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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 889EBC001DE for ; Mon, 24 Jul 2023 06:18:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230190AbjGXGSG (ORCPT ); Mon, 24 Jul 2023 02:18:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52546 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230245AbjGXGSF (ORCPT ); Mon, 24 Jul 2023 02:18:05 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C50D8B9 for ; Sun, 23 Jul 2023 23:18:01 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 552A060F09 for ; Mon, 24 Jul 2023 06:18:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 621B0C433C8; Mon, 24 Jul 2023 06:18:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1690179480; bh=5c7xb0IHx3JZ5+B8JPct/wn8FfV5uYxV2ycb1eSNZyY=; h=Subject:To:Cc:From:Date:From; b=K3TuKP6lZAfmMME/suE/xLy58l79G9UH/ll94tv7MjUBcwXGljbDOBQxvDO1/3/um RW7n9D7WbS25iKGYCIRq86qJ7hgnrjt4iMjucF98pKzI6wf+HhS9PuvZdoGFLp59MR FNleXcwu+rX5+BpxqDVgRZ+BSXQDQdt0xnXbZtE4= Subject: FAILED: patch "[PATCH] ext4: fix off by one issue in" failed to apply to 6.4-stable tree To: ojaswin@linux.ibm.com, tytso@mit.edu Cc: From: Date: Mon, 24 Jul 2023 08:17:57 +0200 Message-ID: <2023072456-starting-gauging-768c@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 6.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.4.y git checkout FETCH_HEAD git cherry-pick -x 5d5460fa7932bed3a9082a6a8852cfbdb46acbe8 # git commit -s git send-email --to '' --in-reply-to '2023072456-starting-gauging-768c@gregkh' --subject-prefix 'PATCH 6.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 5d5460fa7932bed3a9082a6a8852cfbdb46acbe8 Mon Sep 17 00:00:00 2001 From: Ojaswin Mujoo Date: Fri, 9 Jun 2023 16:04:03 +0530 Subject: [PATCH] ext4: fix off by one issue in ext4_mb_choose_next_group_best_avail() In ext4_mb_choose_next_group_best_avail(), we want the start order to be 1 less than goal length and the min_order to be, at max, 1 more than the original length. This commit fixes an off by one issue that arose due to the fact that 1 << fls(n) > (n). After all the processing: order = 1 order below goal len min_order = maximum of the three:- - order - trim_order - 1 order below B2C(s_stripe) - 1 order above original len Cc: stable@kernel.org Fixes: 33122aa930 ("ext4: Add allocation criteria 1.5 (CR1_5)") Signed-off-by: Ojaswin Mujoo Link: https://lore.kernel.org/r/20230609103403.112807-1-ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index a2475b8c9fb5..456150ef6111 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -1006,14 +1006,11 @@ static void ext4_mb_choose_next_group_best_avail(struct ext4_allocation_context * fls() instead since we need to know the actual length while modifying * goal length. */ - order = fls(ac->ac_g_ex.fe_len); + order = fls(ac->ac_g_ex.fe_len) - 1; min_order = order - sbi->s_mb_best_avail_max_trim_order; if (min_order < 0) min_order = 0; - if (1 << min_order < ac->ac_o_ex.fe_len) - min_order = fls(ac->ac_o_ex.fe_len) + 1; - if (sbi->s_stripe > 0) { /* * We are assuming that stripe size is always a multiple of @@ -1021,9 +1018,16 @@ static void ext4_mb_choose_next_group_best_avail(struct ext4_allocation_context */ num_stripe_clusters = EXT4_NUM_B2C(sbi, sbi->s_stripe); if (1 << min_order < num_stripe_clusters) - min_order = fls(num_stripe_clusters); + /* + * We consider 1 order less because later we round + * up the goal len to num_stripe_clusters + */ + min_order = fls(num_stripe_clusters) - 1; } + if (1 << min_order < ac->ac_o_ex.fe_len) + min_order = fls(ac->ac_o_ex.fe_len); + for (i = order; i >= min_order; i--) { int frag_order; /*