io_uring/rw: don't gate retry on completion context

nvme multipath reports that they see spurious -EAGAIN bubbling back to
userspace, which is caused by how they handle retries internally through
a kworker. However, any data that needs preserving or importing for
a read/write request has always been done so at prep time, and we can
sanely skip this check.

Reported-by: "Haeuptle, Michael" <[email protected]>
Link: https://lore.kernel.org/io-uring/DS7PR84MB31105C2C63CFA47BE8CBD6EE95102@DS7PR84MB3110.NAMPRD84.PROD.OUTLOOK.COM/
Signed-off-by: Jens Axboe <[email protected]>

Author: axboe

io_uring/rw.c

@@ -475,12 +475,6 @@ 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->tctx->task, current) || !in_task())
-		return false;
 
 	io_meta_restore(io, &rw->kiocb);
 	iov_iter_restore(&io->iter, &io->iter_state);