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.