From 9728463737db027557e8ba315cbbca6b81122c04 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Thu, 8 Apr 2021 19:28:03 +0100 Subject: [PATCH] io_uring: fix rw req completion WARNING: at fs/io_uring.c:8578 io_ring_exit_work.cold+0x0/0x18 As reissuing is now passed back by REQ_F_REISSUE and kiocb_done() internally uses __io_complete_rw(), it may stop after setting the flag so leaving a dangling request. There are tricky edge cases, e.g. reading beyound file, boundary, so the easiest way is to hand code reissue in kiocb_done() as __io_complete_rw() was doing for us before. Fixes: 230d50d448ac ("io_uring: move reissue into regular IO path") Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/f602250d292f8a84cca9a01d747744d1e797be26.1617842918.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- fs/io_uring.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/fs/io_uring.c b/fs/io_uring.c index f1881ac..bd14327 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2762,6 +2762,7 @@ static void kiocb_done(struct kiocb *kiocb, ssize_t ret, { struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); struct io_async_rw *io = req->async_data; + bool check_reissue = kiocb->ki_complete == io_complete_rw; /* add previously done IO, if any */ if (io && io->bytes_done > 0) { @@ -2777,6 +2778,18 @@ static void kiocb_done(struct kiocb *kiocb, ssize_t ret, __io_complete_rw(req, ret, 0, issue_flags); else io_rw_done(kiocb, ret); + + if (check_reissue && req->flags & REQ_F_REISSUE) { + req->flags &= ~REQ_F_REISSUE; + if (!io_rw_reissue(req)) { + int cflags = 0; + + req_set_fail_links(req); + if (req->flags & REQ_F_BUFFER_SELECTED) + cflags = io_put_rw_kbuf(req); + __io_req_complete(req, issue_flags, ret, cflags); + } + } } static int io_import_fixed(struct io_kiocb *req, int rw, struct iov_iter *iter) -- 2.7.4