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 C830FC43217 for ; Mon, 9 May 2022 15:51:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238645AbiEIPy5 (ORCPT ); Mon, 9 May 2022 11:54:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38872 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238638AbiEIPy4 (ORCPT ); Mon, 9 May 2022 11:54:56 -0400 Received: from mail-il1-x12c.google.com (mail-il1-x12c.google.com [IPv6:2607:f8b0:4864:20::12c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 88B8C20F70 for ; Mon, 9 May 2022 08:51:01 -0700 (PDT) Received: by mail-il1-x12c.google.com with SMTP id y11so9584279ilp.4 for ; Mon, 09 May 2022 08:51:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=fU5PI/Xb9BjpSJMYfn0s6B200MtWs1UXYAflxcZuUBw=; b=7Ii5N06IQSJ73LZUsumC01VDgQI/WABNW1JAPsycrnQ6Xv+LH6edqZWu5nSgyG1+tT WvZfH/n9p4/EXE5z6S0MAe0Tu9umir42ZCSLm5/ATOBpnmbr5+og1RCKgk1yb/EGP7Ts SfE/vL2E7CEDW7g1sTflOb/K5EOoZNV+xciKmBs5KwTP1iDbDl0ksGlq9kwTiFW5rH5G S/hay+3FYWkTHfFnqpZWL3xFULGtMaiYaHYfv1mRuGjurGMGsZUbVr0u8cwAgshKfgRx cC41ST1xUnXH2zIDG9LBemirwnMFxP8HLmZkMGX4Tj8gmLcew6rAIAQN/4Djes6ZuD7D lasg== 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=fU5PI/Xb9BjpSJMYfn0s6B200MtWs1UXYAflxcZuUBw=; b=HtARsXzy+qTLT8WCd6K/4SfEH8wAIUkAKXs+gv/xrBTsrfHN9Mrp+A5AqNkz4KLhZR j+kvZXH1y8I99PwlqRJzvleYsNxnRoJdwke3BVzMOzTMkaJDBH+Cebi3eqc3Or9/uRSf M2r5Z7W5RVYDI8U/xoi6fYcxUD3CNqT/K17zrOcQds99RB8eo0SqFj85RoVPKY8sX1ug Imt0ExvonVtBWppU4B6J9OeZj3FjIegypJDwTpW59KrPEZ2C/q+f67XnUdeUwtz5DlmZ Z7bz73HMAeRF+GMkWqdCi3Ot6hwOz+dPHcur+Uw129biAf0Ur6+o0htKYvhGq+Z23KlT mYvw== X-Gm-Message-State: AOAM531YEG2jNHnXoLw87Q1Ge3gvDkqY3Swc+5Cdg3EgQ7J3u736QGlu 3qEYDG1EboIs0z3UbM3tDr7ohJwZeAnwyw== X-Google-Smtp-Source: ABdhPJygPNRsys0hcfdn3CqfuaIG9sX3D1m2Pzo7ehHQ0D5v0iH/s9KuBCoQJ9rvFQ6LUJIm4Eje6A== X-Received: by 2002:a05:6e02:1bac:b0:2cf:832a:e41 with SMTP id n12-20020a056e021bac00b002cf832a0e41mr6376498ili.102.1652111460683; Mon, 09 May 2022 08:51:00 -0700 (PDT) Received: from m1.localdomain ([207.135.234.126]) by smtp.gmail.com with ESMTPSA id a1-20020a056638004100b0032b3a78177esm3696499jap.66.2022.05.09.08.50.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 May 2022 08:51:00 -0700 (PDT) From: Jens Axboe To: io-uring@vger.kernel.org Cc: asml.silence@gmail.com, haoxu.linux@gmail.com, Jens Axboe Subject: [PATCH 3/6] io_uring: allow allocated fixed files for openat/openat2 Date: Mon, 9 May 2022 09:50:52 -0600 Message-Id: <20220509155055.72735-4-axboe@kernel.dk> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220509155055.72735-1-axboe@kernel.dk> References: <20220509155055.72735-1-axboe@kernel.dk> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org If the application passes in IORING_FILE_INDEX_ALLOC as the file_slot, then that's a hint to allocate a fixed file descriptor rather than have one be passed in directly. This can be useful for having io_uring manage the direct descriptor space. Normal open direct requests will complete with 0 for success, and < 0 in case of error. If io_uring is asked to allocated the direct descriptor, then the direct descriptor is returned in case of success. Signed-off-by: Jens Axboe --- fs/io_uring.c | 32 +++++++++++++++++++++++++++++--- include/uapi/linux/io_uring.h | 9 +++++++++ 2 files changed, 38 insertions(+), 3 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 8c40411a7e78..ef999d0e09de 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -4697,7 +4697,7 @@ static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) return __io_openat_prep(req, sqe); } -static int __maybe_unused io_file_bitmap_get(struct io_ring_ctx *ctx) +static int io_file_bitmap_get(struct io_ring_ctx *ctx) { struct io_file_table *table = &ctx->file_table; unsigned long nr = ctx->nr_user_files; @@ -4722,6 +4722,32 @@ static int __maybe_unused io_file_bitmap_get(struct io_ring_ctx *ctx) return -ENFILE; } +static int io_fixed_fd_install(struct io_kiocb *req, unsigned int issue_flags, + struct file *file, unsigned int file_slot) +{ + int alloc_slot = file_slot == IORING_FILE_INDEX_ALLOC; + struct io_ring_ctx *ctx = req->ctx; + int ret; + + if (alloc_slot) { + io_ring_submit_lock(ctx, issue_flags); + file_slot = io_file_bitmap_get(ctx); + if (unlikely(file_slot < 0)) { + io_ring_submit_unlock(ctx, issue_flags); + return file_slot; + } + } + + ret = io_install_fixed_file(req, file, issue_flags, file_slot); + if (alloc_slot) { + io_ring_submit_unlock(ctx, issue_flags); + if (!ret) + return file_slot; + } + + return ret; +} + static int io_openat2(struct io_kiocb *req, unsigned int issue_flags) { struct open_flags op; @@ -4777,8 +4803,8 @@ static int io_openat2(struct io_kiocb *req, unsigned int issue_flags) if (!fixed) fd_install(ret, file); else - ret = io_install_fixed_file(req, file, issue_flags, - req->open.file_slot - 1); + ret = io_fixed_fd_install(req, issue_flags, file, + req->open.file_slot); err: putname(req->open.filename); req->flags &= ~REQ_F_NEED_CLEANUP; diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 06621a278cb6..b7f02a55032a 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -63,6 +63,15 @@ struct io_uring_sqe { __u64 __pad2[2]; }; +/* + * If sqe->file_index is set to this for opcodes that instantiate a new + * direct descriptor (like openat/openat2/accept), then io_uring will allocate + * an available direct descriptor instead of having the application pass one + * in. The picked direct descriptor will be returned in cqe->res, or -ENFILE + * if the space is full. + */ +#define IORING_FILE_INDEX_ALLOC (~0U) + enum { IOSQE_FIXED_FILE_BIT, IOSQE_IO_DRAIN_BIT, -- 2.35.1