From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1319030E0F2; Mon, 13 Oct 2025 14:57:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760367474; cv=none; b=pj4tout4x26PBinKXovycaJM/pnqmpSzQEpMDnAo/U3X/toeZHJGNZE8u7PBjO3Hvvts6dSorHXiQDjAAzp974gB3wnNmM/aIHMLIqb7R1cUWYn9y3N/P9s3dhme+dLSUKEkM8cNKdrdqKpHml+eIKwhUZ/7/4GPh6F6U8NMMwg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760367474; c=relaxed/simple; bh=P+jy2rSyQAzeON7lSSh/h+nVnl5iyz5Oi4qn5tAWZy4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ukixhg3lDoPZQKcNNamaSyRLHkgaOUho5ihepXitOsOQbNqxbHkHj338OqkmeqlpSTZiOVrGRvDVEA3+HgKqDqLSkigR7ZnbYtJo21d7TVnho1BzdMEIzwP0EFxDJgsOVZYrHK3UFcQ0d7YeGaCvb+DZwY2gN8GsdFK4yE7T1k0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=EoDaWVff; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="EoDaWVff" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8A2B8C4CEE7; Mon, 13 Oct 2025 14:57:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760367473; bh=P+jy2rSyQAzeON7lSSh/h+nVnl5iyz5Oi4qn5tAWZy4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EoDaWVffa7GhbpkadBM4TjcRdxam9tDE3pQ0arsa10JdcvPU8S5m1M4IcsOjfwBm+ fd+16uOvM0Zr7bIijE7yW2ubu3jQV4bqBlxWf63vmzwwn8Pd5hTGeJEG4MmGPONjrW 3sUBh8bajyxK0iBqItfGr8coOBL6i+aFx0pUgj2U= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Li Nan , Yu Kuai , Jens Axboe , Sasha Levin Subject: [PATCH 6.6 024/196] blk-mq: check kobject state_in_sysfs before deleting in blk_mq_unregister_hctx Date: Mon, 13 Oct 2025 16:43:35 +0200 Message-ID: <20251013144316.070210929@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251013144315.184275491@linuxfoundation.org> References: <20251013144315.184275491@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Li Nan [ Upstream commit 4c7ef92f6d4d08a27d676e4c348f4e2922cab3ed ] In __blk_mq_update_nr_hw_queues() the return value of blk_mq_sysfs_register_hctxs() is not checked. If sysfs creation for hctx fails, later changing the number of hw_queues or removing disk will trigger the following warning: kernfs: can not remove 'nr_tags', no directory WARNING: CPU: 2 PID: 637 at fs/kernfs/dir.c:1707 kernfs_remove_by_name_ns+0x13f/0x160 Call Trace: remove_files.isra.1+0x38/0xb0 sysfs_remove_group+0x4d/0x100 sysfs_remove_groups+0x31/0x60 __kobject_del+0x23/0xf0 kobject_del+0x17/0x40 blk_mq_unregister_hctx+0x5d/0x80 blk_mq_sysfs_unregister_hctxs+0x94/0xd0 blk_mq_update_nr_hw_queues+0x124/0x760 nullb_update_nr_hw_queues+0x71/0xf0 [null_blk] nullb_device_submit_queues_store+0x92/0x120 [null_blk] kobjct_del() was called unconditionally even if sysfs creation failed. Fix it by checkig the kobject creation statusbefore deleting it. Fixes: 477e19dedc9d ("blk-mq: adjust debugfs and sysfs register when updating nr_hw_queues") Signed-off-by: Li Nan Reviewed-by: Yu Kuai Link: https://lore.kernel.org/r/20250826084854.1030545-1-linan666@huaweicloud.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-mq-sysfs.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index 156e9bb07abf1..2fb234ab467b1 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -150,9 +150,11 @@ static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx) return; hctx_for_each_ctx(hctx, ctx, i) - kobject_del(&ctx->kobj); + if (ctx->kobj.state_in_sysfs) + kobject_del(&ctx->kobj); - kobject_del(&hctx->kobj); + if (hctx->kobj.state_in_sysfs) + kobject_del(&hctx->kobj); } static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx) -- 2.51.0