From patchwork Fri May 22 20:23:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 11566163 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 72BAA14B7 for ; Fri, 22 May 2020 20:24:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5AC7C207CB for ; Fri, 22 May 2020 20:24:04 +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="XR1Hfpng" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731052AbgEVUYA (ORCPT ); Fri, 22 May 2020 16:24:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52568 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731057AbgEVUXY (ORCPT ); Fri, 22 May 2020 16:23:24 -0400 Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B2AC3C05BD43 for ; Fri, 22 May 2020 13:23:23 -0700 (PDT) Received: by mail-pj1-x1043.google.com with SMTP id q24so5460414pjd.1 for ; Fri, 22 May 2020 13:23:23 -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=pk0mOQuIM8W3goGTEUJ7lPQkF+2EvbiQPRxtP96y/VQ=; b=XR1Hfpngk92X60W6mtjRxmwWQjUpXxr57sMRlRMp6WKXl0EGRM1SyAOYAgYY/8k15p InaZ+j7vcNDYMPyNeT3pDlSC7+7MpYvudX2nOoV8UHce1YTszpzP9mKmUYM9+1SSZXq5 luaLISz3wcOf7+VgrtBaX5me2bW3GJ2GmAjc5UYbYKCQVBBAfA0DmjLo7fD31fEdUXGr jHzVrF/TM6JPGmvwNE0mpRc+1IJz9vT6u7Y4z3e0+t6sID85Socj7145P1lc8My6fsi2 kejNXdw85Mje1pDKxQKcH2qKiA+KYZmlq8rNRp4E3T8t8Bj9P56S+c++YndQX8+ING/I WFPg== 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=pk0mOQuIM8W3goGTEUJ7lPQkF+2EvbiQPRxtP96y/VQ=; b=ZGHn1lYwDbhTDAZKLOynWrDQsYi9/V2IhXG/VsIV8di0yAiiu4rQPqbUQNffK/0jAH s3QMdU5r+4yA6CYJvGlVymIE9WE2bAz1o8lQcTK9tgbFNlsCFfM4cCsfhbENtRB7c1TG EJUhgB5kMwqQu46W1+/CDc59DJI4k+bA7BaOdMEVYphHSZ+Z30BOwBWCmLxmr+Wcs+Gy sKfbuG2/wiqZOPVunWqGE4K80Lnw70Jq5bWmUpFH+ijPoEDdqnbmuA71uJHSxpp/lx/3 R8WIXbtj1+Qr/b92pqGB8CNIaTkSYfnALt2eh3Gk+Az2SmF6aknoeI/nTVlrdoznWROa 7GKg== X-Gm-Message-State: AOAM533m491OeBRZYzTQKerMFaC4nyOpZYkyFrEI5AAKAZC4iQl6CDaI MfqCKnpyQy5VZ2bUt8XYEt3OIFFay5M= X-Google-Smtp-Source: ABdhPJwS7xFlgv35cRDBhVL35NxCpOL//x8P0nJbD9YCPQRRanDgUxHWeCBsTZZ0WIpa+r85qBpFhw== X-Received: by 2002:a17:90a:c594:: with SMTP id l20mr6422753pjt.123.1590179003224; Fri, 22 May 2020 13:23:23 -0700 (PDT) Received: from x1.lan ([2605:e000:100e:8c61:e0db:da55:b0a4:601]) by smtp.gmail.com with ESMTPSA id e19sm7295561pfn.17.2020.05.22.13.23.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 22 May 2020 13:23:22 -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 14:23:04 -0600 Message-Id: <20200522202311.10959-5-axboe@kernel.dk> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200522202311.10959-1-axboe@kernel.dk> References: <20200522202311.10959-1-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 0bc77f431bea..d9d65c74b2f0 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2074,17 +2074,25 @@ 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)) @@ -2172,7 +2180,10 @@ 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;