From patchwork Tue Sep 24 11:57:31 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 13810853 Received: from mail-yb1-f176.google.com (mail-yb1-f176.google.com [209.85.219.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8EAE3824AD for ; Tue, 24 Sep 2024 11:59:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.176 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727179197; cv=none; b=AaiwXr4nJCPTmVqvdRwhCNvue7wb3lGHSg6IEc1LQzi0pllxYC+c0Io8aFAV+lS1l+6CcQQoIvk9rHLkHszV/wxPbTjyrRzBkfE3dc413AJg0B+VcJWuxVPL3/8wtRUoUOB1xLAYSFfY1l57Pq+56ocaU5qUAvfIoFQXL/u5CN0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727179197; c=relaxed/simple; bh=QOC/N8vk6BOMdwuxSmj3j3a/LlaCgEAbn4IyfQ/B98o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=G8UbQbysnxqNlfQVs+h37KtG+YeBLJRf1a6I3DLxEZ6SjskhD8eBhIKhONEFHb1v93pkMsOlQ9BMMcqazZwV0mrJ97AaRqcwLkiq0qShCv/EYCx4n4DT1WQ9n7OEp38OticB4Jk03YD9FAli2tH807umD1CIn2ZvAJn7UlzdieM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk; spf=pass smtp.mailfrom=kernel.dk; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b=VFwTajpM; arc=none smtp.client-ip=209.85.219.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.dk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b="VFwTajpM" Received: by mail-yb1-f176.google.com with SMTP id 3f1490d57ef6-e1d0e1bffc8so4536994276.1 for ; Tue, 24 Sep 2024 04:59:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1727179194; x=1727783994; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=iHcPl3EZ4otcEGCvrDoTgKNq26PHxqo0jU5GtWYyTcQ=; b=VFwTajpM6JAnulVCkeUqvQTImxLBq99DeVEVe1xyBl8a2fklCcztS+Ud7UtDkComUc upjkoDbpsc4v6SGJmMNCGNmI6ci+iu27rLowLUSs41l3jisqrQPiTh+UtKGoXpIUp1hb AqY5DWNDrkrunZHUn/EL2342zs2UFNGnr1FXqA3KhrSWaGauC7eMxM7Xdax01ITavKzB I4liOcgFl5cVYQfEJ6NvuRZZ1+Ci4wc3W755vRdUlm8hxltO170Xt7QhXq1DCMuGDmUN lycM/EM/1i0HFjXRdj5LGnaquab1xd3h2WglzMSRVQ+7qvcYHq5KeIhBQaW3dbNLbPFl 2aUw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1727179194; x=1727783994; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=iHcPl3EZ4otcEGCvrDoTgKNq26PHxqo0jU5GtWYyTcQ=; b=LWrEW4vkQNTe7Vu9iSgfBrQ+jl+ve6Atx1fMgZTjvYdn/FrYUHT82495BrGxsdsC6t z0ritlVWD8z1brT6WUGnrI5/k5TvKlXSHe8gWlDuvALU49gkg/HTRqSFgQC/KXarLQ5o elLoGgA+ip/LfO2bBKOoReB8ikKsnz/OdTCMmeUfjLU84SI0I3F2RtzJGNM0xQp4wlzF Ls3UqIYP3jkhQb68B0p7peQr0FD8yO1eawNX3aNQqPpgFRhzRllbAcFx4d9Z+mHYqyME 4LTHQHNkHg6DKeJdvOkyaWZmug4pyPv0alCWLyfOElclzxzQs/mPKyI6A35fNhryJtUk Fb+w== X-Gm-Message-State: AOJu0YwYtyRlq+meZ818U62vdIjLIKnrKHP34AubSGM1nFu95K2ZdkMx EhDAgKEDSajUYwvhMM6Pztkkk/1rF/NG98IE0dUT9u8XsGVYwrSJTyhUYKFqtPiwUNbHlvFbAdn Ccm6KsA== X-Google-Smtp-Source: AGHT+IFGfYh7OZPVzQIU/1KrNMvDnoD46Pl+Dul2F+GS7gAg4bRt0zK3n63BQkiuFX76s23Upw0vsg== X-Received: by 2002:a05:6902:2613:b0:e20:2245:6fa4 with SMTP id 3f1490d57ef6-e2252fbb135mr11304261276.47.1727179194169; Tue, 24 Sep 2024 04:59:54 -0700 (PDT) Received: from localhost.localdomain ([2600:381:1d13:f852:a731:c08e:e897:179a]) by smtp.gmail.com with ESMTPSA id 3f1490d57ef6-e2499ae6a06sm210598276.4.2024.09.24.04.59.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 24 Sep 2024 04:59:53 -0700 (PDT) From: Jens Axboe To: io-uring@vger.kernel.org Cc: Jens Axboe Subject: [PATCH 2/2] io_uring/msg_ring: add support for sending a sync message Date: Tue, 24 Sep 2024 05:57:31 -0600 Message-ID: <20240924115932.116167-3-axboe@kernel.dk> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240924115932.116167-1-axboe@kernel.dk> References: <20240924115932.116167-1-axboe@kernel.dk> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Normally MSG_RING requires both a source and a destination ring. But some users don't always have a ring avilable to send a message from, yet they still need to notify a target ring. Add support for using io_uring_register(2) without having a source ring, using a file descriptor of -1 for that. Internally those are called blind registration opcodes. Implement IORING_REGISTER_SEND_MSG_RING as a blind opcode, which simply takes an sqe that the application can put on the stack and use the normal liburing helpers to initialize it. Then the app can call: io_uring_register(-1, IORING_REGISTER_SEND_MSG_RING, &sqe, 1); and get the same behavior in terms of the target, where a CQE is posted with the details given in the sqe. For now this takes a single sqe pointer argument, and hence arg must be set to that, and nr_args must be 1. Could easily be extended to take an array of sqes, but for now let's keep it simple. Signed-off-by: Jens Axboe --- include/uapi/linux/io_uring.h | 3 +++ io_uring/msg_ring.c | 29 +++++++++++++++++++++++++++++ io_uring/msg_ring.h | 1 + io_uring/register.c | 30 ++++++++++++++++++++++++++++++ 4 files changed, 63 insertions(+) diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 1fe79e750470..86cb385fe0b5 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -612,6 +612,9 @@ enum io_uring_register_op { /* clone registered buffers from source ring to current ring */ IORING_REGISTER_CLONE_BUFFERS = 30, + /* send MSG_RING without having a ring */ + IORING_REGISTER_SEND_MSG_RING = 31, + /* this goes last */ IORING_REGISTER_LAST, diff --git a/io_uring/msg_ring.c b/io_uring/msg_ring.c index b8c527f08cd5..edea1ffd501c 100644 --- a/io_uring/msg_ring.c +++ b/io_uring/msg_ring.c @@ -331,6 +331,35 @@ int io_msg_ring(struct io_kiocb *req, unsigned int issue_flags) return IOU_OK; } +int io_uring_sync_msg_ring(struct io_uring_sqe *sqe) +{ + struct io_msg io_msg = { }; + struct fd f; + int ret; + + ret = __io_msg_ring_prep(&io_msg, sqe); + if (unlikely(ret)) + return ret; + + /* + * Only data sending supported, not IORING_MSG_SEND_FD as that one + * doesn't make sense without a source ring to send files from. + */ + if (io_msg.cmd != IORING_MSG_DATA) + return -EINVAL; + + ret = -EBADF; + f = fdget(sqe->fd); + if (fd_file(f)) { + ret = -EBADFD; + if (io_is_uring_fops(fd_file(f))) + ret = __io_msg_ring_data(fd_file(f)->private_data, + &io_msg, IO_URING_F_UNLOCKED); + fdput(f); + } + return ret; +} + void io_msg_cache_free(const void *entry) { struct io_kiocb *req = (struct io_kiocb *) entry; diff --git a/io_uring/msg_ring.h b/io_uring/msg_ring.h index 3030f3942f0f..38e7f8f0c944 100644 --- a/io_uring/msg_ring.h +++ b/io_uring/msg_ring.h @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 +int io_uring_sync_msg_ring(struct io_uring_sqe *sqe); int io_msg_ring_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); int io_msg_ring(struct io_kiocb *req, unsigned int issue_flags); void io_msg_ring_cleanup(struct io_kiocb *req); diff --git a/io_uring/register.c b/io_uring/register.c index eca26d4884d9..52b2f9b74af8 100644 --- a/io_uring/register.c +++ b/io_uring/register.c @@ -28,6 +28,7 @@ #include "kbuf.h" #include "napi.h" #include "eventfd.h" +#include "msg_ring.h" #define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \ IORING_REGISTER_LAST + IORING_OP_LAST) @@ -588,6 +589,32 @@ struct file *io_uring_register_get_file(unsigned int fd, bool registered) return ERR_PTR(-EOPNOTSUPP); } +/* + * "blind" registration opcodes are ones where there's no ring given, and + * hence the source fd must be -1. + */ +static int io_uring_register_blind(unsigned int opcode, void __user *arg, + unsigned int nr_args) +{ + switch (opcode) { + case IORING_REGISTER_SEND_MSG_RING: { + struct io_uring_sqe sqe; + + if (!arg || nr_args != 1) + return -EINVAL; + if (copy_from_user(&sqe, arg, sizeof(sqe))) + return -EFAULT; + /* no flags supported */ + if (sqe.flags) + return -EINVAL; + if (sqe.opcode == IORING_OP_MSG_RING) + return io_uring_sync_msg_ring(&sqe); + } + } + + return -EINVAL; +} + SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode, void __user *, arg, unsigned int, nr_args) { @@ -602,6 +629,9 @@ SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode, if (opcode >= IORING_REGISTER_LAST) return -EINVAL; + if (fd == -1) + return io_uring_register_blind(opcode, arg, nr_args); + file = io_uring_register_get_file(fd, use_registered_ring); if (IS_ERR(file)) return PTR_ERR(file);