Commit 14509b74 authored by Shin'ichiro Kawasaki's avatar Shin'ichiro Kawasaki Committed by Jens Axboe
Browse files

null_blk: add configfs variable shared_tags 



Allow setting shared_tags through configfs, which could only be set as a
module parameter. For that purpose, delay tag_set initialization from
null_init() to null_add_dev(). Refer tag_set.ops as the flag to check if
tag_set is initialized or not.

The following parameters can not be set through configfs yet:

    timeout
    requeue
    init_hctx

Signed-off-by: default avatarShin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: default avatarChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20240130042134.2463659-1-shinichiro.kawasaki@wdc.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 48ff13a6

drivers/block/null_blk/main.c

+20 −18
Original line number Diff line number Diff line
@@ -165,8 +165,8 @@ static bool g_blocking; 
module_param_named(blocking, g_blocking, bool, 0444);

MODULE_PARM_DESC(blocking, "Register as a blocking blk-mq driver device");



static bool shared_tags;

module_param(shared_tags, bool, 0444);

static bool g_shared_tags;

module_param_named(shared_tags, g_shared_tags, bool, 0444);

MODULE_PARM_DESC(shared_tags, "Share tag set between devices for blk-mq");



static bool g_shared_tag_bitmap;
@@ -426,6 +426,7 @@ NULLB_DEVICE_ATTR(zone_max_open, uint, NULL); 
NULLB_DEVICE_ATTR(zone_max_active, uint, NULL);

NULLB_DEVICE_ATTR(virt_boundary, bool, NULL);

NULLB_DEVICE_ATTR(no_sched, bool, NULL);

NULLB_DEVICE_ATTR(shared_tags, bool, NULL);

NULLB_DEVICE_ATTR(shared_tag_bitmap, bool, NULL);



static ssize_t nullb_device_power_show(struct config_item *item, char *page)
@@ -571,6 +572,7 @@ static struct configfs_attribute *nullb_device_attrs[] = { 
	&nullb_device_attr_zone_offline,

	&nullb_device_attr_virt_boundary,

	&nullb_device_attr_no_sched,

	&nullb_device_attr_shared_tags,

	&nullb_device_attr_shared_tag_bitmap,

	NULL,

};
@@ -653,10 +655,11 @@ static ssize_t memb_group_features_show(struct config_item *item, char *page) 
			"badblocks,blocking,blocksize,cache_size,"

			"completion_nsec,discard,home_node,hw_queue_depth,"

			"irqmode,max_sectors,mbps,memory_backed,no_sched,"

			"poll_queues,power,queue_mode,shared_tag_bitmap,size,"

			"submit_queues,use_per_node_hctx,virt_boundary,zoned,"

			"zone_capacity,zone_max_active,zone_max_open,"

			"zone_nr_conv,zone_offline,zone_readonly,zone_size\n");

			"poll_queues,power,queue_mode,shared_tag_bitmap,"

			"shared_tags,size,submit_queues,use_per_node_hctx,"

			"virt_boundary,zoned,zone_capacity,zone_max_active,"

			"zone_max_open,zone_nr_conv,zone_offline,zone_readonly,"

			"zone_size\n");

}



CONFIGFS_ATTR_RO(memb_group_, features);
@@ -738,6 +741,7 @@ static struct nullb_device *null_alloc_dev(void) 
	dev->zone_max_active = g_zone_max_active;

	dev->virt_boundary = g_virt_boundary;

	dev->no_sched = g_no_sched;

	dev->shared_tags = g_shared_tags;

	dev->shared_tag_bitmap = g_shared_tag_bitmap;

	return dev;

}
@@ -2124,7 +2128,14 @@ static int null_add_dev(struct nullb_device *dev) 
		goto out_free_nullb;



	if (dev->queue_mode == NULL_Q_MQ) {

		if (shared_tags) {

		if (dev->shared_tags) {

			if (!tag_set.ops) {

				rv = null_init_tag_set(NULL, &tag_set);

				if (rv) {

					tag_set.ops = NULL;

					goto out_cleanup_queues;

				}

			}

			nullb->tag_set = &tag_set;

			rv = 0;

		} else {
@@ -2311,18 +2322,12 @@ static int __init null_init(void) 
		g_submit_queues = 1;

	}



	if (g_queue_mode == NULL_Q_MQ && shared_tags) {

		ret = null_init_tag_set(NULL, &tag_set);

		if (ret)

			return ret;

	}



	config_group_init(&nullb_subsys.su_group);

	mutex_init(&nullb_subsys.su_mutex);



	ret = configfs_register_subsystem(&nullb_subsys);

	if (ret)

		goto err_tagset;

		return ret;



	mutex_init(&lock);
@@ -2349,9 +2354,6 @@ static int __init null_init(void) 
	unregister_blkdev(null_major, "nullb");

err_conf:

	configfs_unregister_subsystem(&nullb_subsys);

err_tagset:

	if (g_queue_mode == NULL_Q_MQ && shared_tags)

		blk_mq_free_tag_set(&tag_set);

	return ret;

}
@@ -2370,7 +2372,7 @@ static void __exit null_exit(void) 
	}

	mutex_unlock(&lock);



	if (g_queue_mode == NULL_Q_MQ && shared_tags)

	if (tag_set.ops)

		blk_mq_free_tag_set(&tag_set);

}

drivers/block/null_blk/null_blk.h

+1 −0
Original line number Diff line number Diff line
@@ -119,6 +119,7 @@ struct nullb_device { 
	bool zoned; /* if device is zoned */

	bool virt_boundary; /* virtual boundary on/off for the device */

	bool no_sched; /* no IO scheduler for the device */

	bool shared_tags; /* share tag set between devices for blk-mq */

	bool shared_tag_bitmap; /* use hostwide shared tags */

};