On Wed, Dec 17, 2014 at 12:06:10AM -0800, Christoph Hellwig wrote: > > This seems to be more or less equivalent to doing a fcntl(F_SETFL) to > > add the O_DIRECT flag to swap_file (which is a struct file *). Swapoff > > calls filp_close on swap_file, so I don't see why it's necessary to > > clear the flag. > > filp_lose doesn't nessecarily destroy the file structure, there might be > other reference to it, e.g. from dup() or descriptor passing. Where the hell would those other references come from? We open the damn thing in sys_swapon(), never put it into descriptor tables, etc. and the only reason why we use filp_close() instead of fput() is that we would miss ->flush() otherwise. Said that, why not simply *open* it with O_DIRECT to start with and be done with that? It's not as if those guys came preopened by caller - swapon(2) gets a pathname and does opening itself. -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>