From patchwork Sat May 23 01:50:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 11566511 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 74F5D913 for ; Sat, 23 May 2020 01:51:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5DAAD2074B for ; Sat, 23 May 2020 01:51:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="z7HrSHy4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387561AbgEWBvH (ORCPT ); Fri, 22 May 2020 21:51:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46944 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387547AbgEWBvD (ORCPT ); Fri, 22 May 2020 21:51:03 -0400 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 03834C08C5C3 for ; Fri, 22 May 2020 18:51:03 -0700 (PDT) Received: by mail-pl1-x641.google.com with SMTP id u22so5100722plq.12 for ; Fri, 22 May 2020 18:51:02 -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=L1+j2GDKy7H0PZDITKGHQ/OK2MPTBbiVlQTxtSNa/Ns=; b=z7HrSHy4DQ2KZLhor2+yKvhwKT3M5/avWRT8S5R2AJrrVQ/VvR19prxLmKkLZNkWzq pHUgk9D6XUmUkOewAT1qi3cXjH9XC3tQueuJoJCrrykyAZZ+GOo3XUCGFcpuqJUu77Cz qk5yHlSqkNewDc77Jj62TymY5U/UdV7bywroR1YBrukWND7+OAWlQLM4T/pruKlF8ECE ovOPYa9TZGG1f8t1lGBZ7YpIwfOtGCnVq9R2LgjgwzOVpCW9Vx8hYR07sVJrBcwLrhzj MPtjnH9yMF6hgSftEGBDEHfwTDDM2yWJWVxvIHOfr8e5Wc+D/P6S2Jyk9whuX1JG/BB8 N9QQ== 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=L1+j2GDKy7H0PZDITKGHQ/OK2MPTBbiVlQTxtSNa/Ns=; b=sB2DTKuhYjvKpP86PLgGLFvrb6TM0MkIIAWlFPN/Mh+YRKqYYYyZ7M+dZPae7yUac4 wadxXuCoAtHSd58jHpOYJIka0faphbfegdjMqc+qMBCJRlIsT4pySd66hOebxP05F/8O KXBRHXv1y64XMx8jxjQtXTySqhjNO2HGLgltATqOnAqi/d23FLH5kqXzxn51edsheAFc PZUgSj/Kwa0gq+kY2OCUJxv0W2fRDRm2Tnza4LxNzgsieWV2GJL1PScQAfp+LrdNk6z5 CEhe5XqFj5BMkeMCfTbNeeovvkG91DyfOXCYkPVNTelLxPoah+/Hpr5qafoCS7yuPjLB MUuQ== X-Gm-Message-State: AOAM533+DuPv9vQYscT8iiZ5lr0DjE+lMsNlb9XywPtZQLQFJFlPTguy KtnF9GbZ/2mU8VaYv0tCK+kPpQ== X-Google-Smtp-Source: ABdhPJw9gKQXC8DtehX4lEQgYciMv55f8G+1qS4JkrtGXjBLDVm3iWFTcJNG1joBJBOAhIVEQbPUvQ== X-Received: by 2002:a17:90a:268f:: with SMTP id m15mr8317135pje.190.1590198662520; Fri, 22 May 2020 18:51:02 -0700 (PDT) Received: from x1.lan ([2605:e000:100e:8c61:e0db:da55:b0a4:601]) by smtp.gmail.com with ESMTPSA id a71sm8255477pje.0.2020.05.22.18.51.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 22 May 2020 18:51:02 -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 04/11] mm: support async buffered reads in generic_file_buffered_read() Date: Fri, 22 May 2020 19:50:42 -0600 Message-Id: <20200523015049.14808-5-axboe@kernel.dk> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200523015049.14808-1-axboe@kernel.dk> References: <20200523015049.14808-1-axboe@kernel.dk> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org 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 | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index a01daafd49fd..b49836ff0fdc 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2086,17 +2086,25 @@ 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 = wait_on_page_locked_killable(page); + if (iocb->ki_flags & IOCB_WAITQ) { + if (written) { + put_page(page); + goto out; + } + error = wait_on_page_locked_async(page, + iocb->private); + } else { + if (iocb->ki_flags & IOCB_NOWAIT) { + put_page(page); + goto would_block; + } + error = wait_on_page_locked_killable(page); + } if (unlikely(error)) goto readpage_error; if (PageUptodate(page)) @@ -2184,7 +2192,10 @@ static ssize_t generic_file_buffered_read(struct kiocb *iocb, page_not_up_to_date: /* Get exclusive access to the page ... */ - error = lock_page_killable(page); + if (iocb->ki_flags & IOCB_WAITQ) + error = lock_page_async(page, iocb->private); + else + error = lock_page_killable(page); if (unlikely(error)) goto readpage_error;