
                break;
        }

        pthread_mutex_lock(&f->zbd_info->mutex);
        f->zbd_info->sectors_with_data -= data_in_zone;
        f->zbd_info->wp_sectors_with_data -= data_in_zone;
        pthread_mutex_unlock(&f->zbd_info->mutex);
        z->wp = z->start;
        z->verify_block = 0;

        td->ts.nr_zone_resets++;

        return ret;
}

/* The caller must hold f->zbd_info->mutex */
static void zbd_close_zone(struct thread_data *td, const struct fio_file *f,
                           unsigned int zone_idx)
{
        uint32_t open_zone_idx = 0;

        for (; open_zone_idx < f->zbd_info->num_open_zones; open_zone_idx++) {
                if (f->zbd_info->open_zones[open_zone_idx] == zone_idx)
                        break;
        }
        if (open_zone_idx == f->zbd_info->num_open_zones)
                return;

        dprint(FD_ZBD, "%s: closing zone %d\n", f->file_name, zone_idx);
        memmove(f->zbd_info->open_zones + open_zone_idx,
                f->zbd_info->open_zones + open_zone_idx + 1,
                (ZBD_MAX_OPEN_ZONES - (open_zone_idx + 1)) *
                sizeof(f->zbd_info->open_zones[0]));
        f->zbd_info->num_open_zones--;
        td->num_open_zones--;
        get_zone(f, zone_idx)->open = 0;
}

/*
 * Reset a range of zones. Returns 0 upon success and 1 upon failure.
 * @td: fio thread data.
 * @f: fio file for which to reset zones
 * @zb: first zone to reset.
 * @ze: first zone not to reset.
 */
static int zbd_reset_zones(struct thread_data *td, struct fio_file *f,
                           struct fio_zone_info *const zb,
                           struct fio_zone_info *const ze)
{
        struct fio_zone_info *z;
        const uint32_t min_bs = td->o.min_bs[DDIR_WRITE];
        int res = 0;

        assert(min_bs);

        dprint(FD_ZBD, "%s: examining zones %u .. %u\n", f->file_name,
                zbd_zone_nr(f, zb), zbd_zone_nr(f, ze));
        for (z = zb; z < ze; z++) {
                uint32_t nz = zbd_zone_nr(f, z);

                if (!z->has_wp)
                        continue;
                zone_lock(td, f, z);
                pthread_mutex_lock(&f->zbd_info->mutex);
                zbd_close_zone(td, f, nz);
                pthread_mutex_unlock(&f->zbd_info->mutex);
                if (z->wp != z->start) {
                        dprint(FD_ZBD, "%s: resetting zone %u\n",
                               f->file_name, zbd_zone_nr(f, z));
                        if (zbd_reset_zone(td, f, z) < 0)
                                res = 1;
                }
                zone_unlock(z);
        }

        return res;
}

/*
 * Reset zbd_info.write_cnt, the counter that counts down towards the next
 * zone reset.
 */
static void _zbd_reset_write_cnt(const struct thread_data *td,
                                 const struct fio_file *f)
{
        assert(0 <= td->o.zrf.u.f && td->o.zrf.u.f <= 1);

        f->zbd_info->write_cnt = td->o.zrf.u.f ?
                min(1.0 / td->o.zrf.u.f, 0.0 + UINT_MAX) : UINT_MAX;
}

static void zbd_reset_write_cnt(const struct thread_data *td,
                                const struct fio_file *f)
{
        pthread_mutex_lock(&f->zbd_info->mutex);
        _zbd_reset_write_cnt(td, f);
        pthread_mutex_unlock(&f->zbd_info->mutex);
}

static bool zbd_dec_and_reset_write_cnt(const struct thread_data *td,
                                        const struct fio_file *f)
{
        uint32_t write_cnt = 0;

        pthread_mutex_lock(&f->zbd_info->mutex);
        assert(f->zbd_info->write_cnt);
        if (f->zbd_info->write_cnt)
                write_cnt = --f->zbd_info->write_cnt;
        if (write_cnt == 0)
                _zbd_reset_write_cnt(td, f);
        pthread_mutex_unlock(&f->zbd_info->mutex);

        return write_cnt == 0;
}

enum swd_action {
        CHECK_SWD,
        SET_SWD,
};

/* Calculate the number of sectors with data (swd) and perform action 'a' */
static uint64_t zbd_process_swd(struct thread_data *td,
                                const struct fio_file *f, enum swd_action a)
{
        struct fio_zone_info *zb, *ze, *z;
        uint64_t swd = 0;
        uint64_t wp_swd = 0;

        zb = get_zone(f, f->min_zone);
        ze = get_zone(f, f->max_zone);
        for (z = zb; z < ze; z++) {
                if (z->has_wp) {
                        zone_lock(td, f, z);
                        wp_swd += z->wp - z->start;
                }
                swd += z->wp - z->start;
        }
        pthread_mutex_lock(&f->zbd_info->mutex);
        switch (a) {
        case CHECK_SWD:
                assert(f->zbd_info->sectors_with_data == swd);
                assert(f->zbd_info->wp_sectors_with_data == wp_swd);
                break;
        case SET_SWD:
                f->zbd_info->sectors_with_data = swd;
                f->zbd_info->wp_sectors_with_data = wp_swd;
                break;
        }
        pthread_mutex_unlock(&f->zbd_info->mutex);
        for (z = zb; z < ze; z++)
                if (z->has_wp)
                        zone_unlock(z);

        return swd;
}

/*
 * The swd check is useful for debugging but takes too much time to leave
 * it enabled all the time. Hence it is disabled by default.
 */
static const bool enable_check_swd = false;

/* Check whether the values of zbd_info.*sectors_with_data are correct. */
static void zbd_check_swd(struct thread_data *td, const struct fio_file *f)
{
        if (!enable_check_swd)
                return;

        zbd_process_swd(td, f, CHECK_SWD);
}

void zbd_file_reset(struct thread_data *td, struct fio_file *f)
{
        struct fio_zone_info *zb, *ze;
        uint64_t swd;

        if (!f->zbd_info || !td_write(td))
                return;

        zb = get_zone(f, f->min_zone);
        ze = get_zone(f, f->max_zone);
        swd = zbd_process_swd(td, f, SET_SWD);
        dprint(FD_ZBD, "%s(%s): swd = %" PRIu64 "\n", __func__, f->file_name,
               swd);
        /*
         * If data verification is enabled reset the affected zones before
         * writing any data to avoid that a zone reset has to be issued while
         * writing data, which causes data loss.
         */
        if (td->o.verify != VERIFY_NONE && td->runstate != TD_VERIFYING)
                zbd_reset_zones(td, f, zb, ze);
        zbd_reset_write_cnt(td, f);
}

/* The caller must hold f->zbd_info->mutex. */
static bool is_zone_open(const struct thread_data *td, const struct fio_file *f,
                         unsigned int zone_idx)
{
        struct zoned_block_device_info *zbdi = f->zbd_info;
        int i;

        assert(td->o.job_max_open_zones == 0 || td->num_open_zones <= td->o.job_max_open_zones);
        assert(td->o.job_max_open_zones <= zbdi->max_open_zones);
        assert(zbdi->num_open_zones <= zbdi->max_open_zones);

        for (i = 0; i < zbdi->num_open_zones; i++)
                if (zbdi->open_zones[i] == zone_idx)
                        return true;

        return false;
}

/*
 * Open a ZBD zone if it was not yet open. Returns true if either the zone was
 * already open or if opening a new zone is allowed. Returns false if the zone
 * was not yet open and opening a new zone would cause the zone limit to be
 * exceeded.
 */
static bool zbd_open_zone(struct thread_data *td, const struct fio_file *f,
                          uint32_t zone_idx)
{
        const uint32_t min_bs = td->o.min_bs[DDIR_WRITE];
        struct fio_zone_info *z = get_zone(f, zone_idx);
        bool res = true;

        if (z->cond == ZBD_ZONE_COND_OFFLINE)
                return false;

        /*
         * Skip full zones with data verification enabled because resetting a
         * zone causes data loss and hence causes verification to fail.
         */
        if (td->o.verify != VERIFY_NONE && zbd_zone_full(f, z, min_bs))
                return false;

        pthread_mutex_lock(&f->zbd_info->mutex);
        if (is_zone_open(td, f, zone_idx)) {
                /*
                 * If the zone is already open and going to be full by writes
                 * in-flight, handle it as a full zone instead of an open zone.
                 */
                if (z->wp >= zbd_zone_capacity_end(z))
                        res = false;
                goto out;
        }
        res = false;
        /* Zero means no limit */
        if (td->o.job_max_open_zones > 0 &&
            td->num_open_zones >= td->o.job_max_open_zones)
                goto out;
        if (f->zbd_info->num_open_zones >= f->zbd_info->max_open_zones)
                goto out;
        dprint(FD_ZBD, "%s: opening zone %d\n", f->file_name, zone_idx);
        f->zbd_info->open_zones[f->zbd_info->num_open_zones++] = zone_idx;
        td->num_open_zones++;
        z->open = 1;
        res = true;

out:
        pthread_mutex_unlock(&f->zbd_info->mutex);
        return res;
}

/* Anything goes as long as it is not a constant. */
static uint32_t pick_random_zone_idx(const struct fio_file *f,
                                     const struct io_u *io_u)
{
        return io_u->offset * f->zbd_info->num_open_zones / f->real_file_size;
}

/*
 * Modify the offset of an I/O unit that does not refer to an open zone such
 * that it refers to an open zone. Close an open zone and open a new zone if
 * necessary. The open zone is searched across sequential zones.
 * This algorithm can only work correctly if all write pointers are
 * a multiple of the fio block size. The caller must neither hold z->mutex
 * nor f->zbd_info->mutex. Returns with z->mutex held upon success.
 */
static struct fio_zone_info *zbd_convert_to_open_zone(struct thread_data *td,
                                                      struct io_u *io_u)
{
        const uint32_t min_bs = td->o.min_bs[io_u->ddir];
        struct fio_file *f = io_u->file;
        struct fio_zone_info *z;
        unsigned int open_zone_idx = -1;
        uint32_t zone_idx, new_zone_idx;
        int i;
        bool wait_zone_close;

        assert(is_valid_offset(f, io_u->offset));

        if (td->o.max_open_zones || td->o.job_max_open_zones) {
                /*
                 * This statement accesses f->zbd_info->open_zones[] on purpose
                 * without locking.
                 */
                zone_idx = f->zbd_info->open_zones[pick_random_zone_idx(f, io_u)];
        } else {
                zone_idx = zbd_zone_idx(f, io_u->offset);
        }
        if (zone_idx < f->min_zone)
                zone_idx = f->min_zone;
        else if (zone_idx >= f->max_zone)
                zone_idx = f->max_zone - 1;
        dprint(FD_ZBD, "%s(%s): starting from zone %d (offset %lld, buflen %lld)\n",
               __func__, f->file_name, zone_idx, io_u->offset, io_u->buflen);

        /*
         * Since z->mutex is the outer lock and f->zbd_info->mutex the inner
         * lock it can happen that the state of the zone with index zone_idx
         * has changed after 'z' has been assigned and before f->zbd_info->mutex
         * has been obtained. Hence the loop.
         */
        for (;;) {
                uint32_t tmp_idx;

                z = get_zone(f, zone_idx);
                if (z->has_wp)
                        zone_lock(td, f, z);
                pthread_mutex_lock(&f->zbd_info->mutex);
                if (z->has_wp) {
                        if (z->cond != ZBD_ZONE_COND_OFFLINE &&
                            td->o.max_open_zones == 0 && td->o.job_max_open_zones == 0)
                                goto examine_zone;
                        if (f->zbd_info->num_open_zones == 0) {
                                dprint(FD_ZBD, "%s(%s): no zones are open\n",
                                       __func__, f->file_name);
                                goto open_other_zone;
                        }
                }

                /*
                 * List of opened zones is per-device, shared across all threads.
                 * Start with quasi-random candidate zone.
                 * Ignore zones which don't belong to thread's offset/size area.
                 */
                open_zone_idx = pick_random_zone_idx(f, io_u);
                assert(!open_zone_idx ||
                       open_zone_idx < f->zbd_info->num_open_zones);
                tmp_idx = open_zone_idx;
                for (i = 0; i < f->zbd_info->num_open_zones; i++) {
                        uint32_t tmpz;

                        if (tmp_idx >= f->zbd_info->num_open_zones)
                                tmp_idx = 0;
                        tmpz = f->zbd_info->open_zones[tmp_idx];
                        if (f->min_zone <= tmpz && tmpz < f->max_zone) {
                                open_zone_idx = tmp_idx;
                                goto found_candidate_zone;
                        }

                        tmp_idx++;
                }

                dprint(FD_ZBD, "%s(%s): no candidate zone\n",
                        __func__, f->file_name);
                pthread_mutex_unlock(&f->zbd_info->mutex);
                if (z->has_wp)
                        zone_unlock(z);
                return NULL;

found_candidate_zone:
                new_zone_idx = f->zbd_info->open_zones[open_zone_idx];
                if (new_zone_idx == zone_idx)
                        break;
                zone_idx = new_zone_idx;
                pthread_mutex_unlock(&f->zbd_info->mutex);
                if (z->has_wp)
                        zone_unlock(z);
        }

        /* Both z->mutex and f->zbd_info->mutex are held. */

examine_zone:
        if (z->wp + min_bs <= zbd_zone_capacity_end(z)) {
                pthread_mutex_unlock(&f->zbd_info->mutex);
                goto out;
        }

open_other_zone:
        /* Check if number of open zones reaches one of limits. */
        wait_zone_close =
                f->zbd_info->num_open_zones == f->max_zone - f->min_zone ||
                (td->o.max_open_zones &&
                 f->zbd_info->num_open_zones == td->o.max_open_zones) ||
                (td->o.job_max_open_zones &&
                 td->num_open_zones == td->o.job_max_open_zones);

        pthread_mutex_unlock(&f->zbd_info->mutex);

        /* Only z->mutex is held. */

        /*
         * When number of open zones reaches to one of limits, wait for
         * zone close before opening a new zone.
         */
        if (wait_zone_close) {
                dprint(FD_ZBD, "%s(%s): quiesce to allow open zones to close\n",
                       __func__, f->file_name);
                io_u_quiesce(td);
        }

        /* Zone 'z' is full, so try to open a new zone. */
        for (i = f->io_size / f->zbd_info->zone_size; i > 0; i--) {
                zone_idx++;
                if (z->has_wp)
                        zone_unlock(z);
                z++;
                if (!is_valid_offset(f, z->start)) {
                        /* Wrap-around. */
                        zone_idx = f->min_zone;
                        z = get_zone(f, zone_idx);
                }
                assert(is_valid_offset(f, z->start));
                if (!z->has_wp)
                        continue;
                zone_lock(td, f, z);
                if (z->open)
                        continue;
                if (zbd_open_zone(td, f, zone_idx))
                        goto out;
        }

        /* Only z->mutex is held. */

        /* Check whether the write fits in any of the already opened zones. */
        pthread_mutex_lock(&f->zbd_info->mutex);
        for (i = 0; i < f->zbd_info->num_open_zones; i++) {
                zone_idx = f->zbd_info->open_zones[i];
                if (zone_idx < f->min_zone || zone_idx >= f->max_zone)
                        continue;
                pthread_mutex_unlock(&f->zbd_info->mutex);
                zone_unlock(z);

                z = get_zone(f, zone_idx);

                zone_lock(td, f, z);
                if (z->wp + min_bs <= zbd_zone_capacity_end(z))
                        goto out;
                pthread_mutex_lock(&f->zbd_info->mutex);
        }
        pthread_mutex_unlock(&f->zbd_info->mutex);
        zone_unlock(z);
        dprint(FD_ZBD, "%s(%s): did not open another zone\n", __func__,
               f->file_name);
        return NULL;

out:
        dprint(FD_ZBD, "%s(%s): returning zone %d\n", __func__, f->file_name,
               zone_idx);
        io_u->offset = z->start;
        assert(z->has_wp);
        assert(z->cond != ZBD_ZONE_COND_OFFLINE);
        return z;
}

/* The caller must hold z->mutex. */
static struct fio_zone_info *zbd_replay_write_order(struct thread_data *td,
                                                    struct io_u *io_u,
                                                    struct fio_zone_info *z)
{
        const struct fio_file *f = io_u->file;
        const uint32_t min_bs = td->o.min_bs[DDIR_WRITE];

        if (!zbd_open_zone(td, f, zbd_zone_nr(f, z))) {
                zone_unlock(z);
                z = zbd_convert_to_open_zone(td, io_u);
                assert(z);
        }

        if (z->verify_block * min_bs >= z->capacity) {
                log_err("%s: %d * %d >= %llu\n", f->file_name, z->verify_block,
                        min_bs, (unsigned long long)z->capacity);
                /*
                 * If the assertion below fails during a test run, adding
                 * "--experimental_verify=1" to the command line may help.
                 */
                assert(false);
        }
        io_u->offset = z->start + z->verify_block * min_bs;
        if (io_u->offset + io_u->buflen >= zbd_zone_capacity_end(z)) {
                log_err("%s: %llu + %llu >= %llu\n", f->file_name, io_u->offset,
                        io_u->buflen, (unsigned long long) zbd_zone_capacity_end(z));
                assert(false);
        }
        z->verify_block += io_u->buflen / min_bs;

        return z;
}

/*
 * Find another zone for which @io_u fits in the readable data in the zone.
 * Search in zones @zb + 1 .. @zl. For random workload, also search in zones
 * @zb - 1 .. @zf.
 *
 * Either returns NULL or returns a zone pointer. When the zone has write
 * pointer, hold the mutex for the zone.
 */
static struct fio_zone_info *
zbd_find_zone(struct thread_data *td, struct io_u *io_u,
              struct fio_zone_info *zb, struct fio_zone_info *zl)
{
        const uint32_t min_bs = td->o.min_bs[io_u->ddir];
        struct fio_file *f = io_u->file;
        struct fio_zone_info *z1, *z2;
        const struct fio_zone_info *const zf = get_zone(f, f->min_zone);

        /*
         * Skip to the next non-empty zone in case of sequential I/O and to
         * the nearest non-empty zone in case of random I/O.
         */
        for (z1 = zb + 1, z2 = zb - 1; z1 < zl || z2 >= zf; z1++, z2--) {
                if (z1 < zl && z1->cond != ZBD_ZONE_COND_OFFLINE) {
                        if (z1->has_wp)
                                zone_lock(td, f, z1);
                        if (z1->start + min_bs <= z1->wp)
                                return z1;
                        if (z1->has_wp)
                                zone_unlock(z1);
                } else if (!td_random(td)) {
                        break;
                }
                if (td_random(td) && z2 >= zf &&
                    z2->cond != ZBD_ZONE_COND_OFFLINE) {
                        if (z2->has_wp)
                                zone_lock(td, f, z2);
                        if (z2->start + min_bs <= z2->wp)
                                return z2;
                        if (z2->has_wp)
                                zone_unlock(z2);
                }
        }
        dprint(FD_ZBD, "%s: adjusting random read offset failed\n",
               f->file_name);
        return NULL;
}

/**
 * zbd_end_zone_io - update zone status at command completion
 * @io_u: I/O unit
 * @z: zone info pointer
 *
 * If the write command made the zone full, close it.
 *
 * The caller must hold z->mutex.
 */
static void zbd_end_zone_io(struct thread_data *td, const struct io_u *io_u,
                            struct fio_zone_info *z)
{
        const struct fio_file *f = io_u->file;

        if (io_u->ddir == DDIR_WRITE &&
            io_u->offset + io_u->buflen >= zbd_zone_capacity_end(z)) {
                pthread_mutex_lock(&f->zbd_info->mutex);
                zbd_close_zone(td, f, zbd_zone_nr(f, z));
                pthread_mutex_unlock(&f->zbd_info->mutex);
        }
}

/**
 * zbd_queue_io - update the write pointer of a sequential zone
 * @io_u: I/O unit
 * @success: Whether or not the I/O unit has been queued successfully
 * @q: queueing status (busy, completed or queued).
 *
 * For write and trim operations, update the write pointer of the I/O unit
 * target zone.
 */
static void zbd_queue_io(struct thread_data *td, struct io_u *io_u, int q,
                         bool success)
{
        const struct fio_file *f = io_u->file;
        struct zoned_block_device_info *zbd_info = f->zbd_info;
        struct fio_zone_info *z;
        uint32_t zone_idx;
        uint64_t zone_end;

        if (!zbd_info)
                return;

        zone_idx = zbd_zone_idx(f, io_u->offset);
        assert(zone_idx < zbd_info->nr_zones);
        z = get_zone(f, zone_idx);

        assert(z->has_wp);

        if (!success)
                goto unlock;

        dprint(FD_ZBD,
               "%s: queued I/O (%lld, %llu) for zone %u\n",
               f->file_name, io_u->offset, io_u->buflen, zone_idx);

        switch (io_u->ddir) {
        case DDIR_WRITE:
                zone_end = min((uint64_t)(io_u->offset + io_u->buflen),
                               zbd_zone_capacity_end(z));
                pthread_mutex_lock(&zbd_info->mutex);
                /*
                 * z->wp > zone_end means that one or more I/O errors
                 * have occurred.
                 */
                if (z->wp <= zone_end) {
                        zbd_info->sectors_with_data += zone_end - z->wp;
                        zbd_info->wp_sectors_with_data += zone_end - z->wp;
                }
                pthread_mutex_unlock(&zbd_info->mutex);
                z->wp = zone_end;
                break;
        case DDIR_TRIM:
                assert(z->wp == z->start);
                break;
        default:
                break;
        }

        if (q == FIO_Q_COMPLETED && !io_u->error)
                zbd_end_zone_io(td, io_u, z);

unlock:
        if (!success || q != FIO_Q_QUEUED) {
                /* BUSY or COMPLETED: unlock the zone */
                zone_unlock(z);
                io_u->zbd_put_io = NULL;
        }
}

/**
 * zbd_put_io - Unlock an I/O unit target zone lock
 * @io_u: I/O unit
 */
static void zbd_put_io(struct thread_data *td, const struct io_u *io_u)
{
        const struct fio_file *f = io_u->file;
        struct zoned_block_device_info *zbd_info = f->zbd_info;
        struct fio_zone_info *z;
        uint32_t zone_idx;

        if (!zbd_info)
                return;

        zone_idx = zbd_zone_idx(f, io_u->offset);
        assert(zone_idx < zbd_info->nr_zones);
        z = get_zone(f, zone_idx);

        assert(z->has_wp);

        dprint(FD_ZBD,
               "%s: terminate I/O (%lld, %llu) for zone %u\n",
               f->file_name, io_u->offset, io_u->buflen, zone_idx);

        zbd_end_zone_io(td, io_u, z);

        zone_unlock(z);
        zbd_check_swd(td, f);
}

/*
 * Windows and MacOS do not define this.
 */
#ifndef EREMOTEIO
#define EREMOTEIO       121     /* POSIX value */
#endif

bool zbd_unaligned_write(int error_code)
{
        switch (error_code) {
        case EIO:
        case EREMOTEIO:
                return true;
        }
        return false;
}

/**
 * setup_zbd_zone_mode - handle zoneskip as necessary for ZBD drives
 * @td: FIO thread data.
 * @io_u: FIO I/O unit.
 *
 * For sequential workloads, change the file offset to skip zoneskip bytes when
 * no more IO can be performed in the current zone.
 * - For read workloads, zoneskip is applied when the io has reached the end of
 *   the zone or the zone write position (when td->o.read_beyond_wp is false).
 * - For write workloads, zoneskip is applied when the zone is full.
 * This applies only to read and write operations.
 */
void setup_zbd_zone_mode(struct thread_data *td, struct io_u *io_u)
{
        struct fio_file *f = io_u->file;
        enum fio_ddir ddir = io_u->ddir;
        struct fio_zone_info *z;
        uint32_t zone_idx;

        assert(td->o.zone_mode == ZONE_MODE_ZBD);
        assert(td->o.zone_size);

        zone_idx = zbd_zone_idx(f, f->last_pos[ddir]);
        z = get_zone(f, zone_idx);

        /*
         * When the zone capacity is smaller than the zone size and the I/O is
         * sequential write, skip to zone end if the latest position is at the
         * zone capacity limit.
         */
        if (z->capacity < f->zbd_info->zone_size && !td_random(td) &&
            ddir == DDIR_WRITE &&
            f->last_pos[ddir] >= zbd_zone_capacity_end(z)) {
                dprint(FD_ZBD,
                       "%s: Jump from zone capacity limit to zone end:"
                       " (%llu -> %llu) for zone %u (%llu)\n",
                       f->file_name, (unsigned long long) f->last_pos[ddir],
                       (unsigned long long) zbd_zone_end(z), zone_idx,
                       (unsigned long long) z->capacity);
                td->io_skip_bytes += zbd_zone_end(z) - f->last_pos[ddir];
                f->last_pos[ddir] = zbd_zone_end(z);
        }

        /*
         * zone_skip is valid only for sequential workloads.
         */
        if (td_random(td) || !td->o.zone_skip)
                return;

        /*
         * It is time to switch to a new zone if:
         * - zone_bytes == zone_size bytes have already been accessed
         * - The last position reached the end of the current zone.
         * - For reads with td->o.read_beyond_wp == false, the last position
         *   reached the zone write pointer.
         */
        if (td->zone_bytes >= td->o.zone_size ||
            f->last_pos[ddir] >= zbd_zone_end(z) ||
            (ddir == DDIR_READ &&
             (!td->o.read_beyond_wp) && f->last_pos[ddir] >= z->wp)) {
                /*
                 * Skip zones.
                 */
                td->zone_bytes = 0;
                f->file_offset += td->o.zone_size + td->o.zone_skip;

                /*
                 * Wrap from the beginning, if we exceed the file size
                 */
                if (f->file_offset >= f->real_file_size)
                        f->file_offset = get_start_offset(td, f);

                f->last_pos[ddir] = f->file_offset;
                td->io_skip_bytes += td->o.zone_skip;
        }
}

/**
 * zbd_adjust_ddir - Adjust an I/O direction for zonemode=zbd.
 *
 * @td: FIO thread data.
 * @io_u: FIO I/O unit.
 * @ddir: I/O direction before adjustment.
 *
 * Return adjusted I/O direction.
 */
enum fio_ddir zbd_adjust_ddir(struct thread_data *td, struct io_u *io_u,
                              enum fio_ddir ddir)
{
        /*
         * In case read direction is chosen for the first random I/O, fio with
         * zonemode=zbd stops because no data can be read from zoned block
         * devices with all empty zones. Overwrite the first I/O direction as
         * write to make sure data to read exists.
         */
        if (ddir != DDIR_READ || !td_rw(td))
                return ddir;

        if (io_u->file->zbd_info->sectors_with_data ||
            td->o.read_beyond_wp)
                return DDIR_READ;

        return DDIR_WRITE;
}

/**
 * zbd_adjust_block - adjust the offset and length as necessary for ZBD drives
 * @td: FIO thread data.
 * @io_u: FIO I/O unit.
 *
 * Locking strategy: returns with z->mutex locked if and only if z refers
 * to a sequential zone and if io_u_accept is returned. z is the zone that
 * corresponds to io_u->offset at the end of this function.
 */
enum io_u_action zbd_adjust_block(struct thread_data *td, struct io_u *io_u)
{
        struct fio_file *f = io_u->file;
        uint32_t zone_idx_b;
        struct fio_zone_info *zb, *zl, *orig_zb;
        uint32_t orig_len = io_u->buflen;
        uint32_t min_bs = td->o.min_bs[io_u->ddir];
        uint64_t new_len;
        int64_t range;

        if (!f->zbd_info)
                return io_u_accept;

        assert(min_bs);
        assert(is_valid_offset(f, io_u->offset));
        assert(io_u->buflen);
        zone_idx_b = zbd_zone_idx(f, io_u->offset);
        zb = get_zone(f, zone_idx_b);
        orig_zb = zb;

        if (!zb->has_wp) {
                /* Accept non-write I/Os for conventional zones. */
                if (io_u->ddir != DDIR_WRITE)
                        return io_u_accept;
                /*
                 * Make sure that writes to conventional zones
                 * don't cross over to any sequential zones.
                 */
                if (!(zb + 1)->has_wp ||
                    io_u->offset + io_u->buflen <= (zb + 1)->start)
                        return io_u_accept;

                if (io_u->offset + min_bs > (zb + 1)->start) {
                        dprint(FD_IO,
                               "%s: off=%llu + min_bs=%u > next zone %llu\n",
                               f->file_name, io_u->offset,
                               min_bs, (unsigned long long) (zb + 1)->start);
                        io_u->offset = zb->start + (zb + 1)->start - io_u->offset;
                        new_len = min(io_u->buflen, (zb + 1)->start - io_u->offset);
                } else {
                        new_len = (zb + 1)->start - io_u->offset;
                }
                io_u->buflen = new_len / min_bs * min_bs;
                return io_u_accept;
        }

        /*
         * Accept the I/O offset for reads if reading beyond the write pointer
         * is enabled.
         */
        if (zb->cond != ZBD_ZONE_COND_OFFLINE &&
            io_u->ddir == DDIR_READ && td->o.read_beyond_wp)
                return io_u_accept;

        zbd_check_swd(td, f);

        zone_lock(td, f, zb);

        switch (io_u->ddir) {
        case DDIR_READ:
                if (td->runstate == TD_VERIFYING && td_write(td)) {
                        zb = zbd_replay_write_order(td, io_u, zb);
                        goto accept;
                }
                /*
                 * Check that there is enough written data in the zone to do an
                 * I/O of at least min_bs B. If there isn't, find a new zone for
                 * the I/O.
                 */
                range = zb->cond != ZBD_ZONE_COND_OFFLINE ?
                        zb->wp - zb->start : 0;
                if (range < min_bs ||
                    ((!td_random(td)) && (io_u->offset + min_bs > zb->wp))) {
                        zone_unlock(zb);
                        zl = get_zone(f, f->max_zone);
                        zb = zbd_find_zone(td, io_u, zb, zl);
                        if (!zb) {
                                dprint(FD_ZBD,
                                       "%s: zbd_find_zone(%lld, %llu) failed\n",
                                       f->file_name, io_u->offset,
                                       io_u->buflen);
                                goto eof;
                        }
                        /*
                         * zbd_find_zone() returned a zone with a range of at
                         * least min_bs.
                         */
                        range = zb->wp - zb->start;
                        assert(range >= min_bs);

                        if (!td_random(td))
                                io_u->offset = zb->start;
                }
                /*
                 * Make sure the I/O is within the zone valid data range while
                 * maximizing the I/O size and preserving randomness.
                 */
                if (range <= io_u->buflen)
                        io_u->offset = zb->start;
                else if (td_random(td))
                        io_u->offset = zb->start +
                                ((io_u->offset - orig_zb->start) %
                                 (range - io_u->buflen)) / min_bs * min_bs;
                /*
                 * When zbd_find_zone() returns a conventional zone,
                 * we can simply accept the new i/o offset here.
                 */
                if (!zb->has_wp)
                        return io_u_accept;
                /*
                 * Make sure the I/O does not cross over the zone wp position.
                 */
                new_len = min((unsigned long long)io_u->buflen,
                              (unsigned long long)(zb->wp - io_u->offset));
                new_len = new_len / min_bs * min_bs;
                if (new_len < io_u->buflen) {
                        io_u->buflen = new_len;
                        dprint(FD_IO, "Changed length from %u into %llu\n",
                               orig_len, io_u->buflen);
                }
                assert(zb->start <= io_u->offset);
                assert(io_u->offset + io_u->buflen <= zb->wp);
                goto accept;
        case DDIR_WRITE:
                if (io_u->buflen > f->zbd_info->zone_size) {
                        td_verror(td, EINVAL, "I/O buflen exceeds zone size");
                        dprint(FD_IO,
                               "%s: I/O buflen %llu exceeds zone size %llu\n",
                               f->file_name, io_u->buflen,
                               (unsigned long long) f->zbd_info->zone_size);
                        goto eof;
                }
                if (!zbd_open_zone(td, f, zone_idx_b)) {
                        zone_unlock(zb);
                        zb = zbd_convert_to_open_zone(td, io_u);
                        if (!zb) {
                                dprint(FD_IO, "%s: can't convert to open zone",
                                       f->file_name);
                                goto eof;
                        }
                        zone_idx_b = zbd_zone_nr(f, zb);
                }
                /* Check whether the zone reset threshold has been exceeded */
                if (td->o.zrf.u.f) {
                        if (f->zbd_info->wp_sectors_with_data >=
                            f->io_size * td->o.zrt.u.f &&
                            zbd_dec_and_reset_write_cnt(td, f)) {
                                zb->reset_zone = 1;
                        }
                }
                /* Reset the zone pointer if necessary */
                if (zb->reset_zone || zbd_zone_full(f, zb, min_bs)) {
                        assert(td->o.verify == VERIFY_NONE);
                        /*
                         * Since previous write requests may have been submitted
                         * asynchronously and since we will submit the zone
                         * reset synchronously, wait until previously submitted
                         * write requests have completed before issuing a
                         * zone reset.
                         */
                        io_u_quiesce(td);
                        zb->reset_zone = 0;
                        if (zbd_reset_zone(td, f, zb) < 0)
                                goto eof;

                        if (zb->capacity < min_bs) {
                                td_verror(td, EINVAL, "ZCAP is less min_bs");
                                log_err("zone capacity %llu smaller than minimum block size %d\n",
                                        (unsigned long long)zb->capacity,
                                        min_bs);
                                goto eof;
                        }
                }
                /* Make writes occur at the write pointer */
                assert(!zbd_zone_full(f, zb, min_bs));
                io_u->offset = zb->wp;
                if (!is_valid_offset(f, io_u->offset)) {
                        td_verror(td, EINVAL, "invalid WP value");
                        dprint(FD_ZBD, "%s: dropped request with offset %llu\n",
                               f->file_name, io_u->offset);
                        goto eof;
                }
                /*
                 * Make sure that the buflen is a multiple of the minimal
                 * block size. Give up if shrinking would make the request too
                 * small.
                 */
                new_len = min((unsigned long long)io_u->buflen,
                              zbd_zone_capacity_end(zb) - io_u->offset);
                new_len = new_len / min_bs * min_bs;
                if (new_len == io_u->buflen)
                        goto accept;
                if (new_len >= min_bs) {
                        io_u->buflen = new_len;
                        dprint(FD_IO, "Changed length from %u into %llu\n",
                               orig_len, io_u->buflen);
                        goto accept;
                }
                td_verror(td, EIO, "zone remainder too small");
                log_err("zone remainder %lld smaller than min block size %d\n",
                        (zbd_zone_capacity_end(zb) - io_u->offset), min_bs);
                goto eof;
        case DDIR_TRIM:
                /* fall-through */
        case DDIR_SYNC:
        case DDIR_DATASYNC:
        case DDIR_SYNC_FILE_RANGE:
        case DDIR_WAIT:
        case DDIR_LAST:
        case DDIR_INVAL:
                goto accept;
        }

        assert(false);

accept:
        assert(zb->has_wp);
        assert(zb->cond != ZBD_ZONE_COND_OFFLINE);
        assert(!io_u->zbd_queue_io);
        assert(!io_u->zbd_put_io);
        io_u->zbd_queue_io = zbd_queue_io;
        io_u->zbd_put_io = zbd_put_io;
        /*
         * Since we return with the zone lock still held,
         * add an annotation to let Coverity know that it
         * is intentional.
         */
        /* coverity[missing_unlock] */
        return io_u_accept;

eof:
        if (zb && zb->has_wp)
                zone_unlock(zb);
        return io_u_eof;
}

/* Return a string with ZBD statistics */
char *zbd_write_status(const struct thread_stat *ts)
{
        char *res;

        if (asprintf(&res, "; %llu zone resets", (unsigned long long) ts->nr_zone_resets) < 0)
                return NULL;
        return res;
}