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 77784C433FE for ; Mon, 27 Sep 2021 17:04:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5CE85611EF for ; Mon, 27 Sep 2021 17:04:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236022AbhI0RGW (ORCPT ); Mon, 27 Sep 2021 13:06:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:44876 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235770AbhI0RFz (ORCPT ); Mon, 27 Sep 2021 13:05:55 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 60D5A6109F; Mon, 27 Sep 2021 17:04:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1632762257; bh=Ym3Vf9ttUlHucIgpHbJ2AKZ57nr98JcZFbq3K6pg2Nc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kaG9reToesE2yxeb8MZupED5VTvSkK0lqaopywd2zZDfxNSkFm+QT7iiV7HVgCAOD CKSkaC1sy1Z25Poj3/kOitid6zOAGuyVnyQgkUxO1nwQXYa31e/KWlITT4xD4fLBTi f24sZfV7+E6Rb+4AzAgym1EJ1tg+Qt/x5G4SGDc4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eli V , Anand Jain , Qu Wenruo , David Sterba Subject: [PATCH 5.4 21/68] btrfs: prevent __btrfs_dump_space_info() to underflow its free space Date: Mon, 27 Sep 2021 19:02:17 +0200 Message-Id: <20210927170220.686912121@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210927170219.901812470@linuxfoundation.org> References: <20210927170219.901812470@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: Qu Wenruo commit 0619b7901473c380abc05d45cf9c70bee0707db3 upstream. It's not uncommon where __btrfs_dump_space_info() gets called under over-commit situations. In that case free space would underflow as total allocated space is not enough to handle all the over-committed space. Such underflow values can sometimes cause confusion for users enabled enospc_debug mount option, and takes some seconds for developers to convert the underflow value to signed result. Just output the free space as s64 to avoid such problem. Reported-by: Eli V Link: https://lore.kernel.org/linux-btrfs/CAJtFHUSy4zgyhf-4d9T+KdJp9w=UgzC2A0V=VtmaeEpcGgm1-Q@mail.gmail.com/ CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Anand Jain Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/space-info.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/fs/btrfs/space-info.c +++ b/fs/btrfs/space-info.c @@ -262,9 +262,10 @@ static void __btrfs_dump_space_info(stru { lockdep_assert_held(&info->lock); - btrfs_info(fs_info, "space_info %llu has %llu free, is %sfull", + /* The free space could be negative in case of overcommit */ + btrfs_info(fs_info, "space_info %llu has %lld free, is %sfull", info->flags, - info->total_bytes - btrfs_space_info_used(info, true), + (s64)(info->total_bytes - btrfs_space_info_used(info, true)), info->full ? "" : "not "); btrfs_info(fs_info, "space_info total=%llu, used=%llu, pinned=%llu, reserved=%llu, may_use=%llu, readonly=%llu",