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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01219C433EF for ; Tue, 16 Nov 2021 01:06:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DDDE0615E6 for ; Tue, 16 Nov 2021 01:06:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238084AbhKPBHv (ORCPT ); Mon, 15 Nov 2021 20:07:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:44626 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245256AbhKOTTz (ORCPT ); Mon, 15 Nov 2021 14:19:55 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5DC8A63521; Mon, 15 Nov 2021 18:31:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1637001084; bh=2MIv9LiFEFxPbAnq85xfdVyJ9L97Z+7EsPlNHKKOsfs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sePEYwe5ycsRNzjsvziAMWvay4pNdWUY/yAc05NQUFUZC+vG1Vi6oW1luKShKpli6 aIDzlKemZEPrgdxmz1lPeoLwJ2ErqV0uwZeJSUhiSyVg3XWPI3aAZ7DVCCJqfE2j45 GD3Hqd4YLuqKIscWp74ElT/oQnj60qsm8V6I2iZ0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Shaoying Xu , Theodore Tso Subject: [PATCH 5.15 053/917] ext4: fix lazy initialization next schedule time computation in more granular unit Date: Mon, 15 Nov 2021 17:52:28 +0100 Message-Id: <20211115165430.567972602@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115165428.722074685@linuxfoundation.org> References: <20211115165428.722074685@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Shaoying Xu commit 39fec6889d15a658c3a3ebb06fd69d3584ddffd3 upstream. Ext4 file system has default lazy inode table initialization setup once it is mounted. However, it has issue on computing the next schedule time that makes the timeout same amount in jiffies but different real time in secs if with various HZ values. Therefore, fix by measuring the current time in a more granular unit nanoseconds and make the next schedule time independent of the HZ value. Fixes: bfff68738f1c ("ext4: add support for lazy inode table initialization") Signed-off-by: Shaoying Xu Cc: stable@vger.kernel.org Signed-off-by: Theodore Ts'o Link: https://lore.kernel.org/r/20210902164412.9994-2-shaoyi@amazon.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/ext4/super.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3263,9 +3263,9 @@ static int ext4_run_li_request(struct ex struct super_block *sb = elr->lr_super; ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count; ext4_group_t group = elr->lr_next_group; - unsigned long timeout = 0; unsigned int prefetch_ios = 0; int ret = 0; + u64 start_time; if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) { elr->lr_next_group = ext4_mb_prefetch(sb, group, @@ -3302,14 +3302,13 @@ static int ext4_run_li_request(struct ex ret = 1; if (!ret) { - timeout = jiffies; + start_time = ktime_get_real_ns(); ret = ext4_init_inode_table(sb, group, elr->lr_timeout ? 0 : 1); trace_ext4_lazy_itable_init(sb, group); if (elr->lr_timeout == 0) { - timeout = (jiffies - timeout) * - EXT4_SB(elr->lr_super)->s_li_wait_mult; - elr->lr_timeout = timeout; + elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) * + EXT4_SB(elr->lr_super)->s_li_wait_mult); } elr->lr_next_sched = jiffies + elr->lr_timeout; elr->lr_next_group = group + 1;