// SPDX-License-Identifier: GPL-2.0
#include <linux/vmalloc.h>
+#include <linux/bitmap.h>
#include "null_blk.h"
#define CREATE_TRACE_POINTS
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];
}
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);
}
+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;
+ unsigned int first_zone, i, zno;
struct blk_zone zone;
int error;
nr_zones = min(nr_zones, dev->nr_zones - first_zone);
trace_nullb_report_zones(nullb, nr_zones);
- for (i = 0; i < nr_zones; i++) {
+ 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.
*/
- memcpy(&zone, &dev->zones[first_zone + i],
- sizeof(struct blk_zone));
+ 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)
{
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)
{
if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
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 */
- return BLK_STS_IOERR;
+ 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:
- /*
- * 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) {
- return BLK_STS_IOERR;
- }
+ 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++;
- if (zone->wp + nr_sectors > zone->start + zone->capacity)
- return BLK_STS_IOERR;
+ return BLK_STS_OK;
+}
- if (zone->cond != BLK_ZONE_COND_EXP_OPEN)
- zone->cond = BLK_ZONE_COND_IMP_OPEN;
+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;
- ret = null_process_cmd(cmd, REQ_OP_WRITE, sector, nr_sectors);
+ 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;
- zone->wp += nr_sectors;
- if (zone->wp == zone->start + zone->capacity)
- zone->cond = BLK_ZONE_COND_FULL;
+ 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:
- /* Invalid zone condition */
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 = null_zone_no(dev, sector);
- struct blk_zone *zone = &dev->zones[zone_no];
+ unsigned int zone_no;
+ struct blk_zone *zone;
+ blk_status_t ret;
size_t i;
- switch (op) {
- case REQ_OP_ZONE_RESET_ALL:
- for (i = 0; i < dev->nr_zones; i++) {
- if (zone[i].type == BLK_ZONE_TYPE_CONVENTIONAL)
- continue;
- zone[i].cond = BLK_ZONE_COND_EMPTY;
- zone[i].wp = zone[i].start;
+ 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);
}
- break;
- case REQ_OP_ZONE_RESET:
- if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
- return BLK_STS_IOERR;
+ return BLK_STS_OK;
+ }
- zone->cond = BLK_ZONE_COND_EMPTY;
- zone->wp = zone->start;
+ 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:
- if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
- return BLK_STS_IOERR;
- if (zone->cond == BLK_ZONE_COND_FULL)
- return BLK_STS_IOERR;
-
- zone->cond = BLK_ZONE_COND_EXP_OPEN;
+ ret = null_open_zone(dev, zone);
break;
case REQ_OP_ZONE_CLOSE:
- if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
- return BLK_STS_IOERR;
- if (zone->cond == BLK_ZONE_COND_FULL)
- return BLK_STS_IOERR;
-
- if (zone->wp == zone->start)
- zone->cond = BLK_ZONE_COND_EMPTY;
- else
- zone->cond = BLK_ZONE_COND_CLOSED;
+ ret = null_close_zone(dev, zone);
break;
case REQ_OP_ZONE_FINISH:
- if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
- return BLK_STS_IOERR;
-
- zone->cond = BLK_ZONE_COND_FULL;
- zone->wp = zone->start + zone->len;
+ ret = null_finish_zone(dev, zone);
break;
default:
- return BLK_STS_NOTSUPP;
+ ret = BLK_STS_NOTSUPP;
+ break;
}
- trace_nullb_zone_op(cmd, zone_no, zone->cond);
- return BLK_STS_OK;
+ 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:
- return null_zone_write(cmd, sector, nr_sectors, false);
+ sts = null_zone_write(cmd, sector, nr_sectors, false);
+ break;
case REQ_OP_ZONE_APPEND:
- return null_zone_write(cmd, sector, nr_sectors, true);
+ 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:
- return null_zone_mgmt(cmd, op, sector);
+ sts = null_zone_mgmt(cmd, op, sector);
+ break;
default:
- return null_process_cmd(cmd, op, sector, nr_sectors);
+ null_lock_zone(dev, zno);
+ sts = null_process_cmd(cmd, op, sector, nr_sectors);
+ null_unlock_zone(dev, zno);
}
+
+ return sts;
}