if (!dev->zones)
return -ENOMEM;
- spin_lock_init(&dev->zone_dev_lock);
- dev->zone_locks = bitmap_zalloc(dev->nr_zones, GFP_KERNEL);
- if (!dev->zone_locks) {
- kvfree(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) {
static inline void null_lock_zone(struct nullb_device *dev, unsigned int zno)
{
- wait_on_bit_lock_io(dev->zone_locks, zno, TASK_UNINTERRUPTIBLE);
+ 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)
{
- clear_and_wake_up_bit(zno, dev->zone_locks);
+ 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,
return null_process_cmd(cmd, REQ_OP_WRITE, sector, nr_sectors);
null_lock_zone(dev, zno);
- spin_lock(&dev->zone_dev_lock);
switch (zone->cond) {
case BLK_ZONE_COND_FULL:
if (zone->cond != BLK_ZONE_COND_EXP_OPEN)
zone->cond = BLK_ZONE_COND_IMP_OPEN;
- spin_unlock(&dev->zone_dev_lock);
+ /*
+ * 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);
- spin_lock(&dev->zone_dev_lock);
+ if (dev->memory_backed)
+ spin_lock_irq(&dev->zone_lock);
+
if (ret != BLK_STS_OK)
goto unlock;
ret = BLK_STS_OK;
unlock:
- spin_unlock(&dev->zone_dev_lock);
null_unlock_zone(dev, zno);
return ret;
null_lock_zone(dev, i);
zone = &dev->zones[i];
if (zone->cond != BLK_ZONE_COND_EMPTY) {
- spin_lock(&dev->zone_dev_lock);
null_reset_zone(dev, zone);
- spin_unlock(&dev->zone_dev_lock);
trace_nullb_zone_op(cmd, i, zone->cond);
}
null_unlock_zone(dev, i);
zone = &dev->zones[zone_no];
null_lock_zone(dev, zone_no);
- spin_lock(&dev->zone_dev_lock);
switch (op) {
case REQ_OP_ZONE_RESET:
break;
}
- spin_unlock(&dev->zone_dev_lock);
-
if (ret == BLK_STS_OK)
trace_nullb_zone_op(cmd, zone_no, zone->cond);