diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/block/null_blk/zoned.c | 617 |
1 files changed, 617 insertions, 0 deletions
diff --git a/drivers/block/null_blk/zoned.c b/drivers/block/null_blk/zoned.c new file mode 100644 index 000000000..41220ce59 --- /dev/null +++ b/drivers/block/null_blk/zoned.c @@ -0,0 +1,617 @@ +// 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" + +#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; +} |