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 417BBC678D5 for ; Mon, 20 Feb 2023 13:48:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232330AbjBTNsI (ORCPT ); Mon, 20 Feb 2023 08:48:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33444 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232338AbjBTNsH (ORCPT ); Mon, 20 Feb 2023 08:48:07 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C73EFF09 for ; Mon, 20 Feb 2023 05:47:58 -0800 (PST) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 1F07760E8A for ; Mon, 20 Feb 2023 13:47:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 336E0C433EF; Mon, 20 Feb 2023 13:47:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1676900877; bh=PsH748ApA7nAeYmOtVc2MaWKu0p5zL5Vv5yzfBw8p+k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EqnMMxdaCZizU9Lfo4Vaz6DrZ18HBU4Z4bIsIzVRwr8Qx1qVsvpi08/zQJ6P8UfJ+ 28Sdsw4L9cbLwKj/9x3yZHe5iYsfrybusad9Cv2nsPUwgksHK5w6cV0l8he6njFy3N JUzOu1eopdkp5ep56iosT6QfAz32TxgBH88KU82M= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Daan De Meyer , Josef Bacik , Anand Jain , David Sterba Subject: [PATCH 5.4 100/156] btrfs: free device in btrfs_close_devices for a single device filesystem Date: Mon, 20 Feb 2023 14:35:44 +0100 Message-Id: <20230220133606.668832255@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230220133602.515342638@linuxfoundation.org> References: <20230220133602.515342638@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Anand Jain commit 5f58d783fd7823b2c2d5954d1126e702f94bfc4c upstream. We have this check to make sure we don't accidentally add older devices that may have disappeared and re-appeared with an older generation from being added to an fs_devices (such as a replace source device). This makes sense, we don't want stale disks in our file system. However for single disks this doesn't really make sense. I've seen this in testing, but I was provided a reproducer from a project that builds btrfs images on loopback devices. The loopback device gets cached with the new generation, and then if it is re-used to generate a new file system we'll fail to mount it because the new fs is "older" than what we have in cache. Fix this by freeing the cache when closing the device for a single device filesystem. This will ensure that the mount command passed device path is scanned successfully during the next mount. CC: stable@vger.kernel.org # 5.10+ Reported-by: Daan De Meyer Signed-off-by: Josef Bacik Signed-off-by: Anand Jain Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Anand Jain Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/volumes.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -354,6 +354,7 @@ void btrfs_free_device(struct btrfs_devi static void free_fs_devices(struct btrfs_fs_devices *fs_devices) { struct btrfs_device *device; + WARN_ON(fs_devices->opened); while (!list_empty(&fs_devices->devices)) { device = list_entry(fs_devices->devices.next, @@ -1401,6 +1402,17 @@ int btrfs_close_devices(struct btrfs_fs_ if (!fs_devices->opened) { seed_devices = fs_devices->seed; fs_devices->seed = NULL; + + /* + * If the struct btrfs_fs_devices is not assembled with any + * other device, it can be re-initialized during the next mount + * without the needing device-scan step. Therefore, it can be + * fully freed. + */ + if (fs_devices->num_devices == 1) { + list_del(&fs_devices->fs_list); + free_fs_devices(fs_devices); + } } mutex_unlock(&uuid_mutex);