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 64DFBC7EE30 for ; Thu, 2 Mar 2023 13:17:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229534AbjCBNRl (ORCPT ); Thu, 2 Mar 2023 08:17:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47572 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230040AbjCBNRk (ORCPT ); Thu, 2 Mar 2023 08:17:40 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 69C5039BBD for ; Thu, 2 Mar 2023 05:16:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1677763013; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HT42klSl4QJ/KZdsdNPkQZTqOKOm4eLpYdcPCrpQR8w=; b=XeW8SQ8nlZjnWBGpSVeVLCnvP349T66Sn4Z1Be0HvxNQVFodN8NjY9RJG77naqU7UI/j42 RGzwaHyc0kqAOXPDW7HBjJ3Cx8IC7ngyPOPYXhgdYfikudvQ8Tx73vpohcQrbfrF+DZulh Tle5HHEvU5CPP4VEm2ntvxCE9THfVIg= 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-372-IyWV56PeO_uom7bKzYLEtQ-1; Thu, 02 Mar 2023 08:16:51 -0500 X-MC-Unique: IyWV56PeO_uom7bKzYLEtQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 62920185A78B; Thu, 2 Mar 2023 13:16:51 +0000 (UTC) Received: from T590 (ovpn-8-26.pek2.redhat.com [10.72.8.26]) by smtp.corp.redhat.com (Postfix) with ESMTPS id F28B72166B26; Thu, 2 Mar 2023 13:16:44 +0000 (UTC) Date: Thu, 2 Mar 2023 21:16:38 +0800 From: Ming Lei To: Andreas Hindborg Cc: linux-block@vger.kernel.org, Hans Holmberg , Matias Bjorling , Niklas Cassel , kernel test robot , Jens Axboe , open list , Damien Le Moal , ming.lei@redhat.com Subject: Re: [PATCH v2] block: ublk: enable zoned storage support Message-ID: References: <20230224200502.391570-1-nmi@metaspace.dk> <87o7pblhi1.fsf@metaspace.dk> <87h6v3l9up.fsf@metaspace.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87h6v3l9up.fsf@metaspace.dk> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Thu, Mar 02, 2023 at 11:07:15AM +0100, Andreas Hindborg wrote: > > Ming Lei writes: > > > On Thu, Mar 2, 2023 at 5:02 PM Ming Lei wrote: > >> > >> On Thu, Mar 02, 2023 at 04:32:21PM +0800, Ming Lei wrote: > >> > On Thu, Mar 02, 2023 at 08:31:07AM +0100, Andreas Hindborg wrote: > >> > > > >> > >> ... > >> > >> > > > >> > > I agree about fetching more zones. However, it is no good to fetch up to > >> > > a max, since the requested zone report may less than max. I was > >> > > >> > Short read should always be supported, so the interface may need to > >> > return how many zones in single command, please refer to nvme_ns_report_zones(). > >> > >> blk_zone is part of uapi, maybe the short read can be figured out by > >> one all-zeroed 'blk_zone'? then no extra uapi data is needed for > >> reporting zones. > > > > oops, we have blk_zone_report data for reporting zones to userspace already, > > see blkdev_report_zones_ioctl(), then this way can be re-used for getting zone > > report from ublk server too, right? > > Yes that would be nice. But I did the report_zone command like a read > operation, so we are not currently copying any buffers to user space > when issuing the command, we just rely on the iod. What I meant is to reuse the format of blk_zone_report for returning multiple 'blk_zone' info in single command. The only change is that you need to allocate one bigger kernel buffer to hold more 'blk_zone' in single report zone request. > I think it would be > better to use the start_sectors and nr_sectors of the iod instead. Then > we don't have to copy the blk_zone_report. What do you think? For IN parameter of report zone command, you still can reuse blk_zone_report: struct blk_zone_report { __u64 sector; __u32 nr_zones; __u32 flags; }; Just by using the 1st two 64b words of iod for holding 'blk_zone_report', and keep the iod->addr field not touched. [1] https://lore.kernel.org/linux-block/20230301140611.163055-1-ming.lei@redhat.com/T/#md36358552d45a7d563940632d4c779a99f72916d Thanks, Ming