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 X-Spam-Level: X-Spam-Status: No, score=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1FA32C433E6 for ; Mon, 8 Mar 2021 12:36:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DCE3D651FE for ; Mon, 8 Mar 2021 12:36:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232469AbhCHMgm (ORCPT ); Mon, 8 Mar 2021 07:36:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:45756 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232019AbhCHMgF (ORCPT ); Mon, 8 Mar 2021 07:36:05 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4D48D651D3; Mon, 8 Mar 2021 12:36:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615206964; bh=UmnkXUqyfdgiK+RwUog45/cxDFGRZwQzWG+yd57ROZk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OTVqyP1007MK1f/JSctEWwxCi8qpJAlE3MUtfD12PCMxfWVcif99ZSZ1zBT/7eh0Q uxECn6epgyIczdCsj6xTKXrgYg5SHnvJlM1xs6HQABpF2poyM5jg4Ps4dhpA2j/kA3 7h6DZM1MLGaitRx2X7MSTBTlWRrOkOyJ8rrLMtEY= From: gregkh@linuxfoundation.org To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chris Murphy , Boris Burkov , David Sterba Subject: [PATCH 5.11 17/44] btrfs: fix spurious free_space_tree remount warning Date: Mon, 8 Mar 2021 13:34:55 +0100 Message-Id: <20210308122719.428529761@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210308122718.586629218@linuxfoundation.org> References: <20210308122718.586629218@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: Greg Kroah-Hartman From: Boris Burkov commit c55a4319c4f2c3ba0a385b1ebc454fa283cfe920 upstream. The intended logic of the check is to catch cases where the desired free_space_tree setting doesn't match the mounted setting, and the remount is anything but ro->rw. However, it makes the mistake of checking equality on a masked integer (btrfs_test_opt) against a boolean (btrfs_fs_compat_ro). If you run the reproducer: $ mount -o space_cache=v2 dev mnt $ mount -o remount,ro mnt you would expect no warning, because the remount is not attempting to change the free space tree setting, but we do see the warning. To fix this, add explicit bool type casts to the condition. I tested a variety of transitions: sudo mount -o space_cache=v2 /dev/vg0/lv0 mnt/lol (fst enabled) mount -o remount,ro mnt/lol (no warning, no fst change) sudo mount -o remount,rw,space_cache=v1,clear_cache (no warning, ro->rw) sudo mount -o remount,rw,space_cache=v2 mnt (warning, rw->rw with change) sudo mount -o remount,ro mnt (no warning, no fst change) sudo mount -o remount,rw,space_cache=v2 mnt (no warning, no fst change) Reported-by: Chris Murphy CC: stable@vger.kernel.org # 5.11 Signed-off-by: Boris Burkov Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/super.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1919,8 +1919,8 @@ static int btrfs_remount(struct super_bl btrfs_resize_thread_pool(fs_info, fs_info->thread_pool_size, old_thread_pool_size); - if (btrfs_test_opt(fs_info, FREE_SPACE_TREE) != - btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) && + if ((bool)btrfs_test_opt(fs_info, FREE_SPACE_TREE) != + (bool)btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) && (!sb_rdonly(sb) || (*flags & SB_RDONLY))) { btrfs_warn(fs_info, "remount supports changing free space tree only from ro to rw");