ext4: calculate free_clusters_count in cluster unit in verify_group_input

The field free_cluster_count in struct ext4_new_group_data should be
in units of clusters.  In verify_group_input() this field is being
filled in units of blocks.  Fortunately, we don't support online
resizing of bigalloc file systems, and for non-bigalloc file systems,
the cluster size == block size.  But fix this in case we do support
online resizing of bigalloc file systems in the future.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230826174712.4059355-9-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/resize.c

@@ -154,8 +154,9 @@ static int verify_group_input(struct super_block *sb,
 
 	overhead = ext4_group_overhead_blocks(sb, group);
 	metaend = start + overhead;
-	input->free_clusters_count = free_blocks_count =
-		input->blocks_count - 2 - overhead - sbi->s_itb_per_group;
+	free_blocks_count = input->blocks_count - 2 - overhead -
+			    sbi->s_itb_per_group;
+	input->free_clusters_count = EXT4_B2C(sbi, free_blocks_count);
 
 	if (test_opt(sb, DEBUG))
 		printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks "