Commit 45919fbf authored by Bart Van Assche's avatar Bart Van Assche Committed by Jens Axboe
Browse files

null_blk: Enable modifying 'submit_queues' after an instance has been configured 



This patch makes it possible to test blk_mq_update_nr_hw_queues() from
inside a VM.

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: default avatarBart Van Assche <bvanassche@acm.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent e29158b4

drivers/block/null_blk_main.c

+50 −25
Original line number Diff line number Diff line
@@ -227,7 +227,7 @@ static ssize_t nullb_device_uint_attr_store(unsigned int *val, 
	int result;



	result = kstrtouint(page, 0, &tmp);

	if (result)

	if (result < 0)

		return result;



	*val = tmp;
@@ -241,7 +241,7 @@ static ssize_t nullb_device_ulong_attr_store(unsigned long *val, 
	unsigned long tmp;



	result = kstrtoul(page, 0, &tmp);

	if (result)

	if (result < 0)

		return result;



	*val = tmp;
@@ -255,7 +255,7 @@ static ssize_t nullb_device_bool_attr_store(bool *val, const char *page, 
	int result;



	result = kstrtobool(page,  &tmp);

	if (result)

	if (result < 0)

		return result;



	*val = tmp;
@@ -263,7 +263,7 @@ static ssize_t nullb_device_bool_attr_store(bool *val, const char *page, 
}



/* The following macro should only be used with TYPE = {uint, ulong, bool}. */

#define NULLB_DEVICE_ATTR(NAME, TYPE)						\

#define NULLB_DEVICE_ATTR(NAME, TYPE, APPLY)					\

static ssize_t									\

nullb_device_##NAME##_show(struct config_item *item, char *page)		\

{										\
@@ -274,32 +274,57 @@ static ssize_t \ 
nullb_device_##NAME##_store(struct config_item *item, const char *page,		\

			    size_t count)					\

{										\

	int (*apply_fn)(struct nullb_device *dev, TYPE new_value) = APPLY;	\

	struct nullb_device *dev = to_nullb_device(item);			\

	TYPE new_value;								\

	int ret;								\

										\

	if (test_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags))			\

		return -EBUSY;							\

	return nullb_device_##TYPE##_attr_store(&dev->NAME, page, count);	\

	ret = nullb_device_##TYPE##_attr_store(&new_value, page, count);	\

	if (ret < 0)								\

		return ret;							\

	if (apply_fn)								\

		ret = apply_fn(dev, new_value);					\

	else if (test_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags)) 		\

		ret = -EBUSY;							\

	if (ret < 0)								\

		return ret;							\

	dev->NAME = new_value;							\

	return count;								\

}										\

CONFIGFS_ATTR(nullb_device_, NAME);



NULLB_DEVICE_ATTR(size, ulong);

NULLB_DEVICE_ATTR(completion_nsec, ulong);

NULLB_DEVICE_ATTR(submit_queues, uint);

NULLB_DEVICE_ATTR(home_node, uint);

NULLB_DEVICE_ATTR(queue_mode, uint);

NULLB_DEVICE_ATTR(blocksize, uint);

NULLB_DEVICE_ATTR(irqmode, uint);

NULLB_DEVICE_ATTR(hw_queue_depth, uint);

NULLB_DEVICE_ATTR(index, uint);

NULLB_DEVICE_ATTR(blocking, bool);

NULLB_DEVICE_ATTR(use_per_node_hctx, bool);

NULLB_DEVICE_ATTR(memory_backed, bool);

NULLB_DEVICE_ATTR(discard, bool);

NULLB_DEVICE_ATTR(mbps, uint);

NULLB_DEVICE_ATTR(cache_size, ulong);

NULLB_DEVICE_ATTR(zoned, bool);

NULLB_DEVICE_ATTR(zone_size, ulong);

NULLB_DEVICE_ATTR(zone_nr_conv, uint);

static int nullb_apply_submit_queues(struct nullb_device *dev,

				     unsigned int submit_queues)

{

	struct nullb *nullb = dev->nullb;

	struct blk_mq_tag_set *set;



	if (!nullb)

		return 0;



	set = nullb->tag_set;

	blk_mq_update_nr_hw_queues(set, submit_queues);

	return set->nr_hw_queues == submit_queues ? 0 : -ENOMEM;

}



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(home_node, uint, NULL);

NULLB_DEVICE_ATTR(queue_mode, uint, NULL);

NULLB_DEVICE_ATTR(blocksize, uint, NULL);

NULLB_DEVICE_ATTR(irqmode, uint, NULL);

NULLB_DEVICE_ATTR(hw_queue_depth, uint, NULL);

NULLB_DEVICE_ATTR(index, uint, NULL);

NULLB_DEVICE_ATTR(blocking, bool, NULL);

NULLB_DEVICE_ATTR(use_per_node_hctx, bool, NULL);

NULLB_DEVICE_ATTR(memory_backed, bool, NULL);

NULLB_DEVICE_ATTR(discard, bool, NULL);

NULLB_DEVICE_ATTR(mbps, uint, NULL);

NULLB_DEVICE_ATTR(cache_size, ulong, NULL);

NULLB_DEVICE_ATTR(zoned, bool, NULL);

NULLB_DEVICE_ATTR(zone_size, ulong, NULL);

NULLB_DEVICE_ATTR(zone_nr_conv, uint, NULL);



static ssize_t nullb_device_power_show(struct config_item *item, char *page)

{

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