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=-15.8 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 E1B3EC4338F for ; Sat, 21 Aug 2021 15:53:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BEA3261206 for ; Sat, 21 Aug 2021 15:53:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233564AbhHUPyN (ORCPT ); Sat, 21 Aug 2021 11:54:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35170 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232716AbhHUPyC (ORCPT ); Sat, 21 Aug 2021 11:54:02 -0400 Received: from mail-wm1-x333.google.com (mail-wm1-x333.google.com [IPv6:2a00:1450:4864:20::333]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 53483C061757; Sat, 21 Aug 2021 08:53:22 -0700 (PDT) Received: by mail-wm1-x333.google.com with SMTP id c129-20020a1c35870000b02902e6b6135279so7900825wma.0; Sat, 21 Aug 2021 08:53:22 -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=nGJoaHfhVSZ+JCi269k+ZI1M+4T/MONcq2oDO9wuY24=; b=HzudfrGwr/GYlsmgCwb2Njw+SHqpNnWBmeds9bc48oK98z5emcXeDKZtWfGME+Emrw 5Q9uNVUBRiZ/UibCxFMpiG6vQRqAdrqDEOgedhpN9XopquhJ7lTtfNy0c5p5njaPekPk 0zYCbE/b3WnBEa/elQObm2Ob98AGPISkGfaWO12/5bW9HdJyZwwW4TXd6GIEpYXelIX/ AlOZ08WCrthDxfoda2pvriqsnagjzBrAl60QrOkqQpQpliyXfRa2I4oQP4+2IVbd3XKw d5IMfatMBug/CjIiZSmY/Bi5dScWoXt0mHfDZYM/2MF4/Ognl5tPbfyIneLQm0Lzk4Da I1Hw== 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=nGJoaHfhVSZ+JCi269k+ZI1M+4T/MONcq2oDO9wuY24=; b=RfTE8MO6ilUXyG+cv/vvHVXST9Dyx7CItgk0/kypQc77GL+CbO02hQru7eo1N2mzgR 00kr4laBNoEw1WRBewszrbw7pq0jTqUpWEH4XT7tB7nIRIRmXmPV3c69wdNajF1ZFBeO cgwjwNQRJSpYpNDwy6+AGN+5zvfh/dX/KVXkoCqqo29vl3mmXJVPz54b0Dp9Eqy6oTXG f5y65pU9evgQndMQzMYFQxs+UxY/65gnxrZ/3sK+K/T1OSUUeq4mspDWph/UJOMCDZ/m M5n/TksYzdWt41pk7tBBJWJ6nBEobEc4V7lJnaRoVyZjAPJjeHr3V7xx+qFy8zOBZAqq yCTQ== X-Gm-Message-State: AOAM533RNNz0U2SmbMix7Vmk8Wzl78o4rNu9YS7QzSoHYJvmL85k4uqi IHTneBwKsOQ9aYB0sLdo4sU= X-Google-Smtp-Source: ABdhPJxBhWaygH+gnsNxHsK5FxlSsZdMYeLbDn5XGvDBovpw75VwSiT9qyyHqruufARZPlY9WYuKRA== X-Received: by 2002:a05:600c:210d:: with SMTP id u13mr8736217wml.57.1629561200931; Sat, 21 Aug 2021 08:53:20 -0700 (PDT) Received: from localhost.localdomain ([85.255.233.174]) by smtp.gmail.com with ESMTPSA id e3sm9479554wro.15.2021.08.21.08.53.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 21 Aug 2021 08:53:20 -0700 (PDT) From: Pavel Begunkov To: Jens Axboe , io-uring@vger.kernel.org, Josh Triplett Cc: "David S . Miller" , Jakub Kicinski , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Stefan Metzmacher Subject: [PATCH v3 2/4] io_uring: openat directly into fixed fd table Date: Sat, 21 Aug 2021 16:52:38 +0100 Message-Id: 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, some users may want to skip the first step and place it directly into io_uring's fixed file table. This patch adds such a capability for IORING_OP_OPENAT and IORING_OP_OPENAT2. The behaviour is controlled by setting sqe->file_index, where 0 implies the old behaviour. If non-zero value is specified, then it will behave as described and place the file into a fixed file slot sqe->file_index - 1. A file table should be already created, the slot should be valid and empty, otherwise the operation will fail. Keep the error codes consistent with IORING_OP_FILES_UPDATE, ENXIO and EINVAL on inappropriate fixed tables, and return EBADF on collision with already registered file. Note: we can't use IOSQE_FIXED_FILE to switch between modes, because accept takes a file, and it already uses the flag with a different meaning. Suggested-by: Josh Triplett Signed-off-by: Pavel Begunkov --- fs/io_uring.c | 82 +++++++++++++++++++++++++++++++---- include/uapi/linux/io_uring.h | 5 ++- 2 files changed, 78 insertions(+), 9 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 0fb75aa72b69..b8ef5ac1f90d 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1063,6 +1063,9 @@ static void io_req_task_queue(struct io_kiocb *req); static void io_submit_flush_completions(struct io_ring_ctx *ctx); static int io_req_prep_async(struct io_kiocb *req); +static int io_install_fixed_file(struct io_kiocb *req, struct file *file, + unsigned int issue_flags); + static struct kmem_cache *req_cachep; static const struct file_operations io_uring_fops; @@ -3815,11 +3818,12 @@ static int io_fallocate(struct io_kiocb *req, unsigned int issue_flags) static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { const char __user *fname; + unsigned index; int ret; if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; - if (unlikely(sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)) + if (unlikely(sqe->ioprio || sqe->buf_index)) return -EINVAL; if (unlikely(req->flags & REQ_F_FIXED_FILE)) return -EBADF; @@ -3836,6 +3840,16 @@ static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe req->open.filename = NULL; return ret; } + + index = READ_ONCE(sqe->file_index); + req->buf_index = index; + if (index) { + if (req->open.how.flags & O_CLOEXEC) + return -EINVAL; + if (req->buf_index != index) + return -EINVAL; + } + req->open.nofile = rlimit(RLIMIT_NOFILE); req->flags |= REQ_F_NEED_CLEANUP; return 0; @@ -3873,8 +3887,8 @@ 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); @@ -3893,9 +3907,11 @@ 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)) { @@ -3904,7 +3920,8 @@ 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 */ @@ -3917,7 +3934,11 @@ 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; @@ -7846,6 +7867,50 @@ 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 = -EBADF; + 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) { @@ -10311,6 +10376,7 @@ static int __init io_uring_init(void) BUILD_BUG_SQE_ELEM(40, __u16, buf_group); BUILD_BUG_SQE_ELEM(42, __u16, personality); BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in); + BUILD_BUG_SQE_ELEM(44, __u32, file_index); BUILD_BUG_ON(sizeof(struct io_uring_files_update) != sizeof(struct io_uring_rsrc_update)); diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 79126d5cd289..45a4f2373694 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -55,7 +55,10 @@ struct io_uring_sqe { } __attribute__((packed)); /* personality to use, if used */ __u16 personality; - __s32 splice_fd_in; + union { + __s32 splice_fd_in; + __u32 file_index; + }; __u64 __pad2[2]; }; -- 2.32.0