From patchwork Tue Nov 30 15:18:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Begunkov X-Patchwork-Id: 12647587 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 41293C433F5 for ; Tue, 30 Nov 2021 15:20:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245425AbhK3PYJ (ORCPT ); Tue, 30 Nov 2021 10:24:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38452 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245085AbhK3PX2 (ORCPT ); Tue, 30 Nov 2021 10:23:28 -0500 Received: from mail-wr1-x435.google.com (mail-wr1-x435.google.com [IPv6:2a00:1450:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D43EDC061D64; Tue, 30 Nov 2021 07:19:26 -0800 (PST) Received: by mail-wr1-x435.google.com with SMTP id d9so24352431wrw.4; Tue, 30 Nov 2021 07:19:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=wY1As03rF5TmjUCuV7yr/sjJ+OmJ/UHrJ+IXfv0oMnk=; b=Fce56+l13k3XBLtYTY3SV8DvM+jDhx35XvC5Ovm+Rcrb5mD33F0PD2UcLtlvRSct3P GJ+lalBXL2WrFdKoglE7FCPv450yNZPvrlEXGB2BfsqYgX4p0x+X2elSRs6oSVJKjrFM vV7IX7WN40jOzoHMlHsqk+4UMpbz4z7PRtdDzt7qDJvCnaoueZuJf+n1rfZOaeudOA+w bcNaTBcZHPe/EVG5tY8uPgZU/cf6mix+qZkKxG54Da6B7JWeOY72Zx5u8to3assLF2jW Flm3LSf/crHM1Q/7E8gkdk3BAyruqUSPmOCDPedzou0KjPgYSaQKEkEpdN+15M1jEo4x 4Vow== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=wY1As03rF5TmjUCuV7yr/sjJ+OmJ/UHrJ+IXfv0oMnk=; b=IiDLxNcZMhwrdMCd+dtPe+44xDyp45sL7rCK8IDQsevsmdKqcQbI4x9NrWGxUCO8No KpXhm6BtFraEmSLV5snwffdYuv67J1qaA69hieaaTwGSbDISTt4h9OgjQQ4BX7VOlqKk h6E9K5ZGr/YIhB+TfQKOcBOu+KY5v/2M0MUOyyURnwnC4+954LoDDfMzAOkN76bYHJYx VWIOVHbNcnxruImp/JOJoarQOQwTDhAzkPZGFdgcodpRBvGgXd4KYYxItj/GUVkaDZ/P yHw/ihwmq2zciIfAPVvM2If372MX5g2o8VKuTI/oSj7FvFYUqHpcCilvjXYjUaK2m6rJ DEjg== X-Gm-Message-State: AOAM531CMf+EYy40AD5oUKFgTLQzYoVcUrllfH6O4hWcYqTIdAw1IS9y tH98MwqCfAlHTsDgliujKZDsXJLURGo= X-Google-Smtp-Source: ABdhPJzbEKvbxueRTlTT7Mp7AlrSXRSpYDRNHgdxY6sidzxX9SNgqMuNTsYQMw9L7Lm+hPZFwlndJQ== X-Received: by 2002:a5d:648e:: with SMTP id o14mr41003106wri.141.1638285565244; Tue, 30 Nov 2021 07:19:25 -0800 (PST) Received: from 127.0.0.1localhost ([85.255.232.109]) by smtp.gmail.com with ESMTPSA id d1sm16168483wrz.92.2021.11.30.07.19.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Nov 2021 07:19:24 -0800 (PST) From: Pavel Begunkov To: io-uring@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jakub Kicinski , Jonathan Lemon , "David S . Miller" , Willem de Bruijn , Eric Dumazet , Hideaki YOSHIFUJI , David Ahern , Jens Axboe , Pavel Begunkov Subject: [RFC 06/12] io_uring: add send notifiers registration Date: Tue, 30 Nov 2021 15:18:54 +0000 Message-Id: <1585ab7d7c7c987450f733b5773bc1ca1f673fce.1638282789.git.asml.silence@gmail.com> X-Mailer: git-send-email 2.34.0 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-State: RFC Add IORING_REGISTER_TX_CTX and IORING_UNREGISTER_TX_CTX. Transmission (i.e. send) context will serve be used to notify the userspace when fixed buffers used for zerocopy sends are released by the kernel. Notification of a single tx context lives in generations, where each generation posts one CQE with ->user_data equal to the specified tag and ->res is a generation number starting from 0. All requests issued against a ctx will get attached to the current generation of notifications. Then, the userspace will be able to request to flush the notification allowing it to post a CQE when all buffers of all requests attached to it are released by the kernel. It'll also switch the generation to a new one with a sequence number incremented by one. Signed-off-by: Pavel Begunkov --- fs/io_uring.c | 72 +++++++++++++++++++++++++++++++++++ include/uapi/linux/io_uring.h | 7 ++++ 2 files changed, 79 insertions(+) diff --git a/fs/io_uring.c b/fs/io_uring.c index 59380e3454ad..a01f91e70fa5 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -94,6 +94,8 @@ #define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES) #define IORING_SQPOLL_CAP_ENTRIES_VALUE 8 +#define IORING_MAX_TX_NOTIFIERS (1U << 10) + /* only define max */ #define IORING_MAX_FIXED_FILES (1U << 15) #define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \ @@ -326,6 +328,15 @@ struct io_submit_state { struct blk_plug plug; }; +struct io_tx_notifier { +}; + +struct io_tx_ctx { + struct io_tx_notifier *notifier; + u64 tag; + u32 seq; +}; + struct io_ring_ctx { /* const or read-mostly hot data */ struct { @@ -373,6 +384,8 @@ struct io_ring_ctx { unsigned nr_user_files; unsigned nr_user_bufs; struct io_mapped_ubuf **user_bufs; + struct io_tx_ctx *tx_ctxs; + unsigned nr_tx_ctxs; struct io_submit_state submit_state; struct list_head timeout_list; @@ -9199,6 +9212,55 @@ static int io_buffer_validate(struct iovec *iov) return 0; } +static int io_sqe_tx_ctx_unregister(struct io_ring_ctx *ctx) +{ + if (!ctx->nr_tx_ctxs) + return -ENXIO; + + kvfree(ctx->tx_ctxs); + ctx->tx_ctxs = NULL; + ctx->nr_tx_ctxs = 0; + return 0; +} + +static int io_sqe_tx_ctx_register(struct io_ring_ctx *ctx, + void __user *arg, unsigned int nr_args) +{ + struct io_uring_tx_ctx_register __user *tx_args = arg; + struct io_uring_tx_ctx_register tx_arg; + unsigned i; + int ret; + + if (ctx->nr_tx_ctxs) + return -EBUSY; + if (!nr_args) + return -EINVAL; + if (nr_args > IORING_MAX_TX_NOTIFIERS) + return -EMFILE; + + ctx->tx_ctxs = kvcalloc(nr_args, sizeof(ctx->tx_ctxs[0]), + GFP_KERNEL_ACCOUNT); + if (!ctx->tx_ctxs) + return -ENOMEM; + + for (i = 0; i < nr_args; i++, ctx->nr_tx_ctxs++) { + struct io_tx_ctx *tx_ctx = &ctx->tx_ctxs[i]; + + if (copy_from_user(&tx_arg, &tx_args[i], sizeof(tx_arg))) { + ret = -EFAULT; + goto out_fput; + } + tx_ctx->tag = tx_arg.tag; + } + return 0; + +out_fput: + kvfree(ctx->tx_ctxs); + ctx->tx_ctxs = NULL; + ctx->nr_tx_ctxs = 0; + return ret; +} + static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, unsigned int nr_args, u64 __user *tags) { @@ -9429,6 +9491,7 @@ static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx) #endif WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list)); + io_sqe_tx_ctx_unregister(ctx); io_mem_free(ctx->rings); io_mem_free(ctx->sq_sqes); @@ -11104,6 +11167,15 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, break; ret = io_register_iowq_max_workers(ctx, arg); break; + case IORING_REGISTER_TX_CTX: + ret = io_sqe_tx_ctx_register(ctx, arg, nr_args); + break; + case IORING_UNREGISTER_TX_CTX: + ret = -EINVAL; + if (arg || nr_args) + break; + ret = io_sqe_tx_ctx_unregister(ctx); + break; default: ret = -EINVAL; break; diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 787f491f0d2a..f2e8d18e40e0 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -325,6 +325,9 @@ enum { /* set/get max number of io-wq workers */ IORING_REGISTER_IOWQ_MAX_WORKERS = 19, + IORING_REGISTER_TX_CTX = 20, + IORING_UNREGISTER_TX_CTX = 21, + /* this goes last */ IORING_REGISTER_LAST }; @@ -365,6 +368,10 @@ struct io_uring_rsrc_update2 { __u32 resv2; }; +struct io_uring_tx_ctx_register { + __u64 tag; +}; + /* Skip updating fd indexes set to this value in the fd table */ #define IORING_REGISTER_FILES_SKIP (-2)