dm zoned: Fix metadata zone size check

When dm zoned has multiple devices, metadata is on the cache device, not
in random zones of the zoned devices. Then the number of metadata zones
shall be checked with the number of cache zones, not random zones.

Fixes: 34f5aff ("dm zoned: separate random and cache zones")
Signed-off-by: Shin'ichiro Kawasaki <[email protected]>
Reviewed-by: Damien Le Moal <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

Author: kawasaki

drivers/md/dm-zoned-metadata.c

@@ -1078,7 +1078,8 @@ static int dmz_check_sb(struct dmz_metadata *zmd, struct dmz_sb *dsb,
 	nr_meta_zones = (le32_to_cpu(sb->nr_meta_blocks) + zmd->zone_nr_blocks - 1)
 		>> zmd->zone_nr_blocks_shift;
 	if (!nr_meta_zones ||
-	    nr_meta_zones >= zmd->nr_rnd_zones) {
+	    (zmd->nr_devs <= 1 && nr_meta_zones >= zmd->nr_rnd_zones) ||
+	    (zmd->nr_devs > 1 && nr_meta_zones >= zmd->nr_cache_zones)) {
 		dmz_dev_err(dev, "Invalid number of metadata blocks");
 		return -ENXIO;
 	}