On Fri, 23 Mar 2012, Andrew Morton wrote: > On Fri, 23 Mar 2012 13:48:35 -0700 (PDT) > Hugh Dickins <hughd@xxxxxxxxxx> wrote: > > > Most system calls taking flags first check that the flags passed in are > > valid, and that helps userspace to detect when new flags are supported. > > > > But swapon never did so: start checking now, to help if we ever want to > > support more swap_flags in future. > > > > It's difficult to get stray bits set in an int, and swapon is not widely > > used, so this is most unlikely to break any userspace; but we can just > > revert if it turns out to do so. > > It would be safer to emit a nasty message then let the swapon proceed > as before. Safer, I suppose, but I really don't expect that case to arise (we'll have been doing those lovely runtime discards without asking for a year now if so). And it does spoil the checking of supported flags. Hugh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>