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 2BA17C43334 for ; Mon, 13 Jun 2022 11:48:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356081AbiFMLsG (ORCPT ); Mon, 13 Jun 2022 07:48:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59374 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1357332AbiFMLp7 (ORCPT ); Mon, 13 Jun 2022 07:45:59 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A0014AE3B; Mon, 13 Jun 2022 03:52:08 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 03459611B3; Mon, 13 Jun 2022 10:52:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06E95C34114; Mon, 13 Jun 2022 10:52:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1655117527; bh=waQKgNy+BWkAicT7he7wv5bSKCqAUiqLzRoxehJRFQ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kxc4nILfNAO4QV30RFGRPjTbpUeZnI6BTOEZsFcA9YOLX0IHFJZzxgiTkuri4aMyD EGdppwohVSq5EMtrIsUHs7XeQN5c55MDjZu6oCJ2CmnXK3fYXmxXWrKLMxu7fc5U5D FLRXV0nDM6pVkIvollfwNg4P5cipBmMI9pJ9vPw8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yu Kuai , Josef Bacik , Jens Axboe , Sasha Levin Subject: [PATCH 5.4 394/411] nbd: fix io hung while disconnecting device Date: Mon, 13 Jun 2022 12:11:07 +0200 Message-Id: <20220613094940.481053342@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220613094928.482772422@linuxfoundation.org> References: <20220613094928.482772422@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Yu Kuai [ Upstream commit 09dadb5985023e27d4740ebd17e6fea4640110e5 ] In our tests, "qemu-nbd" triggers a io hung: INFO: task qemu-nbd:11445 blocked for more than 368 seconds. Not tainted 5.18.0-rc3-next-20220422-00003-g2176915513ca #884 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:qemu-nbd state:D stack: 0 pid:11445 ppid: 1 flags:0x00000000 Call Trace: __schedule+0x480/0x1050 ? _raw_spin_lock_irqsave+0x3e/0xb0 schedule+0x9c/0x1b0 blk_mq_freeze_queue_wait+0x9d/0xf0 ? ipi_rseq+0x70/0x70 blk_mq_freeze_queue+0x2b/0x40 nbd_add_socket+0x6b/0x270 [nbd] nbd_ioctl+0x383/0x510 [nbd] blkdev_ioctl+0x18e/0x3e0 __x64_sys_ioctl+0xac/0x120 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fd8ff706577 RSP: 002b:00007fd8fcdfebf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000040000000 RCX: 00007fd8ff706577 RDX: 000000000000000d RSI: 000000000000ab00 RDI: 000000000000000f RBP: 000000000000000f R08: 000000000000fbe8 R09: 000055fe497c62b0 R10: 00000002aff20000 R11: 0000000000000246 R12: 000000000000006d R13: 0000000000000000 R14: 00007ffe82dc5e70 R15: 00007fd8fcdff9c0 "qemu-ndb -d" will call ioctl 'NBD_DISCONNECT' first, however, following message was found: block nbd0: Send disconnect failed -32 Which indicate that something is wrong with the server. Then, "qemu-nbd -d" will call ioctl 'NBD_CLEAR_SOCK', however ioctl can't clear requests after commit 2516ab1543fd("nbd: only clear the queue on device teardown"). And in the meantime, request can't complete through timeout because nbd_xmit_timeout() will always return 'BLK_EH_RESET_TIMER', which means such request will never be completed in this situation. Now that the flag 'NBD_CMD_INFLIGHT' can make sure requests won't complete multiple times, switch back to call nbd_clear_sock() in nbd_clear_sock_ioctl(), so that inflight requests can be cleared. Signed-off-by: Yu Kuai Reviewed-by: Josef Bacik Link: https://lore.kernel.org/r/20220521073749.3146892-5-yukuai3@huawei.com 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 ef355f14ed2c..09323b0510f0 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1344,7 +1344,7 @@ static int nbd_start_device_ioctl(struct nbd_device *nbd, struct block_device *b static void nbd_clear_sock_ioctl(struct nbd_device *nbd, struct block_device *bdev) { - sock_shutdown(nbd); + nbd_clear_sock(nbd); __invalidate_device(bdev, true); nbd_bdev_reset(bdev); if (test_and_clear_bit(NBD_RT_HAS_CONFIG_REF, -- 2.35.1