From patchwork Mon Feb 11 19:00:30 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806665 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1642A6C2 for ; Mon, 11 Feb 2019 19:00:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 009B02A166 for ; Mon, 11 Feb 2019 19:00:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E6F592B243; Mon, 11 Feb 2019 19:00:57 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7CA022A166 for ; Mon, 11 Feb 2019 19:00:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733251AbfBKTA4 (ORCPT ); Mon, 11 Feb 2019 14:00:56 -0500 Received: from mail-it1-f193.google.com ([209.85.166.193]:34297 "EHLO mail-it1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732948AbfBKTA4 (ORCPT ); Mon, 11 Feb 2019 14:00:56 -0500 Received: by mail-it1-f193.google.com with SMTP id x124so762876itd.1 for ; Mon, 11 Feb 2019 11:00:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=tT12zaPG5ttnRf843TjoHKrkkXLpnihT1wJ80AwYbNQ=; b=fJPa5b3Wex3mfZrEiYLFXWckjjgktFOVxPWIV7dfCmCz4DuMTRSPAeGUBj47ocABIh nDot96IeRYPtkq3uPf6eWzT3zhgIlmEmO8YoaeCcrl4dNO1aEUhTVzIP0M2/SDk7AoX4 HrTkXeWJuftoWfKNBNFxwmlf2thvggwCAOiwF8p1ffFPQ2KgKKjDhrRhwN55Losz/uXS fu1QP8hpTrWoliQ47b+6VTeKthLIYGOJmBGTQsoxpvJoGXBqZhKiRZq6RJE+16sk/iWR SVZHPW7sQMlX+Ae+5IdevpfDzDU155hZyh1mJGPQ0XUpBU4KXAz9pYV9U5t9Y5LHBFbx y7PA== 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; bh=tT12zaPG5ttnRf843TjoHKrkkXLpnihT1wJ80AwYbNQ=; b=ZxVX6edkQJkN9ljc/l2UgBC4gQ9UlzApSTAp5IyYk1mkBxV1a1RwMWOB9NfE2R9AvJ arZfnBOPdLdvRece8sByApNNhTBN6qAgzG32ifqvZ653g9o+U2N+zDRP6NgWIB8t3/bP sJW9+6oXX+e1J+gDJ0nCFd5Abnc/Zfa2KOT6qaLy3b6vd26aIyilbNdeSxeW/zVxOtGO 5A2atpNykbwunVe0QGJKE5b2vNlIuoS/BHfA0TbVokybLUmoAggg5CmRU1FusuoourlQ MHyilWujcFDWsDux0o9UVeAkzEcihInn0ZiRgF1vmOLnE1Nowux9qAvC3U8TFOpQUMZn jSmQ== X-Gm-Message-State: AHQUAuaBZd6fqRM7vWlLPxezWax8saGkEYUHGZfza5E0P3yT0pdnjc99 fq2QdRKtHPKGGz9TGBQwpijjQw== X-Google-Smtp-Source: AHgI3IbyvS8WiHVoHQ//BskfXcqw3nbGfFtJhTkS+LX5caZcdAOkNmnhD+WlpiUbu2hf3aRY3yRk9A== X-Received: by 2002:a24:54d0:: with SMTP id t199mr602912ita.57.1549911655567; Mon, 11 Feb 2019 11:00:55 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.00.53 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:00:54 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 01/19] fs: add an iopoll method to struct file_operations Date: Mon, 11 Feb 2019 12:00:30 -0700 Message-Id: <20190211190049.7888-2-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Christoph Hellwig This new methods is used to explicitly poll for I/O completion for an iocb. It must be called for any iocb submitted asynchronously (that is with a non-null ki_complete) which has the IOCB_HIPRI flag set. The method is assisted by a new ki_cookie field in struct iocb to store the polling cookie. Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- Documentation/filesystems/vfs.txt | 3 +++ include/linux/fs.h | 2 ++ 2 files changed, 5 insertions(+) diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 8dc8e9c2913f..761c6fd24a53 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -857,6 +857,7 @@ struct file_operations { ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); ssize_t (*read_iter) (struct kiocb *, struct iov_iter *); ssize_t (*write_iter) (struct kiocb *, struct iov_iter *); + int (*iopoll)(struct kiocb *kiocb, bool spin); int (*iterate) (struct file *, struct dir_context *); int (*iterate_shared) (struct file *, struct dir_context *); __poll_t (*poll) (struct file *, struct poll_table_struct *); @@ -902,6 +903,8 @@ otherwise noted. write_iter: possibly asynchronous write with iov_iter as source + iopoll: called when aio wants to poll for completions on HIPRI iocbs + iterate: called when the VFS needs to read the directory contents iterate_shared: called when the VFS needs to read the directory contents diff --git a/include/linux/fs.h b/include/linux/fs.h index 29d8e2cfed0e..dedcc2e9265c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -310,6 +310,7 @@ struct kiocb { int ki_flags; u16 ki_hint; u16 ki_ioprio; /* See linux/ioprio.h */ + unsigned int ki_cookie; /* for ->iopoll */ } __randomize_layout; static inline bool is_sync_kiocb(struct kiocb *kiocb) @@ -1787,6 +1788,7 @@ struct file_operations { ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); ssize_t (*read_iter) (struct kiocb *, struct iov_iter *); ssize_t (*write_iter) (struct kiocb *, struct iov_iter *); + int (*iopoll)(struct kiocb *kiocb, bool spin); int (*iterate) (struct file *, struct dir_context *); int (*iterate_shared) (struct file *, struct dir_context *); __poll_t (*poll) (struct file *, struct poll_table_struct *); From patchwork Mon Feb 11 19:00:32 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806669 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1C6356C2 for ; Mon, 11 Feb 2019 19:01:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0DB222AE23 for ; Mon, 11 Feb 2019 19:01:01 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0246A2B243; Mon, 11 Feb 2019 19:01:00 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 940A52B246 for ; Mon, 11 Feb 2019 19:01:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733254AbfBKTBA (ORCPT ); Mon, 11 Feb 2019 14:01:00 -0500 Received: from mail-it1-f196.google.com ([209.85.166.196]:51592 "EHLO mail-it1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728392AbfBKTA7 (ORCPT ); Mon, 11 Feb 2019 14:00:59 -0500 Received: by mail-it1-f196.google.com with SMTP id y184so922081itc.1 for ; Mon, 11 Feb 2019 11:00:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=g1khetRWDSOe+fsRbjBpFbSMReoIe0SnrK1N2gfwJWc=; b=Z4ozwC/7X3SSM/0mGl+KD3mBBUVWxelJ7dxptlPZ8Mr2gqn/f/BHdq6c90kPeoVGah u4xqH26pCCgVSoD5Vl33SyroJh7gWiyQh+4z9KkRngUxr7WxvuO8+ICE/+NM6HaWaRpI QVeHm+0o8ImB1PF9mZbWNzbAPlEpHEI4PXWfher88IFaRUtgpbJ0YHXbINPUm4KxU9Ot SWILECtiW939Z1KdrcRDIRriqZEiThIxtcMkGzh/NXQ4z0KzGuPehySFrtUeEBc0m7GP 1Y8wh6I3nwF8QCLrT83gO/zsY0sF220zo15a0bZevhtdzCQfXVSkkVezr9qg82Vfi4tW ckhg== 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; bh=g1khetRWDSOe+fsRbjBpFbSMReoIe0SnrK1N2gfwJWc=; b=ZiiVxXu0Tqc5hLxCQit5id0e6jZ4kks71se4AOCexPovyWtOrE+JbL+NP4dDnA/uGS EyZdLY8MaKlexPYqZMj6arqkNpoNMDTYeMxub5gqMpJ0v+WT4jWpPE6DHbNYYfJtyipT H8XGlrJGLzIDMYhdQcrxxqgLb4Rf8UcbrU/ULUtJTrosVtTgddZT0Zw1VbvAJ2dr2Kg3 hkMtzqoCIFubAF/UO6nJtOTQUmXaFZnhSAW7fzATJ9Iw3gyLpD9cfj3/uT4gz6hnxtrL /PYwyarRu64vdWWu+9apNsEXIaDE1I1EehX7m3YTvYtdWefz3B3NbzxdjvdUF2CAKSWw AR0Q== X-Gm-Message-State: AHQUAua04pQGq2WQfJPMjomkrrdTSuZo5vEH79KBVsP4HcOK+CJkTCHT T2gp5QILpqGMxWBFuzmf4xbjbA== X-Google-Smtp-Source: AHgI3IaYT7vh/P9qYoqj3E7lreeSHrbk1T+P+BNBixkUttvDIoxjZQAVxerp7En0RDRJP9sfCI0m/g== X-Received: by 2002:a6b:7517:: with SMTP id l23mr7791058ioh.74.1549911658990; Mon, 11 Feb 2019 11:00:58 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.00.57 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:00:58 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 02/19] block: wire up block device iopoll method Date: Mon, 11 Feb 2019 12:00:32 -0700 Message-Id: <20190211190049.7888-4-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Christoph Hellwig Just call blk_poll on the iocb cookie, we can derive the block device from the inode trivially. Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- fs/block_dev.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/fs/block_dev.c b/fs/block_dev.c index 58a4c1217fa8..f18d076a2596 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -293,6 +293,14 @@ struct blkdev_dio { static struct bio_set blkdev_dio_pool; +static int blkdev_iopoll(struct kiocb *kiocb, bool wait) +{ + struct block_device *bdev = I_BDEV(kiocb->ki_filp->f_mapping->host); + struct request_queue *q = bdev_get_queue(bdev); + + return blk_poll(q, READ_ONCE(kiocb->ki_cookie), wait); +} + static void blkdev_bio_end_io(struct bio *bio) { struct blkdev_dio *dio = bio->bi_private; @@ -410,6 +418,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) bio->bi_opf |= REQ_HIPRI; qc = submit_bio(bio); + WRITE_ONCE(iocb->ki_cookie, qc); break; } @@ -2076,6 +2085,7 @@ const struct file_operations def_blk_fops = { .llseek = block_llseek, .read_iter = blkdev_read_iter, .write_iter = blkdev_write_iter, + .iopoll = blkdev_iopoll, .mmap = generic_file_mmap, .fsync = blkdev_fsync, .unlocked_ioctl = block_ioctl, From patchwork Mon Feb 11 19:00:33 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806671 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 232B96C2 for ; Mon, 11 Feb 2019 19:01:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 14F332A166 for ; Mon, 11 Feb 2019 19:01:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 080492AE21; Mon, 11 Feb 2019 19:01:02 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 94E112AE23 for ; Mon, 11 Feb 2019 19:01:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733256AbfBKTBC (ORCPT ); Mon, 11 Feb 2019 14:01:02 -0500 Received: from mail-it1-f193.google.com ([209.85.166.193]:36777 "EHLO mail-it1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733034AbfBKTBB (ORCPT ); Mon, 11 Feb 2019 14:01:01 -0500 Received: by mail-it1-f193.google.com with SMTP id c9so935300itj.1 for ; Mon, 11 Feb 2019 11:01:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=TZRgsZ4kd01/5hUxi2xP0/0l+SjG1tCpnsE1G+JLPfI=; b=H4oMk2n9Y3uwrP4JUnAI8ilC+iYkaG2D04CHxWxz5qtCzTUcHjYeufonFTjx/RKZXL Ww/xPSE/3bSzD0vqIYFl58ULiMQAIEvTW8mZh35LffczPc9vjaIJ+JUhxeAeiC0es19s kS7neX7MO+mWHwyc1URLLhH6zcyQPcRRfWcqKwqj2tW0Z3MIjnUoTBZjycauZyCwDeIF E3wF/FogVrprGArf/6TbbXH5KP2r1z9KZwUUxGQmArDnDH4Z7GaxmZhgPABFGCun+2Lv PS5q7eE41m6qCnr+y/707/g/uDnGS17aleu/izTQvO0/VERO9FWgGLc2eQ8Lk+1fIWd2 vd4A== 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; bh=TZRgsZ4kd01/5hUxi2xP0/0l+SjG1tCpnsE1G+JLPfI=; b=LPw6bvFidTiNgNrwOuaDeYXDx6wjaGMdMg9Hhu6Gzmg4QXpBebIpYySMDBePVpV3eU sW+YrU7lOj9dVd1GnZaCJ6aImnSWQRZAyE3Bhs3j+e2hP+ekN80EcG4CAQTSRka6WeB5 rUuPzTXi/b7Yx5wzgMcHXEfl0AoPFCm74ZePLHYNKRZgdedlI44BjdZROM1Cu4NwxL6b SvYwCcbN4jvKHXOIv2A3cPbO5pTqeh/ocpU3dNgopDR3fsN624yXdFgEnIymKBKwHA7+ OrF6AWb5A34X88swALnCOhy61nPKNsLfNAa92ECsXr5d7XYvljfiyk3IF1pm/XZVJA3M OY3Q== X-Gm-Message-State: AHQUAubPJyzRnnFXGCpbfjDQq52x8JXtFF4239AQfKB0l9rbLbkLZplM aXqOYoTCUcHVXtAmmHkA6pArDQ== X-Google-Smtp-Source: AHgI3Ib6FVnZ96ZPjhFAWG2engWWFkXxsH/pHQLUJpyk+xd9yFJFpJrB0crn/p4wv1HhQojuoFctXg== X-Received: by 2002:a5e:c90d:: with SMTP id z13mr14041088iol.117.1549911660814; Mon, 11 Feb 2019 11:01:00 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.00.59 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:00:59 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 03/19] block: add bio_set_polled() helper Date: Mon, 11 Feb 2019 12:00:33 -0700 Message-Id: <20190211190049.7888-5-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP For the upcoming async polled IO, we can't sleep allocating requests. If we do, then we introduce a deadlock where the submitter already has async polled IO in-flight, but can't wait for them to complete since polled requests must be active found and reaped. Utilize the helper in the blockdev DIRECT_IO code. Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- fs/block_dev.c | 4 ++-- include/linux/bio.h | 14 ++++++++++++++ 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index f18d076a2596..392e2bfb636f 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -247,7 +247,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter, task_io_account_write(ret); } if (iocb->ki_flags & IOCB_HIPRI) - bio.bi_opf |= REQ_HIPRI; + bio_set_polled(&bio, iocb); qc = submit_bio(&bio); for (;;) { @@ -415,7 +415,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES); if (!nr_pages) { if (iocb->ki_flags & IOCB_HIPRI) - bio->bi_opf |= REQ_HIPRI; + bio_set_polled(bio, iocb); qc = submit_bio(bio); WRITE_ONCE(iocb->ki_cookie, qc); diff --git a/include/linux/bio.h b/include/linux/bio.h index 7380b094dcca..f6f0a2b3cbc8 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -823,5 +823,19 @@ static inline int bio_integrity_add_page(struct bio *bio, struct page *page, #endif /* CONFIG_BLK_DEV_INTEGRITY */ +/* + * Mark a bio as polled. Note that for async polled IO, the caller must + * expect -EWOULDBLOCK if we cannot allocate a request (or other resources). + * We cannot block waiting for requests on polled IO, as those completions + * must be found by the caller. This is different than IRQ driven IO, where + * it's safe to wait for IO to complete. + */ +static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb) +{ + bio->bi_opf |= REQ_HIPRI; + if (!is_sync_kiocb(kiocb)) + bio->bi_opf |= REQ_NOWAIT; +} + #endif /* CONFIG_BLOCK */ #endif /* __LINUX_BIO_H */ From patchwork Mon Feb 11 19:00:34 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806673 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2831D6C2 for ; Mon, 11 Feb 2019 19:01:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 192F028619 for ; Mon, 11 Feb 2019 19:01:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0C8DD2AE21; Mon, 11 Feb 2019 19:01:05 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 82D8128619 for ; Mon, 11 Feb 2019 19:01:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733261AbfBKTBE (ORCPT ); Mon, 11 Feb 2019 14:01:04 -0500 Received: from mail-it1-f194.google.com ([209.85.166.194]:56266 "EHLO mail-it1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733034AbfBKTBD (ORCPT ); Mon, 11 Feb 2019 14:01:03 -0500 Received: by mail-it1-f194.google.com with SMTP id f18so840595itb.5 for ; Mon, 11 Feb 2019 11:01:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=R4ODWGM8P+p4ZpHCxyQQv2COHmjw1lWzbuwYr8qvMDY=; b=GSPY1TeRiwu5zZo80HAt0rXaJhIeN9LaOd2SfSVqe6thXGDmI5AIKA87Qo3mBz4gG2 bYCZr7r2ah1APBsAPOXu/QiuUwbEGdt0Z6lwHXBXdgOAWUX/w/XQfeEaGVtcvmEJ7mTF +SRG4UEA4ES/PG3CNDJd0Y51Dm5G/Gzet/gAvrmsytLUpu8b+DtgIew8Nm1HIYA/X0Km WJrXctD18/cHCA9BU2AyGSQj3zVQfLT1Lp78hEZn1ijWeQXeezNzmJ5PyTHra3Xzkec8 kaGlH6sFj0kEwP6+ku+HpDFPNvV2IeCjNdkAwFU37mJaKqG01oQxYwaLn8ct3MYMjjLL uXrg== 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; bh=R4ODWGM8P+p4ZpHCxyQQv2COHmjw1lWzbuwYr8qvMDY=; b=ofneVAWfwvScfxBDvCJCSypixL4sczuRzc1/6QA9Ux9CJUB7y2dm8U5VbTWB18m6qV hqNbIUVdv+fYsPIhodqqHjj4Pq0OqpB6qObEVkP6jbGwO1b4jKjhx/OaGIy584ZnLcnN 9+y9KbbPHmMWRdaTA1btJNuXmQhpFeTYFNCORe4ibdAQL3dP4Ddpfa9NIS5qUVT+tx+e 3Vesgru+BdvhUbR0zQzMad2MXGSqlbrQksfQHLA4yKLKghBRkAkr7JOwVjRMBYnJ5bnt HKqnfNLL3eufvCyGui5Xl4ebHwDVOKvhnwYwUcoda3+mJVR7Pfwu0w8rW1KZGV5ffruv WbsA== X-Gm-Message-State: AHQUAuZKJ5drULp0+BDoE3mTWgjck2o7062xNPHpW8BxHMjZCYWqMyRd EgDt94Eql7CA91DGKg4Db6irSg== X-Google-Smtp-Source: AHgI3IbI0O6mm3AB7/NR1YEVLAy9WC5+TmhLyMglXuBhdDsSij7KTbA/Vfl4cWzyZ6phL/Eb7McLmA== X-Received: by 2002:a6b:7402:: with SMTP id s2mr18641969iog.219.1549911662484; Mon, 11 Feb 2019 11:01:02 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.01.00 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:01:01 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 04/19] iomap: wire up the iopoll method Date: Mon, 11 Feb 2019 12:00:34 -0700 Message-Id: <20190211190049.7888-6-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Christoph Hellwig Store the request queue the last bio was submitted to in the iocb private data in addition to the cookie so that we find the right block device. Also refactor the common direct I/O bio submission code into a nice little helper. Signed-off-by: Christoph Hellwig Modified to use bio_set_polled(). Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- fs/gfs2/file.c | 2 ++ fs/iomap.c | 43 ++++++++++++++++++++++++++++--------------- fs/xfs/xfs_file.c | 1 + include/linux/iomap.h | 1 + 4 files changed, 32 insertions(+), 15 deletions(-) diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index a2dea5bc0427..58a768e59712 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -1280,6 +1280,7 @@ const struct file_operations gfs2_file_fops = { .llseek = gfs2_llseek, .read_iter = gfs2_file_read_iter, .write_iter = gfs2_file_write_iter, + .iopoll = iomap_dio_iopoll, .unlocked_ioctl = gfs2_ioctl, .mmap = gfs2_mmap, .open = gfs2_open, @@ -1310,6 +1311,7 @@ const struct file_operations gfs2_file_fops_nolock = { .llseek = gfs2_llseek, .read_iter = gfs2_file_read_iter, .write_iter = gfs2_file_write_iter, + .iopoll = iomap_dio_iopoll, .unlocked_ioctl = gfs2_ioctl, .mmap = gfs2_mmap, .open = gfs2_open, diff --git a/fs/iomap.c b/fs/iomap.c index 897c60215dd1..2ac9eb746d44 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -1463,6 +1463,28 @@ struct iomap_dio { }; }; +int iomap_dio_iopoll(struct kiocb *kiocb, bool spin) +{ + struct request_queue *q = READ_ONCE(kiocb->private); + + if (!q) + return 0; + return blk_poll(q, READ_ONCE(kiocb->ki_cookie), spin); +} +EXPORT_SYMBOL_GPL(iomap_dio_iopoll); + +static void iomap_dio_submit_bio(struct iomap_dio *dio, struct iomap *iomap, + struct bio *bio) +{ + atomic_inc(&dio->ref); + + if (dio->iocb->ki_flags & IOCB_HIPRI) + bio_set_polled(bio, dio->iocb); + + dio->submit.last_queue = bdev_get_queue(iomap->bdev); + dio->submit.cookie = submit_bio(bio); +} + static ssize_t iomap_dio_complete(struct iomap_dio *dio) { struct kiocb *iocb = dio->iocb; @@ -1575,7 +1597,7 @@ static void iomap_dio_bio_end_io(struct bio *bio) } } -static blk_qc_t +static void iomap_dio_zero(struct iomap_dio *dio, struct iomap *iomap, loff_t pos, unsigned len) { @@ -1589,15 +1611,10 @@ iomap_dio_zero(struct iomap_dio *dio, struct iomap *iomap, loff_t pos, bio->bi_private = dio; bio->bi_end_io = iomap_dio_bio_end_io; - if (dio->iocb->ki_flags & IOCB_HIPRI) - flags |= REQ_HIPRI; - get_page(page); __bio_add_page(bio, page, len, 0); bio_set_op_attrs(bio, REQ_OP_WRITE, flags); - - atomic_inc(&dio->ref); - return submit_bio(bio); + iomap_dio_submit_bio(dio, iomap, bio); } static loff_t @@ -1700,9 +1717,6 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, bio_set_pages_dirty(bio); } - if (dio->iocb->ki_flags & IOCB_HIPRI) - bio->bi_opf |= REQ_HIPRI; - iov_iter_advance(dio->submit.iter, n); dio->size += n; @@ -1710,11 +1724,7 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, copied += n; nr_pages = iov_iter_npages(&iter, BIO_MAX_PAGES); - - atomic_inc(&dio->ref); - - dio->submit.last_queue = bdev_get_queue(iomap->bdev); - dio->submit.cookie = submit_bio(bio); + iomap_dio_submit_bio(dio, iomap, bio); } while (nr_pages); /* @@ -1925,6 +1935,9 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, if (dio->flags & IOMAP_DIO_WRITE_FUA) dio->flags &= ~IOMAP_DIO_NEED_SYNC; + WRITE_ONCE(iocb->ki_cookie, dio->submit.cookie); + WRITE_ONCE(iocb->private, dio->submit.last_queue); + /* * We are about to drop our additional submission reference, which * might be the last reference to the dio. There are three three diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index e47425071e65..60c2da41f0fc 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -1203,6 +1203,7 @@ const struct file_operations xfs_file_operations = { .write_iter = xfs_file_write_iter, .splice_read = generic_file_splice_read, .splice_write = iter_file_splice_write, + .iopoll = iomap_dio_iopoll, .unlocked_ioctl = xfs_file_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = xfs_file_compat_ioctl, diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 9a4258154b25..0fefb5455bda 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -162,6 +162,7 @@ typedef int (iomap_dio_end_io_t)(struct kiocb *iocb, ssize_t ret, unsigned flags); ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, const struct iomap_ops *ops, iomap_dio_end_io_t end_io); +int iomap_dio_iopoll(struct kiocb *kiocb, bool spin); #ifdef CONFIG_SWAP struct file; From patchwork Mon Feb 11 19:00:35 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806677 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DF11A746 for ; Mon, 11 Feb 2019 19:01:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CB24F28619 for ; Mon, 11 Feb 2019 19:01:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BE88F2B246; Mon, 11 Feb 2019 19:01:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4896E28619 for ; Mon, 11 Feb 2019 19:01:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733262AbfBKTBH (ORCPT ); Mon, 11 Feb 2019 14:01:07 -0500 Received: from mail-it1-f194.google.com ([209.85.166.194]:36795 "EHLO mail-it1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733258AbfBKTBH (ORCPT ); Mon, 11 Feb 2019 14:01:07 -0500 Received: by mail-it1-f194.google.com with SMTP id c9so935978itj.1 for ; Mon, 11 Feb 2019 11:01:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=vj4mIUu6WwvDxcU0EUkUm8JV7TKyaWTA+OhhXP9m6+w=; b=i1rFuOle9yfr7dj2QjNo5/wdwnjL+vtMiUQRa76Jlg5UXVITow/lyhABuYfD6NMSWt PAgljMgWe0v1CHakE12VQiPXq8muf9T6mrdGOGi1mYYAgBUvhX7fzSZGLU0VfFrIVM7h 1tgptbYAdP+hS9/3B4RMaKMz8M2OV1SsgQXiFJx0kqemLT6Prb9BFaYOYK5K/SwMy6Ih eEVY72hulQ8M4ihXEO5v+ZW+dDuE8Ua23n/utlPqqDE1yDjCiz8SeBxZnL8xVrM/NT3E RrKVIZABdYU/u/tYo3w1gmA9OBWBXOLg9VwSJwOrNWahWRD1cTrJWpYczMfDdlg+SjYM 7kww== 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; bh=vj4mIUu6WwvDxcU0EUkUm8JV7TKyaWTA+OhhXP9m6+w=; b=Ob6RoyfXuprNSusrDMS5jlp1rJwhupuWXMKjX390HR1CI/1sTTc5JEBE07xTBFysNH ikPTJRpDpfQaEIgUot0jAqFcbc6J3tDecwfmik/rqC40/KjUbfxnTfFO0WUuBQuShhh4 CjRi4uonD+7Q86aN7kQL5P9Q/NtLOfxRm2/1F668uPt0zMaOVtWn2LioadvXjN+wvLJT uyNfIx/TCWvq75aNKRnTbHgUfcQmgS3F4B6Lyi7MOYYhSoiP0Ym/hxBMmOSgyjnPLKiE 4xUXAeJjIiL8Gkq3Vmt5WqBa6ssdLrsfMkoc4eY5+EFY+HOC4CPMD8Zdl8T0pvnANJnC X1yw== X-Gm-Message-State: AHQUAuYnTdPfkgI4DoBmo5j2LkGgagRlND6j9i8b4CF2In3DtW52dkfY Zz8m63tJTt7USZx34YDrODd69Q== X-Google-Smtp-Source: AHgI3IYilt5tFZAGgpqCg13o6GcEsV16s3+ZhYXGnxT+ldNuQ0RWQVdHNNJZeq4hEljpPQ6AJiaoUg== X-Received: by 2002:a24:5a8f:: with SMTP id v137mr545765ita.65.1549911664487; Mon, 11 Feb 2019 11:01:04 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.01.02 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:01:03 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 05/19] Add io_uring IO interface Date: Mon, 11 Feb 2019 12:00:35 -0700 Message-Id: <20190211190049.7888-7-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The submission queue (SQ) and completion queue (CQ) rings are shared between the application and the kernel. This eliminates the need to copy data back and forth to submit and complete IO. IO submissions use the io_uring_sqe data structure, and completions are generated in the form of io_uring_cqe data structures. The SQ ring is an index into the io_uring_sqe array, which makes it possible to submit a batch of IOs without them being contiguous in the ring. The CQ ring is always contiguous, as completion events are inherently unordered, and hence any io_uring_cqe entry can point back to an arbitrary submission. Two new system calls are added for this: io_uring_setup(entries, params) Sets up an io_uring instance for doing async IO. On success, returns a file descriptor that the application can mmap to gain access to the SQ ring, CQ ring, and io_uring_sqes. io_uring_enter(fd, to_submit, min_complete, flags, sigset, sigsetsize) Initiates IO against the rings mapped to this fd, or waits for them to complete, or both. The behavior is controlled by the parameters passed in. If 'to_submit' is non-zero, then we'll try and submit new IO. If IORING_ENTER_GETEVENTS is set, the kernel will wait for 'min_complete' events, if they aren't already available. It's valid to set IORING_ENTER_GETEVENTS and 'min_complete' == 0 at the same time, this allows the kernel to return already completed events without waiting for them. This is useful only for polling, as for IRQ driven IO, the application can just check the CQ ring without entering the kernel. With this setup, it's possible to do async IO with a single system call. Future developments will enable polled IO with this interface, and polled submission as well. The latter will enable an application to do IO without doing ANY system calls at all. For IRQ driven IO, an application only needs to enter the kernel for completions if it wants to wait for them to occur. Each io_uring is backed by a workqueue, to support buffered async IO as well. We will only punt to an async context if the command would need to wait for IO on the device side. Any data that can be accessed directly in the page cache is done inline. This avoids the slowness issue of usual threadpools, since cached data is accessed as quickly as a sync interface. Sample application: http://git.kernel.dk/cgit/fio/plain/t/io_uring.c Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- arch/x86/entry/syscalls/syscall_32.tbl | 2 + arch/x86/entry/syscalls/syscall_64.tbl | 2 + fs/Makefile | 1 + fs/io_uring.c | 1243 ++++++++++++++++++++++++ include/linux/fs.h | 9 + include/linux/sched/user.h | 2 +- include/linux/syscalls.h | 6 + include/uapi/asm-generic/unistd.h | 6 +- include/uapi/linux/io_uring.h | 95 ++ init/Kconfig | 9 + kernel/sys_ni.c | 2 + net/unix/garbage.c | 3 + 12 files changed, 1378 insertions(+), 2 deletions(-) create mode 100644 fs/io_uring.c create mode 100644 include/uapi/linux/io_uring.h diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index 3cf7b533b3d1..481c126259e9 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -398,3 +398,5 @@ 384 i386 arch_prctl sys_arch_prctl __ia32_compat_sys_arch_prctl 385 i386 io_pgetevents sys_io_pgetevents __ia32_compat_sys_io_pgetevents 386 i386 rseq sys_rseq __ia32_sys_rseq +425 i386 io_uring_setup sys_io_uring_setup __ia32_sys_io_uring_setup +426 i386 io_uring_enter sys_io_uring_enter __ia32_sys_io_uring_enter diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index f0b1709a5ffb..6a32a430c8e0 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -343,6 +343,8 @@ 332 common statx __x64_sys_statx 333 common io_pgetevents __x64_sys_io_pgetevents 334 common rseq __x64_sys_rseq +425 common io_uring_setup __x64_sys_io_uring_setup +426 common io_uring_enter __x64_sys_io_uring_enter # # x32-specific system call numbers start at 512 to avoid cache impact diff --git a/fs/Makefile b/fs/Makefile index 293733f61594..8e15d6fc4340 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -30,6 +30,7 @@ obj-$(CONFIG_TIMERFD) += timerfd.o obj-$(CONFIG_EVENTFD) += eventfd.o obj-$(CONFIG_USERFAULTFD) += userfaultfd.o obj-$(CONFIG_AIO) += aio.o +obj-$(CONFIG_IO_URING) += io_uring.o obj-$(CONFIG_FS_DAX) += dax.o obj-$(CONFIG_FS_ENCRYPTION) += crypto/ obj-$(CONFIG_FILE_LOCKING) += locks.o diff --git a/fs/io_uring.c b/fs/io_uring.c new file mode 100644 index 000000000000..1b28d38a9b76 --- /dev/null +++ b/fs/io_uring.c @@ -0,0 +1,1243 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Shared application/kernel submission and completion ring pairs, for + * supporting fast/efficient IO. + * + * A note on the read/write ordering memory barriers that are matched between + * the application and kernel side. When the application reads the CQ ring + * tail, it must use an appropriate smp_rmb() to order with the smp_wmb() + * the kernel uses after writing the tail. Failure to do so could cause a + * delay in when the application notices that completion events available. + * This isn't a fatal condition. Likewise, the application must use an + * appropriate smp_wmb() both before writing the SQ tail, and after writing + * the SQ tail. The first one orders the sqe writes with the tail write, and + * the latter is paired with the smp_rmb() the kernel will issue before + * reading the SQ tail on submission. + * + * Also see the examples in the liburing library: + * + * git://git.kernel.dk/liburing + * + * io_uring also uses READ/WRITE_ONCE() for _any_ store or load that happens + * from data shared between the kernel and application. This is done both + * for ordering purposes, but also to ensure that once a value is loaded from + * data that the application could potentially modify, it remains stable. + * + * Copyright (C) 2018-2019 Jens Axboe + */ +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "internal.h" + +#define IORING_MAX_ENTRIES 4096 + +struct io_uring { + u32 head ____cacheline_aligned_in_smp; + u32 tail ____cacheline_aligned_in_smp; +}; + +struct io_sq_ring { + struct io_uring r; + u32 ring_mask; + u32 ring_entries; + u32 dropped; + u32 flags; + u32 array[]; +}; + +struct io_cq_ring { + struct io_uring r; + u32 ring_mask; + u32 ring_entries; + u32 overflow; + struct io_uring_cqe cqes[]; +}; + +struct io_ring_ctx { + struct { + struct percpu_ref refs; + } ____cacheline_aligned_in_smp; + + struct { + unsigned int flags; + bool compat; + bool account_mem; + + /* SQ ring */ + struct io_sq_ring *sq_ring; + unsigned cached_sq_head; + unsigned sq_entries; + unsigned sq_mask; + struct io_uring_sqe *sq_sqes; + } ____cacheline_aligned_in_smp; + + /* IO offload */ + struct workqueue_struct *sqo_wq; + struct mm_struct *sqo_mm; + + struct { + /* CQ ring */ + struct io_cq_ring *cq_ring; + unsigned cached_cq_tail; + unsigned cq_entries; + unsigned cq_mask; + struct wait_queue_head cq_wait; + struct fasync_struct *cq_fasync; + } ____cacheline_aligned_in_smp; + + struct user_struct *user; + + struct completion ctx_done; + + struct { + struct mutex uring_lock; + wait_queue_head_t wait; + } ____cacheline_aligned_in_smp; + + struct { + spinlock_t completion_lock; + } ____cacheline_aligned_in_smp; + +#if defined(CONFIG_UNIX) + struct socket *ring_sock; +#endif +}; + +struct sqe_submit { + const struct io_uring_sqe *sqe; + unsigned short index; + bool has_user; +}; + +struct io_kiocb { + struct kiocb rw; + + struct sqe_submit submit; + + struct io_ring_ctx *ctx; + struct list_head list; + unsigned int flags; +#define REQ_F_FORCE_NONBLOCK 1 /* inline submission attempt */ + u64 user_data; + + struct work_struct work; +}; + +#define IO_PLUG_THRESHOLD 2 + +static struct kmem_cache *req_cachep; + +static const struct file_operations io_uring_fops; + +struct sock *io_uring_get_socket(struct file *file) +{ +#if defined(CONFIG_UNIX) + if (file->f_op == &io_uring_fops) { + struct io_ring_ctx *ctx = file->private_data; + + return ctx->ring_sock->sk; + } +#endif + return NULL; +} +EXPORT_SYMBOL(io_uring_get_socket); + +static void io_ring_ctx_ref_free(struct percpu_ref *ref) +{ + struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs); + + complete(&ctx->ctx_done); +} + +static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) +{ + struct io_ring_ctx *ctx; + + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return NULL; + + if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free, 0, GFP_KERNEL)) { + kfree(ctx); + return NULL; + } + + ctx->flags = p->flags; + init_waitqueue_head(&ctx->cq_wait); + init_completion(&ctx->ctx_done); + mutex_init(&ctx->uring_lock); + init_waitqueue_head(&ctx->wait); + spin_lock_init(&ctx->completion_lock); + return ctx; +} + +static void io_commit_cqring(struct io_ring_ctx *ctx) +{ + struct io_cq_ring *ring = ctx->cq_ring; + + if (ctx->cached_cq_tail != READ_ONCE(ring->r.tail)) { + /* order cqe stores with ring update */ + smp_wmb(); + WRITE_ONCE(ring->r.tail, ctx->cached_cq_tail); + /* + * Write sider barrier of tail update, app has read side. See + * comment at the top of this file. + */ + smp_wmb(); + + if (wq_has_sleeper(&ctx->cq_wait)) { + wake_up_interruptible(&ctx->cq_wait); + kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN); + } + } +} + +static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx) +{ + struct io_cq_ring *ring = ctx->cq_ring; + unsigned tail; + + tail = ctx->cached_cq_tail; + /* See comment at the top of the file */ + smp_rmb(); + if (tail + 1 == READ_ONCE(ring->r.head)) + return NULL; + + ctx->cached_cq_tail++; + return &ring->cqes[tail & ctx->cq_mask]; +} + +static void io_cqring_fill_event(struct io_ring_ctx *ctx, u64 ki_user_data, + long res, unsigned ev_flags) +{ + struct io_uring_cqe *cqe; + + /* + * If we can't get a cq entry, userspace overflowed the + * submission (by quite a lot). Increment the overflow count in + * the ring. + */ + cqe = io_get_cqring(ctx); + if (cqe) { + WRITE_ONCE(cqe->user_data, ki_user_data); + WRITE_ONCE(cqe->res, res); + WRITE_ONCE(cqe->flags, ev_flags); + } else { + unsigned overflow = READ_ONCE(ctx->cq_ring->overflow); + + WRITE_ONCE(ctx->cq_ring->overflow, overflow + 1); + } +} + +static void io_cqring_add_event(struct io_ring_ctx *ctx, u64 ki_user_data, + long res, unsigned ev_flags) +{ + unsigned long flags; + + spin_lock_irqsave(&ctx->completion_lock, flags); + io_cqring_fill_event(ctx, ki_user_data, res, ev_flags); + io_commit_cqring(ctx); + spin_unlock_irqrestore(&ctx->completion_lock, flags); + + if (waitqueue_active(&ctx->wait)) + wake_up(&ctx->wait); +} + +static void io_ring_drop_ctx_refs(struct io_ring_ctx *ctx, unsigned refs) +{ + percpu_ref_put_many(&ctx->refs, refs); + + if (waitqueue_active(&ctx->wait)) + wake_up(&ctx->wait); +} + +static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx) +{ + struct io_kiocb *req; + + if (!percpu_ref_tryget(&ctx->refs)) + return NULL; + + req = kmem_cache_alloc(req_cachep, __GFP_NOWARN); + if (req) { + req->ctx = ctx; + req->flags = 0; + return req; + } + + io_ring_drop_ctx_refs(ctx, 1); + return NULL; +} + +static void io_free_req(struct io_kiocb *req) +{ + io_ring_drop_ctx_refs(req->ctx, 1); + kmem_cache_free(req_cachep, req); +} + +static void kiocb_end_write(struct kiocb *kiocb) +{ + if (kiocb->ki_flags & IOCB_WRITE) { + struct inode *inode = file_inode(kiocb->ki_filp); + + /* + * Tell lockdep we inherited freeze protection from submission + * thread. + */ + if (S_ISREG(inode->i_mode)) + __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE); + file_end_write(kiocb->ki_filp); + } +} + +static void io_complete_rw(struct kiocb *kiocb, long res, long res2) +{ + struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw); + + kiocb_end_write(kiocb); + + fput(kiocb->ki_filp); + io_cqring_add_event(req->ctx, req->user_data, res, 0); + io_free_req(req); +} + +/* + * If we tracked the file through the SCM inflight mechanism, we could support + * any file. For now, just ensure that anything potentially problematic is done + * inline. + */ +static bool io_file_supports_async(struct file *file) +{ + umode_t mode = file_inode(file)->i_mode; + + if (S_ISBLK(mode) || S_ISCHR(mode)) + return true; + if (S_ISREG(mode) && file->f_op != &io_uring_fops) + return true; + + return false; +} + +static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, + bool force_nonblock) +{ + struct kiocb *kiocb = &req->rw; + unsigned ioprio; + int fd, ret; + + /* For -EAGAIN retry, everything is already prepped */ + if (kiocb->ki_filp) + return 0; + + fd = READ_ONCE(sqe->fd); + kiocb->ki_filp = fget(fd); + if (unlikely(!kiocb->ki_filp)) + return -EBADF; + if (force_nonblock && !io_file_supports_async(kiocb->ki_filp)) + force_nonblock = false; + kiocb->ki_pos = READ_ONCE(sqe->off); + kiocb->ki_flags = iocb_flags(kiocb->ki_filp); + kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp)); + + ioprio = READ_ONCE(sqe->ioprio); + if (ioprio) { + ret = ioprio_check_cap(ioprio); + if (ret) + goto out_fput; + + kiocb->ki_ioprio = ioprio; + } else + kiocb->ki_ioprio = get_current_ioprio(); + + ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags)); + if (unlikely(ret)) + goto out_fput; + if (force_nonblock) { + kiocb->ki_flags |= IOCB_NOWAIT; + req->flags |= REQ_F_FORCE_NONBLOCK; + } + if (kiocb->ki_flags & IOCB_HIPRI) { + ret = -EINVAL; + goto out_fput; + } + + kiocb->ki_complete = io_complete_rw; + return 0; +out_fput: + fput(kiocb->ki_filp); + return ret; +} + +static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret) +{ + switch (ret) { + case -EIOCBQUEUED: + break; + case -ERESTARTSYS: + case -ERESTARTNOINTR: + case -ERESTARTNOHAND: + case -ERESTART_RESTARTBLOCK: + /* + * We can't just restart the syscall, since previously + * submitted sqes may already be in progress. Just fail this + * IO with EINTR. + */ + ret = -EINTR; + /* fall through */ + default: + kiocb->ki_complete(kiocb, ret, 0); + } +} + +static int io_import_iovec(struct io_ring_ctx *ctx, int rw, + const struct sqe_submit *s, struct iovec **iovec, + struct iov_iter *iter) +{ + const struct io_uring_sqe *sqe = s->sqe; + void __user *buf = u64_to_user_ptr(READ_ONCE(sqe->addr)); + size_t sqe_len = READ_ONCE(sqe->len); + + if (!s->has_user) + return EFAULT; + +#ifdef CONFIG_COMPAT + if (ctx->compat) + return compat_import_iovec(rw, buf, sqe_len, UIO_FASTIOV, + iovec, iter); +#endif + + return import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter); +} + +static ssize_t io_read(struct io_kiocb *req, const struct sqe_submit *s, + bool force_nonblock) +{ + struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; + struct kiocb *kiocb = &req->rw; + struct iov_iter iter; + struct file *file; + ssize_t ret; + + ret = io_prep_rw(req, s->sqe, force_nonblock); + if (ret) + return ret; + file = kiocb->ki_filp; + + ret = -EBADF; + if (unlikely(!(file->f_mode & FMODE_READ))) + goto out_fput; + ret = -EINVAL; + if (unlikely(!file->f_op->read_iter)) + goto out_fput; + + ret = io_import_iovec(req->ctx, READ, s, &iovec, &iter); + if (ret) + goto out_fput; + + ret = rw_verify_area(READ, file, &kiocb->ki_pos, iov_iter_count(&iter)); + if (!ret) { + ssize_t ret2; + + /* Catch -EAGAIN return for forced non-blocking submission */ + ret2 = call_read_iter(file, kiocb, &iter); + if (!force_nonblock || ret2 != -EAGAIN) + io_rw_done(kiocb, ret2); + else + ret = -EAGAIN; + } + kfree(iovec); +out_fput: + /* Hold on to the file for -EAGAIN */ + if (unlikely(ret && ret != -EAGAIN)) + fput(file); + return ret; +} + +static ssize_t io_write(struct io_kiocb *req, const struct sqe_submit *s, + bool force_nonblock) +{ + struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; + struct kiocb *kiocb = &req->rw; + struct iov_iter iter; + struct file *file; + ssize_t ret; + + ret = io_prep_rw(req, s->sqe, force_nonblock); + if (ret) + return ret; + /* Hold on to the file for -EAGAIN */ + if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT)) + return -EAGAIN; + + ret = -EBADF; + file = kiocb->ki_filp; + if (unlikely(!(file->f_mode & FMODE_WRITE))) + goto out_fput; + ret = -EINVAL; + if (unlikely(!file->f_op->write_iter)) + goto out_fput; + + ret = io_import_iovec(req->ctx, WRITE, s, &iovec, &iter); + if (ret) + goto out_fput; + + ret = rw_verify_area(WRITE, file, &kiocb->ki_pos, + iov_iter_count(&iter)); + if (!ret) { + /* + * Open-code file_start_write here to grab freeze protection, + * which will be released by another thread in + * io_complete_rw(). Fool lockdep by telling it the lock got + * released so that it doesn't complain about the held lock when + * we return to userspace. + */ + if (S_ISREG(file_inode(file)->i_mode)) { + __sb_start_write(file_inode(file)->i_sb, + SB_FREEZE_WRITE, true); + __sb_writers_release(file_inode(file)->i_sb, + SB_FREEZE_WRITE); + } + kiocb->ki_flags |= IOCB_WRITE; + io_rw_done(kiocb, call_write_iter(file, kiocb, &iter)); + } + kfree(iovec); +out_fput: + if (unlikely(ret)) + fput(file); + return ret; +} + +/* + * IORING_OP_NOP just posts a completion event, nothing else. + */ +static int io_nop(struct io_kiocb *req, u64 user_data) +{ + struct io_ring_ctx *ctx = req->ctx; + long err = 0; + + /* + * Twilight zone - it's possible that someone issued an opcode that + * has a file attached, then got -EAGAIN on submission, and changed + * the sqe before we retried it from async context. Avoid dropping + * a file reference for this malicious case, and flag the error. + */ + if (req->rw.ki_filp) { + err = -EBADF; + fput(req->rw.ki_filp); + } + io_cqring_add_event(ctx, user_data, err, 0); + io_free_req(req); + return 0; +} + +static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, + const struct sqe_submit *s, bool force_nonblock) +{ + ssize_t ret; + int opcode; + + if (unlikely(s->index >= ctx->sq_entries)) + return -EINVAL; + req->user_data = READ_ONCE(s->sqe->user_data); + + opcode = READ_ONCE(s->sqe->opcode); + switch (opcode) { + case IORING_OP_NOP: + ret = io_nop(req, req->user_data); + break; + case IORING_OP_READV: + ret = io_read(req, s, force_nonblock); + break; + case IORING_OP_WRITEV: + ret = io_write(req, s, force_nonblock); + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + +static void io_sq_wq_submit_work(struct work_struct *work) +{ + struct io_kiocb *req = container_of(work, struct io_kiocb, work); + struct sqe_submit *s = &req->submit; + const struct io_uring_sqe *sqe = s->sqe; + struct io_ring_ctx *ctx = req->ctx; + mm_segment_t old_fs = get_fs(); + int ret; + + /* Ensure we clear previously set forced non-block flag */ + req->flags &= ~REQ_F_FORCE_NONBLOCK; + req->rw.ki_flags &= ~IOCB_NOWAIT; + + if (!mmget_not_zero(ctx->sqo_mm)) { + ret = -EFAULT; + goto err; + } + + use_mm(ctx->sqo_mm); + set_fs(USER_DS); + s->has_user = true; + + ret = __io_submit_sqe(ctx, req, s, false); + + set_fs(old_fs); + unuse_mm(ctx->sqo_mm); + mmput(ctx->sqo_mm); +err: + if (ret) { + io_cqring_add_event(ctx, sqe->user_data, ret, 0); + io_free_req(req); + } + + /* async context always use a copy of the sqe */ + kfree(sqe); +} + +static int io_submit_sqe(struct io_ring_ctx *ctx, struct sqe_submit *s) +{ + struct io_kiocb *req; + ssize_t ret; + + /* enforce forwards compatibility on users */ + if (unlikely(s->sqe->flags)) + return -EINVAL; + + req = io_get_req(ctx); + if (unlikely(!req)) + return -EAGAIN; + + req->rw.ki_filp = NULL; + + ret = __io_submit_sqe(ctx, req, s, true); + if (ret == -EAGAIN) { + struct io_uring_sqe *sqe_copy; + + sqe_copy = kmalloc(sizeof(*sqe_copy), GFP_KERNEL); + if (sqe_copy) { + memcpy(sqe_copy, s->sqe, sizeof(*sqe_copy)); + s->sqe = sqe_copy; + + memcpy(&req->submit, s, sizeof(*s)); + INIT_WORK(&req->work, io_sq_wq_submit_work); + queue_work(ctx->sqo_wq, &req->work); + ret = 0; + } + } + if (ret) + io_free_req(req); + + return ret; +} + +static void io_commit_sqring(struct io_ring_ctx *ctx) +{ + struct io_sq_ring *ring = ctx->sq_ring; + + if (ctx->cached_sq_head != READ_ONCE(ring->r.head)) { + WRITE_ONCE(ring->r.head, ctx->cached_sq_head); + /* + * write side barrier of head update, app has read side. See + * comment at the top of this file + */ + smp_wmb(); + } +} + +/* + * Undo last io_get_sqring() + */ +static void io_drop_sqring(struct io_ring_ctx *ctx) +{ + ctx->cached_sq_head--; +} + +/* + * Fetch an sqe, if one is available. Note that s->sqe will point to memory + * that is mapped by userspace. This means that care needs to be taken to + * ensure that reads are stable, as we cannot rely on userspace always + * being a good citizen. If members of the sqe are validated and then later + * used, it's important that those reads are done through READ_ONCE() to + * prevent a re-load down the line. + */ +static bool io_get_sqring(struct io_ring_ctx *ctx, struct sqe_submit *s) +{ + struct io_sq_ring *ring = ctx->sq_ring; + unsigned head; + + /* + * The cached sq head (or cq tail) serves two purposes: + * + * 1) allows us to batch the cost of updating the user visible + * head updates. + * 2) allows the kernel side to track the head on its own, even + * though the application is the one updating it. + */ + head = ctx->cached_sq_head; + /* See comment at the top of this file */ + smp_rmb(); + if (head == READ_ONCE(ring->r.tail)) + return false; + + head = READ_ONCE(ring->array[head & ctx->sq_mask]); + if (head < ctx->sq_entries) { + s->index = head; + s->sqe = &ctx->sq_sqes[head]; + ctx->cached_sq_head++; + return true; + } + + /* drop invalid entries */ + ctx->cached_sq_head++; + ring->dropped++; + /* See comment at the top of this file */ + smp_wmb(); + return false; +} + +static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit) +{ + int i, ret = 0, submit = 0; + struct blk_plug plug; + + if (to_submit > IO_PLUG_THRESHOLD) + blk_start_plug(&plug); + + for (i = 0; i < to_submit; i++) { + struct sqe_submit s; + + if (!io_get_sqring(ctx, &s)) + break; + + s.has_user = true; + ret = io_submit_sqe(ctx, &s); + if (ret) { + io_drop_sqring(ctx); + break; + } + + submit++; + } + io_commit_sqring(ctx); + + if (to_submit > IO_PLUG_THRESHOLD) + blk_finish_plug(&plug); + + return submit ? submit : ret; +} + +/* + * Wait until events become available, if we don't already have some. The + * application must reap them itself, as they reside on the shared cq ring. + */ +static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, + const sigset_t __user *sig, size_t sigsz) +{ + struct io_cq_ring *ring = ctx->cq_ring; + sigset_t ksigmask, sigsaved; + DEFINE_WAIT(wait); + int ret = 0; + + /* See comment at the top of this file */ + smp_rmb(); + if (READ_ONCE(ring->r.head) != READ_ONCE(ring->r.tail)) + return 0; + if (!min_events) + return 0; + + if (sig) { + ret = set_user_sigmask(sig, &ksigmask, &sigsaved, sigsz); + if (ret) + return ret; + } + + do { + prepare_to_wait(&ctx->wait, &wait, TASK_INTERRUPTIBLE); + + ret = 0; + /* See comment at the top of this file */ + smp_rmb(); + if (READ_ONCE(ring->r.head) != READ_ONCE(ring->r.tail)) + break; + + schedule(); + + ret = -EINTR; + if (signal_pending(current)) + break; + } while (1); + + finish_wait(&ctx->wait, &wait); + + if (sig) + restore_user_sigmask(sig, &sigsaved); + + return READ_ONCE(ring->r.head) == READ_ONCE(ring->r.tail) ? ret : 0; +} + +static int io_sq_offload_start(struct io_ring_ctx *ctx) +{ + int ret; + + mmgrab(current->mm); + ctx->sqo_mm = current->mm; + + /* Do QD, or 2 * CPUS, whatever is smallest */ + ctx->sqo_wq = alloc_workqueue("io_ring-wq", WQ_UNBOUND | WQ_FREEZABLE, + min(ctx->sq_entries - 1, 2 * num_online_cpus())); + if (!ctx->sqo_wq) { + ret = -ENOMEM; + goto err; + } + + return 0; +err: + mmdrop(ctx->sqo_mm); + ctx->sqo_mm = NULL; + return ret; +} + +static void io_unaccount_mem(struct user_struct *user, unsigned long nr_pages) +{ + atomic_long_sub(nr_pages, &user->locked_vm); +} + +static int io_account_mem(struct user_struct *user, unsigned long nr_pages) +{ + unsigned long page_limit, cur_pages, new_pages; + + /* Don't allow more pages than we can safely lock */ + page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; + + do { + cur_pages = atomic_long_read(&user->locked_vm); + new_pages = cur_pages + nr_pages; + if (new_pages > page_limit) + return -ENOMEM; + } while (atomic_long_cmpxchg(&user->locked_vm, cur_pages, + new_pages) != cur_pages); + + return 0; +} + +static void io_mem_free(void *ptr) +{ + struct page *page = virt_to_head_page(ptr); + + if (put_page_testzero(page)) + free_compound_page(page); +} + +static void *io_mem_alloc(size_t size) +{ + gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP | + __GFP_NORETRY; + + return (void *) __get_free_pages(gfp_flags, get_order(size)); +} + +static unsigned long ring_pages(unsigned sq_entries, unsigned cq_entries) +{ + struct io_sq_ring *sq_ring; + struct io_cq_ring *cq_ring; + size_t bytes; + + bytes = struct_size(sq_ring, array, sq_entries); + bytes += array_size(sizeof(struct io_uring_sqe), sq_entries); + bytes += struct_size(cq_ring, cqes, cq_entries); + + return (bytes + PAGE_SIZE - 1) / PAGE_SIZE; +} + +static void io_ring_ctx_free(struct io_ring_ctx *ctx) +{ + if (ctx->sqo_wq) + destroy_workqueue(ctx->sqo_wq); + if (ctx->sqo_mm) + mmdrop(ctx->sqo_mm); +#if defined(CONFIG_UNIX) + if (ctx->ring_sock) + sock_release(ctx->ring_sock); +#endif + + io_mem_free(ctx->sq_ring); + io_mem_free(ctx->sq_sqes); + io_mem_free(ctx->cq_ring); + + percpu_ref_exit(&ctx->refs); + if (ctx->account_mem) + io_unaccount_mem(ctx->user, + ring_pages(ctx->sq_entries, ctx->cq_entries)); + free_uid(ctx->user); + kfree(ctx); +} + +static __poll_t io_uring_poll(struct file *file, poll_table *wait) +{ + struct io_ring_ctx *ctx = file->private_data; + __poll_t mask = 0; + + poll_wait(file, &ctx->cq_wait, wait); + /* See comment at the top of this file */ + smp_rmb(); + if (READ_ONCE(ctx->sq_ring->r.tail) + 1 != ctx->cached_sq_head) + mask |= EPOLLOUT | EPOLLWRNORM; + if (READ_ONCE(ctx->cq_ring->r.head) != ctx->cached_cq_tail) + mask |= EPOLLIN | EPOLLRDNORM; + + return mask; +} + +static int io_uring_fasync(int fd, struct file *file, int on) +{ + struct io_ring_ctx *ctx = file->private_data; + + return fasync_helper(fd, file, on, &ctx->cq_fasync); +} + +static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) +{ + mutex_lock(&ctx->uring_lock); + percpu_ref_kill(&ctx->refs); + mutex_unlock(&ctx->uring_lock); + + wait_for_completion(&ctx->ctx_done); + io_ring_ctx_free(ctx); +} + +static int io_uring_release(struct inode *inode, struct file *file) +{ + struct io_ring_ctx *ctx = file->private_data; + + file->private_data = NULL; + io_ring_ctx_wait_and_kill(ctx); + return 0; +} + +static int io_uring_mmap(struct file *file, struct vm_area_struct *vma) +{ + loff_t offset = (loff_t) vma->vm_pgoff << PAGE_SHIFT; + unsigned long sz = vma->vm_end - vma->vm_start; + struct io_ring_ctx *ctx = file->private_data; + unsigned long pfn; + struct page *page; + void *ptr; + + switch (offset) { + case IORING_OFF_SQ_RING: + ptr = ctx->sq_ring; + break; + case IORING_OFF_SQES: + ptr = ctx->sq_sqes; + break; + case IORING_OFF_CQ_RING: + ptr = ctx->cq_ring; + break; + default: + return -EINVAL; + } + + page = virt_to_head_page(ptr); + if (sz > (PAGE_SIZE << compound_order(page))) + return -EINVAL; + + pfn = virt_to_phys(ptr) >> PAGE_SHIFT; + return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot); +} + +SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, + u32, min_complete, u32, flags, const sigset_t __user *, sig, + size_t, sigsz) +{ + struct io_ring_ctx *ctx; + long ret = -EBADF; + int submitted = 0; + struct fd f; + + if (flags & ~IORING_ENTER_GETEVENTS) + return -EINVAL; + + f = fdget(fd); + if (!f.file) + return -EBADF; + + ret = -EOPNOTSUPP; + if (f.file->f_op != &io_uring_fops) + goto out_fput; + + ret = -ENXIO; + ctx = f.file->private_data; + if (!percpu_ref_tryget(&ctx->refs)) + goto out_fput; + + if (to_submit) { + to_submit = min(to_submit, ctx->sq_entries); + + mutex_lock(&ctx->uring_lock); + submitted = io_ring_submit(ctx, to_submit); + mutex_unlock(&ctx->uring_lock); + + if (submitted < 0) + goto out_ctx; + } + if (flags & IORING_ENTER_GETEVENTS) { + /* + * The application could have included the 'to_submit' count + * in how many events it wanted to wait for. If we failed to + * submit the desired count, we may need to adjust the number + * of events to poll/wait for. + */ + if (submitted < to_submit) + min_complete = min_t(unsigned, submitted, min_complete); + + ret = io_cqring_wait(ctx, min_complete, sig, sigsz); + } + +out_ctx: + io_ring_drop_ctx_refs(ctx, 1); +out_fput: + fdput(f); + return submitted ? submitted : ret; +} + +static const struct file_operations io_uring_fops = { + .release = io_uring_release, + .mmap = io_uring_mmap, + .poll = io_uring_poll, + .fasync = io_uring_fasync, +}; + +static int io_allocate_scq_urings(struct io_ring_ctx *ctx, + struct io_uring_params *p) +{ + struct io_sq_ring *sq_ring; + struct io_cq_ring *cq_ring; + size_t size; + + sq_ring = io_mem_alloc(struct_size(sq_ring, array, p->sq_entries)); + if (!sq_ring) + return -ENOMEM; + + ctx->sq_ring = sq_ring; + sq_ring->ring_mask = p->sq_entries - 1; + sq_ring->ring_entries = p->sq_entries; + ctx->sq_mask = sq_ring->ring_mask; + ctx->sq_entries = sq_ring->ring_entries; + + size = array_size(sizeof(struct io_uring_sqe), p->sq_entries); + if (size == SIZE_MAX) + return -EOVERFLOW; + + ctx->sq_sqes = io_mem_alloc(size); + if (!ctx->sq_sqes) { + io_mem_free(ctx->sq_ring); + return -ENOMEM; + } + + cq_ring = io_mem_alloc(struct_size(cq_ring, cqes, p->cq_entries)); + if (!cq_ring) { + io_mem_free(ctx->sq_ring); + io_mem_free(ctx->sq_sqes); + return -ENOMEM; + } + + ctx->cq_ring = cq_ring; + cq_ring->ring_mask = p->cq_entries - 1; + cq_ring->ring_entries = p->cq_entries; + ctx->cq_mask = cq_ring->ring_mask; + ctx->cq_entries = cq_ring->ring_entries; + return 0; +} + +/* + * Allocate an anonymous fd, this is what constitutes the application + * visible backing of an io_uring instance. The application mmaps this + * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled, + * we have to tie this fd to a socket for file garbage collection purposes. + */ +static int io_uring_get_fd(struct io_ring_ctx *ctx) +{ + struct file *file; + int ret; + +#if defined(CONFIG_UNIX) + ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP, + &ctx->ring_sock); + if (ret) + return ret; +#endif + + ret = get_unused_fd_flags(O_RDWR | O_CLOEXEC); + if (ret < 0) + goto err; + + file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx, + O_RDWR | O_CLOEXEC); + if (IS_ERR(file)) { + put_unused_fd(ret); + ret = PTR_ERR(file); + goto err; + } + +#if defined(CONFIG_UNIX) + ctx->ring_sock->file = file; +#endif + fd_install(ret, file); + return ret; +err: +#if defined(CONFIG_UNIX) + sock_release(ctx->ring_sock); + ctx->ring_sock = NULL; +#endif + return ret; +} + +static int io_uring_create(unsigned entries, struct io_uring_params *p) +{ + struct user_struct *user = NULL; + struct io_ring_ctx *ctx; + bool account_mem; + int ret; + + if (!entries || entries > IORING_MAX_ENTRIES) + return -EINVAL; + + /* + * Use twice as many entries for the CQ ring. It's possible for the + * application to drive a higher depth than the size of the SQ ring, + * since the sqes are only used at submission time. This allows for + * some flexibility in overcommitting a bit. + */ + p->sq_entries = roundup_pow_of_two(entries); + p->cq_entries = 2 * p->sq_entries; + + user = get_uid(current_user()); + account_mem = !capable(CAP_IPC_LOCK); + + if (account_mem) { + ret = io_account_mem(user, + ring_pages(p->sq_entries, p->cq_entries)); + if (ret) { + free_uid(user); + return ret; + } + } + + ctx = io_ring_ctx_alloc(p); + if (!ctx) { + if (account_mem) + io_unaccount_mem(user, ring_pages(p->sq_entries, + p->cq_entries)); + free_uid(user); + return -ENOMEM; + } + ctx->compat = in_compat_syscall(); + ctx->account_mem = account_mem; + ctx->user = user; + + ret = io_allocate_scq_urings(ctx, p); + if (ret) + goto err; + + ret = io_sq_offload_start(ctx); + if (ret) + goto err; + + ret = io_uring_get_fd(ctx); + if (ret < 0) + goto err; + + memset(&p->sq_off, 0, sizeof(p->sq_off)); + p->sq_off.head = offsetof(struct io_sq_ring, r.head); + p->sq_off.tail = offsetof(struct io_sq_ring, r.tail); + p->sq_off.ring_mask = offsetof(struct io_sq_ring, ring_mask); + p->sq_off.ring_entries = offsetof(struct io_sq_ring, ring_entries); + p->sq_off.flags = offsetof(struct io_sq_ring, flags); + p->sq_off.dropped = offsetof(struct io_sq_ring, dropped); + p->sq_off.array = offsetof(struct io_sq_ring, array); + + memset(&p->cq_off, 0, sizeof(p->cq_off)); + p->cq_off.head = offsetof(struct io_cq_ring, r.head); + p->cq_off.tail = offsetof(struct io_cq_ring, r.tail); + p->cq_off.ring_mask = offsetof(struct io_cq_ring, ring_mask); + p->cq_off.ring_entries = offsetof(struct io_cq_ring, ring_entries); + p->cq_off.overflow = offsetof(struct io_cq_ring, overflow); + p->cq_off.cqes = offsetof(struct io_cq_ring, cqes); + return ret; +err: + io_ring_ctx_wait_and_kill(ctx); + return ret; +} + +/* + * Sets up an aio uring context, and returns the fd. Applications asks for a + * ring size, we return the actual sq/cq ring sizes (among other things) in the + * params structure passed in. + */ +static long io_uring_setup(u32 entries, struct io_uring_params __user *params) +{ + struct io_uring_params p; + long ret; + int i; + + if (copy_from_user(&p, params, sizeof(p))) + return -EFAULT; + for (i = 0; i < ARRAY_SIZE(p.resv); i++) { + if (p.resv[i]) + return -EINVAL; + } + + if (p.flags) + return -EINVAL; + + ret = io_uring_create(entries, &p); + if (ret < 0) + return ret; + + if (copy_to_user(params, &p, sizeof(p))) + return -EFAULT; + + return ret; +} + +SYSCALL_DEFINE2(io_uring_setup, u32, entries, + struct io_uring_params __user *, params) +{ + return io_uring_setup(entries, params); +} + +static int __init io_uring_init(void) +{ + req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC); + return 0; +}; +__initcall(io_uring_init); diff --git a/include/linux/fs.h b/include/linux/fs.h index dedcc2e9265c..61aa210f0c2b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3517,4 +3517,13 @@ extern void inode_nohighmem(struct inode *inode); extern int vfs_fadvise(struct file *file, loff_t offset, loff_t len, int advice); +#if defined(CONFIG_IO_URING) +extern struct sock *io_uring_get_socket(struct file *file); +#else +static inline struct sock *io_uring_get_socket(struct file *file) +{ + return NULL; +} +#endif + #endif /* _LINUX_FS_H */ diff --git a/include/linux/sched/user.h b/include/linux/sched/user.h index 39ad98c09c58..c7b5f86b91a1 100644 --- a/include/linux/sched/user.h +++ b/include/linux/sched/user.h @@ -40,7 +40,7 @@ struct user_struct { kuid_t uid; #if defined(CONFIG_PERF_EVENTS) || defined(CONFIG_BPF_SYSCALL) || \ - defined(CONFIG_NET) + defined(CONFIG_NET) || defined(CONFIG_IO_URING) atomic_long_t locked_vm; #endif diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 257cccba3062..3072dbaa7869 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -69,6 +69,7 @@ struct file_handle; struct sigaltstack; struct rseq; union bpf_attr; +struct io_uring_params; #include #include @@ -309,6 +310,11 @@ asmlinkage long sys_io_pgetevents_time32(aio_context_t ctx_id, struct io_event __user *events, struct old_timespec32 __user *timeout, const struct __aio_sigset *sig); +asmlinkage long sys_io_uring_setup(u32 entries, + struct io_uring_params __user *p); +asmlinkage long sys_io_uring_enter(unsigned int fd, u32 to_submit, + u32 min_complete, u32 flags, + const sigset_t __user *sig, size_t sigsz); /* fs/xattr.c */ asmlinkage long sys_setxattr(const char __user *path, const char __user *name, diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h index d90127298f12..87871e7b7ea7 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -740,9 +740,13 @@ __SC_COMP(__NR_io_pgetevents, sys_io_pgetevents, compat_sys_io_pgetevents) __SYSCALL(__NR_rseq, sys_rseq) #define __NR_kexec_file_load 294 __SYSCALL(__NR_kexec_file_load, sys_kexec_file_load) +#define __NR_io_uring_setup 425 +__SYSCALL(__NR_io_uring_setup, sys_io_uring_setup) +#define __NR_io_uring_enter 426 +__SYSCALL(__NR_io_uring_enter, sys_io_uring_enter) #undef __NR_syscalls -#define __NR_syscalls 295 +#define __NR_syscalls 427 /* * 32 bit systems traditionally used different diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h new file mode 100644 index 000000000000..ac692823d6f4 --- /dev/null +++ b/include/uapi/linux/io_uring.h @@ -0,0 +1,95 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* + * Header file for the io_uring interface. + * + * Copyright (C) 2019 Jens Axboe + * Copyright (C) 2019 Christoph Hellwig + */ +#ifndef LINUX_IO_URING_H +#define LINUX_IO_URING_H + +#include +#include + +/* + * IO submission data structure (Submission Queue Entry) + */ +struct io_uring_sqe { + __u8 opcode; /* type of operation for this sqe */ + __u8 flags; /* as of now unused */ + __u16 ioprio; /* ioprio for the request */ + __s32 fd; /* file descriptor to do IO on */ + __u64 off; /* offset into file */ + __u64 addr; /* pointer to buffer or iovecs */ + __u32 len; /* buffer size or number of iovecs */ + union { + __kernel_rwf_t rw_flags; + __u32 __resv; + }; + __u64 user_data; /* data to be passed back at completion time */ + __u64 __pad2[3]; +}; + +#define IORING_OP_NOP 0 +#define IORING_OP_READV 1 +#define IORING_OP_WRITEV 2 + +/* + * IO completion data structure (Completion Queue Entry) + */ +struct io_uring_cqe { + __u64 user_data; /* sqe->data submission passed back */ + __s32 res; /* result code for this event */ + __u32 flags; +}; + +/* + * Magic offsets for the application to mmap the data it needs + */ +#define IORING_OFF_SQ_RING 0ULL +#define IORING_OFF_CQ_RING 0x8000000ULL +#define IORING_OFF_SQES 0x10000000ULL + +/* + * Filled with the offset for mmap(2) + */ +struct io_sqring_offsets { + __u32 head; + __u32 tail; + __u32 ring_mask; + __u32 ring_entries; + __u32 flags; + __u32 dropped; + __u32 array; + __u32 resv1; + __u64 resv2; +}; + +struct io_cqring_offsets { + __u32 head; + __u32 tail; + __u32 ring_mask; + __u32 ring_entries; + __u32 overflow; + __u32 cqes; + __u64 resv[2]; +}; + +/* + * io_uring_enter(2) flags + */ +#define IORING_ENTER_GETEVENTS (1U << 0) + +/* + * Passed in for io_uring_setup(2). Copied back with updated info on success + */ +struct io_uring_params { + __u32 sq_entries; + __u32 cq_entries; + __u32 flags; + __u32 resv[7]; + struct io_sqring_offsets sq_off; + struct io_cqring_offsets cq_off; +}; + +#endif diff --git a/init/Kconfig b/init/Kconfig index c9386a365eea..53b54214a36e 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1414,6 +1414,15 @@ config AIO by some high performance threaded applications. Disabling this option saves about 7k. +config IO_URING + bool "Enable IO uring support" if EXPERT + select ANON_INODES + default y + help + This option enables support for the io_uring interface, enabling + applications to submit and complete IO through submission and + completion rings that are shared between the kernel and application. + config ADVISE_SYSCALLS bool "Enable madvise/fadvise syscalls" if EXPERT default y diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index ab9d0e3c6d50..ee5e523564bb 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -46,6 +46,8 @@ COND_SYSCALL(io_getevents); COND_SYSCALL(io_pgetevents); COND_SYSCALL_COMPAT(io_getevents); COND_SYSCALL_COMPAT(io_pgetevents); +COND_SYSCALL(io_uring_setup); +COND_SYSCALL(io_uring_enter); /* fs/xattr.c */ diff --git a/net/unix/garbage.c b/net/unix/garbage.c index c36757e72844..f81854d74c7d 100644 --- a/net/unix/garbage.c +++ b/net/unix/garbage.c @@ -108,6 +108,9 @@ struct sock *unix_get_socket(struct file *filp) /* PF_UNIX ? */ if (s && sock->ops && sock->ops->family == PF_UNIX) u_sock = s; + } else { + /* Could be an io_uring instance */ + u_sock = io_uring_get_socket(filp); } return u_sock; } From patchwork Mon Feb 11 19:00:36 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806675 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 667C4746 for ; Mon, 11 Feb 2019 19:01:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 576632A166 for ; Mon, 11 Feb 2019 19:01:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 48D0F2AE23; Mon, 11 Feb 2019 19:01:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CE98F2A166 for ; Mon, 11 Feb 2019 19:01:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733258AbfBKTBH (ORCPT ); Mon, 11 Feb 2019 14:01:07 -0500 Received: from mail-it1-f195.google.com ([209.85.166.195]:50616 "EHLO mail-it1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733264AbfBKTBH (ORCPT ); Mon, 11 Feb 2019 14:01:07 -0500 Received: by mail-it1-f195.google.com with SMTP id z7so938944iti.0 for ; Mon, 11 Feb 2019 11:01:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=bxYi0FhWuXRKsMffM0NC7yJF4pwiUC98N3zVoSyVJvw=; b=koMEoRJ64skLgy28IDgk9fDtL+YI1Uqu5V+3syXQZDF+R1+lwSt7rWizFwBzSZNxNd 94gB6ctdIUv8ijte5NE3EJZNsVs7YTA9UxKl0Lg0M/VSDw+Bt62gUtbw8cmhTC/gXWkm cdvNke0l/arkRhxLDuGSWwxZ0iqspYNpofEpiKtQ69Q6B9XDH3f9StwRKK/HBPEgk6ns yvbafFfqdLvS0NWD6ygQ3PJg+X4YJVgOZY/h+wEVPq3wnJiX7xRCkRl+mx45S+1BIdlg d8h9+M4S4l0nDer4b3a2idxOjIUNxA2TD7E0yG3h7Yp4zxN3oYCOdE37Bd7OFduSpm9Q vjdw== 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; bh=bxYi0FhWuXRKsMffM0NC7yJF4pwiUC98N3zVoSyVJvw=; b=mj+30mSK7lqcazTtJOHYoAWqexJkY8X3KNMQUwPmEzGKwTBVfrop6150RCtHHMmA16 7Bzn0gdgUwXByBBPY06sH11pxMHzhq5UR9+QYbtCqpAlpQNmVxB885T0TZ+MDWN70gIX tpqYadua6JuDST5XKZr+OZf8XIt5T+i8QhWSCi9R8dFQLlEFuq6lQkt2/5t3EczJ1RcA tCUzeCpV3n5ycdckrSSLMb8QjizCoQfJKFCaJf/ZfzGiADHp2V1fPOdOMxnQyS/0Kh8l K5RoWrZ+PeD+8kqlcc107Vsl9XVefcqFtmA4XOL1pPX5QbBiaunaR1yPgMj/Q9TCiNU8 Zh4Q== X-Gm-Message-State: AHQUAuZVp0dVn+HYyBsXsw3jUjMiGtg752vUdPqDqBVBAThT1Wvy/rNX 9OWFF1fCIi5CDCPH3ZXb89WHrw== X-Google-Smtp-Source: AHgI3IZ7oJ0kY0Lq5zVOFtMxEOOKAhOYiM4EEGLoMkEzA36h5Kb/Nd7bDZ/oZiCQWunX21Os9ya2jw== X-Received: by 2002:a5d:8d18:: with SMTP id p24mr9166675ioj.223.1549911666098; Mon, 11 Feb 2019 11:01:06 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.01.04 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:01:05 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 06/19] io_uring: add fsync support Date: Mon, 11 Feb 2019 12:00:36 -0700 Message-Id: <20190211190049.7888-8-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Christoph Hellwig Add a new fsync opcode, which either syncs a range if one is passed, or the whole file if the offset and length fields are both cleared to zero. A flag is provided to use fdatasync semantics, that is only force out metadata which is required to retrieve the file data, but not others like metadata. Reviewed-by: Hannes Reinecke Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- fs/io_uring.c | 54 +++++++++++++++++++++++++++++++++++ include/uapi/linux/io_uring.h | 8 +++++- 2 files changed, 61 insertions(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 1b28d38a9b76..dc9155b7294e 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -24,6 +24,7 @@ * data that the application could potentially modify, it remains stable. * * Copyright (C) 2018-2019 Jens Axboe + * Copyright (c) 2018-2019 Christoph Hellwig */ #include #include @@ -557,6 +558,56 @@ static int io_nop(struct io_kiocb *req, u64 user_data) return 0; } +static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + int fd; + + /* Prep already done */ + if (req->rw.ki_filp) + return 0; + + if (unlikely(sqe->addr || sqe->ioprio)) + return -EINVAL; + + fd = READ_ONCE(sqe->fd); + req->rw.ki_filp = fget(fd); + if (unlikely(!req->rw.ki_filp)) + return -EBADF; + + return 0; +} + +static int io_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe, + bool force_nonblock) +{ + loff_t sqe_off = READ_ONCE(sqe->off); + loff_t sqe_len = READ_ONCE(sqe->len); + loff_t end = sqe_off + sqe_len; + unsigned fsync_flags; + int ret; + + fsync_flags = READ_ONCE(sqe->fsync_flags); + if (unlikely(fsync_flags & ~IORING_FSYNC_DATASYNC)) + return -EINVAL; + + ret = io_prep_fsync(req, sqe); + if (ret) + return ret; + + /* fsync always requires a blocking context */ + if (force_nonblock) + return -EAGAIN; + + ret = vfs_fsync_range(req->rw.ki_filp, sqe_off, + end > 0 ? end : LLONG_MAX, + fsync_flags & IORING_FSYNC_DATASYNC); + + fput(req->rw.ki_filp); + io_cqring_add_event(req->ctx, sqe->user_data, ret, 0); + io_free_req(req); + return 0; +} + static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, const struct sqe_submit *s, bool force_nonblock) { @@ -578,6 +629,9 @@ static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, case IORING_OP_WRITEV: ret = io_write(req, s, force_nonblock); break; + case IORING_OP_FSYNC: + ret = io_fsync(req, s->sqe, force_nonblock); + break; default: ret = -EINVAL; break; diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index ac692823d6f4..4589d56d0b68 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -24,7 +24,7 @@ struct io_uring_sqe { __u32 len; /* buffer size or number of iovecs */ union { __kernel_rwf_t rw_flags; - __u32 __resv; + __u32 fsync_flags; }; __u64 user_data; /* data to be passed back at completion time */ __u64 __pad2[3]; @@ -33,6 +33,12 @@ struct io_uring_sqe { #define IORING_OP_NOP 0 #define IORING_OP_READV 1 #define IORING_OP_WRITEV 2 +#define IORING_OP_FSYNC 3 + +/* + * sqe->fsync_flags + */ +#define IORING_FSYNC_DATASYNC (1U << 0) /* * IO completion data structure (Completion Queue Entry) From patchwork Mon Feb 11 19:00:37 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806681 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 63B8917FB for ; Mon, 11 Feb 2019 19:01:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 54FEA293A8 for ; Mon, 11 Feb 2019 19:01:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 494E62AE23; Mon, 11 Feb 2019 19:01:12 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DFBEE2A166 for ; Mon, 11 Feb 2019 19:01:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733272AbfBKTBJ (ORCPT ); Mon, 11 Feb 2019 14:01:09 -0500 Received: from mail-it1-f195.google.com ([209.85.166.195]:53336 "EHLO mail-it1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733271AbfBKTBI (ORCPT ); Mon, 11 Feb 2019 14:01:08 -0500 Received: by mail-it1-f195.google.com with SMTP id g85so881013ita.3 for ; Mon, 11 Feb 2019 11:01:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=N5L+SZOM6n3d4tyvoeC4oAEZjHKVlRUZTAgmOG9/DJE=; b=ajceIW/v0OxDrt9X3UUK59HGGr6QzTZQGBjb6tfvaUTbYyijnI2q2kEt9LyTUchIT8 lkdDToWBck6RNpqsh0q63aKfCkyyAl45bwctmbIxjKIsj4Wf++lemvgQkWvFCvdZB/3M QztQ68vUh5/6eefysqU76KtpRb7Q00h2/VeADCQBLUo63Nd7PSoVsMwsqIE/cIZcLhaS qNVOHzep/f2znPr1q40PM8NlH9QTcnoubA2U/TkKgThqv5uqfCHBBEGZJu/DR1yObpSC V104scBZ3ARHqjjGFVyN6biI7IwLSWRfisYD+PTNAgJ4DQ7JwPBcV+TbaUJn28IOQfRN vWOw== 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; bh=N5L+SZOM6n3d4tyvoeC4oAEZjHKVlRUZTAgmOG9/DJE=; b=q3HEmDHJyvLAOkZbQaB7ISh4BriCD0UYLj8hWhqdOP01sXwnlPaCyuyL4kxKWOBECg 5I0MbUlMTmXgDv/7n1Pr3RikxPOn8ZP93srS/1h6ZLd/oIOiwZI3ib5QC5AdhH2g3VET LAZAUvqZKPHMlJPBwQWGvn96obMbW+Jo2hAVmkUT4UtYsG9RU+CbnpdbxoPtqHdxf1E8 5iIuU5GDG+mLg1SVs+y+IyOjrnvarN+8U7I2+mLI97LMP3hvmQ62f+cU54Ow1uMcMw79 wFPuBlPnQ/hWMzCthx0lGwM+HTiYrK0Utz9XuQS6UT1BS5vfRMGtLXbXe4xCe0QAByLs vUCQ== X-Gm-Message-State: AHQUAuZh3NIq+FqV/lbj6sQ9TnXnk7Lb69z3qXiEpx9SQDut7KZjDbxP Ej/nZrom9+AUj7Da2Qk6Y8XlUg== X-Google-Smtp-Source: AHgI3IYkhtJ8Yai6yg0XHIq0L0S5clpVa1k7dfoM3reFETQ5jlv4RwC1zMuO60VbPipAFrUHyqKjhA== X-Received: by 2002:a02:3f29:: with SMTP id d41mr19432593jaa.76.1549911667820; Mon, 11 Feb 2019 11:01:07 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.01.06 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:01:06 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 07/19] io_uring: support for IO polling Date: Mon, 11 Feb 2019 12:00:37 -0700 Message-Id: <20190211190049.7888-9-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add support for a polled io_uring instance. When a read or write is submitted to a polled io_uring, the application must poll for completions on the CQ ring through io_uring_enter(2). Polled IO may not generate IRQ completions, hence they need to be actively found by the application itself. To use polling, io_uring_setup() must be used with the IORING_SETUP_IOPOLL flag being set. It is illegal to mix and match polled and non-polled IO on an io_uring. Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- fs/io_uring.c | 275 ++++++++++++++++++++++++++++++++-- include/uapi/linux/io_uring.h | 5 + 2 files changed, 271 insertions(+), 9 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index dc9155b7294e..30efe5edf6aa 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -124,6 +124,14 @@ struct io_ring_ctx { struct { spinlock_t completion_lock; + bool poll_multi_file; + /* + * ->poll_list is protected by the ctx->uring_lock for + * io_uring instances that don't use IORING_SETUP_SQPOLL. + * For SQPOLL, only the single threaded io_sq_thread() will + * manipulate the list, hence no extra locking is needed there. + */ + struct list_head poll_list; } ____cacheline_aligned_in_smp; #if defined(CONFIG_UNIX) @@ -135,6 +143,7 @@ struct sqe_submit { const struct io_uring_sqe *sqe; unsigned short index; bool has_user; + bool needs_lock; }; struct io_kiocb { @@ -146,12 +155,15 @@ struct io_kiocb { struct list_head list; unsigned int flags; #define REQ_F_FORCE_NONBLOCK 1 /* inline submission attempt */ +#define REQ_F_IOPOLL_COMPLETED 2 /* polled IO has completed */ u64 user_data; + u64 error; struct work_struct work; }; #define IO_PLUG_THRESHOLD 2 +#define IO_IOPOLL_BATCH 8 static struct kmem_cache *req_cachep; @@ -196,6 +208,7 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) mutex_init(&ctx->uring_lock); init_waitqueue_head(&ctx->wait); spin_lock_init(&ctx->completion_lock); + INIT_LIST_HEAD(&ctx->poll_list); return ctx; } @@ -297,12 +310,153 @@ static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx) return NULL; } +static void io_free_req_many(struct io_ring_ctx *ctx, void **reqs, int *nr) +{ + if (*nr) { + kmem_cache_free_bulk(req_cachep, *nr, reqs); + io_ring_drop_ctx_refs(ctx, *nr); + *nr = 0; + } +} + static void io_free_req(struct io_kiocb *req) { io_ring_drop_ctx_refs(req->ctx, 1); kmem_cache_free(req_cachep, req); } +/* + * Find and free completed poll iocbs + */ +static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events, + struct list_head *done) +{ + void *reqs[IO_IOPOLL_BATCH]; + struct io_kiocb *req; + int to_free = 0; + + while (!list_empty(done)) { + req = list_first_entry(done, struct io_kiocb, list); + list_del(&req->list); + + io_cqring_fill_event(ctx, req->user_data, req->error, 0); + + reqs[to_free++] = req; + (*nr_events)++; + + fput(req->rw.ki_filp); + if (to_free == ARRAY_SIZE(reqs)) + io_free_req_many(ctx, reqs, &to_free); + } + io_commit_cqring(ctx); + + io_free_req_many(ctx, reqs, &to_free); +} + +static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events, + long min) +{ + struct io_kiocb *req, *tmp; + LIST_HEAD(done); + bool spin; + int ret; + + /* + * Only spin for completions if we don't have multiple devices hanging + * off our complete list, and we're under the requested amount. + */ + spin = !ctx->poll_multi_file && *nr_events < min; + + ret = 0; + list_for_each_entry_safe(req, tmp, &ctx->poll_list, list) { + struct kiocb *kiocb = &req->rw; + + /* + * Move completed entries to our local list. If we find a + * request that requires polling, break out and complete + * the done list first, if we have entries there. + */ + if (req->flags & REQ_F_IOPOLL_COMPLETED) { + list_move_tail(&req->list, &done); + continue; + } + if (!list_empty(&done)) + break; + + ret = kiocb->ki_filp->f_op->iopoll(kiocb, spin); + if (ret < 0) + break; + + if (ret && spin) + spin = false; + ret = 0; + } + + if (!list_empty(&done)) + io_iopoll_complete(ctx, nr_events, &done); + + return ret; +} + +/* + * Poll for a mininum of 'min' events. Note that if min == 0 we consider that a + * non-spinning poll check - we'll still enter the driver poll loop, but only + * as a non-spinning completion check. + */ +static int io_iopoll_getevents(struct io_ring_ctx *ctx, unsigned int *nr_events, + long min) +{ + while (!list_empty(&ctx->poll_list)) { + int ret; + + ret = io_do_iopoll(ctx, nr_events, min); + if (ret < 0) + return ret; + if (!min || *nr_events >= min) + return 0; + } + + return 1; +} + +/* + * We can't just wait for polled events to come to us, we have to actively + * find and complete them. + */ +static void io_iopoll_reap_events(struct io_ring_ctx *ctx) +{ + if (!(ctx->flags & IORING_SETUP_IOPOLL)) + return; + + mutex_lock(&ctx->uring_lock); + while (!list_empty(&ctx->poll_list)) { + unsigned int nr_events = 0; + + io_iopoll_getevents(ctx, &nr_events, 1); + } + mutex_unlock(&ctx->uring_lock); +} + +static int io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events, + long min) +{ + int ret = 0; + + do { + int tmin = 0; + + if (*nr_events < min) + tmin = min - *nr_events; + + ret = io_iopoll_getevents(ctx, nr_events, tmin); + if (ret <= 0) + break; + ret = 0; + } while (min && !*nr_events && !need_resched()); + + return ret; +} + static void kiocb_end_write(struct kiocb *kiocb) { if (kiocb->ki_flags & IOCB_WRITE) { @@ -329,6 +483,53 @@ static void io_complete_rw(struct kiocb *kiocb, long res, long res2) io_free_req(req); } +static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2) +{ + struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw); + + kiocb_end_write(kiocb); + + req->error = res; + if (res != -EAGAIN) + req->flags |= REQ_F_IOPOLL_COMPLETED; +} + +/* + * After the iocb has been issued, it's safe to be found on the poll list. + * Adding the kiocb to the list AFTER submission ensures that we don't + * find it from a io_iopoll_getevents() thread before the issuer is done + * accessing the kiocb cookie. + */ +static void io_iopoll_req_issued(struct io_kiocb *req) +{ + struct io_ring_ctx *ctx = req->ctx; + + /* + * Track whether we have multiple files in our lists. This will impact + * how we do polling eventually, not spinning if we're on potentially + * different devices. + */ + if (list_empty(&ctx->poll_list)) { + ctx->poll_multi_file = false; + } else if (!ctx->poll_multi_file) { + struct io_kiocb *list_req; + + list_req = list_first_entry(&ctx->poll_list, struct io_kiocb, + list); + if (list_req->rw.ki_filp != req->rw.ki_filp) + ctx->poll_multi_file = true; + } + + /* + * For fast devices, IO may have already completed. If it has, add + * it to the front so we find it first. + */ + if (req->flags & REQ_F_IOPOLL_COMPLETED) + list_add(&req->list, &ctx->poll_list); + else + list_add_tail(&req->list, &ctx->poll_list); +} + /* * If we tracked the file through the SCM inflight mechanism, we could support * any file. For now, just ensure that anything potentially problematic is done @@ -349,6 +550,7 @@ static bool io_file_supports_async(struct file *file) static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, bool force_nonblock) { + struct io_ring_ctx *ctx = req->ctx; struct kiocb *kiocb = &req->rw; unsigned ioprio; int fd, ret; @@ -384,12 +586,22 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, kiocb->ki_flags |= IOCB_NOWAIT; req->flags |= REQ_F_FORCE_NONBLOCK; } - if (kiocb->ki_flags & IOCB_HIPRI) { - ret = -EINVAL; - goto out_fput; - } + if (ctx->flags & IORING_SETUP_IOPOLL) { + ret = -EOPNOTSUPP; + if (!(kiocb->ki_flags & IOCB_DIRECT) || + !kiocb->ki_filp->f_op->iopoll) + goto out_fput; - kiocb->ki_complete = io_complete_rw; + req->error = 0; + kiocb->ki_flags |= IOCB_HIPRI; + kiocb->ki_complete = io_complete_rw_iopoll; + } else { + if (kiocb->ki_flags & IOCB_HIPRI) { + ret = -EINVAL; + goto out_fput; + } + kiocb->ki_complete = io_complete_rw; + } return 0; out_fput: fput(kiocb->ki_filp); @@ -543,6 +755,9 @@ static int io_nop(struct io_kiocb *req, u64 user_data) struct io_ring_ctx *ctx = req->ctx; long err = 0; + if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; + /* * Twilight zone - it's possible that someone issued an opcode that * has a file attached, then got -EAGAIN on submission, and changed @@ -566,6 +781,8 @@ static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe) if (req->rw.ki_filp) return 0; + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; if (unlikely(sqe->addr || sqe->ioprio)) return -EINVAL; @@ -637,7 +854,22 @@ static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, break; } - return ret; + if (ret) + return ret; + + if (ctx->flags & IORING_SETUP_IOPOLL) { + if (req->error == -EAGAIN) + return -EAGAIN; + + /* workqueue context doesn't hold uring_lock, grab it now */ + if (s->needs_lock) + mutex_lock(&ctx->uring_lock); + io_iopoll_req_issued(req); + if (s->needs_lock) + mutex_unlock(&ctx->uring_lock); + } + + return 0; } static void io_sq_wq_submit_work(struct work_struct *work) @@ -661,8 +893,19 @@ static void io_sq_wq_submit_work(struct work_struct *work) use_mm(ctx->sqo_mm); set_fs(USER_DS); s->has_user = true; + s->needs_lock = true; - ret = __io_submit_sqe(ctx, req, s, false); + do { + ret = __io_submit_sqe(ctx, req, s, false); + /* + * We can get EAGAIN for polled IO even though we're forcing + * a sync submission from here, since we can't wait for + * request slots on the block side. + */ + if (ret != -EAGAIN) + break; + cond_resched(); + } while (1); set_fs(old_fs); unuse_mm(ctx->sqo_mm); @@ -793,6 +1036,8 @@ static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit) break; s.has_user = true; + s.needs_lock = false; + ret = io_submit_sqe(ctx, &s); if (ret) { io_drop_sqring(ctx); @@ -938,6 +1183,9 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx) destroy_workqueue(ctx->sqo_wq); if (ctx->sqo_mm) mmdrop(ctx->sqo_mm); + + io_iopoll_reap_events(ctx); + #if defined(CONFIG_UNIX) if (ctx->ring_sock) sock_release(ctx->ring_sock); @@ -984,6 +1232,7 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) percpu_ref_kill(&ctx->refs); mutex_unlock(&ctx->uring_lock); + io_iopoll_reap_events(ctx); wait_for_completion(&ctx->ctx_done); io_ring_ctx_free(ctx); } @@ -1064,6 +1313,8 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, goto out_ctx; } if (flags & IORING_ENTER_GETEVENTS) { + unsigned nr_events = 0; + /* * The application could have included the 'to_submit' count * in how many events it wanted to wait for. If we failed to @@ -1073,7 +1324,13 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, if (submitted < to_submit) min_complete = min_t(unsigned, submitted, min_complete); - ret = io_cqring_wait(ctx, min_complete, sig, sigsz); + if (ctx->flags & IORING_SETUP_IOPOLL) { + mutex_lock(&ctx->uring_lock); + ret = io_iopoll_check(ctx, &nr_events, min_complete); + mutex_unlock(&ctx->uring_lock); + } else { + ret = io_cqring_wait(ctx, min_complete, sig, sigsz); + } } out_ctx: @@ -1270,7 +1527,7 @@ static long io_uring_setup(u32 entries, struct io_uring_params __user *params) return -EINVAL; } - if (p.flags) + if (p.flags & ~IORING_SETUP_IOPOLL) return -EINVAL; ret = io_uring_create(entries, &p); diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 4589d56d0b68..5c457ea396e6 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -30,6 +30,11 @@ struct io_uring_sqe { __u64 __pad2[3]; }; +/* + * io_uring_setup() flags + */ +#define IORING_SETUP_IOPOLL (1U << 0) /* io_context is polled */ + #define IORING_OP_NOP 0 #define IORING_OP_READV 1 #define IORING_OP_WRITEV 2 From patchwork Mon Feb 11 19:00:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806679 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 372836C2 for ; Mon, 11 Feb 2019 19:01:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 28C86293A8 for ; Mon, 11 Feb 2019 19:01:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1CD012B246; Mon, 11 Feb 2019 19:01:12 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9517C293A8 for ; Mon, 11 Feb 2019 19:01:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733008AbfBKTBL (ORCPT ); Mon, 11 Feb 2019 14:01:11 -0500 Received: from mail-it1-f196.google.com ([209.85.166.196]:53344 "EHLO mail-it1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733275AbfBKTBK (ORCPT ); Mon, 11 Feb 2019 14:01:10 -0500 Received: by mail-it1-f196.google.com with SMTP id g85so881209ita.3 for ; Mon, 11 Feb 2019 11:01:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=98aDYmP2NlaZN4eCHJfDt4iyzmD8E6C6eVhxrKQfagM=; b=0q4oihl88JIVkVj7P5QQTgA6OP50+YL+2zLfKSyeZ1Gq9zdKPLsshQ57dbzoAN6OBW wNSuIHitUvk3kJ024E9GUVkklM8zcWUGBvNNYQP+6d0PAlrDp4FJW7oCYvPz1RmD4rX8 9vQV+WfmA7yEJM7g4Y7W4m7LAb+Qa4qVJQihSjhOs0DKhXJMAzzJWZPZxa2/xAQTj4gC 6sIDhAnGUSCNVDRBqHMBTT9SwGXqtbu8dGYa8KVUAlYBV7Vivd2c5ilCSPSAFBVJjNmB gjp/gUecSx3coA8wINzE4NN33RdMZUo8GgWLV7PEyJxCmmYE6KI9DxDuQwbOcRK1Gt2p DOzg== 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; bh=98aDYmP2NlaZN4eCHJfDt4iyzmD8E6C6eVhxrKQfagM=; b=uEQSscUYGID0BIHTe3tF29l/OPeogwdyryYX0wO7K2jl7apbYwMSAC5UPmNkCbF/Aq LgjB0/omXuwhbi8mr4swmJEGHvXuPkVCP80q2JuN3ok7ltYAC++Hdy6K7AmZn6jVWyIa 2nRWLGt3HzaljaulEGDd0WL5NaOhC5M3hyiJthsv1L/Fx3wdRduvt6yGMrP2QjJOI8w6 HFrrjamji8lunMPHyfX+pTZCFQPPn21pMP56yZiJjXBxRC8rn3lrZFkLvNiM2LmBwgWm rOdqtFgR5rdG5EcXkhGiTgIK3cWa4l1oJOgqNk3DSJm4QURsuu7HNKNp1k55vexizy2R 4z8A== X-Gm-Message-State: AHQUAuaDdqg24rarg0zuoPY6THjlHl6tK1BljeVNwMsit1uMDli8hpaf tTDShQcJOpbAHqG3PRZcPuyje0nvcN3LsA== X-Google-Smtp-Source: AHgI3IaQYakLqu4d7tsSe4uUHefkCjp4UQz3CghdYTsIDZMfwaRJHygmOW+QJvjw/FwjrJTQOX+n3g== X-Received: by 2002:a05:660c:a48:: with SMTP id j8mr563250itl.26.1549911669620; Mon, 11 Feb 2019 11:01:09 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.01.07 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:01:08 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 08/19] fs: add fget_many() and fput_many() Date: Mon, 11 Feb 2019 12:00:38 -0700 Message-Id: <20190211190049.7888-10-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Some uses cases repeatedly get and put references to the same file, but the only exposed interface is doing these one at the time. As each of these entail an atomic inc or dec on a shared structure, that cost can add up. Add fget_many(), which works just like fget(), except it takes an argument for how many references to get on the file. Ditto fput_many(), which can drop an arbitrary number of references to a file. Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- fs/file.c | 15 ++++++++++----- fs/file_table.c | 9 +++++++-- include/linux/file.h | 2 ++ include/linux/fs.h | 4 +++- 4 files changed, 22 insertions(+), 8 deletions(-) diff --git a/fs/file.c b/fs/file.c index 3209ee271c41..97df385d6ab0 100644 --- a/fs/file.c +++ b/fs/file.c @@ -705,7 +705,7 @@ void do_close_on_exec(struct files_struct *files) spin_unlock(&files->file_lock); } -static struct file *__fget(unsigned int fd, fmode_t mask) +static struct file *__fget(unsigned int fd, fmode_t mask, unsigned int refs) { struct files_struct *files = current->files; struct file *file; @@ -720,7 +720,7 @@ static struct file *__fget(unsigned int fd, fmode_t mask) */ if (file->f_mode & mask) file = NULL; - else if (!get_file_rcu(file)) + else if (!get_file_rcu_many(file, refs)) goto loop; } rcu_read_unlock(); @@ -728,15 +728,20 @@ static struct file *__fget(unsigned int fd, fmode_t mask) return file; } +struct file *fget_many(unsigned int fd, unsigned int refs) +{ + return __fget(fd, FMODE_PATH, refs); +} + struct file *fget(unsigned int fd) { - return __fget(fd, FMODE_PATH); + return __fget(fd, FMODE_PATH, 1); } EXPORT_SYMBOL(fget); struct file *fget_raw(unsigned int fd) { - return __fget(fd, 0); + return __fget(fd, 0, 1); } EXPORT_SYMBOL(fget_raw); @@ -767,7 +772,7 @@ static unsigned long __fget_light(unsigned int fd, fmode_t mask) return 0; return (unsigned long)file; } else { - file = __fget(fd, mask); + file = __fget(fd, mask, 1); if (!file) return 0; return FDPUT_FPUT | (unsigned long)file; diff --git a/fs/file_table.c b/fs/file_table.c index 5679e7fcb6b0..155d7514a094 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -326,9 +326,9 @@ void flush_delayed_fput(void) static DECLARE_DELAYED_WORK(delayed_fput_work, delayed_fput); -void fput(struct file *file) +void fput_many(struct file *file, unsigned int refs) { - if (atomic_long_dec_and_test(&file->f_count)) { + if (atomic_long_sub_and_test(refs, &file->f_count)) { struct task_struct *task = current; if (likely(!in_interrupt() && !(task->flags & PF_KTHREAD))) { @@ -347,6 +347,11 @@ void fput(struct file *file) } } +void fput(struct file *file) +{ + fput_many(file, 1); +} + /* * synchronous analog of fput(); for kernel threads that might be needed * in some umount() (and thus can't use flush_delayed_fput() without diff --git a/include/linux/file.h b/include/linux/file.h index 6b2fb032416c..3fcddff56bc4 100644 --- a/include/linux/file.h +++ b/include/linux/file.h @@ -13,6 +13,7 @@ struct file; extern void fput(struct file *); +extern void fput_many(struct file *, unsigned int); struct file_operations; struct vfsmount; @@ -44,6 +45,7 @@ static inline void fdput(struct fd fd) } extern struct file *fget(unsigned int fd); +extern struct file *fget_many(unsigned int fd, unsigned int refs); extern struct file *fget_raw(unsigned int fd); extern unsigned long __fdget(unsigned int fd); extern unsigned long __fdget_raw(unsigned int fd); diff --git a/include/linux/fs.h b/include/linux/fs.h index 61aa210f0c2b..80e1b199a4b1 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -952,7 +952,9 @@ static inline struct file *get_file(struct file *f) atomic_long_inc(&f->f_count); return f; } -#define get_file_rcu(x) atomic_long_inc_not_zero(&(x)->f_count) +#define get_file_rcu_many(x, cnt) \ + atomic_long_add_unless(&(x)->f_count, (cnt), 0) +#define get_file_rcu(x) get_file_rcu_many((x), 1) #define fput_atomic(x) atomic_long_add_unless(&(x)->f_count, -1, 1) #define file_count(x) atomic_long_read(&(x)->f_count) From patchwork Mon Feb 11 19:00:39 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806683 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9F39A746 for ; Mon, 11 Feb 2019 19:01:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8C333293A8 for ; Mon, 11 Feb 2019 19:01:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8081A2AE23; Mon, 11 Feb 2019 19:01:14 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B858E293A8 for ; Mon, 11 Feb 2019 19:01:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733278AbfBKTBN (ORCPT ); Mon, 11 Feb 2019 14:01:13 -0500 Received: from mail-it1-f194.google.com ([209.85.166.194]:51636 "EHLO mail-it1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733275AbfBKTBM (ORCPT ); Mon, 11 Feb 2019 14:01:12 -0500 Received: by mail-it1-f194.google.com with SMTP id y184so923754itc.1 for ; Mon, 11 Feb 2019 11:01:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=fEzXSEdtvemzDNbLLxmW/ZdccZCBI4iAZZs/O1veMj4=; b=KcAKnv3dXw+OndwLiUFBHmJ7jkr1b9ANgKXwNXoBCYxfT+lpbn0nEGwKcRd/iHq+3H jCCjOv3htCWmSh2eqDUjh12m9hOy8E5lEu5h+WTR4mcU0yAMeG+FlekUtHKupwP2gD7H YuA7ZjJ1BlJ4zQIdpGutlWhni6jrb/1+lWGb/vTW3ayCLyNhylEZjLiGpeM/22Y+V7Fo t6Mho0Df5gsdJWGz3R5NjRNq1Y9AEscN7xyAIzGyGGfJaghQrlWa5QagQV/IxqDE+EMu yWg5/hhRPbuCqW2myRt5PqeObuFIrFc+Eg+OM4qv/IyvaXjIIkyPlhBL4XqJ3EaGF3qG becg== 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; bh=fEzXSEdtvemzDNbLLxmW/ZdccZCBI4iAZZs/O1veMj4=; b=C+vam8kfTdVIzK4t+v/vbyFzcOzYCGLaHS/iqiiObtnTs0pbNWUSjgBNkxTQp1IUnK LipWOfdGhorccQ5jSSPb7oF+LoeOsmYGAtPM0xj0+15fSGovjucRl6+6DUx6MF6LZxNx KRIw2F5Y0ewGq4rD1IZshzNHQkZIT0E/wNpbpwMaxw1dUSyyudqYqNTIczwYHvwnptkw M+kKchl0T7bIVEMaI7i223+Z8HPlH+jEJ7kNhUvCahqIXOm+RlJdSRw3UNwHj8Zx+b2o uaWj+yov9cNKov2T0EwfASJ11RBLQG3pbVwyxJYEgUy48mPsaeq3b1VxLMp8ylXnMAjW 0N8Q== X-Gm-Message-State: AHQUAua8+pNMiu2JAVy11woJSvOpV2KrgqNTCSrYu3wo7+Dwh6c+kA44 Gdd7dQW4hgYmqQiB2gItamPG4Q== X-Google-Smtp-Source: AHgI3IaRLa40hj/B9u9H+mu3iKONdMvGfZPT037AfFB2R0CHt+3uqWIelgo+MFRwlFg1GDl5zYOFEw== X-Received: by 2002:a02:7e4b:: with SMTP id h72mr9476566jac.129.1549911671410; Mon, 11 Feb 2019 11:01:11 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.01.09 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:01:10 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 09/19] io_uring: use fget/fput_many() for file references Date: Mon, 11 Feb 2019 12:00:39 -0700 Message-Id: <20190211190049.7888-11-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add a separate io_submit_state structure, to cache some of the things we need for IO submission. One such example is file reference batching. io_submit_state. We get as many references as the number of sqes we are submitting, and drop unused ones if we end up switching files. The assumption here is that we're usually only dealing with one fd, and if there are multiple, hopefuly they are at least somewhat ordered. Could trivially be extended to cover multiple fds, if needed. On the completion side we do the same thing, except this is trivially done just locally in io_iopoll_reap(). Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- fs/io_uring.c | 142 ++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 121 insertions(+), 21 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 30efe5edf6aa..7358dd1dbf3f 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -165,6 +165,19 @@ struct io_kiocb { #define IO_PLUG_THRESHOLD 2 #define IO_IOPOLL_BATCH 8 +struct io_submit_state { + struct blk_plug plug; + + /* + * File reference cache + */ + struct file *file; + unsigned int fd; + unsigned int has_refs; + unsigned int used_refs; + unsigned int ios_left; +}; + static struct kmem_cache *req_cachep; static const struct file_operations io_uring_fops; @@ -332,9 +345,11 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events, struct list_head *done) { void *reqs[IO_IOPOLL_BATCH]; + int file_count, to_free; + struct file *file = NULL; struct io_kiocb *req; - int to_free = 0; + file_count = to_free = 0; while (!list_empty(done)) { req = list_first_entry(done, struct io_kiocb, list); list_del(&req->list); @@ -344,12 +359,28 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events, reqs[to_free++] = req; (*nr_events)++; - fput(req->rw.ki_filp); + /* + * Batched puts of the same file, to avoid dirtying the + * file usage count multiple times, if avoidable. + */ + if (!file) { + file = req->rw.ki_filp; + file_count = 1; + } else if (file == req->rw.ki_filp) { + file_count++; + } else { + fput_many(file, file_count); + file = req->rw.ki_filp; + file_count = 1; + } + if (to_free == ARRAY_SIZE(reqs)) io_free_req_many(ctx, reqs, &to_free); } io_commit_cqring(ctx); + if (file) + fput_many(file, file_count); io_free_req_many(ctx, reqs, &to_free); } @@ -530,6 +561,48 @@ static void io_iopoll_req_issued(struct io_kiocb *req) list_add_tail(&req->list, &ctx->poll_list); } +static void io_file_put(struct io_submit_state *state, struct file *file) +{ + if (!state) { + fput(file); + } else if (state->file) { + int diff = state->has_refs - state->used_refs; + + if (diff) + fput_many(state->file, diff); + state->file = NULL; + } +} + +/* + * Get as many references to a file as we have IOs left in this submission, + * assuming most submissions are for one file, or at least that each file + * has more than one submission. + */ +static struct file *io_file_get(struct io_submit_state *state, int fd) +{ + if (!state) + return fget(fd); + + if (state->file) { + if (state->fd == fd) { + state->used_refs++; + state->ios_left--; + return state->file; + } + io_file_put(state, NULL); + } + state->file = fget_many(fd, state->ios_left); + if (!state->file) + return NULL; + + state->fd = fd; + state->has_refs = state->ios_left; + state->used_refs = 1; + state->ios_left--; + return state->file; +} + /* * If we tracked the file through the SCM inflight mechanism, we could support * any file. For now, just ensure that anything potentially problematic is done @@ -548,7 +621,7 @@ static bool io_file_supports_async(struct file *file) } static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, - bool force_nonblock) + bool force_nonblock, struct io_submit_state *state) { struct io_ring_ctx *ctx = req->ctx; struct kiocb *kiocb = &req->rw; @@ -560,7 +633,7 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, return 0; fd = READ_ONCE(sqe->fd); - kiocb->ki_filp = fget(fd); + kiocb->ki_filp = io_file_get(state, fd); if (unlikely(!kiocb->ki_filp)) return -EBADF; if (force_nonblock && !io_file_supports_async(kiocb->ki_filp)) @@ -604,7 +677,10 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, } return 0; out_fput: - fput(kiocb->ki_filp); + /* in case of error, we didn't use this file reference. drop it. */ + if (state) + state->used_refs--; + io_file_put(state, kiocb->ki_filp); return ret; } @@ -650,7 +726,7 @@ static int io_import_iovec(struct io_ring_ctx *ctx, int rw, } static ssize_t io_read(struct io_kiocb *req, const struct sqe_submit *s, - bool force_nonblock) + bool force_nonblock, struct io_submit_state *state) { struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; struct kiocb *kiocb = &req->rw; @@ -658,7 +734,7 @@ static ssize_t io_read(struct io_kiocb *req, const struct sqe_submit *s, struct file *file; ssize_t ret; - ret = io_prep_rw(req, s->sqe, force_nonblock); + ret = io_prep_rw(req, s->sqe, force_nonblock, state); if (ret) return ret; file = kiocb->ki_filp; @@ -694,7 +770,7 @@ static ssize_t io_read(struct io_kiocb *req, const struct sqe_submit *s, } static ssize_t io_write(struct io_kiocb *req, const struct sqe_submit *s, - bool force_nonblock) + bool force_nonblock, struct io_submit_state *state) { struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; struct kiocb *kiocb = &req->rw; @@ -702,7 +778,7 @@ static ssize_t io_write(struct io_kiocb *req, const struct sqe_submit *s, struct file *file; ssize_t ret; - ret = io_prep_rw(req, s->sqe, force_nonblock); + ret = io_prep_rw(req, s->sqe, force_nonblock, state); if (ret) return ret; /* Hold on to the file for -EAGAIN */ @@ -826,7 +902,8 @@ static int io_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe, } static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, - const struct sqe_submit *s, bool force_nonblock) + const struct sqe_submit *s, bool force_nonblock, + struct io_submit_state *state) { ssize_t ret; int opcode; @@ -841,10 +918,10 @@ static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, ret = io_nop(req, req->user_data); break; case IORING_OP_READV: - ret = io_read(req, s, force_nonblock); + ret = io_read(req, s, force_nonblock, state); break; case IORING_OP_WRITEV: - ret = io_write(req, s, force_nonblock); + ret = io_write(req, s, force_nonblock, state); break; case IORING_OP_FSYNC: ret = io_fsync(req, s->sqe, force_nonblock); @@ -896,7 +973,7 @@ static void io_sq_wq_submit_work(struct work_struct *work) s->needs_lock = true; do { - ret = __io_submit_sqe(ctx, req, s, false); + ret = __io_submit_sqe(ctx, req, s, false, NULL); /* * We can get EAGAIN for polled IO even though we're forcing * a sync submission from here, since we can't wait for @@ -920,7 +997,8 @@ static void io_sq_wq_submit_work(struct work_struct *work) kfree(sqe); } -static int io_submit_sqe(struct io_ring_ctx *ctx, struct sqe_submit *s) +static int io_submit_sqe(struct io_ring_ctx *ctx, struct sqe_submit *s, + struct io_submit_state *state) { struct io_kiocb *req; ssize_t ret; @@ -935,7 +1013,7 @@ static int io_submit_sqe(struct io_ring_ctx *ctx, struct sqe_submit *s) req->rw.ki_filp = NULL; - ret = __io_submit_sqe(ctx, req, s, true); + ret = __io_submit_sqe(ctx, req, s, true, state); if (ret == -EAGAIN) { struct io_uring_sqe *sqe_copy; @@ -956,6 +1034,26 @@ static int io_submit_sqe(struct io_ring_ctx *ctx, struct sqe_submit *s) return ret; } +/* + * Batched submission is done, ensure local IO is flushed out. + */ +static void io_submit_state_end(struct io_submit_state *state) +{ + blk_finish_plug(&state->plug); + io_file_put(state, NULL); +} + +/* + * Start submission side cache. + */ +static void io_submit_state_start(struct io_submit_state *state, + struct io_ring_ctx *ctx, unsigned max_ios) +{ + blk_start_plug(&state->plug); + state->file = NULL; + state->ios_left = max_ios; +} + static void io_commit_sqring(struct io_ring_ctx *ctx) { struct io_sq_ring *ring = ctx->sq_ring; @@ -1023,11 +1121,13 @@ static bool io_get_sqring(struct io_ring_ctx *ctx, struct sqe_submit *s) static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit) { + struct io_submit_state state, *statep = NULL; int i, ret = 0, submit = 0; - struct blk_plug plug; - if (to_submit > IO_PLUG_THRESHOLD) - blk_start_plug(&plug); + if (to_submit > IO_PLUG_THRESHOLD) { + io_submit_state_start(&state, ctx, to_submit); + statep = &state; + } for (i = 0; i < to_submit; i++) { struct sqe_submit s; @@ -1038,7 +1138,7 @@ static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit) s.has_user = true; s.needs_lock = false; - ret = io_submit_sqe(ctx, &s); + ret = io_submit_sqe(ctx, &s, statep); if (ret) { io_drop_sqring(ctx); break; @@ -1048,8 +1148,8 @@ static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit) } io_commit_sqring(ctx); - if (to_submit > IO_PLUG_THRESHOLD) - blk_finish_plug(&plug); + if (statep) + io_submit_state_end(statep); return submit ? submit : ret; } From patchwork Mon Feb 11 19:00:40 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806685 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A048A746 for ; Mon, 11 Feb 2019 19:01:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 901D4293A8 for ; Mon, 11 Feb 2019 19:01:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8426C2AE23; Mon, 11 Feb 2019 19:01:15 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 16CBF293A8 for ; Mon, 11 Feb 2019 19:01:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733283AbfBKTBO (ORCPT ); Mon, 11 Feb 2019 14:01:14 -0500 Received: from mail-it1-f193.google.com ([209.85.166.193]:50649 "EHLO mail-it1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733279AbfBKTBO (ORCPT ); Mon, 11 Feb 2019 14:01:14 -0500 Received: by mail-it1-f193.google.com with SMTP id z7so939963iti.0 for ; Mon, 11 Feb 2019 11:01:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=PY8RWKukBN2u0p+dEsi32MAnSMEKxmoGYnYSupUWRtU=; b=HYMj2KKgaFKgYAhrQ78X0Myg6BqE4un54XjULR41q8JOd5ZGKUj9i8VtizQ6sVL/CC XI85nZxDaekeerkPLonaxt77dem+ysu90bzf17iNHZB3zFD0n7CBmqcWyEnxEW5ZLYQD OgUWEe18xy5lTlz4703v+sxyPRtW07GQxZLemC2DMXC/ohjko9Zh51QkSJ/95nN+ywcq 8OXOTFb/N+5cwfthrFoJhRjTs0Jint5WCuLgXDOEBCDyKvZZXos3136iTPjcvYWEcqFd EGnI7nYZjtp+B1bH+4xtb7z4cdMSeJK/2rMqwphMLOlSgVm7O6A3HmsBlr5+ghoGwtXW YN8w== 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; bh=PY8RWKukBN2u0p+dEsi32MAnSMEKxmoGYnYSupUWRtU=; b=cugzi4GTV7S+OjU6YcKV71J0WhzOmucia0AMLde5gir2rirP8hwylIYNRcxulh1tRE eFeU9hGzWHFNVmDKvjDdzttfCAt2aOSFwqHRidlH6OO/iLV8Z90ZCXhTW9gDLNZ9G/L0 emh2WBrtRyKfqAXpUspNzCKp+/Fs12Gw4gH1ns/7JDodTev2mNlJUme+RPR7U53K2qvo k4tZh45kP8jWW6g9Z3YeQvqczOoLa5pSwxTmKsHPJKabbgVQYiOIROZFotfXTdAhCRwm gJq1fYJltNDdZ1xx53ySxhY4Un9T98RBKwWiuTGIK+NN/IWiOLaRFDvrq6JGggycw8sT kHsA== X-Gm-Message-State: AHQUAuYHr7htLfM+HJuf6TB7CaXnRgB1bZCcsj/wEqseP/7w1IcIlADe PM4AfTXJBuBD0ph7hmRzPZfbJQ== X-Google-Smtp-Source: AHgI3IZib91eTczZrLFDS30wS419XHDkSTtBV/qHVU3XkERVV3S65whWZdCpTpQh+M3DnZU3gqQ4+Q== X-Received: by 2002:a6b:b7cf:: with SMTP id h198mr7375215iof.175.1549911673178; Mon, 11 Feb 2019 11:01:13 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.01.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:01:12 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 10/19] io_uring: batch io_kiocb allocation Date: Mon, 11 Feb 2019 12:00:40 -0700 Message-Id: <20190211190049.7888-12-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Similarly to how we use the state->ios_left to know how many references to get to a file, we can use it to allocate the io_kiocb's we need in bulk. Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- fs/io_uring.c | 45 ++++++++++++++++++++++++++++++++++++++------- 1 file changed, 38 insertions(+), 7 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 7358dd1dbf3f..e330252dc5de 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -168,6 +168,13 @@ struct io_kiocb { struct io_submit_state { struct blk_plug plug; + /* + * io_kiocb alloc cache + */ + void *reqs[IO_IOPOLL_BATCH]; + unsigned int free_reqs; + unsigned int cur_req; + /* * File reference cache */ @@ -305,20 +312,40 @@ static void io_ring_drop_ctx_refs(struct io_ring_ctx *ctx, unsigned refs) wake_up(&ctx->wait); } -static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx) +static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx, + struct io_submit_state *state) { struct io_kiocb *req; if (!percpu_ref_tryget(&ctx->refs)) return NULL; - req = kmem_cache_alloc(req_cachep, __GFP_NOWARN); - if (req) { - req->ctx = ctx; - req->flags = 0; - return req; + if (!state) { + req = kmem_cache_alloc(req_cachep, __GFP_NOWARN); + if (unlikely(!req)) + goto out; + } else if (!state->free_reqs) { + size_t sz; + int ret; + + sz = min_t(size_t, state->ios_left, ARRAY_SIZE(state->reqs)); + ret = kmem_cache_alloc_bulk(req_cachep, __GFP_NOWARN, sz, + state->reqs); + if (unlikely(ret <= 0)) + goto out; + state->free_reqs = ret - 1; + state->cur_req = 1; + req = state->reqs[0]; + } else { + req = state->reqs[state->cur_req]; + state->free_reqs--; + state->cur_req++; } + req->ctx = ctx; + req->flags = 0; + return req; +out: io_ring_drop_ctx_refs(ctx, 1); return NULL; } @@ -1007,7 +1034,7 @@ static int io_submit_sqe(struct io_ring_ctx *ctx, struct sqe_submit *s, if (unlikely(s->sqe->flags)) return -EINVAL; - req = io_get_req(ctx); + req = io_get_req(ctx, state); if (unlikely(!req)) return -EAGAIN; @@ -1041,6 +1068,9 @@ static void io_submit_state_end(struct io_submit_state *state) { blk_finish_plug(&state->plug); io_file_put(state, NULL); + if (state->free_reqs) + kmem_cache_free_bulk(req_cachep, state->free_reqs, + &state->reqs[state->cur_req]); } /* @@ -1050,6 +1080,7 @@ static void io_submit_state_start(struct io_submit_state *state, struct io_ring_ctx *ctx, unsigned max_ios) { blk_start_plug(&state->plug); + state->free_reqs = 0; state->file = NULL; state->ios_left = max_ios; } From patchwork Mon Feb 11 19:00:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806687 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 680606C2 for ; Mon, 11 Feb 2019 19:01:22 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 52CEF293A8 for ; Mon, 11 Feb 2019 19:01:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 46B6C2AE23; Mon, 11 Feb 2019 19:01:22 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 461602A166 for ; Mon, 11 Feb 2019 19:01:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733293AbfBKTBQ (ORCPT ); Mon, 11 Feb 2019 14:01:16 -0500 Received: from mail-it1-f193.google.com ([209.85.166.193]:53367 "EHLO mail-it1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733288AbfBKTBQ (ORCPT ); Mon, 11 Feb 2019 14:01:16 -0500 Received: by mail-it1-f193.google.com with SMTP id g85so881974ita.3 for ; Mon, 11 Feb 2019 11:01:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=iZfokheV1pDf6KDbP5uVm/d0XxEaaAaBjvft+e/J+Tk=; b=WE9Gro42TyASM3/sstKFBRRmNOVDxBomuGiI3FfASFbsS65dT01o4A5O3cQQyC0yra l0mea8fB6IRtkhq/8pug67IDNIRaXR4lzpJ7VuKWe+7AYU+ugm0MruSTS+Oo8E5aCznC XMtKmrRC1PHexpyKYBxDPv3kXSAynEWUGoLzipfPPlVHnDrDRyE428l6AymR9mdpsx8G ztUfa6E6GXhdGrFO8IoYsPKRHykT3drZQaXrTimpwV16EEIdxJac/GaFLn1jDJ9tsp27 3VM1G5de4ssKq7rTB3WKRpY5X07p5Pp4K1Lnz4miu5DBdSdtzJuwY3tjmF5JTGQMIo4L GJrg== 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; bh=iZfokheV1pDf6KDbP5uVm/d0XxEaaAaBjvft+e/J+Tk=; b=VL5Uo5CAx/zIHsT5MksuO3ockyEm+ky/IPSDqWnyVoIZOA/64SJh1FK9jsHCA76LNo lCtzPVTs3FuwfuT4VUBbF0AN2ZMEgVUeK6vaqAuRzu77CXX1j0JKOY0XM9P/wM9yS1PM fQjPmX0RO62kDu1YVr6SXJmKRcG3NO3+x2+OJgahwtZKa4Els5gcCPcar1bij7qD58Cj VPRkAiiJ1E7+E9LeypPNSwwvVXp8dwPnhR5wPpG2rdJqzlpZavDtK7Ioz3ltBuQ8chM0 z8117qHSzHAC71hdsilikh5uA15SwkBgR08hasE26B88LQkApcnkLSCFJC5ElWyAmMiV 17+w== X-Gm-Message-State: AHQUAubCrWvd78ARbrdlFtsNoKDk5RR2kVcTzfRcCrajCTuC0SmKK2z6 Jat+EfVfOX74xCNx6cIsL5zramxHdqQdGQ== X-Google-Smtp-Source: AHgI3Ib+L+fa4vTbWmL4naD3xj+0rDp8pYGg8gosF4mS4L5Egh//Z0YHpK/rGMLvBDY5MReh363trQ== X-Received: by 2002:a24:13cb:: with SMTP id 194mr561814itz.0.1549911675065; Mon, 11 Feb 2019 11:01:15 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.01.13 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:01:14 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 11/19] block: implement bio helper to add iter bvec pages to bio Date: Mon, 11 Feb 2019 12:00:41 -0700 Message-Id: <20190211190049.7888-13-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP For an ITER_BVEC, we can just iterate the iov and add the pages to the bio directly. This requires that the caller doesn't releases the pages on IO completion, we add a BIO_NO_PAGE_REF flag for that. The current two callers of bio_iov_iter_get_pages() are updated to check if they need to release pages on completion. This makes them work with bvecs that contain kernel mapped pages already. Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/bio.c | 59 ++++++++++++++++++++++++++++++++------- fs/block_dev.c | 5 ++-- fs/iomap.c | 5 ++-- include/linux/blk_types.h | 1 + 4 files changed, 56 insertions(+), 14 deletions(-) diff --git a/block/bio.c b/block/bio.c index 4db1008309ed..330df572cfb8 100644 --- a/block/bio.c +++ b/block/bio.c @@ -828,6 +828,23 @@ int bio_add_page(struct bio *bio, struct page *page, } EXPORT_SYMBOL(bio_add_page); +static int __bio_iov_bvec_add_pages(struct bio *bio, struct iov_iter *iter) +{ + const struct bio_vec *bv = iter->bvec; + unsigned int len; + size_t size; + + len = min_t(size_t, bv->bv_len, iter->count); + size = bio_add_page(bio, bv->bv_page, len, + bv->bv_offset + iter->iov_offset); + if (size == len) { + iov_iter_advance(iter, size); + return 0; + } + + return -EINVAL; +} + #define PAGE_PTRS_PER_BVEC (sizeof(struct bio_vec) / sizeof(struct page *)) /** @@ -876,23 +893,43 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) } /** - * bio_iov_iter_get_pages - pin user or kernel pages and add them to a bio + * bio_iov_iter_get_pages - add user or kernel pages to a bio * @bio: bio to add pages to - * @iter: iov iterator describing the region to be mapped + * @iter: iov iterator describing the region to be added + * + * This takes either an iterator pointing to user memory, or one pointing to + * kernel pages (BVEC iterator). If we're adding user pages, we pin them and + * map them into the kernel. On IO completion, the caller should put those + * pages. If we're adding kernel pages, we just have to add the pages to the + * bio directly. We don't grab an extra reference to those pages (the user + * should already have that), and we don't put the page on IO completion. + * The caller needs to check if the bio is flagged BIO_NO_PAGE_REF on IO + * completion. If it isn't, then pages should be released. * - * Pins pages from *iter and appends them to @bio's bvec array. The - * pages will have to be released using put_page() when done. * The function tries, but does not guarantee, to pin as many pages as - * fit into the bio, or are requested in *iter, whatever is smaller. - * If MM encounters an error pinning the requested pages, it stops. - * Error is returned only if 0 pages could be pinned. + * fit into the bio, or are requested in *iter, whatever is smaller. If + * MM encounters an error pinning the requested pages, it stops. Error + * is returned only if 0 pages could be pinned. */ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) { + const bool is_bvec = iov_iter_is_bvec(iter); unsigned short orig_vcnt = bio->bi_vcnt; + /* + * If this is a BVEC iter, then the pages are kernel pages. Don't + * release them on IO completion. + */ + if (is_bvec) + bio_set_flag(bio, BIO_NO_PAGE_REF); + do { - int ret = __bio_iov_iter_get_pages(bio, iter); + int ret; + + if (is_bvec) + ret = __bio_iov_bvec_add_pages(bio, iter); + else + ret = __bio_iov_iter_get_pages(bio, iter); if (unlikely(ret)) return bio->bi_vcnt > orig_vcnt ? 0 : ret; @@ -1634,7 +1671,8 @@ static void bio_dirty_fn(struct work_struct *work) next = bio->bi_private; bio_set_pages_dirty(bio); - bio_release_pages(bio); + if (!bio_flagged(bio, BIO_NO_PAGE_REF)) + bio_release_pages(bio); bio_put(bio); } } @@ -1650,7 +1688,8 @@ void bio_check_pages_dirty(struct bio *bio) goto defer; } - bio_release_pages(bio); + if (!bio_flagged(bio, BIO_NO_PAGE_REF)) + bio_release_pages(bio); bio_put(bio); return; defer: diff --git a/fs/block_dev.c b/fs/block_dev.c index 392e2bfb636f..051ab41d1c61 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -338,8 +338,9 @@ static void blkdev_bio_end_io(struct bio *bio) struct bio_vec *bvec; int i; - bio_for_each_segment_all(bvec, bio, i) - put_page(bvec->bv_page); + if (!bio_flagged(bio, BIO_NO_PAGE_REF)) + bio_for_each_segment_all(bvec, bio, i) + put_page(bvec->bv_page); bio_put(bio); } } diff --git a/fs/iomap.c b/fs/iomap.c index 2ac9eb746d44..9389cf0a1c6f 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -1591,8 +1591,9 @@ static void iomap_dio_bio_end_io(struct bio *bio) struct bio_vec *bvec; int i; - bio_for_each_segment_all(bvec, bio, i) - put_page(bvec->bv_page); + if (!bio_flagged(bio, BIO_NO_PAGE_REF)) + bio_for_each_segment_all(bvec, bio, i) + put_page(bvec->bv_page); bio_put(bio); } } diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index d66bf5f32610..791fee35df88 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -215,6 +215,7 @@ struct bio { /* * bio flags */ +#define BIO_NO_PAGE_REF 0 /* don't put release vec pages */ #define BIO_SEG_VALID 1 /* bi_phys_segments valid */ #define BIO_CLONED 2 /* doesn't own data */ #define BIO_BOUNCED 3 /* bio is a bounce bio */ From patchwork Mon Feb 11 19:00:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806703 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BD0BD746 for ; Mon, 11 Feb 2019 19:01:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id ACDE8293A8 for ; Mon, 11 Feb 2019 19:01:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A07AB2AE23; Mon, 11 Feb 2019 19:01:34 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6DC86293A8 for ; Mon, 11 Feb 2019 19:01:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387479AbfBKTBb (ORCPT ); Mon, 11 Feb 2019 14:01:31 -0500 Received: from mail-it1-f195.google.com ([209.85.166.195]:54939 "EHLO mail-it1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733306AbfBKTBS (ORCPT ); Mon, 11 Feb 2019 14:01:18 -0500 Received: by mail-it1-f195.google.com with SMTP id i145so865345ita.4 for ; Mon, 11 Feb 2019 11:01:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=viawGWvZjsP22x76MHwo/S21lApGSwXK+vN46jxzlHc=; b=YjiGY037dyUY4KYdPUKUM2BKAZG/9vDL9bO8O2ESzFgAQU2gRbvwx+mMMFD6QL2XeJ c/s4zxTL+8bTUQdrj5rG/dlv+wYEkk8wQrY5pxsqopz9I+vd1mpuQs3Usp5twrpsVJFS PPmP6FtR110z/et/1ndr6d53jRAuuYu/itJH8Ihsdl/J0VbgKZIvP4WJ+IpFlSb/sPJl C4M1kxfISW6Z6o1ED6Qkw7nXq95pYpp9p3cwOaX4tx5ObVOEXM1p29inIvezeqF4Rp51 YpJn8pQ5U37OPbh/woWdoOrSx7s33qIZkvgn7qhqRKyT1se0Oyr9XPVlcqCnZuocG77F lhjQ== 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; bh=viawGWvZjsP22x76MHwo/S21lApGSwXK+vN46jxzlHc=; b=iBQr9iEgKQPi9MqxiaH4MWXf3Sqk18MA7XQu5POIpcRLV+qjCVAdE3WYkn56uykDH4 h4BOnDBJk4vsECuxlMC9oAoU2Tkx/HDjHJifzeSObNPGLdLuu98D6vlvpg7oX8zcDsPo fIFVRSGqaVOXNheFarsNsJodccm5D13Yxcn3rLaT/2mUlBK6e8Wb3aYijgbyUNVDe6BG LToxAbVRrONIHjv1wMgnCOj27n3i6d6hm54/N/fIyR1qjdZWPqNDLst12nY/pYG/CZFm QZqv2yytfFCODwKAvtoEp15bNKIwmubcWtdOFJkaWIzrL5vUHDWraucp/BPxGF0ANtUN /+WA== X-Gm-Message-State: AHQUAubapt4H8zaROmcM8F+68jyuMp7Sr7VLr8LqterT6B8fGhWcLEyI NiPs6lywmI7XbKJSeaa8uxIZVA== X-Google-Smtp-Source: AHgI3Iaw4duAAk7cxdV31/0CxU376EYuNvvPI093f31jUnpRO0wFYNXycW33vCL8BhVfQ86LTrZilw== X-Received: by 2002:a5e:9741:: with SMTP id h1mr8789550ioq.87.1549911676914; Mon, 11 Feb 2019 11:01:16 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.01.15 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:01:16 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 12/19] io_uring: add support for pre-mapped user IO buffers Date: Mon, 11 Feb 2019 12:00:42 -0700 Message-Id: <20190211190049.7888-14-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If we have fixed user buffers, we can map them into the kernel when we setup the io_uring. That avoids the need to do get_user_pages() for each and every IO. To utilize this feature, the application must call io_uring_register() after having setup an io_uring instance, passing in IORING_REGISTER_BUFFERS as the opcode. The argument must be a pointer to an iovec array, and the nr_args should contain how many iovecs the application wishes to map. If successful, these buffers are now mapped into the kernel, eligible for IO. To use these fixed buffers, the application must use the IORING_OP_READ_FIXED and IORING_OP_WRITE_FIXED opcodes, and then set sqe->index to the desired buffer index. sqe->addr..sqe->addr+seq->len must point to somewhere inside the indexed buffer. The application may register buffers throughout the lifetime of the io_uring instance. It can call io_uring_register() with IORING_UNREGISTER_BUFFERS as the opcode to unregister the current set of buffers, and then register a new set. The application need not unregister buffers explicitly before shutting down the io_uring instance. It's perfectly valid to setup a larger buffer, and then sometimes only use parts of it for an IO. As long as the range is within the originally mapped region, it will work just fine. For now, buffers must not be file backed. If file backed buffers are passed in, the registration will fail with -1/EOPNOTSUPP. This restriction may be relaxed in the future. RLIMIT_MEMLOCK is used to check how much memory we can pin. A somewhat arbitrary 1G per buffer size is also imposed. Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- arch/x86/entry/syscalls/syscall_32.tbl | 1 + arch/x86/entry/syscalls/syscall_64.tbl | 1 + fs/io_uring.c | 373 ++++++++++++++++++++++++- include/linux/syscalls.h | 2 + include/uapi/asm-generic/unistd.h | 4 +- include/uapi/linux/io_uring.h | 13 +- kernel/sys_ni.c | 1 + 7 files changed, 380 insertions(+), 15 deletions(-) diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index 481c126259e9..2eefd2a7c1ce 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -400,3 +400,4 @@ 386 i386 rseq sys_rseq __ia32_sys_rseq 425 i386 io_uring_setup sys_io_uring_setup __ia32_sys_io_uring_setup 426 i386 io_uring_enter sys_io_uring_enter __ia32_sys_io_uring_enter +427 i386 io_uring_register sys_io_uring_register __ia32_sys_io_uring_register diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index 6a32a430c8e0..65c026185e61 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -345,6 +345,7 @@ 334 common rseq __x64_sys_rseq 425 common io_uring_setup __x64_sys_io_uring_setup 426 common io_uring_enter __x64_sys_io_uring_enter +427 common io_uring_register __x64_sys_io_uring_register # # x32-specific system call numbers start at 512 to avoid cache impact diff --git a/fs/io_uring.c b/fs/io_uring.c index e330252dc5de..0eba20d18f53 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -45,6 +45,7 @@ #include #include #include +#include #include #include #include @@ -52,6 +53,8 @@ #include #include #include +#include +#include #include @@ -81,6 +84,13 @@ struct io_cq_ring { struct io_uring_cqe cqes[]; }; +struct io_mapped_ubuf { + u64 ubuf; + size_t len; + struct bio_vec *bvec; + unsigned int nr_bvecs; +}; + struct io_ring_ctx { struct { struct percpu_ref refs; @@ -113,6 +123,10 @@ struct io_ring_ctx { struct fasync_struct *cq_fasync; } ____cacheline_aligned_in_smp; + /* if used, fixed mapped user buffers */ + unsigned nr_user_bufs; + struct io_mapped_ubuf *user_bufs; + struct user_struct *user; struct completion ctx_done; @@ -732,6 +746,46 @@ static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret) } } +static int io_import_fixed(struct io_ring_ctx *ctx, int rw, + const struct io_uring_sqe *sqe, + struct iov_iter *iter) +{ + size_t len = READ_ONCE(sqe->len); + struct io_mapped_ubuf *imu; + unsigned index, buf_index; + size_t offset; + u64 buf_addr; + + /* attempt to use fixed buffers without having provided iovecs */ + if (unlikely(!ctx->user_bufs)) + return -EFAULT; + + buf_index = READ_ONCE(sqe->buf_index); + if (unlikely(buf_index >= ctx->nr_user_bufs)) + return -EFAULT; + + index = array_index_nospec(buf_index, ctx->nr_user_bufs); + imu = &ctx->user_bufs[index]; + buf_addr = READ_ONCE(sqe->addr); + + /* overflow */ + if (buf_addr + len < buf_addr) + return -EFAULT; + /* not inside the mapped region */ + if (buf_addr < imu->ubuf || buf_addr + len > imu->ubuf + imu->len) + return -EFAULT; + + /* + * May not be a start of buffer, set size appropriately + * and advance us to the beginning. + */ + offset = buf_addr - imu->ubuf; + iov_iter_bvec(iter, rw, imu->bvec, imu->nr_bvecs, offset + len); + if (offset) + iov_iter_advance(iter, offset); + return 0; +} + static int io_import_iovec(struct io_ring_ctx *ctx, int rw, const struct sqe_submit *s, struct iovec **iovec, struct iov_iter *iter) @@ -739,6 +793,23 @@ static int io_import_iovec(struct io_ring_ctx *ctx, int rw, const struct io_uring_sqe *sqe = s->sqe; void __user *buf = u64_to_user_ptr(READ_ONCE(sqe->addr)); size_t sqe_len = READ_ONCE(sqe->len); + u8 opcode; + + /* + * We're reading ->opcode for the second time, but the first read + * doesn't care whether it's _FIXED or not, so it doesn't matter + * whether ->opcode changes concurrently. The first read does care + * about whether it is a READ or a WRITE, so we don't trust this read + * for that purpose and instead let the caller pass in the read/write + * flag. + */ + opcode = READ_ONCE(sqe->opcode); + if (opcode == IORING_OP_READ_FIXED || + opcode == IORING_OP_WRITE_FIXED) { + ssize_t ret = io_import_fixed(ctx, rw, sqe, iter); + *iovec = NULL; + return ret; + } if (!s->has_user) return EFAULT; @@ -886,7 +957,7 @@ static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe) if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; - if (unlikely(sqe->addr || sqe->ioprio)) + if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index)) return -EINVAL; fd = READ_ONCE(sqe->fd); @@ -945,9 +1016,19 @@ static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, ret = io_nop(req, req->user_data); break; case IORING_OP_READV: + if (unlikely(s->sqe->buf_index)) + return -EINVAL; ret = io_read(req, s, force_nonblock, state); break; case IORING_OP_WRITEV: + if (unlikely(s->sqe->buf_index)) + return -EINVAL; + ret = io_write(req, s, force_nonblock, state); + break; + case IORING_OP_READ_FIXED: + ret = io_read(req, s, force_nonblock, state); + break; + case IORING_OP_WRITE_FIXED: ret = io_write(req, s, force_nonblock, state); break; case IORING_OP_FSYNC: @@ -976,28 +1057,46 @@ static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, return 0; } +static inline bool io_sqe_needs_user(const struct io_uring_sqe *sqe) +{ + u8 opcode = READ_ONCE(sqe->opcode); + + return !(opcode == IORING_OP_READ_FIXED || + opcode == IORING_OP_WRITE_FIXED); +} + static void io_sq_wq_submit_work(struct work_struct *work) { struct io_kiocb *req = container_of(work, struct io_kiocb, work); struct sqe_submit *s = &req->submit; const struct io_uring_sqe *sqe = s->sqe; struct io_ring_ctx *ctx = req->ctx; - mm_segment_t old_fs = get_fs(); + mm_segment_t old_fs; + bool needs_user; int ret; /* Ensure we clear previously set forced non-block flag */ req->flags &= ~REQ_F_FORCE_NONBLOCK; req->rw.ki_flags &= ~IOCB_NOWAIT; - if (!mmget_not_zero(ctx->sqo_mm)) { - ret = -EFAULT; - goto err; - } - - use_mm(ctx->sqo_mm); - set_fs(USER_DS); - s->has_user = true; s->needs_lock = true; + s->has_user = false; + + /* + * If we're doing IO to fixed buffers, we don't need to get/set + * user context + */ + needs_user = io_sqe_needs_user(s->sqe); + if (needs_user) { + if (!mmget_not_zero(ctx->sqo_mm)) { + ret = -EFAULT; + goto err; + } + use_mm(ctx->sqo_mm); + old_fs = get_fs(); + set_fs(USER_DS); + s->has_user = true; + } do { ret = __io_submit_sqe(ctx, req, s, false, NULL); @@ -1011,9 +1110,11 @@ static void io_sq_wq_submit_work(struct work_struct *work) cond_resched(); } while (1); - set_fs(old_fs); - unuse_mm(ctx->sqo_mm); - mmput(ctx->sqo_mm); + if (needs_user) { + set_fs(old_fs); + unuse_mm(ctx->sqo_mm); + mmput(ctx->sqo_mm); + } err: if (ret) { io_cqring_add_event(ctx, sqe->user_data, ret, 0); @@ -1308,6 +1409,197 @@ static unsigned long ring_pages(unsigned sq_entries, unsigned cq_entries) return (bytes + PAGE_SIZE - 1) / PAGE_SIZE; } +static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx) +{ + int i, j; + + if (!ctx->user_bufs) + return -ENXIO; + + for (i = 0; i < ctx->nr_user_bufs; i++) { + struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; + + for (j = 0; j < imu->nr_bvecs; j++) + put_page(imu->bvec[j].bv_page); + + if (ctx->account_mem) + io_unaccount_mem(ctx->user, imu->nr_bvecs); + kfree(imu->bvec); + imu->nr_bvecs = 0; + } + + kfree(ctx->user_bufs); + ctx->user_bufs = NULL; + ctx->nr_user_bufs = 0; + return 0; +} + +static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst, + void __user *arg, unsigned index) +{ + struct iovec __user *src; + +#ifdef CONFIG_COMPAT + if (ctx->compat) { + struct compat_iovec __user *ciovs; + struct compat_iovec ciov; + + ciovs = (struct compat_iovec __user *) arg; + if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov))) + return -EFAULT; + + dst->iov_base = (void __user *) (unsigned long) ciov.iov_base; + dst->iov_len = ciov.iov_len; + return 0; + } +#endif + src = (struct iovec __user *) arg; + if (copy_from_user(dst, &src[index], sizeof(*dst))) + return -EFAULT; + return 0; +} + +static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg, + unsigned nr_args) +{ + struct vm_area_struct **vmas = NULL; + struct page **pages = NULL; + int i, j, got_pages = 0; + int ret = -EINVAL; + + if (ctx->user_bufs) + return -EBUSY; + if (!nr_args || nr_args > UIO_MAXIOV) + return -EINVAL; + + ctx->user_bufs = kcalloc(nr_args, sizeof(struct io_mapped_ubuf), + GFP_KERNEL); + if (!ctx->user_bufs) + return -ENOMEM; + + for (i = 0; i < nr_args; i++) { + struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; + unsigned long off, start, end, ubuf; + int pret, nr_pages; + struct iovec iov; + size_t size; + + ret = io_copy_iov(ctx, &iov, arg, i); + if (ret) + break; + + /* + * Don't impose further limits on the size and buffer + * constraints here, we'll -EINVAL later when IO is + * submitted if they are wrong. + */ + ret = -EFAULT; + if (!iov.iov_base || !iov.iov_len) + goto err; + + /* arbitrary limit, but we need something */ + if (iov.iov_len > SZ_1G) + goto err; + + ubuf = (unsigned long) iov.iov_base; + end = (ubuf + iov.iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT; + start = ubuf >> PAGE_SHIFT; + nr_pages = end - start; + + if (ctx->account_mem) { + ret = io_account_mem(ctx->user, nr_pages); + if (ret) + goto err; + } + + ret = 0; + if (!pages || nr_pages > got_pages) { + kfree(vmas); + kfree(pages); + pages = kmalloc_array(nr_pages, sizeof(struct page *), + GFP_KERNEL); + vmas = kmalloc_array(nr_pages, + sizeof(struct vma_area_struct *), + GFP_KERNEL); + if (!pages || !vmas) { + ret = -ENOMEM; + if (ctx->account_mem) + io_unaccount_mem(ctx->user, nr_pages); + goto err; + } + got_pages = nr_pages; + } + + imu->bvec = kmalloc_array(nr_pages, sizeof(struct bio_vec), + GFP_KERNEL); + ret = -ENOMEM; + if (!imu->bvec) { + if (ctx->account_mem) + io_unaccount_mem(ctx->user, nr_pages); + goto err; + } + + ret = 0; + down_read(¤t->mm->mmap_sem); + pret = get_user_pages_longterm(ubuf, nr_pages, FOLL_WRITE, + pages, vmas); + if (pret == nr_pages) { + /* don't support file backed memory */ + for (j = 0; j < nr_pages; j++) { + struct vm_area_struct *vma = vmas[j]; + + if (vma->vm_file && + !is_file_hugepages(vma->vm_file)) { + ret = -EOPNOTSUPP; + break; + } + } + } else { + ret = pret < 0 ? pret : -EFAULT; + } + up_read(¤t->mm->mmap_sem); + if (ret) { + /* + * if we did partial map, or found file backed vmas, + * release any pages we did get + */ + if (pret > 0) { + for (j = 0; j < pret; j++) + put_page(pages[j]); + } + if (ctx->account_mem) + io_unaccount_mem(ctx->user, nr_pages); + goto err; + } + + off = ubuf & ~PAGE_MASK; + size = iov.iov_len; + for (j = 0; j < nr_pages; j++) { + size_t vec_len; + + vec_len = min_t(size_t, size, PAGE_SIZE - off); + imu->bvec[j].bv_page = pages[j]; + imu->bvec[j].bv_len = vec_len; + imu->bvec[j].bv_offset = off; + off = 0; + size -= vec_len; + } + /* store original address for later verification */ + imu->ubuf = ubuf; + imu->len = iov.iov_len; + imu->nr_bvecs = nr_pages; + } + kfree(pages); + kfree(vmas); + ctx->nr_user_bufs = nr_args; + return 0; +err: + kfree(pages); + kfree(vmas); + io_sqe_buffer_unregister(ctx); + return ret; +} + static void io_ring_ctx_free(struct io_ring_ctx *ctx) { if (ctx->sqo_wq) @@ -1316,6 +1608,7 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx) mmdrop(ctx->sqo_mm); io_iopoll_reap_events(ctx); + io_sqe_buffer_unregister(ctx); #if defined(CONFIG_UNIX) if (ctx->ring_sock) @@ -1677,6 +1970,60 @@ SYSCALL_DEFINE2(io_uring_setup, u32, entries, return io_uring_setup(entries, params); } +static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, + void __user *arg, unsigned nr_args) +{ + int ret; + + percpu_ref_kill(&ctx->refs); + wait_for_completion(&ctx->ctx_done); + + switch (opcode) { + case IORING_REGISTER_BUFFERS: + ret = io_sqe_buffer_register(ctx, arg, nr_args); + break; + case IORING_UNREGISTER_BUFFERS: + ret = -EINVAL; + if (arg || nr_args) + break; + ret = io_sqe_buffer_unregister(ctx); + break; + default: + ret = -EINVAL; + break; + } + + /* bring the ctx back to life */ + reinit_completion(&ctx->ctx_done); + percpu_ref_reinit(&ctx->refs); + return ret; +} + +SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode, + void __user *, arg, unsigned int, nr_args) +{ + struct io_ring_ctx *ctx; + long ret = -EBADF; + struct fd f; + + f = fdget(fd); + if (!f.file) + return -EBADF; + + ret = -EOPNOTSUPP; + if (f.file->f_op != &io_uring_fops) + goto out_fput; + + ctx = f.file->private_data; + + mutex_lock(&ctx->uring_lock); + ret = __io_uring_register(ctx, opcode, arg, nr_args); + mutex_unlock(&ctx->uring_lock); +out_fput: + fdput(f); + return ret; +} + static int __init io_uring_init(void) { req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC); diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 3072dbaa7869..3681c05ac538 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -315,6 +315,8 @@ asmlinkage long sys_io_uring_setup(u32 entries, asmlinkage long sys_io_uring_enter(unsigned int fd, u32 to_submit, u32 min_complete, u32 flags, const sigset_t __user *sig, size_t sigsz); +asmlinkage long sys_io_uring_register(unsigned int fd, unsigned int op, + void __user *arg, unsigned int nr_args); /* fs/xattr.c */ asmlinkage long sys_setxattr(const char __user *path, const char __user *name, diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h index 87871e7b7ea7..d346229a1eb0 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -744,9 +744,11 @@ __SYSCALL(__NR_kexec_file_load, sys_kexec_file_load) __SYSCALL(__NR_io_uring_setup, sys_io_uring_setup) #define __NR_io_uring_enter 426 __SYSCALL(__NR_io_uring_enter, sys_io_uring_enter) +#define __NR_io_uring_register 427 +__SYSCALL(__NR_io_uring_register, sys_io_uring_register) #undef __NR_syscalls -#define __NR_syscalls 427 +#define __NR_syscalls 428 /* * 32 bit systems traditionally used different diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 5c457ea396e6..cf28f7a11f12 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -27,7 +27,10 @@ struct io_uring_sqe { __u32 fsync_flags; }; __u64 user_data; /* data to be passed back at completion time */ - __u64 __pad2[3]; + union { + __u16 buf_index; /* index into fixed buffers, if used */ + __u64 __pad2[3]; + }; }; /* @@ -39,6 +42,8 @@ struct io_uring_sqe { #define IORING_OP_READV 1 #define IORING_OP_WRITEV 2 #define IORING_OP_FSYNC 3 +#define IORING_OP_READ_FIXED 4 +#define IORING_OP_WRITE_FIXED 5 /* * sqe->fsync_flags @@ -103,4 +108,10 @@ struct io_uring_params { struct io_cqring_offsets cq_off; }; +/* + * io_uring_register(2) opcodes and arguments + */ +#define IORING_REGISTER_BUFFERS 0 +#define IORING_UNREGISTER_BUFFERS 1 + #endif diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index ee5e523564bb..1bb6604dc19f 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -48,6 +48,7 @@ COND_SYSCALL_COMPAT(io_getevents); COND_SYSCALL_COMPAT(io_pgetevents); COND_SYSCALL(io_uring_setup); COND_SYSCALL(io_uring_enter); +COND_SYSCALL(io_uring_register); /* fs/xattr.c */ From patchwork Mon Feb 11 19:00:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806697 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DA1C66C2 for ; Mon, 11 Feb 2019 19:01:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CC8A0293A8 for ; Mon, 11 Feb 2019 19:01:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C120A2B243; Mon, 11 Feb 2019 19:01:32 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C71D2293A8 for ; Mon, 11 Feb 2019 19:01:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732994AbfBKTBV (ORCPT ); Mon, 11 Feb 2019 14:01:21 -0500 Received: from mail-it1-f196.google.com ([209.85.166.196]:37070 "EHLO mail-it1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733288AbfBKTBU (ORCPT ); Mon, 11 Feb 2019 14:01:20 -0500 Received: by mail-it1-f196.google.com with SMTP id b5so914821iti.2 for ; Mon, 11 Feb 2019 11:01:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=80yuM+MDzhESEs22kJBxcN12JeS3xfhO17J+3EYvHLY=; b=LyCQ5kIgQ7fR57aRpzPUBIhtXkFxFWszK96n9Da2tLUzuZMNjQzt9CYhBaaH8W8Ps9 FCgvPcPjrUEQGime534QMQBT+LYe26ZZwR7Vv7UXXBznlo/aXxAV8bIQAYExO63z+1s3 seCTrHeM/Tnuo6IQVOT3EmhVpddR+FLwpJH8c2aL1ebDLrqBhvcrRPcsZC5pqrS/Dn9A d2YgvtjzM6JRC2bl98enTsvATTRJPSDpZY9l3BZS+TzOUenafnYlpBKHemzNip5mvQJm UGS96JgKk1HRG+L/F0HvwICZdsiVwI/RAboiavuw70OmA9CqN0OQNjc2RpdqdS2e2Mif 8UeA== 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; bh=80yuM+MDzhESEs22kJBxcN12JeS3xfhO17J+3EYvHLY=; b=cm5IsTwISd/lckmtVOu06W3CyqltuFYJyOYK8qUipfihwZFlMCZeWdzneDIXJPldBW rfCUUP5bqs5+3n5OFyuE5nEidrIFj7G9PHBP6DkCsEdl6M2h3dUr0eOkADMmkaGm8bVN utALyH+Fb3H8Zf/Tf9cRV9A6B1RdSYJP9k6pVPeLJ0SQQtpZ5qRxv3/C41twiSZNo08H GE3UwpU2jAklpk7pG8efuzECh1qus4XNYcfWeqMf7DG+LDAHPHVSHanpYjLrIrB4XF6d eJEgZtswJeGSdNd8mI09pm0LbkdN8vD2DQwMfXnzXSoi9BlJ6/wm6WJcZtf2J5dXUvXK Ph9g== X-Gm-Message-State: AHQUAuaCZ5Bdn8buV06dlOPjzCuuS4yHI/1OwHKogc1dD3Gz6POZwC6S 6sVWcMGP15nWRlou4AnF+CEqSw== X-Google-Smtp-Source: AHgI3IbImTgvCI2O1GywpUrKGiA9lmXiyq+hPPB0vLfcPAT7FdIAw84jgq7jInoadzkXhBtU16CQbQ== X-Received: by 2002:a24:3a0d:: with SMTP id m13mr527604itm.74.1549911679454; Mon, 11 Feb 2019 11:01:19 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.01.17 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:01:17 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 13/19] net: split out functions related to registering inflight socket files Date: Mon, 11 Feb 2019 12:00:43 -0700 Message-Id: <20190211190049.7888-15-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We need this functionality for the io_uring file registration, but we cannot rely on it since CONFIG_UNIX can be modular. Move the helpers to a separate file, that's always builtin to the kernel if CONFIG_UNIX is m/y. No functional changes in this patch, just moving code around. Reviewed-by: Hannes Reinecke Acked-by: David S. Miller Signed-off-by: Jens Axboe --- include/net/af_unix.h | 1 + net/Makefile | 2 +- net/unix/Kconfig | 5 ++ net/unix/Makefile | 2 + net/unix/af_unix.c | 63 +----------------- net/unix/garbage.c | 71 +------------------- net/unix/scm.c | 151 ++++++++++++++++++++++++++++++++++++++++++ net/unix/scm.h | 10 +++ 8 files changed, 174 insertions(+), 131 deletions(-) create mode 100644 net/unix/scm.c create mode 100644 net/unix/scm.h diff --git a/include/net/af_unix.h b/include/net/af_unix.h index ddbba838d048..3426d6dacc45 100644 --- a/include/net/af_unix.h +++ b/include/net/af_unix.h @@ -10,6 +10,7 @@ void unix_inflight(struct user_struct *user, struct file *fp); void unix_notinflight(struct user_struct *user, struct file *fp); +void unix_destruct_scm(struct sk_buff *skb); void unix_gc(void); void wait_for_unix_gc(void); struct sock *unix_get_socket(struct file *filp); diff --git a/net/Makefile b/net/Makefile index bdaf53925acd..449fc0b221f8 100644 --- a/net/Makefile +++ b/net/Makefile @@ -18,7 +18,7 @@ obj-$(CONFIG_NETFILTER) += netfilter/ obj-$(CONFIG_INET) += ipv4/ obj-$(CONFIG_TLS) += tls/ obj-$(CONFIG_XFRM) += xfrm/ -obj-$(CONFIG_UNIX) += unix/ +obj-$(CONFIG_UNIX_SCM) += unix/ obj-$(CONFIG_NET) += ipv6/ obj-$(CONFIG_BPFILTER) += bpfilter/ obj-$(CONFIG_PACKET) += packet/ diff --git a/net/unix/Kconfig b/net/unix/Kconfig index 8b31ab85d050..3b9e450656a4 100644 --- a/net/unix/Kconfig +++ b/net/unix/Kconfig @@ -19,6 +19,11 @@ config UNIX Say Y unless you know what you are doing. +config UNIX_SCM + bool + depends on UNIX + default y + config UNIX_DIAG tristate "UNIX: socket monitoring interface" depends on UNIX diff --git a/net/unix/Makefile b/net/unix/Makefile index ffd0a275c3a7..54e58cc4f945 100644 --- a/net/unix/Makefile +++ b/net/unix/Makefile @@ -10,3 +10,5 @@ unix-$(CONFIG_SYSCTL) += sysctl_net_unix.o obj-$(CONFIG_UNIX_DIAG) += unix_diag.o unix_diag-y := diag.o + +obj-$(CONFIG_UNIX_SCM) += scm.o diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 74d1eed7cbd4..2ce32dbb2feb 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -119,6 +119,8 @@ #include #include +#include "scm.h" + struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE]; EXPORT_SYMBOL_GPL(unix_socket_table); DEFINE_SPINLOCK(unix_table_lock); @@ -1486,67 +1488,6 @@ static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int peer) return err; } -static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) -{ - int i; - - scm->fp = UNIXCB(skb).fp; - UNIXCB(skb).fp = NULL; - - for (i = scm->fp->count-1; i >= 0; i--) - unix_notinflight(scm->fp->user, scm->fp->fp[i]); -} - -static void unix_destruct_scm(struct sk_buff *skb) -{ - struct scm_cookie scm; - memset(&scm, 0, sizeof(scm)); - scm.pid = UNIXCB(skb).pid; - if (UNIXCB(skb).fp) - unix_detach_fds(&scm, skb); - - /* Alas, it calls VFS */ - /* So fscking what? fput() had been SMP-safe since the last Summer */ - scm_destroy(&scm); - sock_wfree(skb); -} - -/* - * The "user->unix_inflight" variable is protected by the garbage - * collection lock, and we just read it locklessly here. If you go - * over the limit, there might be a tiny race in actually noticing - * it across threads. Tough. - */ -static inline bool too_many_unix_fds(struct task_struct *p) -{ - struct user_struct *user = current_user(); - - if (unlikely(user->unix_inflight > task_rlimit(p, RLIMIT_NOFILE))) - return !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN); - return false; -} - -static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) -{ - int i; - - if (too_many_unix_fds(current)) - return -ETOOMANYREFS; - - /* - * Need to duplicate file references for the sake of garbage - * collection. Otherwise a socket in the fps might become a - * candidate for GC while the skb is not yet queued. - */ - UNIXCB(skb).fp = scm_fp_dup(scm->fp); - if (!UNIXCB(skb).fp) - return -ENOMEM; - - for (i = scm->fp->count - 1; i >= 0; i--) - unix_inflight(scm->fp->user, scm->fp->fp[i]); - return 0; -} - static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds) { int err = 0; diff --git a/net/unix/garbage.c b/net/unix/garbage.c index f81854d74c7d..8bbe1b8e4ff7 100644 --- a/net/unix/garbage.c +++ b/net/unix/garbage.c @@ -86,80 +86,13 @@ #include #include +#include "scm.h" + /* Internal data structures and random procedures: */ -static LIST_HEAD(gc_inflight_list); static LIST_HEAD(gc_candidates); -static DEFINE_SPINLOCK(unix_gc_lock); static DECLARE_WAIT_QUEUE_HEAD(unix_gc_wait); -unsigned int unix_tot_inflight; - -struct sock *unix_get_socket(struct file *filp) -{ - struct sock *u_sock = NULL; - struct inode *inode = file_inode(filp); - - /* Socket ? */ - if (S_ISSOCK(inode->i_mode) && !(filp->f_mode & FMODE_PATH)) { - struct socket *sock = SOCKET_I(inode); - struct sock *s = sock->sk; - - /* PF_UNIX ? */ - if (s && sock->ops && sock->ops->family == PF_UNIX) - u_sock = s; - } else { - /* Could be an io_uring instance */ - u_sock = io_uring_get_socket(filp); - } - return u_sock; -} - -/* Keep the number of times in flight count for the file - * descriptor if it is for an AF_UNIX socket. - */ - -void unix_inflight(struct user_struct *user, struct file *fp) -{ - struct sock *s = unix_get_socket(fp); - - spin_lock(&unix_gc_lock); - - if (s) { - struct unix_sock *u = unix_sk(s); - - if (atomic_long_inc_return(&u->inflight) == 1) { - BUG_ON(!list_empty(&u->link)); - list_add_tail(&u->link, &gc_inflight_list); - } else { - BUG_ON(list_empty(&u->link)); - } - unix_tot_inflight++; - } - user->unix_inflight++; - spin_unlock(&unix_gc_lock); -} - -void unix_notinflight(struct user_struct *user, struct file *fp) -{ - struct sock *s = unix_get_socket(fp); - - spin_lock(&unix_gc_lock); - - if (s) { - struct unix_sock *u = unix_sk(s); - - BUG_ON(!atomic_long_read(&u->inflight)); - BUG_ON(list_empty(&u->link)); - - if (atomic_long_dec_and_test(&u->inflight)) - list_del_init(&u->link); - unix_tot_inflight--; - } - user->unix_inflight--; - spin_unlock(&unix_gc_lock); -} - static void scan_inflight(struct sock *x, void (*func)(struct unix_sock *), struct sk_buff_head *hitlist) { diff --git a/net/unix/scm.c b/net/unix/scm.c new file mode 100644 index 000000000000..8c40f2b32392 --- /dev/null +++ b/net/unix/scm.c @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "scm.h" + +unsigned int unix_tot_inflight; +EXPORT_SYMBOL(unix_tot_inflight); + +LIST_HEAD(gc_inflight_list); +EXPORT_SYMBOL(gc_inflight_list); + +DEFINE_SPINLOCK(unix_gc_lock); +EXPORT_SYMBOL(unix_gc_lock); + +struct sock *unix_get_socket(struct file *filp) +{ + struct sock *u_sock = NULL; + struct inode *inode = file_inode(filp); + + /* Socket ? */ + if (S_ISSOCK(inode->i_mode) && !(filp->f_mode & FMODE_PATH)) { + struct socket *sock = SOCKET_I(inode); + struct sock *s = sock->sk; + + /* PF_UNIX ? */ + if (s && sock->ops && sock->ops->family == PF_UNIX) + u_sock = s; + } else { + /* Could be an io_uring instance */ + u_sock = io_uring_get_socket(filp); + } + return u_sock; +} +EXPORT_SYMBOL(unix_get_socket); + +/* Keep the number of times in flight count for the file + * descriptor if it is for an AF_UNIX socket. + */ +void unix_inflight(struct user_struct *user, struct file *fp) +{ + struct sock *s = unix_get_socket(fp); + + spin_lock(&unix_gc_lock); + + if (s) { + struct unix_sock *u = unix_sk(s); + + if (atomic_long_inc_return(&u->inflight) == 1) { + BUG_ON(!list_empty(&u->link)); + list_add_tail(&u->link, &gc_inflight_list); + } else { + BUG_ON(list_empty(&u->link)); + } + unix_tot_inflight++; + } + user->unix_inflight++; + spin_unlock(&unix_gc_lock); +} + +void unix_notinflight(struct user_struct *user, struct file *fp) +{ + struct sock *s = unix_get_socket(fp); + + spin_lock(&unix_gc_lock); + + if (s) { + struct unix_sock *u = unix_sk(s); + + BUG_ON(!atomic_long_read(&u->inflight)); + BUG_ON(list_empty(&u->link)); + + if (atomic_long_dec_and_test(&u->inflight)) + list_del_init(&u->link); + unix_tot_inflight--; + } + user->unix_inflight--; + spin_unlock(&unix_gc_lock); +} + +/* + * The "user->unix_inflight" variable is protected by the garbage + * collection lock, and we just read it locklessly here. If you go + * over the limit, there might be a tiny race in actually noticing + * it across threads. Tough. + */ +static inline bool too_many_unix_fds(struct task_struct *p) +{ + struct user_struct *user = current_user(); + + if (unlikely(user->unix_inflight > task_rlimit(p, RLIMIT_NOFILE))) + return !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN); + return false; +} + +int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) +{ + int i; + + if (too_many_unix_fds(current)) + return -ETOOMANYREFS; + + /* + * Need to duplicate file references for the sake of garbage + * collection. Otherwise a socket in the fps might become a + * candidate for GC while the skb is not yet queued. + */ + UNIXCB(skb).fp = scm_fp_dup(scm->fp); + if (!UNIXCB(skb).fp) + return -ENOMEM; + + for (i = scm->fp->count - 1; i >= 0; i--) + unix_inflight(scm->fp->user, scm->fp->fp[i]); + return 0; +} +EXPORT_SYMBOL(unix_attach_fds); + +void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) +{ + int i; + + scm->fp = UNIXCB(skb).fp; + UNIXCB(skb).fp = NULL; + + for (i = scm->fp->count-1; i >= 0; i--) + unix_notinflight(scm->fp->user, scm->fp->fp[i]); +} +EXPORT_SYMBOL(unix_detach_fds); + +void unix_destruct_scm(struct sk_buff *skb) +{ + struct scm_cookie scm; + + memset(&scm, 0, sizeof(scm)); + scm.pid = UNIXCB(skb).pid; + if (UNIXCB(skb).fp) + unix_detach_fds(&scm, skb); + + /* Alas, it calls VFS */ + /* So fscking what? fput() had been SMP-safe since the last Summer */ + scm_destroy(&scm); + sock_wfree(skb); +} +EXPORT_SYMBOL(unix_destruct_scm); diff --git a/net/unix/scm.h b/net/unix/scm.h new file mode 100644 index 000000000000..5a255a477f16 --- /dev/null +++ b/net/unix/scm.h @@ -0,0 +1,10 @@ +#ifndef NET_UNIX_SCM_H +#define NET_UNIX_SCM_H + +extern struct list_head gc_inflight_list; +extern spinlock_t unix_gc_lock; + +int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb); +void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb); + +#endif From patchwork Mon Feb 11 19:00:44 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806689 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2545B746 for ; Mon, 11 Feb 2019 19:01:26 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 11A06293A8 for ; Mon, 11 Feb 2019 19:01:26 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0333F2AE23; Mon, 11 Feb 2019 19:01:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3D4C72A166 for ; Mon, 11 Feb 2019 19:01:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387467AbfBKTBX (ORCPT ); Mon, 11 Feb 2019 14:01:23 -0500 Received: from mail-it1-f194.google.com ([209.85.166.194]:54953 "EHLO mail-it1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387460AbfBKTBW (ORCPT ); Mon, 11 Feb 2019 14:01:22 -0500 Received: by mail-it1-f194.google.com with SMTP id i145so865933ita.4 for ; Mon, 11 Feb 2019 11:01:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=3ysc6tu7CxPtkMnQw0aOZcD8UmrCdA515qngMtXARWM=; b=l9L7kP6ipiDu7LstSfQhLqbisVdf3P5fIraBks9PIAie0C6omRc9VVxDdmwoRTVu61 o/4r3Mo6+kKHTmiY1qP0yPo92L1j77vSmiZx1dkYQSMg/MztL0rPqPuSP5JsnHi3tycx F2PshM6xd4goicnFm+n6HnXhMhnCM8woABxM6IWslkNlNuU5n9o7E9xSRexQxTOlaMBx hhcWiXCIu0wt2o+QKVwEsr+rQy2JItFB844iOSYlvTdq0mLG3n7t9KkWXnKpSGozwLUD xxaTwAypwbXSDArivUTamTpnGrXlcpYT/hUwOuwlsdzIiJ7POzfDFBbZKyxc7elL/XMb +SvA== 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; bh=3ysc6tu7CxPtkMnQw0aOZcD8UmrCdA515qngMtXARWM=; b=Mk7X0GoS+tiaju0F5/5ENhCnCnliIxOLy43scCHHdpdH7fPscm6p2Flhq76lux9tEw jZGi9TvEdnt4ee2M18eH7xvEqBS4dDdB2EB8qZOs7mHQmIMamLFZwXmfxhDTDnldsLnM l2eT4cLZbwaCh23tq4tV8wxpg83T9N8hGUu32yslJqdNjECZF+6tTTJy1klmYlCmK0EF 8FcrdkgVmd4BEmxPiSraBY3j4GBYuQQPhMJpdJ/Uo7bEt7u9ZDMFj89LajekkQz2RHcC CxP3I+rXKJTZMUcdkNNmFNX/ZtEmM7YfBNPfG5Cj+NGWTixFFYCEmBXmzOoQcfSkBkJO 6GGA== X-Gm-Message-State: AHQUAubNAIy69/mq6yTyzxWBo337gRWoDYo9CxUOd4dzTW1fWQJ7Ylp7 +zRyfFSevysqN5gjjheyo8e+5A== X-Google-Smtp-Source: AHgI3Iaydfr/c3Kq9nO16HHKKCLflkDy0f/MaDjPaBNNnMajdfzFegI+4ZjljWSa+FEDB2GNQhH60w== X-Received: by 2002:a05:660c:b0b:: with SMTP id f11mr589344itk.169.1549911681373; Mon, 11 Feb 2019 11:01:21 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.01.19 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:01:20 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 14/19] io_uring: add file set registration Date: Mon, 11 Feb 2019 12:00:44 -0700 Message-Id: <20190211190049.7888-16-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We normally have to fget/fput for each IO we do on a file. Even with the batching we do, the cost of the atomic inc/dec of the file usage count adds up. This adds IORING_REGISTER_FILES, and IORING_UNREGISTER_FILES opcodes for the io_uring_register(2) system call. The arguments passed in must be an array of __s32 holding file descriptors, and nr_args should hold the number of file descriptors the application wishes to pin for the duration of the io_uring instance (or until IORING_UNREGISTER_FILES is called). When used, the application must set IOSQE_FIXED_FILE in the sqe->flags member. Then, instead of setting sqe->fd to the real fd, it sets sqe->fd to the index in the array passed in to IORING_REGISTER_FILES. Files are automatically unregistered when the io_uring instance is torn down. An application need only unregister if it wishes to register a new set of fds. Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- fs/io_uring.c | 267 ++++++++++++++++++++++++++++++---- include/uapi/linux/io_uring.h | 9 +- 2 files changed, 246 insertions(+), 30 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 0eba20d18f53..167c7f96666f 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -49,6 +49,7 @@ #include #include #include +#include #include #include #include @@ -61,6 +62,7 @@ #include "internal.h" #define IORING_MAX_ENTRIES 4096 +#define IORING_MAX_FIXED_FILES 1024 struct io_uring { u32 head ____cacheline_aligned_in_smp; @@ -123,6 +125,14 @@ struct io_ring_ctx { struct fasync_struct *cq_fasync; } ____cacheline_aligned_in_smp; + /* + * If used, fixed file set. Writers must ensure that ->refs is dead, + * readers must ensure that ->refs is alive as long as the file* is + * used. Only updated through io_uring_register(2). + */ + struct file **user_files; + unsigned nr_user_files; + /* if used, fixed mapped user buffers */ unsigned nr_user_bufs; struct io_mapped_ubuf *user_bufs; @@ -170,6 +180,7 @@ struct io_kiocb { unsigned int flags; #define REQ_F_FORCE_NONBLOCK 1 /* inline submission attempt */ #define REQ_F_IOPOLL_COMPLETED 2 /* polled IO has completed */ +#define REQ_F_FIXED_FILE 4 /* ctx owns file */ u64 user_data; u64 error; @@ -404,15 +415,17 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events, * Batched puts of the same file, to avoid dirtying the * file usage count multiple times, if avoidable. */ - if (!file) { - file = req->rw.ki_filp; - file_count = 1; - } else if (file == req->rw.ki_filp) { - file_count++; - } else { - fput_many(file, file_count); - file = req->rw.ki_filp; - file_count = 1; + if (!(req->flags & REQ_F_FIXED_FILE)) { + if (!file) { + file = req->rw.ki_filp; + file_count = 1; + } else if (file == req->rw.ki_filp) { + file_count++; + } else { + fput_many(file, file_count); + file = req->rw.ki_filp; + file_count = 1; + } } if (to_free == ARRAY_SIZE(reqs)) @@ -544,13 +557,19 @@ static void kiocb_end_write(struct kiocb *kiocb) } } +static void io_fput(struct io_kiocb *req) +{ + if (!(req->flags & REQ_F_FIXED_FILE)) + fput(req->rw.ki_filp); +} + static void io_complete_rw(struct kiocb *kiocb, long res, long res2) { struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw); kiocb_end_write(kiocb); - fput(kiocb->ki_filp); + io_fput(req); io_cqring_add_event(req->ctx, req->user_data, res, 0); io_free_req(req); } @@ -666,19 +685,29 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, { struct io_ring_ctx *ctx = req->ctx; struct kiocb *kiocb = &req->rw; - unsigned ioprio; + unsigned ioprio, flags; int fd, ret; /* For -EAGAIN retry, everything is already prepped */ if (kiocb->ki_filp) return 0; + flags = READ_ONCE(sqe->flags); fd = READ_ONCE(sqe->fd); - kiocb->ki_filp = io_file_get(state, fd); - if (unlikely(!kiocb->ki_filp)) - return -EBADF; - if (force_nonblock && !io_file_supports_async(kiocb->ki_filp)) - force_nonblock = false; + + if (flags & IOSQE_FIXED_FILE) { + if (unlikely(!ctx->user_files || + (unsigned) fd >= ctx->nr_user_files)) + return -EBADF; + kiocb->ki_filp = ctx->user_files[fd]; + req->flags |= REQ_F_FIXED_FILE; + } else { + kiocb->ki_filp = io_file_get(state, fd); + if (unlikely(!kiocb->ki_filp)) + return -EBADF; + if (force_nonblock && !io_file_supports_async(kiocb->ki_filp)) + force_nonblock = false; + } kiocb->ki_pos = READ_ONCE(sqe->off); kiocb->ki_flags = iocb_flags(kiocb->ki_filp); kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp)); @@ -718,10 +747,14 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, } return 0; out_fput: - /* in case of error, we didn't use this file reference. drop it. */ - if (state) - state->used_refs--; - io_file_put(state, kiocb->ki_filp); + if (!(flags & IOSQE_FIXED_FILE)) { + /* + * in case of error, we didn't use this file reference. drop it. + */ + if (state) + state->used_refs--; + io_file_put(state, kiocb->ki_filp); + } return ret; } @@ -863,7 +896,7 @@ static ssize_t io_read(struct io_kiocb *req, const struct sqe_submit *s, out_fput: /* Hold on to the file for -EAGAIN */ if (unlikely(ret && ret != -EAGAIN)) - fput(file); + io_fput(req); return ret; } @@ -917,7 +950,7 @@ static ssize_t io_write(struct io_kiocb *req, const struct sqe_submit *s, kfree(iovec); out_fput: if (unlikely(ret)) - fput(file); + io_fput(req); return ret; } @@ -940,7 +973,7 @@ static int io_nop(struct io_kiocb *req, u64 user_data) */ if (req->rw.ki_filp) { err = -EBADF; - fput(req->rw.ki_filp); + io_fput(req); } io_cqring_add_event(ctx, user_data, err, 0); io_free_req(req); @@ -949,21 +982,32 @@ static int io_nop(struct io_kiocb *req, u64 user_data) static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe) { + struct io_ring_ctx *ctx = req->ctx; + unsigned flags; int fd; /* Prep already done */ if (req->rw.ki_filp) return 0; - if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index)) return -EINVAL; fd = READ_ONCE(sqe->fd); - req->rw.ki_filp = fget(fd); - if (unlikely(!req->rw.ki_filp)) - return -EBADF; + flags = READ_ONCE(sqe->flags); + + if (flags & IOSQE_FIXED_FILE) { + if (unlikely(!ctx->user_files || fd >= ctx->nr_user_files)) + return -EBADF; + req->rw.ki_filp = ctx->user_files[fd]; + req->flags |= REQ_F_FIXED_FILE; + } else { + req->rw.ki_filp = fget(fd); + if (unlikely(!req->rw.ki_filp)) + return -EBADF; + } return 0; } @@ -993,7 +1037,7 @@ static int io_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe, end > 0 ? end : LLONG_MAX, fsync_flags & IORING_FSYNC_DATASYNC); - fput(req->rw.ki_filp); + io_fput(req); io_cqring_add_event(req->ctx, sqe->user_data, ret, 0); io_free_req(req); return 0; @@ -1132,7 +1176,7 @@ static int io_submit_sqe(struct io_ring_ctx *ctx, struct sqe_submit *s, ssize_t ret; /* enforce forwards compatibility on users */ - if (unlikely(s->sqe->flags)) + if (unlikely(s->sqe->flags & ~IOSQE_FIXED_FILE)) return -EINVAL; req = io_get_req(ctx, state); @@ -1335,6 +1379,161 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, return READ_ONCE(ring->r.head) == READ_ONCE(ring->r.tail) ? ret : 0; } +static void __io_sqe_files_unregister(struct io_ring_ctx *ctx) +{ +#if defined(CONFIG_UNIX) + if (ctx->ring_sock) { + struct sock *sock = ctx->ring_sock->sk; + struct sk_buff *skb; + + while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL) + kfree_skb(skb); + } +#else + int i; + + for (i = 0; i < ctx->nr_user_files; i++) + fput(ctx->user_files[i]); +#endif +} + +static int io_sqe_files_unregister(struct io_ring_ctx *ctx) +{ + if (!ctx->user_files) + return -ENXIO; + + __io_sqe_files_unregister(ctx); + kfree(ctx->user_files); + ctx->user_files = NULL; + return 0; +} + +#if defined(CONFIG_UNIX) +/* + * Ensure the UNIX gc is aware of our file set, so we are certain that + * the io_uring can be safely unregistered on process exit, even if we have + * loops in the file referencing. + */ +static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset) +{ + struct sock *sk = ctx->ring_sock->sk; + struct scm_fp_list *fpl; + struct sk_buff *skb; + int i; + + fpl = kzalloc(sizeof(*fpl), GFP_KERNEL); + if (!fpl) + return -ENOMEM; + + skb = alloc_skb(0, GFP_KERNEL); + if (!skb) { + kfree(fpl); + return -ENOMEM; + } + + skb->sk = sk; + skb->destructor = unix_destruct_scm; + + fpl->user = get_uid(ctx->user); + for (i = 0; i < nr; i++) { + fpl->fp[i] = get_file(ctx->user_files[i + offset]); + unix_inflight(fpl->user, fpl->fp[i]); + } + + fpl->max = fpl->count = nr; + UNIXCB(skb).fp = fpl; + refcount_add(skb->truesize, &sk->sk_wmem_alloc); + skb_queue_head(&sk->sk_receive_queue, skb); + + for (i = 0; i < nr; i++) + fput(fpl->fp[i]); + + return 0; +} + +/* + * If UNIX sockets are enabled, fd passing can cause a reference cycle which + * causes regular reference counting to break down. We rely on the UNIX + * garbage collection to take care of this problem for us. + */ +static int io_sqe_files_scm(struct io_ring_ctx *ctx) +{ + unsigned left, total; + int ret = 0; + + total = 0; + left = ctx->nr_user_files; + while (left) { + unsigned this_files = min_t(unsigned, left, SCM_MAX_FD); + int ret; + + ret = __io_sqe_files_scm(ctx, this_files, total); + if (ret) + break; + left -= this_files; + total += this_files; + } + + return ret; +} +#else +static int io_sqe_files_scm(struct io_ring_ctx *ctx) +{ + return 0; +} +#endif + +static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, + unsigned nr_args) +{ + __s32 __user *fds = (__s32 __user *) arg; + int fd, ret = 0; + unsigned i; + + if (ctx->user_files) + return -EBUSY; + if (!nr_args) + return -EINVAL; + if (nr_args > IORING_MAX_FIXED_FILES) + return -EMFILE; + + ctx->user_files = kcalloc(nr_args, sizeof(struct file *), GFP_KERNEL); + if (!ctx->user_files) + return -ENOMEM; + + for (i = 0; i < nr_args; i++) { + ret = -EFAULT; + if (copy_from_user(&fd, &fds[i], sizeof(fd))) + break; + + ctx->user_files[i] = fget(fd); + + ret = -EBADF; + if (!ctx->user_files[i]) + break; + /* + * Don't allow io_uring instances to be registered. If UNIX + * isn't enabled, then this causes a reference cycle and this + * instance can never get freed. If UNIX is enabled we'll + * handle it just fine, but there's still no point in allowing + * a ring fd as it doesn't support regular read/write anyway. + */ + if (ctx->user_files[i]->f_op == &io_uring_fops) { + fput(ctx->user_files[i]); + break; + } + ctx->nr_user_files++; + ret = 0; + } + + if (!ret) + ret = io_sqe_files_scm(ctx); + if (ret) + io_sqe_files_unregister(ctx); + + return ret; +} + static int io_sq_offload_start(struct io_ring_ctx *ctx) { int ret; @@ -1609,6 +1808,7 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx) io_iopoll_reap_events(ctx); io_sqe_buffer_unregister(ctx); + io_sqe_files_unregister(ctx); #if defined(CONFIG_UNIX) if (ctx->ring_sock) @@ -1988,6 +2188,15 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, break; ret = io_sqe_buffer_unregister(ctx); break; + case IORING_REGISTER_FILES: + ret = io_sqe_files_register(ctx, arg, nr_args); + break; + case IORING_UNREGISTER_FILES: + ret = -EINVAL; + if (arg || nr_args) + break; + ret = io_sqe_files_unregister(ctx); + break; default: ret = -EINVAL; break; diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index cf28f7a11f12..6257478d55e9 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -16,7 +16,7 @@ */ struct io_uring_sqe { __u8 opcode; /* type of operation for this sqe */ - __u8 flags; /* as of now unused */ + __u8 flags; /* IOSQE_ flags */ __u16 ioprio; /* ioprio for the request */ __s32 fd; /* file descriptor to do IO on */ __u64 off; /* offset into file */ @@ -33,6 +33,11 @@ struct io_uring_sqe { }; }; +/* + * sqe->flags + */ +#define IOSQE_FIXED_FILE (1U << 0) /* use fixed fileset */ + /* * io_uring_setup() flags */ @@ -113,5 +118,7 @@ struct io_uring_params { */ #define IORING_REGISTER_BUFFERS 0 #define IORING_UNREGISTER_BUFFERS 1 +#define IORING_REGISTER_FILES 2 +#define IORING_UNREGISTER_FILES 3 #endif From patchwork Mon Feb 11 19:00:45 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806693 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CFEF617FB for ; Mon, 11 Feb 2019 19:01:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BFAC22AE23 for ; Mon, 11 Feb 2019 19:01:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B18BD2B243; Mon, 11 Feb 2019 19:01:28 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B39A8293A8 for ; Mon, 11 Feb 2019 19:01:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387472AbfBKTB0 (ORCPT ); Mon, 11 Feb 2019 14:01:26 -0500 Received: from mail-it1-f196.google.com ([209.85.166.196]:51694 "EHLO mail-it1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387473AbfBKTBY (ORCPT ); Mon, 11 Feb 2019 14:01:24 -0500 Received: by mail-it1-f196.google.com with SMTP id y184so925482itc.1 for ; Mon, 11 Feb 2019 11:01:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=X+kfFxgsbJ5SWhuSmmeD8j2b8pHrlDNcu4HQ+LPuogI=; b=Unki+2umPEGB8yl3twOKO8a8Ab7RHlwk4Bdt3nxaFy9wfmw6/hd5bWZ/nJUDuQrvTU y88nTrFvgD6nkEceSv7JAYvo9xTAK+D4Ye5wqVGEEFpdZpQtKjn5j9B5XvivIUwEEG2y WxMNUjAmylQweCjuYgA0+H4STCgyu8aJNFYqDbb9dyr2KrKURpCX1ia1e/zNlIfsfeq2 MAG+PKP8yUAvgGWx+pXwY7VEZQhorGrwAixU4maDyu66HnUrwiNbmr6faXaNFyOsRV3G iNsFX3tKfSCkqpqThSpUng10frBG47M7HWMq6TaAp9Fl/0lQvxPfR1/bFNB1Db151pf6 e8iw== 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; bh=X+kfFxgsbJ5SWhuSmmeD8j2b8pHrlDNcu4HQ+LPuogI=; b=PYjnYjsuNZeML9FjuWHpQq9RYlNrbdDsEMHdqYMUKSjOlCh1L1iO2NR00VcgGxO1cI sSGygQaFFBAXJcSFtmMlTs+WvBC3lC+23qcbxFAt2u7GadxaKKqFVThtg4axm50VFg48 VxL06L6d1jkE+iJrTDD70IiUZ1F/VK/NjIhtR51AUJGGTqvVKMQBMKMhvzdAuVKdsS4y NQ/wDrRHJwIHJrUyUiJG+10vKtIPBzPoWW/0bTvIsD+0dmIPma72NC77tiaHW3KhwJVO 6/Bre1+BXe03xUsZXZAABZc9Ay5ryS7h8trzO1UGgfq2kBqEMkPT1CTmqDTSVPySN6rv z6bA== X-Gm-Message-State: AHQUAublpmefyaDEJczGcKMa5fJZZYFK2qkM/wlXfyYJFJe0JGFiWiWf R8lSOtq0QnBFR2qbhzoiu/SbCg== X-Google-Smtp-Source: AHgI3IZZqAM9NZEBjMLqgC7MDRfG5Lz9BDRmPTT2zz5n9AGliq0dAGiyv81eRhZ1TfkTm89e26Gr7Q== X-Received: by 2002:a6b:8bcd:: with SMTP id n196mr18842996iod.295.1549911683227; Mon, 11 Feb 2019 11:01:23 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.01.21 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:01:22 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 15/19] io_uring: add submission polling Date: Mon, 11 Feb 2019 12:00:45 -0700 Message-Id: <20190211190049.7888-17-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This enables an application to do IO, without ever entering the kernel. By using the SQ ring to fill in new sqes and watching for completions on the CQ ring, we can submit and reap IOs without doing a single system call. The kernel side thread will poll for new submissions, and in case of HIPRI/polled IO, it'll also poll for completions. By default, we allow 1 second of active spinning. This can by changed by passing in a different grace period at io_uring_register(2) time. If the thread exceeds this idle time without having any work to do, it will set: sq_ring->flags |= IORING_SQ_NEED_WAKEUP. The application will have to call io_uring_enter() to start things back up again. If IO is kept busy, that will never be needed. Basically an application that has this feature enabled will guard it's io_uring_enter(2) call with: read_barrier(); if (*sq_ring->flags & IORING_SQ_NEED_WAKEUP) io_uring_enter(fd, 0, 0, IORING_ENTER_SQ_WAKEUP); instead of calling it unconditionally. It's mandatory to use fixed files with this feature. Failure to do so will result in the application getting an -EBADF CQ entry when submitting IO. Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- fs/io_uring.c | 248 +++++++++++++++++++++++++++++++++- include/uapi/linux/io_uring.h | 12 +- 2 files changed, 252 insertions(+), 8 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 167c7f96666f..24c280076e81 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -44,6 +44,7 @@ #include #include #include +#include #include #include #include @@ -108,12 +109,16 @@ struct io_ring_ctx { unsigned cached_sq_head; unsigned sq_entries; unsigned sq_mask; + unsigned sq_thread_idle; struct io_uring_sqe *sq_sqes; } ____cacheline_aligned_in_smp; /* IO offload */ struct workqueue_struct *sqo_wq; + struct task_struct *sqo_thread; /* if using sq thread polling */ struct mm_struct *sqo_mm; + wait_queue_head_t sqo_wait; + unsigned sqo_stop; struct { /* CQ ring */ @@ -168,6 +173,7 @@ struct sqe_submit { unsigned short index; bool has_user; bool needs_lock; + bool needs_fixed_file; }; struct io_kiocb { @@ -327,6 +333,8 @@ static void io_cqring_add_event(struct io_ring_ctx *ctx, u64 ki_user_data, if (waitqueue_active(&ctx->wait)) wake_up(&ctx->wait); + if (waitqueue_active(&ctx->sqo_wait)) + wake_up(&ctx->sqo_wait); } static void io_ring_drop_ctx_refs(struct io_ring_ctx *ctx, unsigned refs) @@ -680,9 +688,10 @@ static bool io_file_supports_async(struct file *file) return false; } -static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, +static int io_prep_rw(struct io_kiocb *req, const struct sqe_submit *s, bool force_nonblock, struct io_submit_state *state) { + const struct io_uring_sqe *sqe = s->sqe; struct io_ring_ctx *ctx = req->ctx; struct kiocb *kiocb = &req->rw; unsigned ioprio, flags; @@ -702,6 +711,8 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, kiocb->ki_filp = ctx->user_files[fd]; req->flags |= REQ_F_FIXED_FILE; } else { + if (s->needs_fixed_file) + return -EBADF; kiocb->ki_filp = io_file_get(state, fd); if (unlikely(!kiocb->ki_filp)) return -EBADF; @@ -865,7 +876,7 @@ static ssize_t io_read(struct io_kiocb *req, const struct sqe_submit *s, struct file *file; ssize_t ret; - ret = io_prep_rw(req, s->sqe, force_nonblock, state); + ret = io_prep_rw(req, s, force_nonblock, state); if (ret) return ret; file = kiocb->ki_filp; @@ -909,7 +920,7 @@ static ssize_t io_write(struct io_kiocb *req, const struct sqe_submit *s, struct file *file; ssize_t ret; - ret = io_prep_rw(req, s->sqe, force_nonblock, state); + ret = io_prep_rw(req, s, force_nonblock, state); if (ret) return ret; /* Hold on to the file for -EAGAIN */ @@ -1295,6 +1306,170 @@ static bool io_get_sqring(struct io_ring_ctx *ctx, struct sqe_submit *s) return false; } +static int io_submit_sqes(struct io_ring_ctx *ctx, struct sqe_submit *sqes, + unsigned int nr, bool has_user, bool mm_fault) +{ + struct io_submit_state state, *statep = NULL; + int ret, i, submitted = 0; + + if (nr > IO_PLUG_THRESHOLD) { + io_submit_state_start(&state, ctx, nr); + statep = &state; + } + + for (i = 0; i < nr; i++) { + if (unlikely(mm_fault)) { + ret = -EFAULT; + } else { + sqes[i].has_user = has_user; + sqes[i].needs_lock = true; + sqes[i].needs_fixed_file = true; + ret = io_submit_sqe(ctx, &sqes[i], statep); + } + if (!ret) { + submitted++; + continue; + } + + io_cqring_add_event(ctx, sqes[i].sqe->user_data, ret, 0); + } + + if (statep) + io_submit_state_end(&state); + + return submitted; +} + +static int io_sq_thread(void *data) +{ + struct sqe_submit sqes[IO_IOPOLL_BATCH]; + struct io_ring_ctx *ctx = data; + struct mm_struct *cur_mm = NULL; + mm_segment_t old_fs; + DEFINE_WAIT(wait); + unsigned inflight; + unsigned long timeout; + + old_fs = get_fs(); + set_fs(USER_DS); + + timeout = inflight = 0; + while (!kthread_should_stop() && !ctx->sqo_stop) { + bool all_fixed, mm_fault = false; + int i; + + if (inflight) { + unsigned nr_events = 0; + + if (ctx->flags & IORING_SETUP_IOPOLL) { + /* + * We disallow the app entering submit/complete + * with polling, but we still need to lock the + * ring to prevent racing with polled issue + * that got punted to a workqueue. + */ + mutex_lock(&ctx->uring_lock); + io_iopoll_check(ctx, &nr_events, 0); + mutex_unlock(&ctx->uring_lock); + } else { + /* + * Normal IO, just pretend everything completed. + * We don't have to poll completions for that. + */ + nr_events = inflight; + } + + inflight -= nr_events; + if (!inflight) + timeout = jiffies + ctx->sq_thread_idle; + } + + if (!io_get_sqring(ctx, &sqes[0])) { + /* + * We're polling. If we're within the defined idle + * period, then let us spin without work before going + * to sleep. + */ + if (inflight || !time_after(jiffies, timeout)) { + cpu_relax(); + continue; + } + + /* + * Drop cur_mm before scheduling, we can't hold it for + * long periods (or over schedule()). Do this before + * adding ourselves to the waitqueue, as the unuse/drop + * may sleep. + */ + if (cur_mm) { + unuse_mm(cur_mm); + mmput(cur_mm); + cur_mm = NULL; + } + + prepare_to_wait(&ctx->sqo_wait, &wait, + TASK_INTERRUPTIBLE); + + /* Tell userspace we may need a wakeup call */ + ctx->sq_ring->flags |= IORING_SQ_NEED_WAKEUP; + smp_wmb(); + + if (!io_get_sqring(ctx, &sqes[0])) { + if (kthread_should_stop()) { + finish_wait(&ctx->sqo_wait, &wait); + break; + } + if (signal_pending(current)) + flush_signals(current); + schedule(); + finish_wait(&ctx->sqo_wait, &wait); + + ctx->sq_ring->flags &= ~IORING_SQ_NEED_WAKEUP; + smp_wmb(); + continue; + } + finish_wait(&ctx->sqo_wait, &wait); + + ctx->sq_ring->flags &= ~IORING_SQ_NEED_WAKEUP; + smp_wmb(); + } + + i = 0; + all_fixed = true; + do { + if (all_fixed && io_sqe_needs_user(sqes[i].sqe)) + all_fixed = false; + + i++; + if (i == ARRAY_SIZE(sqes)) + break; + } while (io_get_sqring(ctx, &sqes[i])); + + io_commit_sqring(ctx); + + /* Unless all new commands are FIXED regions, grab mm */ + if (!all_fixed && !cur_mm) { + mm_fault = !mmget_not_zero(ctx->sqo_mm); + if (!mm_fault) { + use_mm(ctx->sqo_mm); + cur_mm = ctx->sqo_mm; + } + } + + inflight += io_submit_sqes(ctx, sqes, i, cur_mm != NULL, + mm_fault); + } + + io_iopoll_reap_events(ctx); + + set_fs(old_fs); + if (cur_mm) { + unuse_mm(cur_mm); + mmput(cur_mm); + } + return 0; +} + static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit) { struct io_submit_state state, *statep = NULL; @@ -1313,6 +1488,7 @@ static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit) s.has_user = true; s.needs_lock = false; + s.needs_fixed_file = false; ret = io_submit_sqe(ctx, &s, statep); if (ret) { @@ -1534,13 +1710,47 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, return ret; } -static int io_sq_offload_start(struct io_ring_ctx *ctx) +static int io_sq_offload_start(struct io_ring_ctx *ctx, + struct io_uring_params *p) { int ret; + init_waitqueue_head(&ctx->sqo_wait); mmgrab(current->mm); ctx->sqo_mm = current->mm; + ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle); + if (!ctx->sq_thread_idle) + ctx->sq_thread_idle = HZ; + + ret = -EINVAL; + if (!cpu_possible(p->sq_thread_cpu)) + goto err; + + if (ctx->flags & IORING_SETUP_SQPOLL) { + if (p->flags & IORING_SETUP_SQ_AFF) { + int cpu; + + cpu = array_index_nospec(p->sq_thread_cpu, NR_CPUS); + ctx->sqo_thread = kthread_create_on_cpu(io_sq_thread, + ctx, cpu, + "io_uring-sq"); + } else { + ctx->sqo_thread = kthread_create(io_sq_thread, ctx, + "io_uring-sq"); + } + if (IS_ERR(ctx->sqo_thread)) { + ret = PTR_ERR(ctx->sqo_thread); + ctx->sqo_thread = NULL; + goto err; + } + wake_up_process(ctx->sqo_thread); + } else if (p->flags & IORING_SETUP_SQ_AFF) { + /* Can't have SQ_AFF without SQPOLL */ + ret = -EINVAL; + goto err; + } + /* Do QD, or 2 * CPUS, whatever is smallest */ ctx->sqo_wq = alloc_workqueue("io_ring-wq", WQ_UNBOUND | WQ_FREEZABLE, min(ctx->sq_entries - 1, 2 * num_online_cpus())); @@ -1551,6 +1761,12 @@ static int io_sq_offload_start(struct io_ring_ctx *ctx) return 0; err: + if (ctx->sqo_thread) { + ctx->sqo_stop = 1; + mb(); + kthread_stop(ctx->sqo_thread); + ctx->sqo_thread = NULL; + } mmdrop(ctx->sqo_mm); ctx->sqo_mm = NULL; return ret; @@ -1801,6 +2017,11 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg, static void io_ring_ctx_free(struct io_ring_ctx *ctx) { + if (ctx->sqo_thread) { + ctx->sqo_stop = 1; + mb(); + kthread_stop(ctx->sqo_thread); + } if (ctx->sqo_wq) destroy_workqueue(ctx->sqo_wq); if (ctx->sqo_mm) @@ -1910,7 +2131,7 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, int submitted = 0; struct fd f; - if (flags & ~IORING_ENTER_GETEVENTS) + if (flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP)) return -EINVAL; f = fdget(fd); @@ -1926,6 +2147,18 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, if (!percpu_ref_tryget(&ctx->refs)) goto out_fput; + /* + * For SQ polling, the thread will do all submissions and completions. + * Just return the requested submit count, and wake the thread if + * we were asked to. + */ + if (ctx->flags & IORING_SETUP_SQPOLL) { + if (flags & IORING_ENTER_SQ_WAKEUP) + wake_up(&ctx->sqo_wait); + submitted = to_submit; + goto out_ctx; + } + if (to_submit) { to_submit = min(to_submit, ctx->sq_entries); @@ -2103,7 +2336,7 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p) if (ret) goto err; - ret = io_sq_offload_start(ctx); + ret = io_sq_offload_start(ctx, p); if (ret) goto err; @@ -2151,7 +2384,8 @@ static long io_uring_setup(u32 entries, struct io_uring_params __user *params) return -EINVAL; } - if (p.flags & ~IORING_SETUP_IOPOLL) + if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL | + IORING_SETUP_SQ_AFF)) return -EINVAL; ret = io_uring_create(entries, &p); diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 6257478d55e9..0ec74bab8dbe 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -42,6 +42,8 @@ struct io_uring_sqe { * io_uring_setup() flags */ #define IORING_SETUP_IOPOLL (1U << 0) /* io_context is polled */ +#define IORING_SETUP_SQPOLL (1U << 1) /* SQ poll thread */ +#define IORING_SETUP_SQ_AFF (1U << 2) /* sq_thread_cpu is valid */ #define IORING_OP_NOP 0 #define IORING_OP_READV 1 @@ -86,6 +88,11 @@ struct io_sqring_offsets { __u64 resv2; }; +/* + * sq_ring->flags + */ +#define IORING_SQ_NEED_WAKEUP (1U << 0) /* needs io_uring_enter wakeup */ + struct io_cqring_offsets { __u32 head; __u32 tail; @@ -100,6 +107,7 @@ struct io_cqring_offsets { * io_uring_enter(2) flags */ #define IORING_ENTER_GETEVENTS (1U << 0) +#define IORING_ENTER_SQ_WAKEUP (1U << 1) /* * Passed in for io_uring_setup(2). Copied back with updated info on success @@ -108,7 +116,9 @@ struct io_uring_params { __u32 sq_entries; __u32 cq_entries; __u32 flags; - __u32 resv[7]; + __u32 sq_thread_cpu; + __u32 sq_thread_idle; + __u32 resv[5]; struct io_sqring_offsets sq_off; struct io_cqring_offsets cq_off; }; From patchwork Mon Feb 11 19:00:46 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806691 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 635D76C2 for ; Mon, 11 Feb 2019 19:01:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 560112AE23 for ; Mon, 11 Feb 2019 19:01:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 49EBE2B243; Mon, 11 Feb 2019 19:01:28 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E9A232AE23 for ; Mon, 11 Feb 2019 19:01:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387473AbfBKTB0 (ORCPT ); Mon, 11 Feb 2019 14:01:26 -0500 Received: from mail-it1-f196.google.com ([209.85.166.196]:53414 "EHLO mail-it1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733289AbfBKTB0 (ORCPT ); Mon, 11 Feb 2019 14:01:26 -0500 Received: by mail-it1-f196.google.com with SMTP id g85so883278ita.3 for ; Mon, 11 Feb 2019 11:01:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=Q8VhM/to/dzC4LkTSiVPV4UGBDV+ReSxEMSKO3PuRJ8=; b=C84gSm0rqjMc4waInNUluvmDHqiqqP+cjSKkajFJGoKTGmqN2WqDX/sX/48lbOmwni DUC07OBg60eowKk7WXG2AjK7fMaJvDOeiiigGfr68PzkKClGCEFFMZBndnKgHMbttPmn sss8k7/01EQBAOHMzvCJ/QwMnuBUv+Erfb/CdPRqah5WhbHENKHMsxWheQz2BWSeZMZA 18KKlTXk0Nxv/UMJkM9SXYp+nHQAY5YRF2yNNDak7u2SWNbScyApB1f+H6A7JDmoTFq6 K6jKlcKsDLYDgAWCBSf3m4LjCl1ewFylHxKw9wDajk4prmsYEYNthauDTbzsY2KUZ9Z/ I87A== 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; bh=Q8VhM/to/dzC4LkTSiVPV4UGBDV+ReSxEMSKO3PuRJ8=; b=Mwu16wvj9y8d/ApIHKHD34rEUpWOeX/IzFxPYjeWRR9J65CMhL5paZ/wdtPNyNp/Ox qqtLaBPEwR9/GN+VqYNuI/vtxXUgnychkk9Ugp6YPvjOIMYMclTMusn0cG0ENT5RoL6w wJaancFIPww4uTBhDPyNFCcEpKF5rtZO5Q1gdkOq8VG0V2qMkFPcPeb5397AubH5TkHd U+C9yvwL7ZA1CE9alUp3NjCgv8FAUs9JyK8NIXgR/WxNlWbRThEO7zIcxTLgQhDZhum/ u0ktJsBd5yJtm4xBBdnNWJu8OCUmHgJEgxbQk8jbDv2RnT2m4PI4rrAK60yMBOIBt/7M GlhA== X-Gm-Message-State: AHQUAuasENCXgPEKHphoLg7KrNHi+BHqQ8EYpq0P15ubmHK4i2+zUvfo s2UK6/b/tXOtRG7K32b5jI3YrQ== X-Google-Smtp-Source: AHgI3IY4E4w3zs5oLhDi547VPCXja2o/P81PRWJwIsJRv9MT4oFuik3Slo+zTKsRIfHIvswvZtJIKA== X-Received: by 2002:a24:7c58:: with SMTP id a85mr611580itd.9.1549911685165; Mon, 11 Feb 2019 11:01:25 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.01.23 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:01:24 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 16/19] io_uring: add io_kiocb ref count Date: Mon, 11 Feb 2019 12:00:46 -0700 Message-Id: <20190211190049.7888-18-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We'll use this for the POLL implementation. Regular requests will NOT be using references, so initialize it to 0. Any real use of the io_kiocb ref will initialize it to at least 2. Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- fs/io_uring.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 24c280076e81..33b6c6167595 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -184,6 +184,7 @@ struct io_kiocb { struct io_ring_ctx *ctx; struct list_head list; unsigned int flags; + refcount_t refs; #define REQ_F_FORCE_NONBLOCK 1 /* inline submission attempt */ #define REQ_F_IOPOLL_COMPLETED 2 /* polled IO has completed */ #define REQ_F_FIXED_FILE 4 /* ctx owns file */ @@ -377,6 +378,7 @@ static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx, req->ctx = ctx; req->flags = 0; + refcount_set(&req->refs, 0); return req; out: io_ring_drop_ctx_refs(ctx, 1); @@ -394,8 +396,10 @@ static void io_free_req_many(struct io_ring_ctx *ctx, void **reqs, int *nr) static void io_free_req(struct io_kiocb *req) { - io_ring_drop_ctx_refs(req->ctx, 1); - kmem_cache_free(req_cachep, req); + if (!refcount_read(&req->refs) || refcount_dec_and_test(&req->refs)) { + io_ring_drop_ctx_refs(req->ctx, 1); + kmem_cache_free(req_cachep, req); + } } /* From patchwork Mon Feb 11 19:00:47 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806695 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 424E16C2 for ; Mon, 11 Feb 2019 19:01:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3351B293A8 for ; Mon, 11 Feb 2019 19:01:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 272642AE23; Mon, 11 Feb 2019 19:01:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 42FE4293A8 for ; Mon, 11 Feb 2019 19:01:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387487AbfBKTB3 (ORCPT ); Mon, 11 Feb 2019 14:01:29 -0500 Received: from mail-it1-f196.google.com ([209.85.166.196]:37104 "EHLO mail-it1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387479AbfBKTB2 (ORCPT ); Mon, 11 Feb 2019 14:01:28 -0500 Received: by mail-it1-f196.google.com with SMTP id b5so916022iti.2 for ; Mon, 11 Feb 2019 11:01:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=LugoW4t8WMFUDrGfWGwmC0p1oM4DdT+q5DTejT5bTok=; b=f3D4BADT2B1x+hz9AWzg5RRUD+CwO0QBEAh9b8Pl1hLWVOPWg4r11pLQdNRY52ZNNF DCRPUNIbwmk54cgpUkiVY8x6ZZfznL5TTiulU5gE+VXgaXO3H8a0rEYJOvbksHfiw3hK ehjBfuawn7qrdoSuTSQjFsP7yU8o7MtDPR7PSMHDojyyJuOHDIEt9FJlWAjtrNB1cXWC MAdwLy3PesL9setgEhpF64XHMZse+P7dHeHjQL7ICl8prsPQTjG+2nmV+RddmCAYShCU Xw7r9aLiWXocElPT0Z74f1cku9V6xmfAnsMZ/4QkvVmr348IdYrMc7xqP+jWHp8akcrn PBwQ== 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; bh=LugoW4t8WMFUDrGfWGwmC0p1oM4DdT+q5DTejT5bTok=; b=cnB/3/ViSHX9e4a82asM971AH9nmK8O1tVEQyRD6ffMKGdsqJHkYaeQ8XTI245w+rO ebzGd+V8v5TDiyQO5A1j0EoGjDEGPV66yFs8liB2Uq3ghA6N5c0Uxd190t9iKYogqo1t 3VQfWqybYB6N05xqUGEPPHYwW7PHhDkHar2Xs7F6xjqhDBqVeQyLcyenWqmZishZdh73 vQbJdSBzCzZEUy8EhssHkI2i+ROq66TordpDtpElWhJ/u8xhkG7GY2+a7/J920e4ysnp VBD5vmQeq0tBs5hpP+qKWsMdc35VqZ3X6GJjKvdKdROEUFQzFBH5+GaHyli/YiQ6+51T wC1A== X-Gm-Message-State: AHQUAuZKrvtMau6rD/CfVg7IMTkmoikbKzCrhCBvxhgXlTfFdlczXHsg 8f5cQk6c+fHlJObgJUV0flnpLA== X-Google-Smtp-Source: AHgI3IbEL6G10hMt0FXQSTXJXY7VUOJNiI1UL1MTrqnxb/UuvzwrS6TWN4ypnLcc63YJcgbSpdtj4A== X-Received: by 2002:a24:7687:: with SMTP id z129mr623689itb.29.1549911687109; Mon, 11 Feb 2019 11:01:27 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.01.25 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:01:26 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 17/19] io_uring: add support for IORING_OP_POLL Date: Mon, 11 Feb 2019 12:00:47 -0700 Message-Id: <20190211190049.7888-19-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This is basically a direct port of bfe4037e722e, which implements a one-shot poll command through aio. Description below is based on that commit as well. However, instead of adding a POLL command and relying on io_cancel(2) to remove it, we mimic the epoll(2) interface of having a command to add a poll notification, IORING_OP_POLL_ADD, and one to remove it again, IORING_OP_POLL_REMOVE. To poll for a file descriptor the application should submit an sqe of type IORING_OP_POLL. It will poll the fd for the events specified in the poll_events field. Unlike poll or epoll without EPOLLONESHOT this interface always works in one shot mode, that is once the sqe is completed, it will have to be resubmitted. Reviewed-by: Hannes Reinecke Based-on-code-from: Christoph Hellwig Signed-off-by: Jens Axboe --- fs/io_uring.c | 261 +++++++++++++++++++++++++++++++++- include/uapi/linux/io_uring.h | 3 + 2 files changed, 263 insertions(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 33b6c6167595..a0513d4bc35d 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -161,6 +161,7 @@ struct io_ring_ctx { * manipulate the list, hence no extra locking is needed there. */ struct list_head poll_list; + struct list_head cancel_list; } ____cacheline_aligned_in_smp; #if defined(CONFIG_UNIX) @@ -176,8 +177,20 @@ struct sqe_submit { bool needs_fixed_file; }; +struct io_poll_iocb { + struct file *file; + struct wait_queue_head *head; + __poll_t events; + bool woken; + bool canceled; + struct wait_queue_entry wait; +}; + struct io_kiocb { - struct kiocb rw; + union { + struct kiocb rw; + struct io_poll_iocb poll; + }; struct sqe_submit submit; @@ -261,6 +274,7 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) init_waitqueue_head(&ctx->wait); spin_lock_init(&ctx->completion_lock); INIT_LIST_HEAD(&ctx->poll_list); + INIT_LIST_HEAD(&ctx->cancel_list); return ctx; } @@ -1058,6 +1072,244 @@ static int io_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe, return 0; } +static void io_poll_remove_one(struct io_kiocb *req) +{ + struct io_poll_iocb *poll = &req->poll; + + spin_lock(&poll->head->lock); + WRITE_ONCE(poll->canceled, true); + if (!list_empty(&poll->wait.entry)) { + list_del_init(&poll->wait.entry); + queue_work(req->ctx->sqo_wq, &req->work); + } + spin_unlock(&poll->head->lock); + + list_del_init(&req->list); +} + +static void io_poll_remove_all(struct io_ring_ctx *ctx) +{ + struct io_kiocb *req; + + spin_lock_irq(&ctx->completion_lock); + while (!list_empty(&ctx->cancel_list)) { + req = list_first_entry(&ctx->cancel_list, struct io_kiocb,list); + io_poll_remove_one(req); + } + spin_unlock_irq(&ctx->completion_lock); +} + +/* + * Find a running poll command that matches one specified in sqe->addr, + * and remove it if found. + */ +static int io_poll_remove(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_ring_ctx *ctx = req->ctx; + struct io_kiocb *poll_req, *next; + int ret = -ENOENT; + + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; + if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index || + sqe->poll_events) + return -EINVAL; + + spin_lock_irq(&ctx->completion_lock); + list_for_each_entry_safe(poll_req, next, &ctx->cancel_list, list) { + if (READ_ONCE(sqe->addr) == poll_req->user_data) { + io_poll_remove_one(poll_req); + ret = 0; + break; + } + } + spin_unlock_irq(&ctx->completion_lock); + + io_cqring_add_event(req->ctx, sqe->user_data, ret, 0); + io_free_req(req); + return 0; +} + +static void io_poll_complete(struct io_kiocb *req, __poll_t mask) +{ + io_cqring_add_event(req->ctx, req->user_data, mangle_poll(mask), 0); + io_fput(req); + io_free_req(req); +} + +static void io_poll_complete_work(struct work_struct *work) +{ + struct io_kiocb *req = container_of(work, struct io_kiocb, work); + struct io_poll_iocb *poll = &req->poll; + struct poll_table_struct pt = { ._key = poll->events }; + struct io_ring_ctx *ctx = req->ctx; + __poll_t mask = 0; + + if (!READ_ONCE(poll->canceled)) + mask = vfs_poll(poll->file, &pt) & poll->events; + + /* + * Note that ->ki_cancel callers also delete iocb from active_reqs after + * calling ->ki_cancel. We need the ctx_lock roundtrip here to + * synchronize with them. In the cancellation case the list_del_init + * itself is not actually needed, but harmless so we keep it in to + * avoid further branches in the fast path. + */ + spin_lock_irq(&ctx->completion_lock); + if (!mask && !READ_ONCE(poll->canceled)) { + add_wait_queue(poll->head, &poll->wait); + spin_unlock_irq(&ctx->completion_lock); + return; + } + list_del_init(&req->list); + spin_unlock_irq(&ctx->completion_lock); + + io_poll_complete(req, mask); +} + +static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync, + void *key) +{ + struct io_poll_iocb *poll = container_of(wait, struct io_poll_iocb, + wait); + struct io_kiocb *req = container_of(poll, struct io_kiocb, poll); + struct io_ring_ctx *ctx = req->ctx; + __poll_t mask = key_to_poll(key); + + poll->woken = true; + + /* for instances that support it check for an event match first: */ + if (mask) { + if (!(mask & poll->events)) + return 0; + + /* try to complete the iocb inline if we can: */ + if (spin_trylock(&ctx->completion_lock)) { + list_del(&req->list); + spin_unlock(&ctx->completion_lock); + + list_del_init(&poll->wait.entry); + io_poll_complete(req, mask); + return 1; + } + } + + list_del_init(&poll->wait.entry); + queue_work(ctx->sqo_wq, &req->work); + return 1; +} + +struct io_poll_table { + struct poll_table_struct pt; + struct io_kiocb *req; + int error; +}; + +static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head, + struct poll_table_struct *p) +{ + struct io_poll_table *pt = container_of(p, struct io_poll_table, pt); + + if (unlikely(pt->req->poll.head)) { + pt->error = -EINVAL; + return; + } + + pt->error = 0; + pt->req->poll.head = head; + add_wait_queue(head, &pt->req->poll.wait); +} + +static int io_poll_add(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_poll_iocb *poll = &req->poll; + struct io_ring_ctx *ctx = req->ctx; + struct io_poll_table ipt; + unsigned flags; + __poll_t mask; + u16 events; + int fd; + + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; + if (sqe->addr || sqe->ioprio || sqe->off || sqe->len || sqe->buf_index) + return -EINVAL; + + INIT_WORK(&req->work, io_poll_complete_work); + events = READ_ONCE(sqe->poll_events); + poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP; + + flags = READ_ONCE(sqe->flags); + fd = READ_ONCE(sqe->fd); + + if (flags & IOSQE_FIXED_FILE) { + if (unlikely(!ctx->user_files || fd >= ctx->nr_user_files)) + return -EBADF; + poll->file = ctx->user_files[fd]; + req->flags |= REQ_F_FIXED_FILE; + } else { + poll->file = fget(fd); + } + if (unlikely(!poll->file)) + return -EBADF; + + poll->head = NULL; + poll->woken = false; + poll->canceled = false; + + ipt.pt._qproc = io_poll_queue_proc; + ipt.pt._key = poll->events; + ipt.req = req; + ipt.error = -EINVAL; /* same as no support for IOCB_CMD_POLL */ + + /* initialized the list so that we can do list_empty checks */ + INIT_LIST_HEAD(&poll->wait.entry); + init_waitqueue_func_entry(&poll->wait, io_poll_wake); + + /* one for removal from waitqueue, one for this function */ + refcount_set(&req->refs, 2); + + mask = vfs_poll(poll->file, &ipt.pt) & poll->events; + if (unlikely(!poll->head)) { + /* we did not manage to set up a waitqueue, done */ + goto out; + } + + spin_lock_irq(&ctx->completion_lock); + spin_lock(&poll->head->lock); + if (poll->woken) { + /* wake_up context handles the rest */ + mask = 0; + ipt.error = 0; + } else if (mask || ipt.error) { + /* if we get an error or a mask we are done */ + WARN_ON_ONCE(list_empty(&poll->wait.entry)); + list_del_init(&poll->wait.entry); + } else { + /* actually waiting for an event */ + list_add_tail(&req->list, &ctx->cancel_list); + } + spin_unlock(&poll->head->lock); + spin_unlock_irq(&ctx->completion_lock); + +out: + if (unlikely(ipt.error)) { + if (!(flags & IOSQE_FIXED_FILE)) + fput(poll->file); + /* + * Drop one of our refs to this req, __io_submit_sqe() will + * drop the other one since we're returning an error. + */ + io_free_req(req); + return ipt.error; + } + + if (mask) + io_poll_complete(req, mask); + io_free_req(req); + return 0; +} + static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, const struct sqe_submit *s, bool force_nonblock, struct io_submit_state *state) @@ -1093,6 +1345,12 @@ static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, case IORING_OP_FSYNC: ret = io_fsync(req, s->sqe, force_nonblock); break; + case IORING_OP_POLL_ADD: + ret = io_poll_add(req, s->sqe); + break; + case IORING_OP_POLL_REMOVE: + ret = io_poll_remove(req, s->sqe); + break; default: ret = -EINVAL; break; @@ -2081,6 +2339,7 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) percpu_ref_kill(&ctx->refs); mutex_unlock(&ctx->uring_lock); + io_poll_remove_all(ctx); io_iopoll_reap_events(ctx); wait_for_completion(&ctx->ctx_done); io_ring_ctx_free(ctx); diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 0ec74bab8dbe..e23408692118 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -25,6 +25,7 @@ struct io_uring_sqe { union { __kernel_rwf_t rw_flags; __u32 fsync_flags; + __u16 poll_events; }; __u64 user_data; /* data to be passed back at completion time */ union { @@ -51,6 +52,8 @@ struct io_uring_sqe { #define IORING_OP_FSYNC 3 #define IORING_OP_READ_FIXED 4 #define IORING_OP_WRITE_FIXED 5 +#define IORING_OP_POLL_ADD 6 +#define IORING_OP_POLL_REMOVE 7 /* * sqe->fsync_flags From patchwork Mon Feb 11 19:00:48 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806701 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4E560746 for ; Mon, 11 Feb 2019 19:01:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3EC60293A8 for ; Mon, 11 Feb 2019 19:01:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 32A752AE23; Mon, 11 Feb 2019 19:01:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 30DB82A166 for ; Mon, 11 Feb 2019 19:01:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387495AbfBKTBb (ORCPT ); Mon, 11 Feb 2019 14:01:31 -0500 Received: from mail-it1-f196.google.com ([209.85.166.196]:37110 "EHLO mail-it1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387479AbfBKTBa (ORCPT ); Mon, 11 Feb 2019 14:01:30 -0500 Received: by mail-it1-f196.google.com with SMTP id b5so916309iti.2 for ; Mon, 11 Feb 2019 11:01:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=dR9zfDOVcdqDjymCroOlYbc9PPo0y7QrVWMjVOKoMiA=; b=vSbty8NJ/RcwcYCXuoONpqX8H5qqFGA17ZLdrSUA/IAYGL70ms1Yfr2ex6TmqY8mhg kuoKvEOrdXLxix29A9PS26K5SRQ2G0u+jkBHbPsWlAvqbVTNWqmch+95P00TTJf1CNbN gxjibUwJq9t/S9Hk46Re6UaUj9AceVvp04lLDUmLkZQDTIHPPveyD3eDOdz9T1FfXNje i3dYApAwVsI5nF6nqGY2z2eyc/L7gZfuGZ+O4hN7WIKAuUwIGsbs2ekKmQNr16CoJmLT twQN143b3rfK439mng95natOzhW5aa5Mki2Ehi9xZlVtVBkxJ7jxE4fppcXJR0fUBl6n O1lA== 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; bh=dR9zfDOVcdqDjymCroOlYbc9PPo0y7QrVWMjVOKoMiA=; b=Y2LCH0fNsST+yAtM7DGAN5z1JATrWUWSVxOum5yDwXHHLtKZQXix9zMagsYlyveTEA VG9oZ/ZKmUeHXZ9AzFbe1SgutoYILtLotqzQecoGCKNtF3tWUWHbyCDqemm1k0jXvN7K 4l8WbnDx6iqsuoJL7IyYxAgNDtjQBPXovD5R2IrsV/QGrL+K9HSNbvIRV39u0T36Ly8D zGZSzrQXtq/Ege9zI1ptwSPB6pUh4InDs1/eBXlPT011ZMKCD0nOst4nphYtetVr0izr FWVSY6bRiWSAbNrsb2qXxvCe+bN1yMBBYWCKSsN7WHDFPvdIxpYv3ViojI5b8oLS7Lk0 +jKg== X-Gm-Message-State: AHQUAuZ5jAIY2F+mBB+85lX/V/OT7VlSyq8Gh7MRzzjVIGHsoSDgR1NG lBoYlEbuxHEhRApZrN5hfpoKgA== X-Google-Smtp-Source: AHgI3IauvODBsw8bUTwPmwe8GEbeESTa0DxuV27xsuF8cUvYVg9lMhlQNFEjhYv0Lv49cXlIF79u5A== X-Received: by 2002:a24:5a8f:: with SMTP id v137mr547100ita.65.1549911688799; Mon, 11 Feb 2019 11:01:28 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.01.27 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:01:27 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 18/19] io_uring: allow workqueue item to handle multiple buffered requests Date: Mon, 11 Feb 2019 12:00:48 -0700 Message-Id: <20190211190049.7888-20-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Right now we punt any buffered request that ends up triggering an -EAGAIN to an async workqueue. This works fine in terms of providing async execution of them, but it also can create quite a lot of work queue items. For sequentially buffered IO, it's advantageous to serialize the issue of them. For reads, the first one will trigger a read-ahead, and subsequent request merely end up waiting on later pages to complete. For writes, devices usually respond better to streamed sequential writes. Add state to track the last buffered request we punted to a work queue, and if the next one is sequential to the previous, attempt to get the previous work item to handle it. We limit the number of sequential add-ons to the a multiple (8) of the max read-ahead size of the file. This should be a good number for both reads and wries, as it defines the max IO size the device can do directly. This drastically cuts down on the number of context switches we need to handle buffered sequential IO, and a basic test case of copying a big file with io_uring sees a 5x speedup. Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- fs/io_uring.c | 281 ++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 229 insertions(+), 52 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index a0513d4bc35d..ce446f59f092 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -94,6 +94,16 @@ struct io_mapped_ubuf { unsigned int nr_bvecs; }; +struct async_list { + spinlock_t lock; + atomic_t cnt; + struct list_head list; + + struct file *file; + off_t io_end; + size_t io_pages; +}; + struct io_ring_ctx { struct { struct percpu_ref refs; @@ -164,6 +174,8 @@ struct io_ring_ctx { struct list_head cancel_list; } ____cacheline_aligned_in_smp; + struct async_list pending_async[2]; + #if defined(CONFIG_UNIX) struct socket *ring_sock; #endif @@ -201,6 +213,7 @@ struct io_kiocb { #define REQ_F_FORCE_NONBLOCK 1 /* inline submission attempt */ #define REQ_F_IOPOLL_COMPLETED 2 /* polled IO has completed */ #define REQ_F_FIXED_FILE 4 /* ctx owns file */ +#define REQ_F_SEQ_PREV 8 /* sequential with previous */ u64 user_data; u64 error; @@ -257,6 +270,7 @@ static void io_ring_ctx_ref_free(struct percpu_ref *ref) static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) { struct io_ring_ctx *ctx; + int i; ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); if (!ctx) @@ -272,6 +286,11 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) init_completion(&ctx->ctx_done); mutex_init(&ctx->uring_lock); init_waitqueue_head(&ctx->wait); + for (i = 0; i < ARRAY_SIZE(ctx->pending_async); i++) { + spin_lock_init(&ctx->pending_async[i].lock); + INIT_LIST_HEAD(&ctx->pending_async[i].list); + atomic_set(&ctx->pending_async[i].cnt, 0); + } spin_lock_init(&ctx->completion_lock); INIT_LIST_HEAD(&ctx->poll_list); INIT_LIST_HEAD(&ctx->cancel_list); @@ -885,6 +904,47 @@ static int io_import_iovec(struct io_ring_ctx *ctx, int rw, return import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter); } +/* + * Make a note of the last file/offset/direction we punted to async + * context. We'll use this information to see if we can piggy back a + * sequential request onto the previous one, if it's still hasn't been + * completed by the async worker. + */ +static void io_async_list_note(int rw, struct io_kiocb *req, size_t len) +{ + struct async_list *async_list = &req->ctx->pending_async[rw]; + struct kiocb *kiocb = &req->rw; + struct file *filp = kiocb->ki_filp; + off_t io_end = kiocb->ki_pos + len; + + if (filp == async_list->file && kiocb->ki_pos == async_list->io_end) { + unsigned long max_pages; + + /* Use 8x RA size as a decent limiter for both reads/writes */ + max_pages = filp->f_ra.ra_pages; + if (!max_pages) + max_pages = VM_MAX_READAHEAD >> (PAGE_SHIFT - 10); + max_pages *= 8; + + /* If max pages are exceeded, reset the state */ + len >>= PAGE_SHIFT; + if (async_list->io_pages + len <= max_pages) { + req->flags |= REQ_F_SEQ_PREV; + async_list->io_pages += len; + } else { + io_end = 0; + async_list->io_pages = 0; + } + } + + /* New file? Reset state. */ + if (async_list->file != filp) { + async_list->io_pages = 0; + async_list->file = filp; + } + async_list->io_end = io_end; +} + static ssize_t io_read(struct io_kiocb *req, const struct sqe_submit *s, bool force_nonblock, struct io_submit_state *state) { @@ -892,6 +952,7 @@ static ssize_t io_read(struct io_kiocb *req, const struct sqe_submit *s, struct kiocb *kiocb = &req->rw; struct iov_iter iter; struct file *file; + size_t iov_count; ssize_t ret; ret = io_prep_rw(req, s, force_nonblock, state); @@ -910,16 +971,24 @@ static ssize_t io_read(struct io_kiocb *req, const struct sqe_submit *s, if (ret) goto out_fput; - ret = rw_verify_area(READ, file, &kiocb->ki_pos, iov_iter_count(&iter)); + iov_count = iov_iter_count(&iter); + ret = rw_verify_area(READ, file, &kiocb->ki_pos, iov_count); if (!ret) { ssize_t ret2; /* Catch -EAGAIN return for forced non-blocking submission */ ret2 = call_read_iter(file, kiocb, &iter); - if (!force_nonblock || ret2 != -EAGAIN) + if (!force_nonblock || ret2 != -EAGAIN) { io_rw_done(kiocb, ret2); - else + } else { + /* + * If ->needs_lock is true, we're already in async + * context. + */ + if (!s->needs_lock) + io_async_list_note(READ, req, iov_count); ret = -EAGAIN; + } } kfree(iovec); out_fput: @@ -936,14 +1005,12 @@ static ssize_t io_write(struct io_kiocb *req, const struct sqe_submit *s, struct kiocb *kiocb = &req->rw; struct iov_iter iter; struct file *file; + size_t iov_count; ssize_t ret; ret = io_prep_rw(req, s, force_nonblock, state); if (ret) return ret; - /* Hold on to the file for -EAGAIN */ - if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT)) - return -EAGAIN; ret = -EBADF; file = kiocb->ki_filp; @@ -957,8 +1024,17 @@ static ssize_t io_write(struct io_kiocb *req, const struct sqe_submit *s, if (ret) goto out_fput; - ret = rw_verify_area(WRITE, file, &kiocb->ki_pos, - iov_iter_count(&iter)); + iov_count = iov_iter_count(&iter); + + ret = -EAGAIN; + if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT)) { + /* If ->needs_lock is true, we're already in async context. */ + if (!s->needs_lock) + io_async_list_note(WRITE, req, iov_count); + goto out_free; + } + + ret = rw_verify_area(WRITE, file, &kiocb->ki_pos, iov_count); if (!ret) { /* * Open-code file_start_write here to grab freeze protection, @@ -976,9 +1052,11 @@ static ssize_t io_write(struct io_kiocb *req, const struct sqe_submit *s, kiocb->ki_flags |= IOCB_WRITE; io_rw_done(kiocb, call_write_iter(file, kiocb, &iter)); } +out_free: kfree(iovec); out_fput: - if (unlikely(ret)) + /* Hold on to the file for -EAGAIN */ + if (unlikely(ret && ret != -EAGAIN)) io_fput(req); return ret; } @@ -1374,6 +1452,21 @@ static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, return 0; } +static struct async_list *io_async_list_from_sqe(struct io_ring_ctx *ctx, + const struct io_uring_sqe *sqe) +{ + switch (sqe->opcode) { + case IORING_OP_READV: + case IORING_OP_READ_FIXED: + return &ctx->pending_async[READ]; + case IORING_OP_WRITEV: + case IORING_OP_WRITE_FIXED: + return &ctx->pending_async[WRITE]; + default: + return NULL; + } +} + static inline bool io_sqe_needs_user(const struct io_uring_sqe *sqe) { u8 opcode = READ_ONCE(sqe->opcode); @@ -1385,61 +1478,138 @@ static inline bool io_sqe_needs_user(const struct io_uring_sqe *sqe) static void io_sq_wq_submit_work(struct work_struct *work) { struct io_kiocb *req = container_of(work, struct io_kiocb, work); - struct sqe_submit *s = &req->submit; - const struct io_uring_sqe *sqe = s->sqe; struct io_ring_ctx *ctx = req->ctx; + struct mm_struct *cur_mm = NULL; + struct async_list *async_list; + LIST_HEAD(req_list); mm_segment_t old_fs; - bool needs_user; int ret; - /* Ensure we clear previously set forced non-block flag */ - req->flags &= ~REQ_F_FORCE_NONBLOCK; - req->rw.ki_flags &= ~IOCB_NOWAIT; + async_list = io_async_list_from_sqe(ctx, req->submit.sqe); +restart: + do { + struct sqe_submit *s = &req->submit; + const struct io_uring_sqe *sqe = s->sqe; + + /* Ensure we clear previously set forced non-block flag */ + req->flags &= ~REQ_F_FORCE_NONBLOCK; + req->rw.ki_flags &= ~IOCB_NOWAIT; - s->needs_lock = true; - s->has_user = false; + ret = 0; + if (io_sqe_needs_user(sqe) && !cur_mm) { + if (!mmget_not_zero(ctx->sqo_mm)) { + ret = -EFAULT; + } else { + cur_mm = ctx->sqo_mm; + use_mm(cur_mm); + old_fs = get_fs(); + set_fs(USER_DS); + } + } + + if (!ret) { + s->has_user = cur_mm != NULL; + s->needs_lock = true; + do { + ret = __io_submit_sqe(ctx, req, s, false, NULL); + /* + * We can get EAGAIN for polled IO even though + * we're forcing a sync submission from here, + * since we can't wait for request slots on the + * block side. + */ + if (ret != -EAGAIN) + break; + cond_resched(); + } while (1); + } + if (ret) { + io_cqring_add_event(ctx, sqe->user_data, ret, 0); + io_free_req(req); + } + + /* async context always use a copy of the sqe */ + kfree(sqe); + + if (!async_list) + break; + if (!list_empty(&req_list)) { + req = list_first_entry(&req_list, struct io_kiocb, + list); + list_del(&req->list); + continue; + } + if (list_empty(&async_list->list)) + break; + + req = NULL; + spin_lock(&async_list->lock); + if (list_empty(&async_list->list)) { + spin_unlock(&async_list->lock); + break; + } + list_splice_init(&async_list->list, &req_list); + spin_unlock(&async_list->lock); + + req = list_first_entry(&req_list, struct io_kiocb, list); + list_del(&req->list); + } while (req); /* - * If we're doing IO to fixed buffers, we don't need to get/set - * user context + * Rare case of racing with a submitter. If we find the count has + * dropped to zero AND we have pending work items, then restart + * the processing. This is a tiny race window. */ - needs_user = io_sqe_needs_user(s->sqe); - if (needs_user) { - if (!mmget_not_zero(ctx->sqo_mm)) { - ret = -EFAULT; - goto err; + if (async_list) { + ret = atomic_dec_return(&async_list->cnt); + while (!ret && !list_empty(&async_list->list)) { + spin_lock(&async_list->lock); + atomic_inc(&async_list->cnt); + list_splice_init(&async_list->list, &req_list); + spin_unlock(&async_list->lock); + + if (!list_empty(&req_list)) { + req = list_first_entry(&req_list, + struct io_kiocb, list); + list_del(&req->list); + goto restart; + } + ret = atomic_dec_return(&async_list->cnt); } - use_mm(ctx->sqo_mm); - old_fs = get_fs(); - set_fs(USER_DS); - s->has_user = true; } - do { - ret = __io_submit_sqe(ctx, req, s, false, NULL); - /* - * We can get EAGAIN for polled IO even though we're forcing - * a sync submission from here, since we can't wait for - * request slots on the block side. - */ - if (ret != -EAGAIN) - break; - cond_resched(); - } while (1); - - if (needs_user) { + if (cur_mm) { set_fs(old_fs); - unuse_mm(ctx->sqo_mm); - mmput(ctx->sqo_mm); - } -err: - if (ret) { - io_cqring_add_event(ctx, sqe->user_data, ret, 0); - io_free_req(req); + unuse_mm(cur_mm); + mmput(cur_mm); } +} - /* async context always use a copy of the sqe */ - kfree(sqe); +/* + * See if we can piggy back onto previously submitted work, that is still + * running. We currently only allow this if the new request is sequential + * to the previous one we punted. + */ +static bool io_add_to_prev_work(struct async_list *list, struct io_kiocb *req) +{ + bool ret = false; + + if (!list) + return false; + if (!(req->flags & REQ_F_SEQ_PREV)) + return false; + if (!atomic_read(&list->cnt)) + return false; + + ret = true; + spin_lock(&list->lock); + list_add_tail(&req->list, &list->list); + if (!atomic_read(&list->cnt)) { + list_del_init(&req->list); + ret = false; + } + spin_unlock(&list->lock); + return ret; } static int io_submit_sqe(struct io_ring_ctx *ctx, struct sqe_submit *s, @@ -1464,12 +1634,19 @@ static int io_submit_sqe(struct io_ring_ctx *ctx, struct sqe_submit *s, sqe_copy = kmalloc(sizeof(*sqe_copy), GFP_KERNEL); if (sqe_copy) { + struct async_list *list; + memcpy(sqe_copy, s->sqe, sizeof(*sqe_copy)); s->sqe = sqe_copy; memcpy(&req->submit, s, sizeof(*s)); - INIT_WORK(&req->work, io_sq_wq_submit_work); - queue_work(ctx->sqo_wq, &req->work); + list = io_async_list_from_sqe(ctx, s->sqe); + if (!io_add_to_prev_work(list, req)) { + if (list) + atomic_inc(&list->cnt); + INIT_WORK(&req->work, io_sq_wq_submit_work); + queue_work(ctx->sqo_wq, &req->work); + } ret = 0; } } From patchwork Mon Feb 11 19:00:49 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 10806699 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 225BD17FB for ; Mon, 11 Feb 2019 19:01:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1578F293A8 for ; Mon, 11 Feb 2019 19:01:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 09DA82B23D; Mon, 11 Feb 2019 19:01:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6DFA82AE23 for ; Mon, 11 Feb 2019 19:01:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733306AbfBKTBb (ORCPT ); Mon, 11 Feb 2019 14:01:31 -0500 Received: from mail-it1-f196.google.com ([209.85.166.196]:55349 "EHLO mail-it1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387489AbfBKTBb (ORCPT ); Mon, 11 Feb 2019 14:01:31 -0500 Received: by mail-it1-f196.google.com with SMTP id f18so844293itb.5 for ; Mon, 11 Feb 2019 11:01:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=dMslq0N8X0t1H0ZLeYb4gEGrDwD3teAaU8eAnimA430=; b=mUGWBufn4wcyW+HO0KyTqNIVRGzO3XqzBm/LtFbCITxllraKTtIQ+E77/tcV6nQxy9 ZqWUr/3RuG4mzPaDhiocvNQWidwcHhpMUyG3ptAZ0U+Z5NU3oIero/P5dD8xJ15es38t lvbWbmt3u/OkR/nlOQ2UFez7GCHekTC7/4TGBc8oBAkl5c7UQiMNijRECkUcvoHQ8/1Q QwFu/FeLaFKk6z+HATuycUiG0hhfWiA47gNHSwGwWRN+2g5QLQViKyz4Jd+DQI6dS073 KgYqkRglV3ZUovDfFMD3KbjC4+Lw55xoGsdKzHukNdlakVHpkLWRmSx7rwPe+I6cXzE4 rmQQ== 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; bh=dMslq0N8X0t1H0ZLeYb4gEGrDwD3teAaU8eAnimA430=; b=obWt3r7g8caNI3Jhka9fnjQdh7vqXcMDIpK45accSja5bdpPHN2v414P3fAi52T2Yr MNVNURHs7BRVNNM4y2VuTZ4EmsPTYYoxTW42rprbHXh/5G+tn/TC5auWMq95uHsRjoQn wUftlIYhlVxKdt+r60l2aqo4HBhMY0YAjPtvqVlfJOCHeLJGiel3xLIKwaS5Qne/W/zb H5L7ot4OW9bj+4KWrF51o1IbQ7QdDPy5Hd6HGy2g2Iz68yHsxTkas6eaUe8WeqQTGmwL ctyg6RE5LINoV+ExRaeqvBEZkHFICigx21czMZzMSm0u8Q3uJt6zjA5qHL6JBbmyzYUr XKSA== X-Gm-Message-State: AHQUAuaZWCH3SdHYsQrKbQXl7iSJZQJOgFzK0NRvzlY778vZNUZ7YusT 3NzVwtAWOcKz5oeQS5WSfgKFcd638bsg4Q== X-Google-Smtp-Source: AHgI3IY+Cyoy72RcMCSAyVY0KhC9DiD4rvauwBtj7oHyWgWqcTzq3XmtTgNsI9BzlFMySxx2hPba8A== X-Received: by 2002:a5e:df03:: with SMTP id f3mr17491310ioq.292.1549911690399; Mon, 11 Feb 2019 11:01:30 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h184sm62446ith.41.2019.02.11.11.01.28 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 11:01:29 -0800 (PST) From: Jens Axboe To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, viro@ZenIV.linux.org.uk, Jens Axboe Subject: [PATCH 19/19] io_uring: add io_uring_event cache hit information Date: Mon, 11 Feb 2019 12:00:49 -0700 Message-Id: <20190211190049.7888-21-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190211190049.7888-1-axboe@kernel.dk> References: <20190211190049.7888-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add hint on whether a read was served out of the page cache, or if it hit media. This is useful for buffered async IO, O_DIRECT reads would never have this set (for obvious reasons). If the read hit page cache, cqe->flags will have IOCQE_FLAG_CACHEHIT set. Signed-off-by: Jens Axboe --- fs/io_uring.c | 7 ++++++- include/uapi/linux/io_uring.h | 5 +++++ 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index ce446f59f092..a4973af1c272 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -611,11 +611,16 @@ static void io_fput(struct io_kiocb *req) static void io_complete_rw(struct kiocb *kiocb, long res, long res2) { struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw); + unsigned ev_flags = 0; kiocb_end_write(kiocb); io_fput(req); - io_cqring_add_event(req->ctx, req->user_data, res, 0); + + if (res > 0 && (req->flags & REQ_F_FORCE_NONBLOCK)) + ev_flags = IOCQE_FLAG_CACHEHIT; + + io_cqring_add_event(req->ctx, req->user_data, res, ev_flags); io_free_req(req); } diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index e23408692118..24906e99fdc7 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -69,6 +69,11 @@ struct io_uring_cqe { __u32 flags; }; +/* + * io_uring_event->flags + */ +#define IOCQE_FLAG_CACHEHIT (1U << 0) /* IO did not hit media */ + /* * Magic offsets for the application to mmap the data it needs */