3 files changed, 29 insertions, 25 deletions

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 64845634d89f..2675cffbd9a4 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -527,19 +527,6 @@ static void io_queue_iowq(struct io_kiocb *req)
 		io_queue_linked_timeout(link);
 }
 
-static void io_tw_requeue_iowq(struct io_kiocb *req, struct io_tw_state *ts)
-{
-	req->flags &= ~REQ_F_REISSUE;
-	io_queue_iowq(req);
-}
-
-void io_tw_queue_iowq(struct io_kiocb *req)
-{
-	req->flags |= REQ_F_REISSUE | REQ_F_BL_NO_RECYCLE;
-	req->io_task_work.func = io_tw_requeue_iowq;
-	io_req_task_work_add(req);
-}
-
 static __cold void io_queue_deferred(struct io_ring_ctx *ctx)
 {
 	while (!list_empty(&ctx->defer_list)) {
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index b83a719c5443..624ca9076a50 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -75,7 +75,6 @@ struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
 void __io_req_task_work_add(struct io_kiocb *req, unsigned flags);
 bool io_alloc_async_data(struct io_kiocb *req);
 void io_req_task_queue(struct io_kiocb *req);
-void io_tw_queue_iowq(struct io_kiocb *req);
 void io_req_task_complete(struct io_kiocb *req, struct io_tw_state *ts);
 void io_req_task_queue_fail(struct io_kiocb *req, int ret);
 void io_req_task_submit(struct io_kiocb *req, struct io_tw_state *ts);
diff --git a/io_uring/rw.c b/io_uring/rw.c
index 4fed829fe97c..a6bf2ea8db91 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -396,9 +396,16 @@ static inline loff_t *io_kiocb_update_pos(struct io_kiocb *req)
 	return NULL;
 }
 
+#ifdef CONFIG_BLOCK
+static void io_resubmit_prep(struct io_kiocb *req)
+{
+	struct io_async_rw *io = req->async_data;
+
+	iov_iter_restore(&io->iter, &io->iter_state);
+}
+
 static bool io_rw_should_reissue(struct io_kiocb *req)
 {
-#ifdef CONFIG_BLOCK
 	umode_t mode = file_inode(req->file)->i_mode;
 	struct io_ring_ctx *ctx = req->ctx;
 
@@ -414,11 +421,23 @@ static bool io_rw_should_reissue(struct io_kiocb *req)
 	 */
 	if (percpu_ref_is_dying(&ctx->refs))
 		return false;
+	/*
+	 * Play it safe and assume not safe to re-import and reissue if we're
+	 * not in the original thread group (or in task context).
+	 */
+	if (!same_thread_group(req->task, current) || !in_task())
+		return false;
 	return true;
+}
 #else
+static void io_resubmit_prep(struct io_kiocb *req)
+{
+}
+static bool io_rw_should_reissue(struct io_kiocb *req)
+{
 	return false;
-#endif
 }
+#endif
 
 static void io_req_end_write(struct io_kiocb *req)
 {
@@ -455,7 +474,7 @@ static bool __io_complete_rw_common(struct io_kiocb *req, long res)
 			 * current cycle.
 			 */
 			io_req_io_end(req);
-			io_tw_queue_iowq(req);
+			req->flags |= REQ_F_REISSUE | REQ_F_BL_NO_RECYCLE;
 			return true;
 		}
 		req_set_fail(req);
@@ -521,7 +540,7 @@ static void io_complete_rw_iopoll(struct kiocb *kiocb, long res)
 		io_req_end_write(req);
 	if (unlikely(res != req->cqe.res)) {
 		if (res == -EAGAIN && io_rw_should_reissue(req)) {
-			io_tw_queue_iowq(req);
+			req->flags |= REQ_F_REISSUE | REQ_F_BL_NO_RECYCLE;
 			return;
 		}
 		req->cqe.res = res;
@@ -583,10 +602,8 @@ static int kiocb_done(struct io_kiocb *req, ssize_t ret,
 	}
 
 	if (req->flags & REQ_F_REISSUE) {
-		struct io_async_rw *io = req->async_data;
-
 		req->flags &= ~REQ_F_REISSUE;
-		iov_iter_restore(&io->iter, &io->iter_state);
+		io_resubmit_prep(req);
 		return -EAGAIN;
 	}
 	return IOU_ISSUE_SKIP_COMPLETE;
@@ -839,8 +856,7 @@ static int __io_read(struct io_kiocb *req, unsigned int issue_flags)
 	ret = io_iter_do_read(rw, &io->iter);
 
 	if (ret == -EAGAIN || (req->flags & REQ_F_REISSUE)) {
-		if (req->flags & REQ_F_REISSUE)
-			return IOU_ISSUE_SKIP_COMPLETE;
+		req->flags &= ~REQ_F_REISSUE;
 		/* If we can poll, just do that. */
 		if (io_file_can_poll(req))
 			return -EAGAIN;
@@ -1035,8 +1051,10 @@ int io_write(struct io_kiocb *req, unsigned int issue_flags)
 	else
 		ret2 = -EINVAL;
 
-	if (req->flags & REQ_F_REISSUE)
-		return IOU_ISSUE_SKIP_COMPLETE;
+	if (req->flags & REQ_F_REISSUE) {
+		req->flags &= ~REQ_F_REISSUE;
+		ret2 = -EAGAIN;
+	}
 
 	/*
 	 * Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just