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 X-Spam-Level: X-Spam-Status: No, score=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 17C46C07E95 for ; Wed, 7 Jul 2021 11:40:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F1C5361C9A for ; Wed, 7 Jul 2021 11:40:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231454AbhGGLnE (ORCPT ); Wed, 7 Jul 2021 07:43:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58970 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231430AbhGGLm7 (ORCPT ); Wed, 7 Jul 2021 07:42:59 -0400 Received: from mail-wm1-x32d.google.com (mail-wm1-x32d.google.com [IPv6:2a00:1450:4864:20::32d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0232AC061574; Wed, 7 Jul 2021 04:40:18 -0700 (PDT) Received: by mail-wm1-x32d.google.com with SMTP id t14-20020a05600c198eb029020c8aac53d4so10815637wmq.1; Wed, 07 Jul 2021 04:40:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=nUgNmahITe4pb/nCz15r+HpV62R8U3wmAbaVj3QGhAE=; b=pbZHcOimUJ/xd4rW0wF9FfJFSvpiZM799wsg2z4+MjbR/uTb/oPC8s51R8orCMvaN0 M8Hcsh7gKmNAqHUuBtn24+OpBbqSRxNoru1CNhTA9Y+6OZXSvD6sL7HogvM6b5Gi/sdT sSAAvxpDcNaiBlUaUiTI5Eo8KQmEQQ9tcJvfaxkK5GRI4iR2a2yIjUothFx/wR73TWm0 zy1RkRchgo6D4XWlm3uhLlcjIoMTqeQU3ce7InQ3Jp6o7TvpEB4SGucy2OAs6SY+9uf/ sQZ1fODB2nU2fEPRI3QgaUGnJBhfpRVdukSkD2gnGnNh3BfGqR9gD2hU7QJSTMhiNo/0 3nZA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=nUgNmahITe4pb/nCz15r+HpV62R8U3wmAbaVj3QGhAE=; b=pOYJaz5doRpee9fU30VeX8n/h812n4+4Mhk50824lqNKpliYl2yDFVW2bZ9UPD1i0C X6Gj68UFUVCXfFpUwAcpcc4u6k74vtnevFV3bEp1qjtXj7HV1hPEESyf1/xssIfYuoCx oi+LM6GNvcuGUpTL7ZH7EpDc9rTLns+UWVEMo/xi8+Tm2lyKuTfU1AN1jrAt5B20JUKm zGa/cfYJSaEw+SFRCc0ug7/V5vSiN7ISiWRvb2sJSK+TN0Pwp4qbDmSsO7jRS5QtxIXu YdOMdEFmmoKMqcF4odVnHAlN/S4nUZdOAvbwP++/7N0QuJKNyRuhYWsUZ1UMpDZUaxgG oqWg== X-Gm-Message-State: AOAM532381oQpHROScg5Y2vFpLM2/1wKVrtH3Vq+iMsqtv12o79yxX2Z BQpQHQw5K5Gle4M1g+dgDFvmPGJ92m6ffA== X-Google-Smtp-Source: ABdhPJwHgT+gyl//qD0uuV+t70wrbmfyjgyHtg6PwjXjyw3h7MPu+G3x8N1hBc4vV//figZ/xecyww== X-Received: by 2002:a7b:cb1a:: with SMTP id u26mr6326052wmj.125.1625658016617; Wed, 07 Jul 2021 04:40:16 -0700 (PDT) Received: from localhost.localdomain ([85.255.234.206]) by smtp.gmail.com with ESMTPSA id p9sm18415790wmm.17.2021.07.07.04.40.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 Jul 2021 04:40:16 -0700 (PDT) From: Pavel Begunkov To: Jens Axboe , io-uring@vger.kernel.org Cc: "David S . Miller" , Jakub Kicinski , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH 1/4] io_uring: allow open directly into fixed fd table Date: Wed, 7 Jul 2021 12:39:43 +0100 Message-Id: <159bcb182a7a6df58c4de444e511d9ea464048ac.1625657451.git.asml.silence@gmail.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Instead of opening a file into a process's file table as usual and then registering the fd within io_uring, we can skip the first step and place it directly into io_uring's fixed file table. Add support for that for both OPENAT opcodes. The behaviour is controlled by setting sqe->file_index, where 0 implies the old behaviour, and non-0 values is translated into index (file_index-1). The field is u16, hence sets a limit on how many slots it covers. Signed-off-by: Pavel Begunkov --- fs/io_uring.c | 75 ++++++++++++++++++++++++++++++----- include/uapi/linux/io_uring.h | 2 + 2 files changed, 68 insertions(+), 9 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 599b11152505..17d2c0eb89dc 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1075,6 +1075,8 @@ static bool io_poll_remove_waitqs(struct io_kiocb *req); static int io_req_prep_async(struct io_kiocb *req); static void io_fallback_req_func(struct work_struct *unused); +static int io_install_fixed_file(struct io_kiocb *req, struct file *file, + unsigned int issue_flags); static struct kmem_cache *req_cachep; @@ -3745,11 +3747,10 @@ static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe const char __user *fname; int ret; - if (unlikely(sqe->ioprio || sqe->buf_index)) + if (unlikely(sqe->ioprio)) return -EINVAL; if (unlikely(req->flags & REQ_F_FIXED_FILE)) return -EBADF; - /* open.how should be already initialised */ if (!(req->open.how.flags & O_PATH) && force_o_largefile()) req->open.how.flags |= O_LARGEFILE; @@ -3762,6 +3763,10 @@ static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe req->open.filename = NULL; return ret; } + req->buf_index = READ_ONCE(sqe->file_index); + if (req->buf_index && (req->open.how.flags & O_CLOEXEC)) + return -EINVAL; + req->open.nofile = rlimit(RLIMIT_NOFILE); req->flags |= REQ_F_NEED_CLEANUP; return 0; @@ -3804,8 +3809,8 @@ static int io_openat2(struct io_kiocb *req, unsigned int issue_flags) { struct open_flags op; struct file *file; - bool nonblock_set; - bool resolve_nonblock; + bool resolve_nonblock, nonblock_set; + bool fixed = !!req->buf_index; int ret; ret = build_open_flags(&req->open.how, &op); @@ -3824,9 +3829,11 @@ static int io_openat2(struct io_kiocb *req, unsigned int issue_flags) op.open_flag |= O_NONBLOCK; } - ret = __get_unused_fd_flags(req->open.how.flags, req->open.nofile); - if (ret < 0) - goto err; + if (!fixed) { + ret = __get_unused_fd_flags(req->open.how.flags, req->open.nofile); + if (ret < 0) + goto err; + } file = do_filp_open(req->open.dfd, req->open.filename, &op); if (IS_ERR(file)) { @@ -3835,7 +3842,8 @@ static int io_openat2(struct io_kiocb *req, unsigned int issue_flags) * marginal gain for something that is now known to be a slower * path. So just put it, and we'll get a new one when we retry. */ - put_unused_fd(ret); + if (!fixed) + put_unused_fd(ret); ret = PTR_ERR(file); /* only retry if RESOLVE_CACHED wasn't already set by application */ @@ -3848,7 +3856,11 @@ static int io_openat2(struct io_kiocb *req, unsigned int issue_flags) if ((issue_flags & IO_URING_F_NONBLOCK) && !nonblock_set) file->f_flags &= ~O_NONBLOCK; fsnotify_open(file); - fd_install(ret, file); + + if (!fixed) + fd_install(ret, file); + else + ret = io_install_fixed_file(req, file, issue_flags); err: putname(req->open.filename); req->flags &= ~REQ_F_NEED_CLEANUP; @@ -7776,6 +7788,50 @@ static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file, #endif } +static int io_install_fixed_file(struct io_kiocb *req, struct file *file, + unsigned int issue_flags) +{ + struct io_ring_ctx *ctx = req->ctx; + int i = req->buf_index - 1; + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; + struct io_fixed_file *file_slot; + int ret = -EBADF; + + if (WARN_ON_ONCE(req->buf_index == 0)) + goto err; + + io_ring_submit_lock(ctx, !force_nonblock); + if (file->f_op == &io_uring_fops) + goto err; + ret = -ENXIO; + if (!ctx->file_data) + goto err; + ret = -EINVAL; + if (i > ctx->nr_user_files) + goto err; + + i = array_index_nospec(i, ctx->nr_user_files); + file_slot = io_fixed_file_slot(&ctx->file_table, i); + ret = -EEXIST; + if (file_slot->file_ptr) + goto err; + + *io_get_tag_slot(ctx->file_data, i) = 0; + io_fixed_file_set(file_slot, file); + ret = io_sqe_file_register(ctx, file, i); + if (ret) { + file_slot->file_ptr = 0; + goto err; + } + + ret = 0; +err: + io_ring_submit_unlock(ctx, !force_nonblock); + if (ret) + fput(file); + return ret; +} + static int io_queue_rsrc_removal(struct io_rsrc_data *data, unsigned idx, struct io_rsrc_node *node, void *rsrc) { @@ -10231,6 +10287,7 @@ static int __init io_uring_init(void) BUILD_BUG_SQE_ELEM(32, __u64, user_data); BUILD_BUG_SQE_ELEM(40, __u16, buf_index); BUILD_BUG_SQE_ELEM(40, __u16, buf_group); + BUILD_BUG_SQE_ELEM(40, __u16, file_index); BUILD_BUG_SQE_ELEM(42, __u16, personality); BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in); diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 79126d5cd289..f105deb4da1d 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -52,6 +52,8 @@ struct io_uring_sqe { __u16 buf_index; /* for grouped buffer selection */ __u16 buf_group; + /* index into fixed files */ + __u16 file_index; } __attribute__((packed)); /* personality to use, if used */ __u16 personality; -- 2.32.0