From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3B06EC433EF for ; Tue, 28 Jun 2022 15:17:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347624AbiF1PRl (ORCPT ); Tue, 28 Jun 2022 11:17:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347622AbiF1PRk (ORCPT ); Tue, 28 Jun 2022 11:17:40 -0400 Received: from mail-io1-xd2f.google.com (mail-io1-xd2f.google.com [IPv6:2607:f8b0:4864:20::d2f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1901F32053 for ; Tue, 28 Jun 2022 08:17:39 -0700 (PDT) Received: by mail-io1-xd2f.google.com with SMTP id s17so13179193iob.7 for ; Tue, 28 Jun 2022 08:17:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=jRkMzSQzgOMgPIEkkuhPs2nAj1hHj9sd4Ri+U/HJKsQ=; b=3CnJqKTXL8Azv13zI2BEkSJuzpXac2RqDDiOAhEjehAxPPpCfR/JKGJcUIxgjN4nJX UzoOj2eOSG+/3jGxVWbefGBrAfLd6DdDZNxaYc/2ry9rwJ6tX0gc5Nt9dj41IHBrTzVx xeYO183OIKOjnaDOivHFWm7PZUjw3Rbwc6O004zLSTWlHUwXjuTfEOqnLyFcD97k+xRi MRk1fxHzMntbEFlbzRX6a5Jwqxm/wUTVbVsOL6hG3Tn2Ii/VDlq+3k96M5bDHDi4+mra TJHuLFOF2TaCSDsGiV7RumT/xbm0t4MET9rgcmD2vKYHJvr1p3FWH+6xK94eaGHE9Tme 4peg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=jRkMzSQzgOMgPIEkkuhPs2nAj1hHj9sd4Ri+U/HJKsQ=; b=pQs4EaGetbX0Gk+uMByHrCUlyiq8UyufyQ/hFD8QTcmRHwYD4JdkTk1tgbtQCiM4Mu iaHqbhhjtMOBhoMVtvxD5NJbeeBUoiJs56rlzAVBylCwAEX37p6xqMxtYwC2K+/nRVyl VRekfDk8VmmYeoDj+hQVoBsjnrj+QKs4+ujY0KarIrW4cbNTfe6Nj7UZTNFS4qXOrNCg 0zYX9GzcrcQEruHHSNwC6XII44qVNTRT78SJPbThaKO26SvtlJAQ1oqs4FbFZqakzWx2 VNV/8v43AcrQtUoMPHgTgHDQDNMVuyYGfqDnhh+ls732SPTNX8PQcJYtAHKDTogu48zH nZrQ== X-Gm-Message-State: AJIora/qpPmY/fMjuunRPdqeH0gvWA8uTYeki4kLE0mmgXFLxZZl8zBf c1dExf2y0ovA9DXH9rqfjTcBLg== X-Google-Smtp-Source: AGRyM1si+3E1+d8q6BXGRJWygzB54R9wQkcd0jeCC63qrY1a+b74XrvjSgqWaAxnjYXhhFCyLW6CCA== X-Received: by 2002:a5d:9d9b:0:b0:669:cd74:7e0d with SMTP id ay27-20020a5d9d9b000000b00669cd747e0dmr10131641iob.7.1656429458412; Tue, 28 Jun 2022 08:17:38 -0700 (PDT) Received: from [192.168.1.172] ([207.135.234.126]) by smtp.gmail.com with ESMTPSA id k15-20020a02a70f000000b00331b9a3c5adsm6092281jam.170.2022.06.28.08.17.37 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 28 Jun 2022 08:17:37 -0700 (PDT) Message-ID: <8af6250c-9f83-3a33-fa73-e6df0982ff63@kernel.dk> Date: Tue, 28 Jun 2022 09:17:35 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:91.0) Gecko/20100101 Thunderbird/91.10.0 Subject: Re: [PATCH for-next 8/8] io_uring: multishot recv Content-Language: en-US To: Dylan Yudaken , Pavel Begunkov , io-uring@vger.kernel.org Cc: Kernel-team@fb.com, linux-kernel@vger.kernel.org References: <20220628150228.1379645-1-dylany@fb.com> <20220628150228.1379645-9-dylany@fb.com> From: Jens Axboe In-Reply-To: <20220628150228.1379645-9-dylany@fb.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 6/28/22 9:02 AM, Dylan Yudaken wrote: > @@ -399,13 +401,22 @@ int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) > sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr)); > sr->len = READ_ONCE(sqe->len); > sr->flags = READ_ONCE(sqe->addr2); > - if (sr->flags & ~IORING_RECVSEND_POLL_FIRST) > + if (sr->flags & ~(RECVMSG_FLAGS)) > return -EINVAL; > sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL; > if (sr->msg_flags & MSG_DONTWAIT) > req->flags |= REQ_F_NOWAIT; > if (sr->msg_flags & MSG_ERRQUEUE) > req->flags |= REQ_F_CLEAR_POLLIN; > + if (sr->flags & IORING_RECV_MULTISHOT) { > + if (!(req->flags & REQ_F_BUFFER_SELECT)) > + return -EINVAL; > + if (sr->msg_flags & MSG_WAITALL) > + return -EINVAL; > + if (req->opcode == IORING_OP_RECV && sr->len) > + return -EINVAL; > + req->flags |= REQ_F_APOLL_MULTISHOT; > + } Do we want to forbid not using provided buffers? If you have a ping-pong type setup, eg you know you'll have to send something before you receive anything again, seems like it'd be feasible to use this with a normal buffer? I strongly suspect that most use cases will use provided buffers for this, just wondering if there are any particular reasons for forbidding it explicitly. > > #ifdef CONFIG_COMPAT > if (req->ctx->compat) > @@ -415,6 +426,14 @@ int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) > return 0; > } > > +static inline void io_recv_prep_retry(struct io_kiocb *req) > +{ > + struct io_sr_msg *sr = io_kiocb_to_cmd(req); > + > + sr->done_io = 0; > + sr->len = 0; /* get from the provided buffer */ > +} > + > int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) > { > struct io_sr_msg *sr = io_kiocb_to_cmd(req); > @@ -424,6 +443,7 @@ int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) > unsigned flags; > int ret, min_ret = 0; > bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; > + size_t len = sr->len; > > sock = sock_from_file(req->file); > if (unlikely(!sock)) > @@ -442,16 +462,17 @@ int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) > (sr->flags & IORING_RECVSEND_POLL_FIRST)) > return io_setup_async_msg(req, kmsg); > > +retry_multishot: > if (io_do_buffer_select(req)) { > void __user *buf; > > - buf = io_buffer_select(req, &sr->len, issue_flags); > + buf = io_buffer_select(req, &len, issue_flags); > if (!buf) > return -ENOBUFS; > kmsg->fast_iov[0].iov_base = buf; > - kmsg->fast_iov[0].iov_len = sr->len; > + kmsg->fast_iov[0].iov_len = len; > iov_iter_init(&kmsg->msg.msg_iter, READ, kmsg->fast_iov, 1, > - sr->len); > + len); > } > > flags = sr->msg_flags; > @@ -463,8 +484,15 @@ int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) > kmsg->msg.msg_get_inq = 1; > ret = __sys_recvmsg_sock(sock, &kmsg->msg, sr->umsg, kmsg->uaddr, flags); > if (ret < min_ret) { > - if (ret == -EAGAIN && force_nonblock) > - return io_setup_async_msg(req, kmsg); > + if (ret == -EAGAIN && force_nonblock) { > + ret = io_setup_async_msg(req, kmsg); > + if (ret == -EAGAIN && (req->flags & IO_APOLL_MULTI_POLLED) == > + IO_APOLL_MULTI_POLLED) { > + io_kbuf_recycle(req, issue_flags); > + ret = IOU_ISSUE_SKIP_COMPLETE; > + } > + return ret; > + } > if (ret == -ERESTARTSYS) > ret = -EINTR; > if (ret > 0 && io_net_retry(sock, flags)) { > @@ -491,8 +519,24 @@ int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) > cflags = io_put_kbuf(req, issue_flags); > if (kmsg->msg.msg_inq) > cflags |= IORING_CQE_F_SOCK_NONEMPTY; > + > + if (!(req->flags & REQ_F_APOLL_MULTISHOT)) { > + io_req_set_res(req, ret, cflags); > + return IOU_OK; > + } > + > + if (ret > 0) { > + if (io_post_aux_cqe(req->ctx, req->cqe.user_data, ret, > + cflags | IORING_CQE_F_MORE)) { > + io_recv_prep_retry(req); > + goto retry_multishot; > + } else { > + ret = -ECANCELED; > + } > + } > + > io_req_set_res(req, ret, cflags); > - return IOU_OK; > + return req->flags & REQ_F_POLLED ? IOU_STOP_MULTISHOT : ret; > } Minor style, but I prefer avoiding ternaries if possible. This is much easier to read for me: if (req->flags & REQ_F_POLLED) return IOU_STOP_MULTISHOT; return ret; > @@ -505,6 +549,7 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags) > unsigned flags; > int ret, min_ret = 0; > bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; > + size_t len = sr->len; > > if (!(req->flags & REQ_F_POLLED) && > (sr->flags & IORING_RECVSEND_POLL_FIRST)) > @@ -514,16 +559,17 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags) > if (unlikely(!sock)) > return -ENOTSOCK; > > +retry_multishot: > if (io_do_buffer_select(req)) { > void __user *buf; > > - buf = io_buffer_select(req, &sr->len, issue_flags); > + buf = io_buffer_select(req, &len, issue_flags); > if (!buf) > return -ENOBUFS; > sr->buf = buf; > } > > - ret = import_single_range(READ, sr->buf, sr->len, &iov, &msg.msg_iter); > + ret = import_single_range(READ, sr->buf, len, &iov, &msg.msg_iter); > if (unlikely(ret)) > goto out_free; > > @@ -543,8 +589,14 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags) > > ret = sock_recvmsg(sock, &msg, flags); > if (ret < min_ret) { > - if (ret == -EAGAIN && force_nonblock) > - return -EAGAIN; > + if (ret == -EAGAIN && force_nonblock) { > + if ((req->flags & IO_APOLL_MULTI_POLLED) == IO_APOLL_MULTI_POLLED) { > + io_kbuf_recycle(req, issue_flags); > + ret = IOU_ISSUE_SKIP_COMPLETE; > + } > + > + return ret; > + } Maybe: if ((req->flags & IO_APOLL_MULTI_POLLED) == IO_APOLL_MULTI_POLLED) { io_kbuf_recycle(req, issue_flags); return IOU_ISSUE_SKIP_COMPLETE; } return ret; > @@ -570,8 +622,25 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags) > cflags = io_put_kbuf(req, issue_flags); > if (msg.msg_inq) > cflags |= IORING_CQE_F_SOCK_NONEMPTY; > + > + > + if (!(req->flags & REQ_F_APOLL_MULTISHOT)) { > + io_req_set_res(req, ret, cflags); > + return IOU_OK; > + } > + > + if (ret > 0) { > + if (io_post_aux_cqe(req->ctx, req->cqe.user_data, ret, > + cflags | IORING_CQE_F_MORE)) { > + io_recv_prep_retry(req); > + goto retry_multishot; > + } else { > + ret = -ECANCELED; > + } > + } > + > io_req_set_res(req, ret, cflags); > - return IOU_OK; > + return req->flags & REQ_F_POLLED ? IOU_STOP_MULTISHOT : ret; > } Same here, and maybe this needs to be a helper so you could just do return io_recv_finish(req, ret, cflags); or something like that? It's non-trivial duplicated code. -- Jens Axboe