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- // SPDX-License-Identifier: GPL-2.0
- #include <linux/vmalloc.h>
- #include <linux/bitmap.h>
- #include "null_blk.h"
- #define CREATE_TRACE_POINTS
- #include "null_blk_trace.h"
- #define MB_TO_SECTS(mb) (((sector_t)mb * SZ_1M) >> SECTOR_SHIFT)
- static inline unsigned int null_zone_no(struct nullb_device *dev, sector_t sect)
- {
- return sect >> ilog2(dev->zone_size_sects);
- }
- int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q)
- {
- sector_t dev_capacity_sects, zone_capacity_sects;
- sector_t sector = 0;
- unsigned int i;
- if (!is_power_of_2(dev->zone_size)) {
- pr_err("zone_size must be power-of-two\n");
- return -EINVAL;
- }
- if (dev->zone_size > dev->size) {
- pr_err("Zone size larger than device capacity\n");
- return -EINVAL;
- }
- if (!dev->zone_capacity)
- dev->zone_capacity = dev->zone_size;
- if (dev->zone_capacity > dev->zone_size) {
- pr_err("null_blk: zone capacity (%lu MB) larger than zone size (%lu MB)\n",
- dev->zone_capacity, dev->zone_size);
- return -EINVAL;
- }
- zone_capacity_sects = MB_TO_SECTS(dev->zone_capacity);
- dev_capacity_sects = MB_TO_SECTS(dev->size);
- dev->zone_size_sects = MB_TO_SECTS(dev->zone_size);
- dev->nr_zones = dev_capacity_sects >> ilog2(dev->zone_size_sects);
- if (dev_capacity_sects & (dev->zone_size_sects - 1))
- dev->nr_zones++;
- dev->zones = kvmalloc_array(dev->nr_zones, sizeof(struct blk_zone),
- GFP_KERNEL | __GFP_ZERO);
- if (!dev->zones)
- return -ENOMEM;
- /*
- * With memory backing, the zone_lock spinlock needs to be temporarily
- * released to avoid scheduling in atomic context. To guarantee zone
- * information protection, use a bitmap to lock zones with
- * wait_on_bit_lock_io(). Sleeping on the lock is OK as memory backing
- * implies that the queue is marked with BLK_MQ_F_BLOCKING.
- */
- spin_lock_init(&dev->zone_lock);
- if (dev->memory_backed) {
- dev->zone_locks = bitmap_zalloc(dev->nr_zones, GFP_KERNEL);
- if (!dev->zone_locks) {
- kvfree(dev->zones);
- return -ENOMEM;
- }
- }
- if (dev->zone_nr_conv >= dev->nr_zones) {
- dev->zone_nr_conv = dev->nr_zones - 1;
- pr_info("changed the number of conventional zones to %u",
- dev->zone_nr_conv);
- }
- /* Max active zones has to be < nbr of seq zones in order to be enforceable */
- if (dev->zone_max_active >= dev->nr_zones - dev->zone_nr_conv) {
- dev->zone_max_active = 0;
- pr_info("zone_max_active limit disabled, limit >= zone count\n");
- }
- /* Max open zones has to be <= max active zones */
- if (dev->zone_max_active && dev->zone_max_open > dev->zone_max_active) {
- dev->zone_max_open = dev->zone_max_active;
- pr_info("changed the maximum number of open zones to %u\n",
- dev->nr_zones);
- } else if (dev->zone_max_open >= dev->nr_zones - dev->zone_nr_conv) {
- dev->zone_max_open = 0;
- pr_info("zone_max_open limit disabled, limit >= zone count\n");
- }
- for (i = 0; i < dev->zone_nr_conv; i++) {
- struct blk_zone *zone = &dev->zones[i];
- zone->start = sector;
- zone->len = dev->zone_size_sects;
- zone->capacity = zone->len;
- zone->wp = zone->start + zone->len;
- zone->type = BLK_ZONE_TYPE_CONVENTIONAL;
- zone->cond = BLK_ZONE_COND_NOT_WP;
- sector += dev->zone_size_sects;
- }
- for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
- struct blk_zone *zone = &dev->zones[i];
- zone->start = zone->wp = sector;
- if (zone->start + dev->zone_size_sects > dev_capacity_sects)
- zone->len = dev_capacity_sects - zone->start;
- else
- zone->len = dev->zone_size_sects;
- zone->capacity =
- min_t(sector_t, zone->len, zone_capacity_sects);
- zone->type = BLK_ZONE_TYPE_SEQWRITE_REQ;
- zone->cond = BLK_ZONE_COND_EMPTY;
- sector += dev->zone_size_sects;
- }
- q->limits.zoned = BLK_ZONED_HM;
- blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q);
- blk_queue_required_elevator_features(q, ELEVATOR_F_ZBD_SEQ_WRITE);
- return 0;
- }
- int null_register_zoned_dev(struct nullb *nullb)
- {
- struct nullb_device *dev = nullb->dev;
- struct request_queue *q = nullb->q;
- if (queue_is_mq(q)) {
- int ret = blk_revalidate_disk_zones(nullb->disk, NULL);
- if (ret)
- return ret;
- } else {
- blk_queue_chunk_sectors(q, dev->zone_size_sects);
- q->nr_zones = blkdev_nr_zones(nullb->disk);
- }
- blk_queue_max_zone_append_sectors(q, dev->zone_size_sects);
- blk_queue_max_open_zones(q, dev->zone_max_open);
- blk_queue_max_active_zones(q, dev->zone_max_active);
- return 0;
- }
- void null_free_zoned_dev(struct nullb_device *dev)
- {
- bitmap_free(dev->zone_locks);
- kvfree(dev->zones);
- dev->zones = NULL;
- }
- static inline void null_lock_zone(struct nullb_device *dev, unsigned int zno)
- {
- if (dev->memory_backed)
- wait_on_bit_lock_io(dev->zone_locks, zno, TASK_UNINTERRUPTIBLE);
- spin_lock_irq(&dev->zone_lock);
- }
- static inline void null_unlock_zone(struct nullb_device *dev, unsigned int zno)
- {
- spin_unlock_irq(&dev->zone_lock);
- if (dev->memory_backed)
- clear_and_wake_up_bit(zno, dev->zone_locks);
- }
- int null_report_zones(struct gendisk *disk, sector_t sector,
- unsigned int nr_zones, report_zones_cb cb, void *data)
- {
- struct nullb *nullb = disk->private_data;
- struct nullb_device *dev = nullb->dev;
- unsigned int first_zone, i, zno;
- struct blk_zone zone;
- int error;
- first_zone = null_zone_no(dev, sector);
- if (first_zone >= dev->nr_zones)
- return 0;
- nr_zones = min(nr_zones, dev->nr_zones - first_zone);
- trace_nullb_report_zones(nullb, nr_zones);
- zno = first_zone;
- for (i = 0; i < nr_zones; i++, zno++) {
- /*
- * Stacked DM target drivers will remap the zone information by
- * modifying the zone information passed to the report callback.
- * So use a local copy to avoid corruption of the device zone
- * array.
- */
- null_lock_zone(dev, zno);
- memcpy(&zone, &dev->zones[zno], sizeof(struct blk_zone));
- null_unlock_zone(dev, zno);
- error = cb(&zone, i, data);
- if (error)
- return error;
- }
- return nr_zones;
- }
- /*
- * This is called in the case of memory backing from null_process_cmd()
- * with the target zone already locked.
- */
- size_t null_zone_valid_read_len(struct nullb *nullb,
- sector_t sector, unsigned int len)
- {
- struct nullb_device *dev = nullb->dev;
- struct blk_zone *zone = &dev->zones[null_zone_no(dev, sector)];
- unsigned int nr_sectors = len >> SECTOR_SHIFT;
- /* Read must be below the write pointer position */
- if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL ||
- sector + nr_sectors <= zone->wp)
- return len;
- if (sector > zone->wp)
- return 0;
- return (zone->wp - sector) << SECTOR_SHIFT;
- }
- static blk_status_t null_close_zone(struct nullb_device *dev, struct blk_zone *zone)
- {
- if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
- return BLK_STS_IOERR;
- switch (zone->cond) {
- case BLK_ZONE_COND_CLOSED:
- /* close operation on closed is not an error */
- return BLK_STS_OK;
- case BLK_ZONE_COND_IMP_OPEN:
- dev->nr_zones_imp_open--;
- break;
- case BLK_ZONE_COND_EXP_OPEN:
- dev->nr_zones_exp_open--;
- break;
- case BLK_ZONE_COND_EMPTY:
- case BLK_ZONE_COND_FULL:
- default:
- return BLK_STS_IOERR;
- }
- if (zone->wp == zone->start) {
- zone->cond = BLK_ZONE_COND_EMPTY;
- } else {
- zone->cond = BLK_ZONE_COND_CLOSED;
- dev->nr_zones_closed++;
- }
- return BLK_STS_OK;
- }
- static void null_close_first_imp_zone(struct nullb_device *dev)
- {
- unsigned int i;
- for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
- if (dev->zones[i].cond == BLK_ZONE_COND_IMP_OPEN) {
- null_close_zone(dev, &dev->zones[i]);
- return;
- }
- }
- }
- static blk_status_t null_check_active(struct nullb_device *dev)
- {
- if (!dev->zone_max_active)
- return BLK_STS_OK;
- if (dev->nr_zones_exp_open + dev->nr_zones_imp_open +
- dev->nr_zones_closed < dev->zone_max_active)
- return BLK_STS_OK;
- return BLK_STS_ZONE_ACTIVE_RESOURCE;
- }
- static blk_status_t null_check_open(struct nullb_device *dev)
- {
- if (!dev->zone_max_open)
- return BLK_STS_OK;
- if (dev->nr_zones_exp_open + dev->nr_zones_imp_open < dev->zone_max_open)
- return BLK_STS_OK;
- if (dev->nr_zones_imp_open) {
- if (null_check_active(dev) == BLK_STS_OK) {
- null_close_first_imp_zone(dev);
- return BLK_STS_OK;
- }
- }
- return BLK_STS_ZONE_OPEN_RESOURCE;
- }
- /*
- * This function matches the manage open zone resources function in the ZBC standard,
- * with the addition of max active zones support (added in the ZNS standard).
- *
- * The function determines if a zone can transition to implicit open or explicit open,
- * while maintaining the max open zone (and max active zone) limit(s). It may close an
- * implicit open zone in order to make additional zone resources available.
- *
- * ZBC states that an implicit open zone shall be closed only if there is not
- * room within the open limit. However, with the addition of an active limit,
- * it is not certain that closing an implicit open zone will allow a new zone
- * to be opened, since we might already be at the active limit capacity.
- */
- static blk_status_t null_check_zone_resources(struct nullb_device *dev, struct blk_zone *zone)
- {
- blk_status_t ret;
- switch (zone->cond) {
- case BLK_ZONE_COND_EMPTY:
- ret = null_check_active(dev);
- if (ret != BLK_STS_OK)
- return ret;
- fallthrough;
- case BLK_ZONE_COND_CLOSED:
- return null_check_open(dev);
- default:
- /* Should never be called for other states */
- WARN_ON(1);
- return BLK_STS_IOERR;
- }
- }
- static blk_status_t null_zone_write(struct nullb_cmd *cmd, sector_t sector,
- unsigned int nr_sectors, bool append)
- {
- struct nullb_device *dev = cmd->nq->dev;
- unsigned int zno = null_zone_no(dev, sector);
- struct blk_zone *zone = &dev->zones[zno];
- blk_status_t ret;
- trace_nullb_zone_op(cmd, zno, zone->cond);
- if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) {
- if (append)
- return BLK_STS_IOERR;
- return null_process_cmd(cmd, REQ_OP_WRITE, sector, nr_sectors);
- }
- null_lock_zone(dev, zno);
- switch (zone->cond) {
- case BLK_ZONE_COND_FULL:
- /* Cannot write to a full zone */
- ret = BLK_STS_IOERR;
- goto unlock;
- case BLK_ZONE_COND_EMPTY:
- case BLK_ZONE_COND_CLOSED:
- ret = null_check_zone_resources(dev, zone);
- if (ret != BLK_STS_OK)
- goto unlock;
- break;
- case BLK_ZONE_COND_IMP_OPEN:
- case BLK_ZONE_COND_EXP_OPEN:
- break;
- default:
- /* Invalid zone condition */
- ret = BLK_STS_IOERR;
- goto unlock;
- }
- /*
- * Regular writes must be at the write pointer position.
- * Zone append writes are automatically issued at the write
- * pointer and the position returned using the request or BIO
- * sector.
- */
- if (append) {
- sector = zone->wp;
- if (cmd->bio)
- cmd->bio->bi_iter.bi_sector = sector;
- else
- cmd->rq->__sector = sector;
- } else if (sector != zone->wp) {
- ret = BLK_STS_IOERR;
- goto unlock;
- }
- if (zone->wp + nr_sectors > zone->start + zone->capacity) {
- ret = BLK_STS_IOERR;
- goto unlock;
- }
- if (zone->cond == BLK_ZONE_COND_CLOSED) {
- dev->nr_zones_closed--;
- dev->nr_zones_imp_open++;
- } else if (zone->cond == BLK_ZONE_COND_EMPTY) {
- dev->nr_zones_imp_open++;
- }
- if (zone->cond != BLK_ZONE_COND_EXP_OPEN)
- zone->cond = BLK_ZONE_COND_IMP_OPEN;
- /*
- * Memory backing allocation may sleep: release the zone_lock spinlock
- * to avoid scheduling in atomic context. Zone operation atomicity is
- * still guaranteed through the zone_locks bitmap.
- */
- if (dev->memory_backed)
- spin_unlock_irq(&dev->zone_lock);
- ret = null_process_cmd(cmd, REQ_OP_WRITE, sector, nr_sectors);
- if (dev->memory_backed)
- spin_lock_irq(&dev->zone_lock);
- if (ret != BLK_STS_OK)
- goto unlock;
- zone->wp += nr_sectors;
- if (zone->wp == zone->start + zone->capacity) {
- if (zone->cond == BLK_ZONE_COND_EXP_OPEN)
- dev->nr_zones_exp_open--;
- else if (zone->cond == BLK_ZONE_COND_IMP_OPEN)
- dev->nr_zones_imp_open--;
- zone->cond = BLK_ZONE_COND_FULL;
- }
- ret = BLK_STS_OK;
- unlock:
- null_unlock_zone(dev, zno);
- return ret;
- }
- static blk_status_t null_open_zone(struct nullb_device *dev, struct blk_zone *zone)
- {
- blk_status_t ret;
- if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
- return BLK_STS_IOERR;
- switch (zone->cond) {
- case BLK_ZONE_COND_EXP_OPEN:
- /* open operation on exp open is not an error */
- return BLK_STS_OK;
- case BLK_ZONE_COND_EMPTY:
- ret = null_check_zone_resources(dev, zone);
- if (ret != BLK_STS_OK)
- return ret;
- break;
- case BLK_ZONE_COND_IMP_OPEN:
- dev->nr_zones_imp_open--;
- break;
- case BLK_ZONE_COND_CLOSED:
- ret = null_check_zone_resources(dev, zone);
- if (ret != BLK_STS_OK)
- return ret;
- dev->nr_zones_closed--;
- break;
- case BLK_ZONE_COND_FULL:
- default:
- return BLK_STS_IOERR;
- }
- zone->cond = BLK_ZONE_COND_EXP_OPEN;
- dev->nr_zones_exp_open++;
- return BLK_STS_OK;
- }
- static blk_status_t null_finish_zone(struct nullb_device *dev, struct blk_zone *zone)
- {
- blk_status_t ret;
- if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
- return BLK_STS_IOERR;
- switch (zone->cond) {
- case BLK_ZONE_COND_FULL:
- /* finish operation on full is not an error */
- return BLK_STS_OK;
- case BLK_ZONE_COND_EMPTY:
- ret = null_check_zone_resources(dev, zone);
- if (ret != BLK_STS_OK)
- return ret;
- break;
- case BLK_ZONE_COND_IMP_OPEN:
- dev->nr_zones_imp_open--;
- break;
- case BLK_ZONE_COND_EXP_OPEN:
- dev->nr_zones_exp_open--;
- break;
- case BLK_ZONE_COND_CLOSED:
- ret = null_check_zone_resources(dev, zone);
- if (ret != BLK_STS_OK)
- return ret;
- dev->nr_zones_closed--;
- break;
- default:
- return BLK_STS_IOERR;
- }
- zone->cond = BLK_ZONE_COND_FULL;
- zone->wp = zone->start + zone->len;
- return BLK_STS_OK;
- }
- static blk_status_t null_reset_zone(struct nullb_device *dev, struct blk_zone *zone)
- {
- if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
- return BLK_STS_IOERR;
- switch (zone->cond) {
- case BLK_ZONE_COND_EMPTY:
- /* reset operation on empty is not an error */
- return BLK_STS_OK;
- case BLK_ZONE_COND_IMP_OPEN:
- dev->nr_zones_imp_open--;
- break;
- case BLK_ZONE_COND_EXP_OPEN:
- dev->nr_zones_exp_open--;
- break;
- case BLK_ZONE_COND_CLOSED:
- dev->nr_zones_closed--;
- break;
- case BLK_ZONE_COND_FULL:
- break;
- default:
- return BLK_STS_IOERR;
- }
- zone->cond = BLK_ZONE_COND_EMPTY;
- zone->wp = zone->start;
- return BLK_STS_OK;
- }
- static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_opf op,
- sector_t sector)
- {
- struct nullb_device *dev = cmd->nq->dev;
- unsigned int zone_no;
- struct blk_zone *zone;
- blk_status_t ret;
- size_t i;
- if (op == REQ_OP_ZONE_RESET_ALL) {
- for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
- null_lock_zone(dev, i);
- zone = &dev->zones[i];
- if (zone->cond != BLK_ZONE_COND_EMPTY) {
- null_reset_zone(dev, zone);
- trace_nullb_zone_op(cmd, i, zone->cond);
- }
- null_unlock_zone(dev, i);
- }
- return BLK_STS_OK;
- }
- zone_no = null_zone_no(dev, sector);
- zone = &dev->zones[zone_no];
- null_lock_zone(dev, zone_no);
- switch (op) {
- case REQ_OP_ZONE_RESET:
- ret = null_reset_zone(dev, zone);
- break;
- case REQ_OP_ZONE_OPEN:
- ret = null_open_zone(dev, zone);
- break;
- case REQ_OP_ZONE_CLOSE:
- ret = null_close_zone(dev, zone);
- break;
- case REQ_OP_ZONE_FINISH:
- ret = null_finish_zone(dev, zone);
- break;
- default:
- ret = BLK_STS_NOTSUPP;
- break;
- }
- if (ret == BLK_STS_OK)
- trace_nullb_zone_op(cmd, zone_no, zone->cond);
- null_unlock_zone(dev, zone_no);
- return ret;
- }
- blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd, enum req_opf op,
- sector_t sector, sector_t nr_sectors)
- {
- struct nullb_device *dev = cmd->nq->dev;
- unsigned int zno = null_zone_no(dev, sector);
- blk_status_t sts;
- switch (op) {
- case REQ_OP_WRITE:
- sts = null_zone_write(cmd, sector, nr_sectors, false);
- break;
- case REQ_OP_ZONE_APPEND:
- sts = null_zone_write(cmd, sector, nr_sectors, true);
- break;
- case REQ_OP_ZONE_RESET:
- case REQ_OP_ZONE_RESET_ALL:
- case REQ_OP_ZONE_OPEN:
- case REQ_OP_ZONE_CLOSE:
- case REQ_OP_ZONE_FINISH:
- sts = null_zone_mgmt(cmd, op, sector);
- break;
- default:
- null_lock_zone(dev, zno);
- sts = null_process_cmd(cmd, op, sector, nr_sectors);
- null_unlock_zone(dev, zno);
- }
- return sts;
- }
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