On Fri, Aug 27, 2021 at 06:49:22PM +0200, Andreas Gruenbacher wrote: > In iomap_dio_rw, when iomap_apply returns an -EFAULT error and the > IOMAP_DIO_PARTIAL flag is set, complete the request synchronously and > return a partial result. This allows the caller to deal with the page > fault and retry the remainder of the request. > > Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx> > --- > fs/iomap/direct-io.c | 6 ++++++ > include/linux/iomap.h | 7 +++++++ > 2 files changed, 13 insertions(+) > > diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c > index 8054f5d6c273..ba88fe51b77a 100644 > --- a/fs/iomap/direct-io.c > +++ b/fs/iomap/direct-io.c > @@ -561,6 +561,12 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, > ret = iomap_apply(inode, pos, count, iomap_flags, ops, dio, > iomap_dio_actor); > if (ret <= 0) { > + if (ret == -EFAULT && dio->size && > + (dio_flags & IOMAP_DIO_PARTIAL)) { > + wait_for_completion = true; > + ret = 0; Do we need a NOWAIT check here to skip the wait_for_completion for that case?