io_uring: don't check PF_EXITING from syscall

io_sq_thread_acquire_mm_files() can find a PF_EXITING task only when
it's called from task_work context. Don't check it in all other cases,
that are when we're in io_uring_enter().

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 9c58be0..66bbb0d 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1213,8 +1213,6 @@ static int __io_sq_thread_acquire_mm_files(struct io_ring_ctx *ctx,
 static inline int io_sq_thread_acquire_mm_files(struct io_ring_ctx *ctx,
                                                struct io_kiocb *req)
 {
-       if (unlikely(current->flags & PF_EXITING))
-               return -EFAULT;
        if (!(ctx->flags & IORING_SETUP_SQPOLL))
                return 0;
        return __io_sq_thread_acquire_mm_files(ctx, req);
@@ -2338,7 +2336,8 @@ static void __io_req_task_submit(struct io_kiocb *req)
 
        /* ctx stays valid until unlock, even if we drop all ours ctx->refs */
        mutex_lock(&ctx->uring_lock);
-       if (!ctx->sqo_dead && !io_sq_thread_acquire_mm_files(ctx, req))
+       if (!ctx->sqo_dead && !(current->flags & PF_EXITING) &&
+           !io_sq_thread_acquire_mm_files(ctx, req))
                __io_queue_sqe(req);
        else
                __io_req_task_cancel(req, -EFAULT);