The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From a1bb3cd58913338e1b627ea6b8c03c2ae82d293f Mon Sep 17 00:00:00 2001
From: Pavel Begunkov asml.silence@gmail.com Date: Tue, 26 Jan 2021 15:28:26 +0000 Subject: [PATCH] io_uring: fix __io_uring_files_cancel() with TASK_UNINTERRUPTIBLE
If the tctx inflight number haven't changed because of cancellation, __io_uring_task_cancel() will continue leaving the task in TASK_UNINTERRUPTIBLE state, that's not expected by __io_uring_files_cancel(). Ensure we always call finish_wait() before retrying.
Cc: stable@vger.kernel.org # 5.9+ Signed-off-by: Pavel Begunkov asml.silence@gmail.com Signed-off-by: Jens Axboe axboe@kernel.dk
diff --git a/fs/io_uring.c b/fs/io_uring.c index 2166c469789d..09aada153a71 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -9124,16 +9124,15 @@ void __io_uring_task_cancel(void) prepare_to_wait(&tctx->wait, &wait, TASK_UNINTERRUPTIBLE);
/* - * If we've seen completions, retry. This avoids a race where - * a completion comes in before we did prepare_to_wait(). + * If we've seen completions, retry without waiting. This + * avoids a race where a completion comes in before we did + * prepare_to_wait(). */ - if (inflight != tctx_inflight(tctx)) - continue; - schedule(); + if (inflight == tctx_inflight(tctx)) + schedule(); finish_wait(&tctx->wait, &wait); } while (1);
- finish_wait(&tctx->wait, &wait); atomic_dec(&tctx->in_idle);
io_uring_remove_task_files(tctx);