null_blk: fix zone size paramter check

For zoned=1 mode, the zone size must be a power of 2. Check this not
only when the zone size is specified during modprobe, but also when
creating a zoned null_blk device using configfs.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/null_blk_main.c

@@ -1607,7 +1607,7 @@ static int null_init_tag_set(struct nullb *nullb, struct blk_mq_tag_set *set)
 	return blk_mq_alloc_tag_set(set);
 }
 
-static void null_validate_conf(struct nullb_device *dev)
+static int null_validate_conf(struct nullb_device *dev)
 {
 	dev->blocksize = round_down(dev->blocksize, 512);
 	dev->blocksize = clamp_t(unsigned int, dev->blocksize, 512, 4096);
@@ -1634,6 +1634,14 @@ static void null_validate_conf(struct nullb_device *dev)
 	/* can not stop a queue */
 	if (dev->queue_mode == NULL_Q_BIO)
 		dev->mbps = 0;
+
+	if (dev->zoned &&
+	    (!dev->zone_size || !is_power_of_2(dev->zone_size))) {
+		pr_err("zone_size must be power-of-two\n");
+		return -EINVAL;
+	}
+
+	return 0;
 }
 
 #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
@@ -1666,7 +1674,9 @@ static int null_add_dev(struct nullb_device *dev)
 	struct nullb *nullb;
 	int rv;
 
-	null_validate_conf(dev);
+	rv = null_validate_conf(dev);
+	if (rv)
+		return rv;
 
 	nullb = kzalloc_node(sizeof(*nullb), GFP_KERNEL, dev->home_node);
 	if (!nullb) {
@@ -1792,11 +1802,6 @@ static int __init null_init(void)
 		g_bs = PAGE_SIZE;
 	}
 
-	if (!is_power_of_2(g_zone_size)) {
-		pr_err("zone_size must be power-of-two\n");
-		return -EINVAL;
-	}
-
 	if (g_home_node != NUMA_NO_NODE && g_home_node >= nr_online_nodes) {
 		pr_err("invalid home_node value\n");
 		g_home_node = NUMA_NO_NODE;