block: Enforce power-of-2 physical block size

The merging/splitting code and other queue limits checking depends on the
physical block size being a power-of-2, so enforce it.

Signed-off-by: John Garry <[email protected]>

Author: johnpgarry

block/blk-settings.c

@@ -268,6 +268,10 @@ int blk_validate_limits(struct queue_limits *lim)
 	}
 	if (lim->physical_block_size < lim->logical_block_size)
 		lim->physical_block_size = lim->logical_block_size;
+	else if (!is_power_of_2(lim->physical_block_size)) {
+		pr_warn("Invalid physical block size (%d)\n", lim->physical_block_size);
+		return -EINVAL;
+	}
 
 	/*
 	 * The minimum I/O size defaults to the physical block size unless