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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 023B7C43381 for ; Mon, 18 Mar 2019 17:16:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CCACC20863 for ; Mon, 18 Mar 2019 17:16:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727188AbfCRRQ1 (ORCPT ); Mon, 18 Mar 2019 13:16:27 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:46648 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726765AbfCRRQ1 (ORCPT ); Mon, 18 Mar 2019 13:16:27 -0400 Received: by mail-pg1-f194.google.com with SMTP id a22so11805562pgg.13; Mon, 18 Mar 2019 10:16:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:mime-version:content-transfer-encoding; bh=V4E1evcqLqxZDwrDpf1S27x2FhHzdkvtC33qAjLzojw=; b=k70YN2MjuvxTsPlE+Ntb4dm/K0jBmhHpFBds3jpqqLYMrCFz3yk/1FLMyHcSZiV+fa gX1ukPmpLrEfSHv+CjjahlsgpICTBVcgNvnekY1TRsi33srN4NPOR1sDbgeCE01Fka99 BGD8pI8oYJP++elbbuNdnfAc099sVtbWMxGT+NYO9Vbutf0d83r1W5RSQqtZrr8b4Nmz FtLwsHuyf6Z7cCugWsglxSFQWFgfsGAEA9LhxMuUCPB0yGu10glfCwYe3oFEc5KchJbh kbYNzFr+ELqjdls2GPwJT6onJOWMoUxtcbiOa6vDqjwws/9Ejv0NRRcJsOxmXPTm0K8Z 9OtA== X-Gm-Message-State: APjAAAWkfOaEd2opYf1CddOaKJqN/MYcZL1xxuSp24iHRo1c6Ydzc1f1 PpXSmDVT9yLvyOP4EXwy4es1QadJo1w= X-Google-Smtp-Source: APXvYqxUm3w2rctlqHvfzCxw5PpFZYfXdmB7cCThe5p5W3sSylHV9U4SRMmLhsnxCXJG82eEKv71YQ== X-Received: by 2002:a65:6210:: with SMTP id d16mr18684648pgv.189.1552929386882; Mon, 18 Mar 2019 10:16:26 -0700 (PDT) Received: from ?IPv6:2620:15c:2cd:203:5cdc:422c:7b28:ebb5? ([2620:15c:2cd:203:5cdc:422c:7b28:ebb5]) by smtp.gmail.com with ESMTPSA id z6sm47644372pgo.31.2019.03.18.10.16.25 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 18 Mar 2019 10:16:25 -0700 (PDT) Message-ID: <1552929384.152266.27.camel@acm.org> Subject: Re: [PATCH 5/8] nbd: use blk_mq_queue_tag_busy_iter From: Bart Van Assche To: Jianchao Wang , axboe@kernel.dk Cc: hch@lst.de, jthumshirn@suse.de, hare@suse.de, josef@toxicpanda.com, sagi@grimberg.me, keith.busch@intel.com, jsmart2021@gmail.com, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org Date: Mon, 18 Mar 2019 10:16:24 -0700 In-Reply-To: <1552640264-26101-6-git-send-email-jianchao.w.wang@oracle.com> References: <1552640264-26101-1-git-send-email-jianchao.w.wang@oracle.com> <1552640264-26101-6-git-send-email-jianchao.w.wang@oracle.com> Content-Type: text/plain; charset="UTF-7" X-Mailer: Evolution 3.26.2-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Fri, 2019-03-15 at 16:57 +-0800, Jianchao Wang wrote: +AD4 blk+AF8-mq+AF8-tagset+AF8-busy+AF8-iter is not safe that it could get stale request +AD4 in tags-+AD4-rqs+AFsAXQ. Use blk+AF8-mq+AF8-queue+AF8-tag+AF8-busy+AF8-iter here. +AD4 +AD4 Signed-off-by: Jianchao Wang +ADw-jianchao.w.wang+AEA-oracle.com+AD4 +AD4 --- +AD4 drivers/block/nbd.c +AHw 2 +- +AD4 1 file changed, 1 insertion(), 1 deletion(-) +AD4 +AD4 diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c +AD4 index 7c9a949..9e7e828 100644 +AD4 --- a/drivers/block/nbd.c +AD4 +-+-+- b/drivers/block/nbd.c +AD4 +AEAAQA -747,7 +-747,7 +AEAAQA static bool nbd+AF8-clear+AF8-req(struct request +ACo-req, void +ACo-data, bool reserved) +AD4 static void nbd+AF8-clear+AF8-que(struct nbd+AF8-device +ACo-nbd) +AD4 +AHs +AD4 blk+AF8-mq+AF8-quiesce+AF8-queue(nbd-+AD4-disk-+AD4-queue)+ADs +AD4 - blk+AF8-mq+AF8-tagset+AF8-busy+AF8-iter(+ACY-nbd-+AD4-tag+AF8-set, nbd+AF8-clear+AF8-req, NULL)+ADs +AD4 +- blk+AF8-mq+AF8-queue+AF8-tag+AF8-busy+AF8-iter(nbd-+AD4-disk-+AD4-queue, nbd+AF8-clear+AF8-req, NULL, true)+ADs +AD4 blk+AF8-mq+AF8-unquiesce+AF8-queue(nbd-+AD4-disk-+AD4-queue)+ADs +AD4 dev+AF8-dbg(disk+AF8-to+AF8-dev(nbd-+AD4-disk), +ACI-queue cleared+AFw-n+ACI)+ADs +AD4 +AH0 Hi Jianchao, The nbd driver calls nbd+AF8-clear+AF8-que() after having called sock+AF8-shutdown(). So what makes you think that it's not safe to call blk+AF8-mq+AF8-tagset+AF8-busy+AF8-iter() from nbd+AF8-clear+AF8-que()? Thanks, Bart.