2012/8/19, Marco Stornelli <marco.stornelli@xxxxxxxxx>: > Il 19/08/2012 04:17, Fengguang Wu ha scritto: >> On Sat, Aug 18, 2012 at 05:49:21AM -0400, Namjae Jeon wrote: >>> unsigned long bdi_dirty_limit(struct backing_dev_info *bdi, unsigned long >>> dirty) >>> >>> Above function return type is unsigned long, but return value is >>> kept in "u64 bdi_dirty". >>> It can return incorrect value by type casting. >> >> I don't see how the cast can return wrong value. >> The u64 is necessary for the intermediate calculations. >> >> Thanks, >> Fengguang >> > > We are sure u64 is 8byte long, but unsigned long is 4byte long on 32-bit > machine, so if bdi_dirty can assume values bigger than 2^32 there is an > implicit truncate of its value, isn't it? Yes, right. Thanks. > > Marco > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
