From patchwork Thu Jun 2 08:21:29 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 12867628 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id CC4C5C43334 for ; Thu, 2 Jun 2022 08:08:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1BAE26B0072; Thu, 2 Jun 2022 04:08:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 169AC6B0074; Thu, 2 Jun 2022 04:08:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 07BFF6B0075; Thu, 2 Jun 2022 04:08:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id E98426B0072 for ; Thu, 2 Jun 2022 04:08:11 -0400 (EDT) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id C220B608C3 for ; Thu, 2 Jun 2022 08:08:11 +0000 (UTC) X-FDA: 79532567982.12.92DD0C0 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by imf13.hostedemail.com (Postfix) with ESMTP id 310FC20070 for ; Thu, 2 Jun 2022 08:07:36 +0000 (UTC) Received: from kwepemi500025.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4LDJTR4TJ2zRhYy; Thu, 2 Jun 2022 16:04:59 +0800 (CST) Received: from kwepemm600009.china.huawei.com (7.193.23.164) by kwepemi500025.china.huawei.com (7.221.188.170) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 2 Jun 2022 16:08:06 +0800 Received: from huawei.com (10.175.127.227) by kwepemm600009.china.huawei.com (7.193.23.164) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 2 Jun 2022 16:08:05 +0800 From: Yu Kuai To: , , CC: , , , , , Subject: [PATCH -next] mm/filemap: fix that first page is not mark accessed in filemap_read() Date: Thu, 2 Jun 2022 16:21:29 +0800 Message-ID: <20220602082129.2805890-1-yukuai3@huawei.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemm600009.china.huawei.com (7.193.23.164) X-CFilter-Loop: Reflected X-Stat-Signature: 3efssa6o4hi3njw11iz6zh1t46mc3a34 X-Rspam-User: Authentication-Results: imf13.hostedemail.com; dkim=none; spf=pass (imf13.hostedemail.com: domain of yukuai3@huawei.com designates 45.249.212.188 as permitted sender) smtp.mailfrom=yukuai3@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 310FC20070 X-HE-Tag: 1654157256-176428 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000027, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: In filemap_read(), 'ra->prev_pos' is set to 'iocb->ki_pos + copied', while it should be 'iocb->ki_ops'. For consequence, folio_mark_accessed() will not be called for 'fbatch.folios[0]' since 'iocb->ki_pos' is always equal to 'ra->prev_pos'. Fixes: 06c0444290ce ("mm/filemap.c: generic_file_buffered_read() now uses find_get_pages_contig") Signed-off-by: Yu Kuai Reported-by: Yu Kuai Signed-off-by: Kent Overstreet Reported-by: kernel test robot --- mm/filemap.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index 9daeaab36081..0b776e504d35 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2728,10 +2728,11 @@ ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *iter, flush_dcache_folio(folio); copied = copy_folio_to_iter(folio, offset, bytes, iter); - - already_read += copied; - iocb->ki_pos += copied; - ra->prev_pos = iocb->ki_pos; + if (copied) { + ra->prev_pos = iocb->ki_pos; + already_read += copied; + iocb->ki_pos += copied; + } if (copied < bytes) { error = -EFAULT;