From nobody Fri Dec 19 16:01:18 2025 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 90DE9FA3742 for ; Mon, 24 Oct 2022 16:55:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235113AbiJXQyN (ORCPT ); Mon, 24 Oct 2022 12:54:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34412 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235436AbiJXQtf (ORCPT ); Mon, 24 Oct 2022 12:49:35 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB7DFB62; Mon, 24 Oct 2022 08:32:53 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 6EE22B818B2; Mon, 24 Oct 2022 12:53:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0EF3AC433D7; Mon, 24 Oct 2022 12:53:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666616022; bh=BZEIFEUmeeXSxmDXckwWq4R0JJOlPtiqcyBKnTZUr8w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AZ86wXSXzbkvLWd2tKnvEILTy/Vt+aBkZhJsO3uIrku232Uez0N+AFhVaEpc19YUs 0nn/Fz0Oo5cTmBb4OAEA3gQ94f3T6FJU6fg7Gf6Wpd7Y2G6UlDKQpXu/98O4MqG3eM fDHVoUjDOkqWkQeIA3ReF9HbxL6l+X2e1FmiVBCA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Anand Jain , Qu Wenruo , David Sterba , Sasha Levin Subject: [PATCH 5.15 472/530] btrfs: dump extra info if one free space cache has more bitmaps than it should Date: Mon, 24 Oct 2022 13:33:36 +0200 Message-Id: <20221024113106.405859063@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221024113044.976326639@linuxfoundation.org> References: <20221024113044.976326639@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Qu Wenruo [ Upstream commit 62cd9d4474282a1eb84f945955c56cbfc42e1ffe ] There is an internal report on hitting the following ASSERT() in recalculate_thresholds(): ASSERT(ctl->total_bitmaps <=3D max_bitmaps); Above @max_bitmaps is calculated using the following variables: - bytes_per_bg 8 * 4096 * 4096 (128M) for x86_64/x86. - block_group->length The length of the block group. @max_bitmaps is the rounded up value of block_group->length / 128M. Normally one free space cache should not have more bitmaps than above value, but when it happens the ASSERT() can be triggered if CONFIG_BTRFS_ASSERT is also enabled. But the ASSERT() itself won't provide enough info to know which is going wrong. Is the bg too small thus it only allows one bitmap? Or is there something else wrong? So although I haven't found extra reports or crash dump to do further investigation, add the extra info to make it more helpful to debug. Reviewed-by: Anand Jain Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- fs/btrfs/free-space-cache.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index da0eee7c9e5f..529907ea3825 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -672,6 +672,12 @@ static void recalculate_thresholds(struct btrfs_free_s= pace_ctl *ctl) =20 max_bitmaps =3D max_t(u64, max_bitmaps, 1); =20 + if (ctl->total_bitmaps > max_bitmaps) + btrfs_err(block_group->fs_info, +"invalid free space control: bg start=3D%llu len=3D%llu total_bitmaps=3D%u= unit=3D%u max_bitmaps=3D%llu bytes_per_bg=3D%llu", + block_group->start, block_group->length, + ctl->total_bitmaps, ctl->unit, max_bitmaps, + bytes_per_bg); ASSERT(ctl->total_bitmaps <=3D max_bitmaps); =20 /* --=20 2.35.1