From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) (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 551203DD87F for ; Mon, 27 Jul 2026 07:56:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785138980; cv=none; b=dB2yxqitjjQMCTmoaIWtPRI33IIaj1Iz4vplRlVg1vnhovksKAW1ilyjFaH8Em5xv0/1Eg0RbNQH1OeZMnNZZJRqEAGL/7uVYFy0m9jRMfnO0KHhyv9YUe+6X4iVTGl7GkhH6ZvukcMCvDg13wbhv74p4T6hIlbzw6E1maYKYbY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785138980; c=relaxed/simple; bh=tXsqMdrw5s3A57Re3nu1Lvibgv/MTbvkc3N4Oy9Ealk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OfD6E0QQp6iV2cJsFYOWaCWioiECQJMvZbdaf5Kxx5ikGJQ7jTn8O3ko/ol9cuqv1ddDZ/sUoZ4BUX6KW0G+cx1aHUkX68HybmVvytgXwe6p7vn3zPVJd+b37Co+iIgzfHvokODhIunJ3lHIEBEJOF1dtxvS7GsurmyeBSdyjSM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.198]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTPS id 4h7rVg53QHzKHMPY for ; Mon, 27 Jul 2026 15:55:23 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.252]) by mail.maildlp.com (Postfix) with ESMTP id 348F2407CC for ; Mon, 27 Jul 2026 15:56:15 +0800 (CST) Received: from huaweicloud.com (unknown [10.50.85.155]) by APP3 (Coremail) with UTF8SMTPSA id _Ch0CgC3pkUbD2dqjEJ1AA--.26468S6; Mon, 27 Jul 2026 15:56:15 +0800 (CST) From: Yang Erkun To: josef@toxicpanda.com, axboe@kernel.dk, hch@lst.de, yukuai@kernel.org Cc: yi.zhang@huawei.com, chengzhihao1@huawei.com, echo.chenlin@huawei.com, leo.lilong@huaweicloud.com, wangkefeng.wang@huawei.com, huawei.libin@huawei.com, leijitang@huawei.com, linux-block@vger.kernel.org, nbd@other.debian.org Subject: [PATCH v4 2/7] nbd: disallow NBD_SET_SOCK on an active device Date: Mon, 27 Jul 2026 15:47:13 +0800 Message-ID: <20260727074718.414868-3-yangerkun@huawei.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260727074718.414868-1-yangerkun@huawei.com> References: <20260727074718.414868-1-yangerkun@huawei.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:_Ch0CgC3pkUbD2dqjEJ1AA--.26468S6 X-Coremail-Antispam: 1UD129KBjvdXoWrKrW3WFyUWw48Jw1kWF13CFg_yoWDCwb_Cr yruw18Xws3GFW3u39093W5Zryjya1I9F4v9F12yrZ3XFy2vas3ZFn2vrZxAw1UXrWjgFsr Aryj9ws7Ar4ftjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbvAYFVCjjxCrM7AC8VAFwI0_Wr0E3s1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l82xGYIkIc2x26280x7IE14v26r15M2 8IrcIa0xkI8VCY1x0267AKxVW5JVCq3wA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK 021l84ACjcxK6xIIjxv20xvE14v26r1I6r4UM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r 4j6F4UM28EF7xvwVC2z280aVAFwI0_Cr1j6rxdM28EF7xvwVC2z280aVCY1x0267AKxVW0 oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7V C0I7IYx2IY67AKxVWUGVWUXwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j 6r4UM4x0Y48IcxkI7VAKI48JM4IIrI8v6xkF7I0E8cxan2IY04v7MxkF7I0En4kS14v26r 1q6r43MxAIw28IcxkI7VAKI48JMxAIw28IcVAKzI0EY4vE52x082I5MxC20s026xCaFVCj c4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4 CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1x MIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF 4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsG vfC2KfnxnUUI43ZEXa7IUbGjg7UUUUU== Sender: yangerkun@huaweicloud.com X-CM-SenderInfo: 51dqwvhunx0q5kxd4v5lfo033gof0z/ We cannot add a socket to an already running nbd device, the reconfigure for netlink can only active an inactive socket. But for ioctl path, we can call NBD_SET_SOCK after NBD_DO_IT, reject this using nbd->pid which has been setted when NBD_DO_IT. Besides, it is the root cause for commit b98e762e3d71 ("nbd: freeze the queue while we're adding connections"). Signed-off-by: Yang Erkun --- drivers/block/nbd.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index b1a5acd57426..7ec85f94f742 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1278,6 +1278,13 @@ static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg, /* Arg will be cast to int, check it to avoid overflow */ if (arg > INT_MAX) return -EINVAL; + + if (nbd->pid) { + dev_err(disk_to_dev(nbd->disk), + "Cannot add socket to a running device\n"); + return -EBUSY; + } + sock = nbd_get_socket(nbd, arg, &err); if (!sock) return err; -- 2.52.0