| // SPDX-License-Identifier: GPL-2.0 |
| #include <linux/vmalloc.h> |
| #include <linux/bitmap.h> |
| #include "null_blk.h" |
| |
| #define CREATE_TRACE_POINTS |
| #include "trace.h" |
| |
| #undef pr_fmt |
| #define pr_fmt(fmt) "null_blk: " fmt |
| |
| static inline sector_t mb_to_sects(unsigned long mb) |
| { |
| return ((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); |
| } |
| |
| static inline void null_lock_zone_res(struct nullb_device *dev) |
| { |
| if (dev->need_zone_res_mgmt) |
| spin_lock_irq(&dev->zone_res_lock); |
| } |
| |
| static inline void null_unlock_zone_res(struct nullb_device *dev) |
| { |
| if (dev->need_zone_res_mgmt) |
| spin_unlock_irq(&dev->zone_res_lock); |
| } |
| |
| static inline void null_init_zone_lock(struct nullb_device *dev, |
| struct nullb_zone *zone) |
| { |
| if (!dev->memory_backed) |
| spin_lock_init(&zone->spinlock); |
| else |
| mutex_init(&zone->mutex); |
| } |
| |
| static inline void null_lock_zone(struct nullb_device *dev, |
| struct nullb_zone *zone) |
| { |
| if (!dev->memory_backed) |
| spin_lock_irq(&zone->spinlock); |
| else |
| mutex_lock(&zone->mutex); |
| } |
| |
| static inline void null_unlock_zone(struct nullb_device *dev, |
| struct nullb_zone *zone) |
| { |
| if (!dev->memory_backed) |
| spin_unlock_irq(&zone->spinlock); |
| else |
| mutex_unlock(&zone->mutex); |
| } |
| |
| int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q) |
| { |
| sector_t dev_capacity_sects, zone_capacity_sects; |
| struct nullb_zone *zone; |
| 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("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 = round_up(dev_capacity_sects, dev->zone_size_sects) |
| >> ilog2(dev->zone_size_sects); |
| |
| dev->zones = kvmalloc_array(dev->nr_zones, sizeof(struct nullb_zone), |
| GFP_KERNEL | __GFP_ZERO); |
| if (!dev->zones) |
| return -ENOMEM; |
| |
| spin_lock_init(&dev->zone_res_lock); |
| |
| 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"); |
| } |
| dev->need_zone_res_mgmt = dev->zone_max_active || dev->zone_max_open; |
| dev->imp_close_zone_no = dev->zone_nr_conv; |
| |
| for (i = 0; i < dev->zone_nr_conv; i++) { |
| zone = &dev->zones[i]; |
| |
| null_init_zone_lock(dev, zone); |
| 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++) { |
| zone = &dev->zones[i]; |
| |
| null_init_zone_lock(dev, zone); |
| 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; |
| } |
| |
| return 0; |
| } |
| |
| int null_register_zoned_dev(struct nullb *nullb) |
| { |
| struct nullb_device *dev = nullb->dev; |
| struct request_queue *q = nullb->q; |
| |
| disk_set_zoned(nullb->disk, BLK_ZONED_HM); |
| blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q); |
| blk_queue_required_elevator_features(q, ELEVATOR_F_ZBD_SEQ_WRITE); |
| |
| 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); |
| nullb->disk->nr_zones = bdev_nr_zones(nullb->disk->part0); |
| } |
| |
| blk_queue_max_zone_append_sectors(q, dev->zone_size_sects); |
| disk_set_max_open_zones(nullb->disk, dev->zone_max_open); |
| disk_set_max_active_zones(nullb->disk, dev->zone_max_active); |
| |
| return 0; |
| } |
| |
| void null_free_zoned_dev(struct nullb_device *dev) |
| { |
| kvfree(dev->zones); |
| dev->zones = NULL; |
| } |
| |
| 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; |
| struct nullb_zone *zone; |
| struct blk_zone blkz; |
| 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); |
| |
| memset(&blkz, 0, sizeof(struct blk_zone)); |
| zone = &dev->zones[first_zone]; |
| for (i = 0; i < nr_zones; i++, zone++) { |
| /* |
| * 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, zone); |
| blkz.start = zone->start; |
| blkz.len = zone->len; |
| blkz.wp = zone->wp; |
| blkz.type = zone->type; |
| blkz.cond = zone->cond; |
| blkz.capacity = zone->capacity; |
| null_unlock_zone(dev, zone); |
| |
| error = cb(&blkz, 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 nullb_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 nullb_zone *zone) |
| { |
| 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_imp_open_zone(struct nullb_device *dev) |
| { |
| struct nullb_zone *zone; |
| unsigned int zno, i; |
| |
| zno = dev->imp_close_zone_no; |
| if (zno >= dev->nr_zones) |
| zno = dev->zone_nr_conv; |
| |
| for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) { |
| zone = &dev->zones[zno]; |
| zno++; |
| if (zno >= dev->nr_zones) |
| zno = dev->zone_nr_conv; |
| |
| if (zone->cond == BLK_ZONE_COND_IMP_OPEN) { |
| __null_close_zone(dev, zone); |
| dev->imp_close_zone_no = zno; |
| 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_imp_open_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 nullb_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 nullb_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, zone); |
| |
| if (zone->cond == BLK_ZONE_COND_FULL) { |
| /* Cannot write to a full zone */ |
| 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 (dev->queue_mode == NULL_Q_MQ) |
| cmd->rq->__sector = sector; |
| else |
| cmd->bio->bi_iter.bi_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 || |
| zone->cond == BLK_ZONE_COND_EMPTY) { |
| null_lock_zone_res(dev); |
| |
| ret = null_check_zone_resources(dev, zone); |
| if (ret != BLK_STS_OK) { |
| null_unlock_zone_res(dev); |
| 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; |
| |
| null_unlock_zone_res(dev); |
| } |
| |
| ret = null_process_cmd(cmd, REQ_OP_WRITE, sector, nr_sectors); |
| if (ret != BLK_STS_OK) |
| goto unlock; |
| |
| zone->wp += nr_sectors; |
| if (zone->wp == zone->start + zone->capacity) { |
| null_lock_zone_res(dev); |
| 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; |
| null_unlock_zone_res(dev); |
| } |
| |
| ret = BLK_STS_OK; |
| |
| unlock: |
| null_unlock_zone(dev, zone); |
| |
| return ret; |
| } |
| |
| static blk_status_t null_open_zone(struct nullb_device *dev, |
| struct nullb_zone *zone) |
| { |
| blk_status_t ret = BLK_STS_OK; |
| |
| if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) |
| return BLK_STS_IOERR; |
| |
| null_lock_zone_res(dev); |
| |
| switch (zone->cond) { |
| case BLK_ZONE_COND_EXP_OPEN: |
| /* open operation on exp open is not an error */ |
| goto unlock; |
| case BLK_ZONE_COND_EMPTY: |
| ret = null_check_zone_resources(dev, zone); |
| if (ret != BLK_STS_OK) |
| goto unlock; |
| 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) |
| goto unlock; |
| dev->nr_zones_closed--; |
| break; |
| case BLK_ZONE_COND_FULL: |
| default: |
| ret = BLK_STS_IOERR; |
| goto unlock; |
| } |
| |
| zone->cond = BLK_ZONE_COND_EXP_OPEN; |
| dev->nr_zones_exp_open++; |
| |
| unlock: |
| null_unlock_zone_res(dev); |
| |
| return ret; |
| } |
| |
| static blk_status_t null_close_zone(struct nullb_device *dev, |
| struct nullb_zone *zone) |
| { |
| blk_status_t ret; |
| |
| if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) |
| return BLK_STS_IOERR; |
| |
| null_lock_zone_res(dev); |
| ret = __null_close_zone(dev, zone); |
| null_unlock_zone_res(dev); |
| |
| return ret; |
| } |
| |
| static blk_status_t null_finish_zone(struct nullb_device *dev, |
| struct nullb_zone *zone) |
| { |
| blk_status_t ret = BLK_STS_OK; |
| |
| if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) |
| return BLK_STS_IOERR; |
| |
| null_lock_zone_res(dev); |
| |
| switch (zone->cond) { |
| case BLK_ZONE_COND_FULL: |
| /* finish operation on full is not an error */ |
| goto unlock; |
| case BLK_ZONE_COND_EMPTY: |
| ret = null_check_zone_resources(dev, zone); |
| if (ret != BLK_STS_OK) |
| goto unlock; |
| 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) |
| goto unlock; |
| dev->nr_zones_closed--; |
| break; |
| default: |
| ret = BLK_STS_IOERR; |
| goto unlock; |
| } |
| |
| zone->cond = BLK_ZONE_COND_FULL; |
| zone->wp = zone->start + zone->len; |
| |
| unlock: |
| null_unlock_zone_res(dev); |
| |
| return ret; |
| } |
| |
| static blk_status_t null_reset_zone(struct nullb_device *dev, |
| struct nullb_zone *zone) |
| { |
| if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) |
| return BLK_STS_IOERR; |
| |
| null_lock_zone_res(dev); |
| |
| switch (zone->cond) { |
| case BLK_ZONE_COND_EMPTY: |
| /* reset operation on empty is not an error */ |
| null_unlock_zone_res(dev); |
| 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: |
| null_unlock_zone_res(dev); |
| return BLK_STS_IOERR; |
| } |
| |
| zone->cond = BLK_ZONE_COND_EMPTY; |
| zone->wp = zone->start; |
| |
| null_unlock_zone_res(dev); |
| |
| if (dev->memory_backed) |
| return null_handle_discard(dev, zone->start, zone->len); |
| |
| return BLK_STS_OK; |
| } |
| |
| static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_op op, |
| sector_t sector) |
| { |
| struct nullb_device *dev = cmd->nq->dev; |
| unsigned int zone_no; |
| struct nullb_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++) { |
| zone = &dev->zones[i]; |
| null_lock_zone(dev, zone); |
| if (zone->cond != BLK_ZONE_COND_EMPTY) { |
| null_reset_zone(dev, zone); |
| trace_nullb_zone_op(cmd, i, zone->cond); |
| } |
| null_unlock_zone(dev, zone); |
| } |
| return BLK_STS_OK; |
| } |
| |
| zone_no = null_zone_no(dev, sector); |
| zone = &dev->zones[zone_no]; |
| |
| null_lock_zone(dev, zone); |
| |
| 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); |
| |
| return ret; |
| } |
| |
| blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd, enum req_op op, |
| sector_t sector, sector_t nr_sectors) |
| { |
| struct nullb_device *dev; |
| struct nullb_zone *zone; |
| blk_status_t sts; |
| |
| switch (op) { |
| case REQ_OP_WRITE: |
| return null_zone_write(cmd, sector, nr_sectors, false); |
| case REQ_OP_ZONE_APPEND: |
| return null_zone_write(cmd, sector, nr_sectors, true); |
| 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: |
| return null_zone_mgmt(cmd, op, sector); |
| default: |
| dev = cmd->nq->dev; |
| zone = &dev->zones[null_zone_no(dev, sector)]; |
| |
| null_lock_zone(dev, zone); |
| sts = null_process_cmd(cmd, op, sector, nr_sectors); |
| null_unlock_zone(dev, zone); |
| return sts; |
| } |
| } |