osdc/Striper.cc: fix OVERFLOW_BEFORE_WIDEN

Fix for:
CID 1247719 (#1 of 1): Unintentional integer overflow
(OVERFLOW_BEFORE_WIDEN)
 overflow_before_widen: Potentially overflowing expression
 stripe_count * object_size with type unsigned int (32 bits,
 unsigned) is evaluated using 32-bit arithmetic before being
 used in a context which expects an expression of type
 uint64_t (64 bits, unsigned).

Signed-off-by: Danny Al-Gaaf <[email protected]>

Author: dalgaaf

src/osdc/Striper.cc

@@ -218,7 +218,7 @@ uint64_t Striper::get_num_objects(const ceph_file_layout& layout, uint64_t size)
   __u32 object_size = layout.fl_object_size;
   __u32 stripe_unit = layout.fl_stripe_unit;
   __u32 stripe_count = layout.fl_stripe_count;
-  uint64_t period = stripe_count * object_size;
+  uint64_t period = (uint64_t)stripe_count * object_size;
   uint64_t num_periods = (size + period - 1) / period;
   uint64_t remainder_bytes = size % period;
   uint64_t remainder_objs = 0;