Commit 3938f5fb authored by Guoqing Jiang's avatar Guoqing Jiang Committed by Song Liu
Browse files

md: add serialize_policy sysfs node for raid1 



With the new sysfs node, we can use it to control if raid1 array
wants io serialization or not. So mddev_create_serial_pool and
mddev_destroy_serial_pool are called in serialize_policy_store
to enable or disable the serialization.

Signed-off-by: default avatarGuoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: default avatarSong Liu <songliubraving@fb.com>
parent 11d3a9f6

drivers/md/md.c

+52 −0
Original line number Diff line number Diff line
@@ -5304,6 +5304,57 @@ static struct md_sysfs_entry md_fail_last_dev = 
__ATTR(fail_last_dev, S_IRUGO | S_IWUSR, fail_last_dev_show,

       fail_last_dev_store);



static ssize_t serialize_policy_show(struct mddev *mddev, char *page)

{

	if (mddev->pers == NULL || (mddev->pers->level != 1))

		return sprintf(page, "n/a\n");

	else

		return sprintf(page, "%d\n", mddev->serialize_policy);

}



/*

 * Setting serialize_policy to true to enforce write IO is not reordered

 * for raid1.

 */

static ssize_t

serialize_policy_store(struct mddev *mddev, const char *buf, size_t len)

{

	int err;

	bool value;



	err = kstrtobool(buf, &value);

	if (err)

		return err;



	if (value == mddev->serialize_policy)

		return len;



	err = mddev_lock(mddev);

	if (err)

		return err;

	if (mddev->pers == NULL || (mddev->pers->level != 1)) {

		pr_err("md: serialize_policy is only effective for raid1\n");

		err = -EINVAL;

		goto unlock;

	}



	mddev_suspend(mddev);

	if (value)

		mddev_create_serial_pool(mddev, NULL, true);

	else

		mddev_destroy_serial_pool(mddev, NULL, true);

	mddev->serialize_policy = value;

	mddev_resume(mddev);

unlock:

	mddev_unlock(mddev);

	return err ?: len;

}



static struct md_sysfs_entry md_serialize_policy =

__ATTR(serialize_policy, S_IRUGO | S_IWUSR, serialize_policy_show,

       serialize_policy_store);





static struct attribute *md_default_attrs[] = {

	&md_level.attr,

	&md_layout.attr,
@@ -5321,6 +5372,7 @@ static struct attribute *md_default_attrs[] = { 
	&max_corr_read_errors.attr,

	&md_consistency_policy.attr,

	&md_fail_last_dev.attr,

	&md_serialize_policy.attr,

	NULL,

};

drivers/md/md.h

+1 −0
Original line number Diff line number Diff line
@@ -494,6 +494,7 @@ struct mddev { 


	bool	has_superblocks:1;

	bool	fail_last_dev:1;

	bool	serialize_policy:1;

};



enum recovery_flags {

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