ext4: do not use stripe_width if it is not set

Avoid using stripe_width for sbi->s_stripe value if it is not actually
set. It prevents using the stride for sbi->s_stripe.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/super.c

@@ -2637,9 +2637,9 @@ static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
 
 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
 		ret = sbi->s_stripe;
-	else if (stripe_width <= sbi->s_blocks_per_group)
+	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
 		ret = stripe_width;
-	else if (stride <= sbi->s_blocks_per_group)
+	else if (stride && stride <= sbi->s_blocks_per_group)
 		ret = stride;
 	else
 		ret = 0;