From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38F63C433E0 for ; Sat, 23 May 2020 18:58:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E7F7F20872 for ; Sat, 23 May 2020 18:58:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="MWKaekWv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E7F7F20872 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id BA8C38000D; Sat, 23 May 2020 14:58:07 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AE55F80007; Sat, 23 May 2020 14:58:07 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 90F6D8000D; Sat, 23 May 2020 14:58:07 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0250.hostedemail.com [216.40.44.250]) by kanga.kvack.org (Postfix) with ESMTP id 78B5280007 for ; Sat, 23 May 2020 14:58:07 -0400 (EDT) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 3EF76824556B for ; Sat, 23 May 2020 18:58:07 +0000 (UTC) X-FDA: 76848893814.07.scarf79_29c40856d390a X-HE-Tag: scarf79_29c40856d390a X-Filterd-Recvd-Size: 5349 Received: from mail-pf1-f193.google.com (mail-pf1-f193.google.com [209.85.210.193]) by imf08.hostedemail.com (Postfix) with ESMTP for ; Sat, 23 May 2020 18:58:06 +0000 (UTC) Received: by mail-pf1-f193.google.com with SMTP id z26so6746791pfk.12 for ; Sat, 23 May 2020 11:58:06 -0700 (PDT) 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 :mime-version:content-transfer-encoding; bh=QLIKOC51UDi6y8ydZtCT2FsP1dt+ucWxar6wAIDn3TQ=; b=MWKaekWvtx+WTMH7SA8TxEwVGEMQRZ6Y3Djw7RNC7oEYUCXetIPXBjtiJgnyF71Y0b UMa3s3nv9VNBNz/E5zE58K6odN5gP1YpWtoRtR26Jtt0hxzlYhRsfCdDXvyf1atMh5bs o3zeYxTrMI80Xwj9+WtyiI7NO1qDg3KQpO4qdC3SwkxvfVqMOsKdB1CW997onc1jjj0s glvIv02sptmvS0nrlsCIZFZqjJuVPnwA32f5p/IDDJg82jymdpaM0DYrJhhfbQg3g/lN 7krBmUvtb5GR2kiVrgRdtyjFenuM4+KBhSnVAZc+Y4QeRkSFLNE8OUmPmx2atAUI+eH/ IZtQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=QLIKOC51UDi6y8ydZtCT2FsP1dt+ucWxar6wAIDn3TQ=; b=VF8S5AhNjrwXWOHO5HZ54LmmlGr71RS1csTWwj9wtjxDsCVbvHiAfSQbU+I4Vg7Y/t OceJYjjv1N17xS/sAkBE0GxYYwEJLkl6xZKl+4Jth2QJ0ntvscri2QCfTgYkg/SKEy4A /BOmLTcFUpHNt1RLmTe8f7a1GcxWI4eDw0FiBbTbd50IVPNx1GQ3pQD44B3wuoX9Pb08 QMJCfxvPAKuy813aw0TtgK0IextL4UMs5aEdQpWMf4bRvL0GiBD30mW/7qRdlRT2ycth Up7arbTCh7YogSd1t3TA5kwy91AJLrGlR6f7kQHbXebsSA6hyFODxSMT7eXHrbf2XZ20 y3eA== X-Gm-Message-State: AOAM533pKF2iblRF11vu4wnnxJDvPTj7ftpNaqvnTC3m2YyxUaXbQQp0 yrKOQhQzbjQOqU418MbwtznaTUIATJLC8g== X-Google-Smtp-Source: ABdhPJxlGEJfDdI/CHMnwiSfxbLnvzCi9W829t09wDrbokAThLoEnwexsOcrvdVDPXc3WyV+F2HO2Q== X-Received: by 2002:a65:66d5:: with SMTP id c21mr18973961pgw.155.1590260285870; Sat, 23 May 2020 11:58:05 -0700 (PDT) Received: from x1.lan ([2605:e000:100e:8c61:c94:a67a:9209:cf5f]) by smtp.gmail.com with ESMTPSA id 25sm9297319pjk.50.2020.05.23.11.58.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 23 May 2020 11:58:05 -0700 (PDT) From: Jens Axboe To: io-uring@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Jens Axboe Subject: [PATCH 05/12] mm: support async buffered reads in generic_file_buffered_read() Date: Sat, 23 May 2020 12:57:48 -0600 Message-Id: <20200523185755.8494-6-axboe@kernel.dk> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200523185755.8494-1-axboe@kernel.dk> References: <20200523185755.8494-1-axboe@kernel.dk> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Use the async page locking infrastructure, if IOCB_WAITQ is set in the passed in iocb. The caller must expect an -EIOCBQUEUED return value, which means that IO is started but not done yet. This is similar to how O_DIRECT signals the same operation. Once the callback is received by the caller for IO completion, the caller must retry the operation. Signed-off-by: Jens Axboe --- mm/filemap.c | 33 ++++++++++++++++++++++++++------- 1 file changed, 26 insertions(+), 7 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index c746541b1d49..a3b86c9acdc8 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1219,6 +1219,14 @@ static int __wait_on_page_locked_async(struct page= *page, return ret; } =20 +static int wait_on_page_locked_async(struct page *page, + struct wait_page_queue *wait) +{ + if (!PageLocked(page)) + return 0; + return __wait_on_page_locked_async(compound_head(page), wait, false); +} + /** * put_and_wait_on_page_locked - Drop a reference and wait for it to be = unlocked * @page: The page to wait for. @@ -2058,17 +2066,25 @@ static ssize_t generic_file_buffered_read(struct = kiocb *iocb, index, last_index - index); } if (!PageUptodate(page)) { - if (iocb->ki_flags & IOCB_NOWAIT) { - put_page(page); - goto would_block; - } - /* * See comment in do_read_cache_page on why * wait_on_page_locked is used to avoid unnecessarily * serialisations and why it's safe. */ - error =3D wait_on_page_locked_killable(page); + if (iocb->ki_flags & IOCB_WAITQ) { + if (written) { + put_page(page); + goto out; + } + error =3D wait_on_page_locked_async(page, + iocb->private); + } else { + if (iocb->ki_flags & IOCB_NOWAIT) { + put_page(page); + goto would_block; + } + error =3D wait_on_page_locked_killable(page); + } if (unlikely(error)) goto readpage_error; if (PageUptodate(page)) @@ -2156,7 +2172,10 @@ static ssize_t generic_file_buffered_read(struct k= iocb *iocb, =20 page_not_up_to_date: /* Get exclusive access to the page ... */ - error =3D lock_page_killable(page); + if (iocb->ki_flags & IOCB_WAITQ) + error =3D lock_page_async(page, iocb->private); + else + error =3D lock_page_killable(page); if (unlikely(error)) goto readpage_error; =20 --=20 2.26.2