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 X-Spam-Level: X-Spam-Status: No, score=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64564C56201 for ; Mon, 26 Oct 2020 23:59:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E01920773 for ; Mon, 26 Oct 2020 23:59:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603756783; bh=cGWIoh6h6aOYlfAIP7Hm21DZreYR0Se6xpETKsgYV8I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PHz+wMv3c5TnvhP8SBrqgVHWTuGLRsvr8XHlIpamCJisBQf0P3HAXq+GFJjKEtPWQ 3hR6juWspxcx+RQT44FvazLMNOOWWKHkpOWuFGr8YX62RKHKzpuU0lgNP2E1cF+4ju CrUjan3Ic5JQ5pbF9DA4peTs/gT/8LeQL6udDVPw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2410899AbgJZX7m (ORCPT ); Mon, 26 Oct 2020 19:59:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:37240 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2436621AbgJZX4v (ORCPT ); Mon, 26 Oct 2020 19:56:51 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7FCA520882; Mon, 26 Oct 2020 23:56:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603756611; bh=cGWIoh6h6aOYlfAIP7Hm21DZreYR0Se6xpETKsgYV8I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cvexm3YBGmxPaCliIvS4g18uCwtzLrkgfUxyJF5SSEFev4tfd9oCJoHdRRv30QriH fjkQqs+Sa5UvUp8ka7ibKrJ++3b9gagdJR6z3EW8/MKTJcIN0nRsOLQYQWUNSFzZh+ 9mqzT0fjU3N+W2JUqf7EfJEXhf0YHYhqJ/haVjsg= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Xiubo Li , Josef Bacik , Jens Axboe , Sasha Levin , linux-block@vger.kernel.org, nbd@other.debian.org Subject: [PATCH AUTOSEL 5.4 78/80] nbd: make the config put is called before the notifying the waiter Date: Mon, 26 Oct 2020 19:55:14 -0400 Message-Id: <20201026235516.1025100-78-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201026235516.1025100-1-sashal@kernel.org> References: <20201026235516.1025100-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: Xiubo Li [ Upstream commit 87aac3a80af5cbad93e63250e8a1e19095ba0d30 ] There has one race case for ceph's rbd-nbd tool. When do mapping it may fail with EBUSY from ioctl(nbd, NBD_DO_IT), but actually the nbd device has already unmaped. It dues to if just after the wake_up(), the recv_work() is scheduled out and defers calling the nbd_config_put(), though the map process has exited the "nbd->recv_task" is not cleared. Signed-off-by: Xiubo Li Reviewed-by: Josef Bacik Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/nbd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 7c577cabb9c3b..742f8160b6e28 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -787,9 +787,9 @@ static void recv_work(struct work_struct *work) blk_mq_complete_request(blk_mq_rq_from_pdu(cmd)); } + nbd_config_put(nbd); atomic_dec(&config->recv_threads); wake_up(&config->recv_wq); - nbd_config_put(nbd); kfree(args); } -- 2.25.1