} \
CONFIGFS_ATTR(nullb_device_, NAME);
-static int nullb_apply_submit_queues(struct nullb_device *dev,
- unsigned int submit_queues)
+static int nullb_update_nr_hw_queues(struct nullb_device *dev,
+ unsigned int submit_queues,
+ unsigned int poll_queues)
+
{
- struct nullb *nullb = dev->nullb;
struct blk_mq_tag_set *set;
+ int ret, nr_hw_queues;
- if (!nullb)
+ if (!dev->nullb)
return 0;
/*
+ * Make sure at least one queue exists for each of submit and poll.
+ */
+ if (!submit_queues || !poll_queues)
+ return -EINVAL;
+
+ /*
* Make sure that null_init_hctx() does not access nullb->queues[] past
* the end of that array.
*/
- if (submit_queues > nr_cpu_ids)
+ if (submit_queues > nr_cpu_ids || poll_queues > g_poll_queues)
return -EINVAL;
- set = nullb->tag_set;
- blk_mq_update_nr_hw_queues(set, submit_queues);
- return set->nr_hw_queues == submit_queues ? 0 : -ENOMEM;
+
+ /*
+ * Keep previous and new queue numbers in nullb_device for reference in
+ * the call back function null_map_queues().
+ */
+ dev->prev_submit_queues = dev->submit_queues;
+ dev->prev_poll_queues = dev->poll_queues;
+ dev->submit_queues = submit_queues;
+ dev->poll_queues = poll_queues;
+
+ set = dev->nullb->tag_set;
+ nr_hw_queues = submit_queues + poll_queues;
+ blk_mq_update_nr_hw_queues(set, nr_hw_queues);
+ ret = set->nr_hw_queues == nr_hw_queues ? 0 : -ENOMEM;
+
+ if (ret) {
+ /* on error, revert the queue numbers */
+ dev->submit_queues = dev->prev_submit_queues;
+ dev->poll_queues = dev->prev_poll_queues;
+ }
+
+ return ret;
+}
+
+static int nullb_apply_submit_queues(struct nullb_device *dev,
+ unsigned int submit_queues)
+{
+ return nullb_update_nr_hw_queues(dev, submit_queues, dev->poll_queues);
+}
+
+static int nullb_apply_poll_queues(struct nullb_device *dev,
+ unsigned int poll_queues)
+{
+ return nullb_update_nr_hw_queues(dev, dev->submit_queues, poll_queues);
}
NULLB_DEVICE_ATTR(size, ulong, NULL);
NULLB_DEVICE_ATTR(completion_nsec, ulong, NULL);
NULLB_DEVICE_ATTR(submit_queues, uint, nullb_apply_submit_queues);
-NULLB_DEVICE_ATTR(poll_queues, uint, nullb_apply_submit_queues);
+NULLB_DEVICE_ATTR(poll_queues, uint, nullb_apply_poll_queues);
NULLB_DEVICE_ATTR(home_node, uint, NULL);
NULLB_DEVICE_ATTR(queue_mode, uint, NULL);
NULLB_DEVICE_ATTR(blocksize, uint, NULL);
dev->size = g_gb * 1024;
dev->completion_nsec = g_completion_nsec;
dev->submit_queues = g_submit_queues;
+ dev->prev_submit_queues = g_submit_queues;
dev->poll_queues = g_poll_queues;
+ dev->prev_poll_queues = g_poll_queues;
dev->home_node = g_home_node;
dev->queue_mode = g_queue_mode;
dev->blocksize = g_bs;
{
struct nullb *nullb = set->driver_data;
int i, qoff;
+ unsigned int submit_queues = g_submit_queues;
+ unsigned int poll_queues = g_poll_queues;
+
+ if (nullb) {
+ struct nullb_device *dev = nullb->dev;
+
+ /*
+ * Refer nr_hw_queues of the tag set to check if the expected
+ * number of hardware queues are prepared. If block layer failed
+ * to prepare them, use previous numbers of submit queues and
+ * poll queues to map queues.
+ */
+ if (set->nr_hw_queues ==
+ dev->submit_queues + dev->poll_queues) {
+ submit_queues = dev->submit_queues;
+ poll_queues = dev->poll_queues;
+ } else if (set->nr_hw_queues ==
+ dev->prev_submit_queues + dev->prev_poll_queues) {
+ submit_queues = dev->prev_submit_queues;
+ poll_queues = dev->prev_poll_queues;
+ } else {
+ pr_warn("tag set has unexpected nr_hw_queues: %d\n",
+ set->nr_hw_queues);
+ return -EINVAL;
+ }
+ }
for (i = 0, qoff = 0; i < set->nr_maps; i++) {
struct blk_mq_queue_map *map = &set->map[i];
switch (i) {
case HCTX_TYPE_DEFAULT:
- if (nullb)
- map->nr_queues = nullb->dev->submit_queues;
- else
- map->nr_queues = g_submit_queues;
+ map->nr_queues = submit_queues;
break;
case HCTX_TYPE_READ:
map->nr_queues = 0;
continue;
case HCTX_TYPE_POLL:
- if (nullb)
- map->nr_queues = nullb->dev->poll_queues;
- else
- map->nr_queues = g_poll_queues;
+ map->nr_queues = poll_queues;
break;
}
map->queue_offset = qoff;
dev->submit_queues = nr_cpu_ids;
else if (dev->submit_queues == 0)
dev->submit_queues = 1;
+ dev->prev_submit_queues = dev->submit_queues;
+
+ if (dev->poll_queues > g_poll_queues)
+ dev->poll_queues = g_poll_queues;
+ else if (dev->poll_queues == 0)
+ dev->poll_queues = 1;
+ dev->prev_poll_queues = dev->poll_queues;
dev->queue_mode = min_t(unsigned int, dev->queue_mode, NULL_Q_MQ);
dev->irqmode = min_t(unsigned int, dev->irqmode, NULL_IRQ_TIMER);