I think we should not set the flag only for regular file, I will resend it later. Please ignore this patch. Thanks, Jiufei On 2020/5/25 下午6:48, Jiufei Xue wrote: > When read from an ondisk file that was opened O_NONBLOCK, it will always > return EAGAIN to the user if the page is not cached. It is not > compatible with interfaces such as aio_read() and normal sys_read(). > > Files that care about this flag (eg. pipe, eventfd) will deal with it > on their own. So I don't think we should set REQ_F_NOWAIT in > io_prep_rw() to provent from queueing the async work. > > Signed-off-by: Jiufei Xue <jiufei.xue@xxxxxxxxxxxxxxxxx> > --- > fs/io_uring.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/fs/io_uring.c b/fs/io_uring.c > index bb25e39..65ae59b 100644 > --- a/fs/io_uring.c > +++ b/fs/io_uring.c > @@ -2080,8 +2080,7 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, > kiocb->ki_ioprio = get_current_ioprio(); > > /* don't allow async punt if RWF_NOWAIT was requested */ > - if ((kiocb->ki_flags & IOCB_NOWAIT) || > - (req->file->f_flags & O_NONBLOCK)) > + if (kiocb->ki_flags & IOCB_NOWAIT) > req->flags |= REQ_F_NOWAIT; > > if (force_nonblock) >
