Commit bdac94e2 authored by Stefan Haberland's avatar Stefan Haberland Committed by Jens Axboe
Browse files

s390/dasd: add aq_requeue sysfs attribute 



Add a sysfs attribute to control if all IO requests will be requeued to
the blocklayer in case of an autoquiesce event or not.

A value of 1 means that in case of an autoquiesce event all IO requests
will be requeued to the blocklayer.

A value of 0 means that the device will only be stopped.

Signed-off-by: default avatarStefan Haberland <sth@linux.ibm.com>
Reviewed-by: default avatarJan Hoeppner <hoeppner@linux.ibm.com>
Reviewed-by: default avatarHalil Pasic <pasic@linux.ibm.com>
Link: https://lore.kernel.org/r/20230405142017.2446986-5-sth@linux.ibm.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 9558a8e9

drivers/s390/block/dasd_devmap.c

+36 −0
Original line number Diff line number Diff line
@@ -1517,6 +1517,41 @@ static ssize_t dasd_aq_mask_store(struct device *dev, struct device_attribute *a 


static DEVICE_ATTR(aq_mask, 0644, dasd_aq_mask_show, dasd_aq_mask_store);



/*

 * aq_requeue controls if requests are returned to the blocklayer on quiesce

 * or if requests are only not started

 */

static ssize_t dasd_aqr_show(struct device *dev, struct device_attribute *attr,

			     char *buf)

{

	struct dasd_devmap *devmap;

	int flag;



	devmap = dasd_find_busid(dev_name(dev));

	if (!IS_ERR(devmap))

		flag = (devmap->features & DASD_FEATURE_REQUEUEQUIESCE) != 0;

	else

		flag = (DASD_FEATURE_DEFAULT &

			DASD_FEATURE_REQUEUEQUIESCE) != 0;

	return sysfs_emit(buf, "%d\n", flag);

}



static ssize_t dasd_aqr_store(struct device *dev, struct device_attribute *attr,

			      const char *buf, size_t count)

{

	bool val;

	int rc;



	if (kstrtobool(buf, &val))

		return -EINVAL;



	rc = dasd_set_feature(to_ccwdev(dev), DASD_FEATURE_REQUEUEQUIESCE, val);



	return rc ? : count;

}



static DEVICE_ATTR(aq_requeue, 0644, dasd_aqr_show, dasd_aqr_store);



/*

 * expiration time for default requests

 */
@@ -2367,6 +2402,7 @@ static struct attribute * dasd_attrs[] = { 
	&dev_attr_copy_role.attr,

	&dev_attr_ping.attr,

	&dev_attr_aq_mask.attr,

	&dev_attr_aq_requeue.attr,

	NULL,

};