From c0810993a2d5bcedf094d17fdfbf2afe2bd179e1 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 9 Jun 2020 19:23:05 -0600 Subject: [PATCH] io_uring: allow O_NONBLOCK async retry to #28736503 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: stable@vger.kernel.org Fixes: 490e89676a52 ("io_uring: only force async punt if poll based retry can't handle it") Signed-off-by: Jens Axboe Signed-off-by: Xiaoguang Wang Acked-by: Joseph Qi --- fs/io_uring.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index dc1a7e4463d5..4b4485a8cb9c 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2052,6 +2052,10 @@ static bool io_file_supports_async(struct file *file, int rw) 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; @@ -2094,8 +2098,7 @@ 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) @@ -2736,7 +2739,8 @@ static int io_write(struct io_kiocb *req, bool force_nonblock) 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; } -- GitLab