md: use new apis to suspend array for sysfs apis

Convert to use new apis in following sysfs apis:
 - level_store
 - suspend_lo_store
 - suspend_hi_store
 - serialize_policy_store

These are not hot path, so performance is not concerned.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231010151958.145896-11-yukuai1@huaweicloud.com

drivers/md/md.c

@@ -4019,7 +4019,7 @@ level_store(struct mddev *mddev, const char *buf, size_t len)
 	if (slen == 0 || slen >= sizeof(clevel))
 		return -EINVAL;
 
-	rv = mddev_lock(mddev);
+	rv = mddev_suspend_and_lock(mddev);
 	if (rv)
 		return rv;
 
@@ -4112,7 +4112,6 @@ level_store(struct mddev *mddev, const char *buf, size_t len)
 	}
 
 	/* Looks like we have a winner */
-	mddev_suspend(mddev);
 	mddev_detach(mddev);
 
 	spin_lock(&mddev->lock);
@@ -4198,14 +4197,13 @@ level_store(struct mddev *mddev, const char *buf, size_t len)
 	blk_set_stacking_limits(&mddev->queue->limits);
 	pers->run(mddev);
 	set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
-	mddev_resume(mddev);
 	if (!mddev->thread)
 		md_update_sb(mddev, 1);
 	sysfs_notify_dirent_safe(mddev->sysfs_level);
 	md_new_event();
 	rv = len;
 out_unlock:
-	mddev_unlock(mddev);
+	mddev_unlock_and_resume(mddev);
 	return rv;
 }
 
@@ -5293,15 +5291,13 @@ suspend_lo_store(struct mddev *mddev, const char *buf, size_t len)
 	if (new != (sector_t)new)
 		return -EINVAL;
 
-	err = mddev_lock(mddev);
+	err = __mddev_suspend(mddev, true);
 	if (err)
 		return err;
 
-	mddev_suspend(mddev);
 	WRITE_ONCE(mddev->suspend_lo, new);
-	mddev_resume(mddev);
+	__mddev_resume(mddev);
 
-	mddev_unlock(mddev);
 	return len;
 }
 static struct md_sysfs_entry md_suspend_lo =
@@ -5326,15 +5322,13 @@ suspend_hi_store(struct mddev *mddev, const char *buf, size_t len)
 	if (new != (sector_t)new)
 		return -EINVAL;
 
-	err = mddev_lock(mddev);
+	err = __mddev_suspend(mddev, true);
 	if (err)
 		return err;
 
-	mddev_suspend(mddev);
 	WRITE_ONCE(mddev->suspend_hi, new);
-	mddev_resume(mddev);
+	__mddev_resume(mddev);
 
-	mddev_unlock(mddev);
 	return len;
 }
 static struct md_sysfs_entry md_suspend_hi =
@@ -5582,7 +5576,7 @@ serialize_policy_store(struct mddev *mddev, const char *buf, size_t len)
 	if (value == mddev->serialize_policy)
 		return len;
 
-	err = mddev_lock(mddev);
+	err = mddev_suspend_and_lock(mddev);
 	if (err)
 		return err;
 	if (mddev->pers == NULL || (mddev->pers->level != 1)) {
@@ -5591,15 +5585,13 @@ serialize_policy_store(struct mddev *mddev, const char *buf, size_t len)
 		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);
+	mddev_unlock_and_resume(mddev);
 	return err ?: len;
 }