From patchwork Mon Jan 24 21:59:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 12723011 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 DE08EC433F5 for ; Mon, 24 Jan 2022 23:48:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2364610AbiAXXsi (ORCPT ); Mon, 24 Jan 2022 18:48:38 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:33620 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1578855AbiAXWEJ (ORCPT ); Mon, 24 Jan 2022 17:04:09 -0500 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 BDE39B81233; Mon, 24 Jan 2022 22:03:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 47004C340E7; Mon, 24 Jan 2022 22:03:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1643061829; bh=e8qGIsAwD8DVQC0GNO45q/1wa3k3d7Q+DpR8gTvss3M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ugkMEX0juyhCZ0B4pLW2Mpr2boc7ujY0PFzg8DlmYDl2E/2jM6CnRw/15v8jMhayy lrYKDF6B+nsYKxqs6Ve4vL8c5loQXXPGSfjANcAxp1Eural1t7d3DX1T1fS6ezQKkt S5KGTOfyR79rq3AFzRf1/SIB/Ua5H5IpCaOU0rXaeFMtBlWfqG9EWAGoEDS2mmci6Y g+kjRHxXpiCJAbKtJl0fUP5fo6Cy2NA4F8xVR7UZdSy673mtLi9Sq1ABufucof7DWC hE+pCAqbvJnZ1HjOYBOIdMZqEI4jeuUBuqUFrNkJut9Z56HQGcF7YUlj8SbWZfSId6 YzS/dV4vFY61w== From: Eric Biggers To: linux-block@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-scsi@vger.kernel.org, linux-mmc@vger.kernel.org, Greg Kroah-Hartman , Bart Van Assche , Hannes Reinecke Subject: [PATCH v4 2/3] block: don't delete queue kobject before its children Date: Mon, 24 Jan 2022 13:59:37 -0800 Message-Id: <20220124215938.2769-3-ebiggers@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124215938.2769-1-ebiggers@kernel.org> References: <20220124215938.2769-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org 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()") Reviewed-by: Hannes Reinecke Reviewed-by: Greg Kroah-Hartman Reviewed-by: Bart Van Assche Signed-off-by: Eric Biggers Reviewed-by: Christoph Hellwig --- 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 a02b42ad9a6e0..66deaa9f3bc97 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -954,15 +954,17 @@ 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 we've deleted all child objects, we can delete the queue. */ + kobject_uevent(&q->kobj, KOBJ_REMOVE); + kobject_del(&q->kobj); + mutex_unlock(&q->sysfs_dir_lock); kobject_put(&disk_to_dev(disk)->kobj);