From 860e1c7f8b0b43fbf91b4d689adfaa13adb89452 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Fri, 14 Apr 2023 15:53:13 +0800 Subject: [PATCH] io_uring: complete request via task work in case of DEFER_TASKRUN So far io_req_complete_post() only covers DEFER_TASKRUN by completing request via task work when the request is completed from IOWQ. However, uring command could be completed from any context, and if io uring is setup with DEFER_TASKRUN, the command is required to be completed from current context, otherwise wait on IORING_ENTER_GETEVENTS can't be wakeup, and may hang forever. The issue can be observed on removing ublk device, but turns out it is one generic issue for uring command & DEFER_TASKRUN, so solve it in io_uring core code. Fixes: e6aeb2721d3b ("io_uring: complete all requests in task context") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/linux-block/b3fc9991-4c53-9218-a8cc-5b4dd3952108@kernel.dk/ Reported-by: Jens Axboe Cc: Kanchan Joshi Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- io_uring/io_uring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 2a8b8c304d2a..4a865f0e85d0 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -998,7 +998,7 @@ static void __io_req_complete_post(struct io_kiocb *req) void io_req_complete_post(struct io_kiocb *req, unsigned issue_flags) { - if (req->ctx->task_complete && (issue_flags & IO_URING_F_IOWQ)) { + if (req->ctx->task_complete && req->ctx->submitter_task != current) { req->io_task_work.func = io_req_task_complete; io_req_task_work_add(req); } else if (!(issue_flags & IO_URING_F_UNLOCKED) ||