From 355afaeb578abac907217c256a844cfafb0337b2 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 2 Sep 2020 09:30:31 -0600 Subject: [PATCH] io_uring: no read/write-retry on -EAGAIN error and O_NONBLOCK marked file Actually two things that need fixing up here: - The io_rw_reissue() -EAGAIN retry is explicit to block devices and regular files, so don't ever attempt to do that on other types of files. - If we hit -EAGAIN on a nonblock marked file, don't arm poll handler for it. It should just complete with -EAGAIN. Cc: stable@vger.kernel.org Reported-by: Norman Maurer Signed-off-by: Jens Axboe --- fs/io_uring.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/fs/io_uring.c b/fs/io_uring.c index b1ccd7072d93..64c5a52fad12 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2300,8 +2300,11 @@ end_req: static bool io_rw_reissue(struct io_kiocb *req, long res) { #ifdef CONFIG_BLOCK + umode_t mode = file_inode(req->file)->i_mode; int ret; + if (!S_ISBLK(mode) && !S_ISREG(mode)) + return false; if ((res != -EAGAIN && res != -EOPNOTSUPP) || io_wq_current_is_worker()) return false; @@ -3146,6 +3149,9 @@ static int io_read(struct io_kiocb *req, bool force_nonblock, /* IOPOLL retry should happen for io-wq threads */ if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL)) goto done; + /* no retry on NONBLOCK marked file */ + if (req->file->f_flags & O_NONBLOCK) + goto done; /* some cases will consume bytes even on error returns */ iov_iter_revert(iter, iov_count - iov_iter_count(iter)); ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false); @@ -3287,10 +3293,14 @@ static int io_write(struct io_kiocb *req, bool force_nonblock, */ if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT)) ret2 = -EAGAIN; + /* no retry on NONBLOCK marked file */ + if (ret2 == -EAGAIN && (req->file->f_flags & O_NONBLOCK)) + goto done; if (!force_nonblock || ret2 != -EAGAIN) { /* IOPOLL retry should happen for io-wq threads */ if ((req->ctx->flags & IORING_SETUP_IOPOLL) && ret2 == -EAGAIN) goto copy_iov; +done: kiocb_done(kiocb, ret2, cs); } else { copy_iov: -- 2.39.5