From: Jens Axboe <[email protected]> commit c5b856255cbc3b664d686a83fa9397a835e063de upstream.
We can assume that O_NONBLOCK is always honored, even if we don't have a ->read/write_iter() for the file type. Also unify the read/write checking for allowing async punt, having the write side factoring in the REQ_F_NOWAIT flag as well. Cc: [email protected] Fixes: 490e89676a52 ("io_uring: only force async punt if poll based retry can't handle it") Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/io_uring.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2038,6 +2038,10 @@ static bool io_file_supports_async(struc if (S_ISREG(mode) && file->f_op != &io_uring_fops) return true; + /* any ->read/write should understand O_NONBLOCK */ + if (file->f_flags & O_NONBLOCK) + return true; + if (!(file->f_mode & FMODE_NOWAIT)) return false; @@ -2080,8 +2084,7 @@ static int io_prep_rw(struct io_kiocb *r 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) @@ -2722,7 +2725,8 @@ copy_iov: if (ret) goto out_free; /* any defer here is final, must blocking retry */ - if (!file_can_poll(req->file)) + if (!(req->flags & REQ_F_NOWAIT) && + !file_can_poll(req->file)) req->flags |= REQ_F_MUST_PUNT; return -EAGAIN; }
