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 7BC6FC4332F for ; Mon, 15 Nov 2021 19:05:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 62712633F3 for ; Mon, 15 Nov 2021 19:05:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243977AbhKOTIP (ORCPT ); Mon, 15 Nov 2021 14:08:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:57854 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231428AbhKORlr (ORCPT ); Mon, 15 Nov 2021 12:41:47 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id DF052632F0; Mon, 15 Nov 2021 17:27:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1636997242; bh=TxN76q50vqjwJgelsAA/eoQ3t0Y9uTwPbHLLF9WTJkQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q56JKfYwd09R/bQV7qyEk5mys/1QChhMg6NC0rSZ6Us7yHSCuu72gAPWbOCmiQkob yllxyCMeuuvkgYmZG0gdpcgzzBfaBaNIlJbtBQ52HH/THqu9JsBcLlUjkBOIcHqZaX W5TbgVjIytXJxCgnw46XEpgSKOCY3ChZebc6XepQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Shaoying Xu , Theodore Tso Subject: [PATCH 5.10 043/575] ext4: fix lazy initialization next schedule time computation in more granular unit Date: Mon, 15 Nov 2021 17:56:08 +0100 Message-Id: <20211115165345.125318943@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115165343.579890274@linuxfoundation.org> References: <20211115165343.579890274@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: linux-kernel@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 @@ -3436,9 +3436,9 @@ 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, @@ -3475,14 +3475,13 @@ 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;