Commit 87b42a15 authored by Yu Kuai's avatar Yu Kuai
Browse files

scsi: core: make fair tag sharing configurable via sysfs 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8RGGC
CVE: NA

-----------------------------------------------

Add a sysfs attribute to SCSI hosts for configuring fair tag sharing.

Originally-from: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/all/20231130193139.880955-4-bvanassche@acm.org/


Signed-off-by: default avatarYu Kuai <yukuai3@huawei.com>
parent 9b569e2b

drivers/scsi/scsi_sysfs.c

+39 −0
Original line number Diff line number Diff line
@@ -403,6 +403,44 @@ show_nr_hw_queues(struct device *dev, struct device_attribute *attr, char *buf) 
}

static DEVICE_ATTR(nr_hw_queues, S_IRUGO, show_nr_hw_queues, NULL);



static ssize_t

fair_sharing_show(struct device *dev, struct device_attribute *attr, char *buf)

{

	struct Scsi_Host *shost = class_to_shost(dev);

	struct blk_mq_tag_set *tag_set = &shost->tag_set;



	return sprintf(buf, "%d\n",

		       !(tag_set->flags & BLK_MQ_F_DISABLE_FAIR_TAG_SHARING));

}



static ssize_t

fair_sharing_store(struct device *dev, struct device_attribute *attr,

		   const char *buf, size_t count)

{

	struct Scsi_Host *shost = class_to_shost(dev);

	struct blk_mq_tag_set *tag_set = &shost->tag_set;

	bool enable;

	int res = kstrtobool(buf, &enable);



	if (res < 0)

		return res;



	if (!(tag_set->flags & BLK_MQ_F_DISABLE_FAIR_TAG_SHARING) == enable)

		return count;



	mutex_lock(&tag_set->tag_list_lock);

	if (!(tag_set->flags & BLK_MQ_F_DISABLE_FAIR_TAG_SHARING) == enable)

		goto out_unlock;



	tag_set->flags ^= BLK_MQ_F_DISABLE_FAIR_TAG_SHARING;

	blk_mq_update_fair_tag_sharing(tag_set);



out_unlock:

	mutex_unlock(&tag_set->tag_list_lock);

	return count;

}

static DEVICE_ATTR_RW(fair_sharing);



static struct attribute *scsi_sysfs_shost_attrs[] = {

	&dev_attr_use_blk_mq.attr,

	&dev_attr_unique_id.attr,
@@ -421,6 +459,7 @@ static struct attribute *scsi_sysfs_shost_attrs[] = { 
	&dev_attr_host_reset.attr,

	&dev_attr_eh_deadline.attr,

	&dev_attr_nr_hw_queues.attr,

	&dev_attr_fair_sharing.attr,

	NULL

};