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: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20240130042134.2463659-1-shinichiro.kawasaki@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Shin'ichiro Kawasaki 2024-01-30 13:21:34 +09:00 committed by Jens Axboe
parent 48ff13a618
commit 14509b748f
2 changed files with 21 additions and 18 deletions

View file

@ -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);
}

View file

@ -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 */
};