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 A73A0ECAAD4 for ; Sat, 3 Sep 2022 11:19:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230229AbiICLTC (ORCPT ); Sat, 3 Sep 2022 07:19:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42686 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229586AbiICLS7 (ORCPT ); Sat, 3 Sep 2022 07:18:59 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 19A5F7CAAD for ; Sat, 3 Sep 2022 04:18:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1662203937; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=WVDVVWLcyoS66ybhgFS8BXSJnOHhZUbQUeCNcx7RrB4=; b=ezUX+wiKWgf+tZlhXuEc7jzGPeuDIj78wl+Z76hmV/ARQTMMg0ejfCrBeT0z5uztlvr+qX RTOUQ5UopbQufS19eZnFJ/FHh/u3juKjna3zCB8ktYYrEMa045kGXTW01V/b8LRfuhUjBN bDlpKNzIXGF2PKEefVm1t1/ZgnOPZjI= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-587-puFBncOuNquK3TCf8cwGpQ-1; Sat, 03 Sep 2022 07:18:54 -0400 X-MC-Unique: puFBncOuNquK3TCf8cwGpQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8010580418F; Sat, 3 Sep 2022 11:18:53 +0000 (UTC) Received: from T590 (ovpn-8-16.pek2.redhat.com [10.72.8.16]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7D04F14152E0; Sat, 3 Sep 2022 11:18:48 +0000 (UTC) Date: Sat, 3 Sep 2022 19:18:49 +0800 From: Ming Lei To: ZiyangZhang Cc: axboe@kernel.dk, xiaoguang.wang@linux.alibaba.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, joseph.qi@linux.alibaba.com Subject: Re: [RFC PATCH V2 3/6] ublk_drv: define macros for recovery feature and check them Message-ID: References: <20220831155136.23434-1-ZiyangZhang@linux.alibaba.com> <20220831155136.23434-4-ZiyangZhang@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220831155136.23434-4-ZiyangZhang@linux.alibaba.com> X-Scanned-By: MIMEDefang 2.85 on 10.11.54.7 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 31, 2022 at 11:51:33PM +0800, ZiyangZhang wrote: > Define some macros for recovery feature. Especially define a new state: > UBLK_S_DEV_RECOVERING which implies the ublk_device is recovering. > > UBLK_F_USER_RECOVERY implies that: > (1) ublk_drv enables recovery feature. It won't let monitor_work to > automatically abort rqs and release the device. Instead, it waits > for user's START_USER_RECOVERY ctrl-cmd. > > (2) In monitor_work after a crash, ublk_drv ends(aborts) rqs issued to > userspace(ublksrv) before crash. > > (3) In task work and ublk_queue_rq() after a crash, ublk_drv requeues > rqs dispatched after crash. > > UBLK_F_USER_RECOVERY_REISSUE implies that: > (1) everything UBLK_F_USER_RECOVERY implies except > (2) ublk_drv requeues rqs issued to userspace(ublksrv) before crash. > > UBLK_F_USER_RECOVERY_REISSUE is designed for backends which: > (1) tolerate double-writes because we may issue the same rq twice. > (2) cannot let frontend users get I/O error, such as a RDONLY system. > > Signed-off-by: ZiyangZhang > --- > drivers/block/ublk_drv.c | 31 ++++++++++++++++++++++++++++++- > include/uapi/linux/ublk_cmd.h | 7 +++++++ > 2 files changed, 37 insertions(+), 1 deletion(-) > > diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c > index 0c6db0978ed0..0c3d32e8d686 100644 > --- a/drivers/block/ublk_drv.c > +++ b/drivers/block/ublk_drv.c > @@ -49,7 +49,9 @@ > /* All UBLK_F_* have to be included into UBLK_F_ALL */ > #define UBLK_F_ALL (UBLK_F_SUPPORT_ZERO_COPY \ > | UBLK_F_URING_CMD_COMP_IN_TASK \ > - | UBLK_F_NEED_GET_DATA) > + | UBLK_F_NEED_GET_DATA \ > + | UBLK_F_USER_RECOVERY \ > + | UBLK_F_USER_RECOVERY_REISSUE) > > /* All UBLK_PARAM_TYPE_* should be included here */ > #define UBLK_PARAM_TYPE_ALL (UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DISCARD) > @@ -323,6 +325,33 @@ static inline int ublk_queue_cmd_buf_size(struct ublk_device *ub, int q_id) > PAGE_SIZE); > } > > +/* > + * TODO: UBLK_F_USER_RECOVERY should be a flag for device, not for queue, > + * since "some queues are aborted while others are recoverd" is really weird. > + */ > +static inline bool ublk_can_use_recovery(struct ublk_device *ub) > +{ > + struct ublk_queue *ubq = ublk_get_queue(ub, 0); This way is too tricky, just wondering why you don't passe ubq to ublk_can_use_recovery()? Thanks, Ming