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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 AFCDFC433E6 for ; Wed, 24 Feb 2021 20:04:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 73CD064F30 for ; Wed, 24 Feb 2021 20:04:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235195AbhBXUEW (ORCPT ); Wed, 24 Feb 2021 15:04:22 -0500 Received: from mail.kernel.org ([198.145.29.99]:55458 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235395AbhBXUDD (ORCPT ); Wed, 24 Feb 2021 15:03:03 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0925164F0F; Wed, 24 Feb 2021 20:02:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1614196946; bh=50RIy6gSVGR+5nbDqH9C0gXkkbUIElU5fJL77nzYvfw=; h=Date:From:To:Subject:In-Reply-To:From; b=myw2uQA8sBOF5+XPNimNk9n/hQcCGChZz6qld3KilPpUFsrnTcm6I2YEIs/KPMmBC /g8aL1SfEGHauHXNZTKdhUDJyorFoSdKRSENeAtFV0b0eVfFR3z6hjhnPvFFCKsoaj dnvr4UUUwpuZ84MnhS9nmeAkEsKS9CMnHyRB3Nx0= Date: Wed, 24 Feb 2021 12:02:25 -0800 From: Andrew Morton To: akpm@linux-foundation.org, hch@lst.de, kent.overstreet@gmail.com, linmiaohe@huawei.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, willy@infradead.org Subject: [patch 041/173] mm/filemap: move the iocb checks into filemap_update_page Message-ID: <20210224200225.5JimbKIaH%akpm@linux-foundation.org> In-Reply-To: <20210224115824.1e289a6895087f10c41dd8d6@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: "Matthew Wilcox (Oracle)" Subject: mm/filemap: move the iocb checks into filemap_update_page We don't need to give up when a non-blocking request sees a !Uptodate page. We may be able to satisfy the read from a partially-uptodate page. Link: https://lkml.kernel.org/r/20210122160140.223228-13-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Kent Overstreet Reviewed-by: Christoph Hellwig Cc: Miaohe Lin Signed-off-by: Andrew Morton --- mm/filemap.c | 24 ++++++++++-------------- 1 file changed, 10 insertions(+), 14 deletions(-) --- a/mm/filemap.c~mm-filemap-move-the-iocb-checks-into-filemap_update_page +++ a/mm/filemap.c @@ -2240,15 +2240,16 @@ static int filemap_update_page(struct ki struct inode *inode = mapping->host; int error; - if (iocb->ki_flags & IOCB_WAITQ) { - error = lock_page_async(page, iocb->ki_waitq); - if (error) - return error; - } else { - if (!trylock_page(page)) { + if (!trylock_page(page)) { + if (iocb->ki_flags & (IOCB_NOWAIT | IOCB_NOIO)) + return -EAGAIN; + if (!(iocb->ki_flags & IOCB_WAITQ)) { put_and_wait_on_page_locked(page, TASK_KILLABLE); return AOP_TRUNCATED_PAGE; } + error = __lock_page_async(page, iocb->ki_waitq); + if (error) + return error; } if (!page->mapping) @@ -2366,14 +2367,9 @@ got_pages: } if (!PageUptodate(page)) { - if ((iocb->ki_flags & IOCB_NOWAIT) || - ((iocb->ki_flags & IOCB_WAITQ) && pvec->nr > 1)) { - put_page(page); - pvec->nr--; - err = -EAGAIN; - goto err; - } - + if ((iocb->ki_flags & IOCB_WAITQ) && + pagevec_count(pvec) > 1) + iocb->ki_flags |= IOCB_NOWAIT; err = filemap_update_page(iocb, mapping, iter, page, pg_pos, pg_count); if (err) { _