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 170F3C433F5 for ; Tue, 30 Nov 2021 07:09:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238970AbhK3HNO (ORCPT ); Tue, 30 Nov 2021 02:13:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37520 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234559AbhK3HNO (ORCPT ); Tue, 30 Nov 2021 02:13:14 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3E97CC061574; Mon, 29 Nov 2021 23:09:55 -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 sin.source.kernel.org (Postfix) with ESMTPS id BF03ACE1814; Tue, 30 Nov 2021 07:09:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2DACBC53FC1; Tue, 30 Nov 2021 07:09:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1638256190; bh=kLuGWOj0/CeNyazjZ0443VRhbHXKaiSe5ZXsMM3dZ+Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=KTkyqgZnTc7ZIL5IAI7yvIO9d3CjLkYX8CTok2BgGUg/ZKUO0qud2UQfhdqJ1l2Gn zuoylXn5MHW31XyIkUSx6K8+MBEyvEAn/3qHEWtz8JvSAS8FpFsffMNF6+YI6kgOdw t1ka0Df/7ZmeS6YJCG7JsbvI8nNMzdWi1xgx7+xE= Date: Tue, 30 Nov 2021 08:09:45 +0100 From: Greg Kroah-Hartman To: Eric Biggers Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-scsi@vger.kernel.org, linux-mmc@vger.kernel.org, Bart Van Assche Subject: Re: [PATCH v2 2/3] block: don't delete queue kobject before its children Message-ID: References: <20211130040306.148925-1-ebiggers@kernel.org> <20211130040306.148925-3-ebiggers@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211130040306.148925-3-ebiggers@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Mon, Nov 29, 2021 at 08:03:05PM -0800, Eric Biggers wrote: > From: Eric Biggers > > kobjects aren't supposed to be deleted before their child kobjects are > deleted. Apparently this is usually benign; however, a WARN will be > triggered if one of the child kobjects has a named attribute group: > > sysfs group 'modes' not found for kobject 'crypto' > WARNING: CPU: 0 PID: 1 at fs/sysfs/group.c:278 sysfs_remove_group+0x72/0x80 > ... > Call Trace: > sysfs_remove_groups+0x29/0x40 fs/sysfs/group.c:312 > __kobject_del+0x20/0x80 lib/kobject.c:611 > kobject_cleanup+0xa4/0x140 lib/kobject.c:696 > kobject_release lib/kobject.c:736 [inline] > kref_put include/linux/kref.h:65 [inline] > kobject_put+0x53/0x70 lib/kobject.c:753 > blk_crypto_sysfs_unregister+0x10/0x20 block/blk-crypto-sysfs.c:159 > blk_unregister_queue+0xb0/0x110 block/blk-sysfs.c:962 > del_gendisk+0x117/0x250 block/genhd.c:610 > > Fix this by moving the kobject_del() and the corresponding > kobject_uevent() to the correct place. > > Fixes: 2c2086afc2b8 ("block: Protect less code with sysfs_lock in blk_{un,}register_queue()") > Signed-off-by: Eric Biggers > --- > block/blk-sysfs.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c > index 91d3805a6ec6b..1368dfe3ee500 100644 > --- a/block/blk-sysfs.c > +++ b/block/blk-sysfs.c > @@ -951,15 +951,17 @@ void blk_unregister_queue(struct gendisk *disk) > */ > if (queue_is_mq(q)) > blk_mq_unregister_dev(disk_to_dev(disk), q); > - > - kobject_uevent(&q->kobj, KOBJ_REMOVE); > - kobject_del(&q->kobj); > blk_trace_remove_sysfs(disk_to_dev(disk)); > > mutex_lock(&q->sysfs_lock); > elv_unregister_queue(q); > disk_unregister_independent_access_ranges(disk); > mutex_unlock(&q->sysfs_lock); > + > + /* Now that all child objects were deleted, the queue can be deleted. */ > + kobject_uevent(&q->kobj, KOBJ_REMOVE); > + kobject_del(&q->kobj); > + > mutex_unlock(&q->sysfs_dir_lock); > > kobject_put(&disk_to_dev(disk)->kobj); > -- > 2.34.1 > Reviewed-by: Greg Kroah-Hartman