On Sat, Jan 06, 2018 at 07:08:53PM +0000, Al Viro wrote: > On Thu, Jan 04, 2018 at 09:00:14AM +0100, Christoph Hellwig wrote: > > These abstract out calls to the poll method in preparation for changes to > > those methods. > > FWIW, I would make vfs_poll() > > static inline __poll_t vfs_poll(struct file *file, struct poll_table_struct *pt) > { > if (unlikely(!file->f_op->poll)) > return DEFAULT_POLLMASK; > return file->f_op->poll(file, pt); > } > > That's safe for any struct file, some of the callers already do just that, > the ones that have vfs_poll() under the check for file_can_poll() will > simply optimize that piece away and the few that rely upon the knowledge > of file_operations they are dealing with (vhost, etc.) can bloody well > cope with the cost of the check. Sure, works for me.