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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 12BA8C433E6 for ; Mon, 18 Jan 2021 18:26:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DD06722D03 for ; Mon, 18 Jan 2021 18:26:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393196AbhARS00 (ORCPT ); Mon, 18 Jan 2021 13:26:26 -0500 Received: from verein.lst.de ([213.95.11.211]:49154 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2407597AbhARSZ5 (ORCPT ); Mon, 18 Jan 2021 13:25:57 -0500 Received: by verein.lst.de (Postfix, from userid 2407) id A2DE96736F; Mon, 18 Jan 2021 19:25:15 +0100 (CET) Date: Mon, 18 Jan 2021 19:25:15 +0100 From: Christoph Hellwig To: Damien Le Moal Cc: Christoph Hellwig , Chaitanya Kulkarni , "linux-block@vger.kernel.org" , "linux-nvme@lists.infradead.org" , "sagi@grimberg.me" Subject: Re: [PATCH V9 4/9] nvmet: add ZBD over ZNS backend support Message-ID: <20210118182515.GC11082@lst.de> References: <20210112042623.6316-1-chaitanya.kulkarni@wdc.com> <20210112042623.6316-5-chaitanya.kulkarni@wdc.com> <20210112074805.GA24443@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Tue, Jan 12, 2021 at 07:52:27AM +0000, Damien Le Moal wrote: > > > > I do not understand the logic here, given that NVMe does not have > > conventional zones. > > 512e SAS & SATA SMR drives (512B logical, 4K physical) are a big thing, and for > these, all writes in sequential zones must be 4K aligned. So I suggested to > Chaitanya to simply use the physical block size as the LBA size for the target > to avoid weird IO errors that would not make sense in ZNS/NVMe world (e.g. 512B > aligned write requests failing). But in NVMe the physical block size exposes the atomic write unit, which could be way too large. Іf we want to do this cleanly we need to expose a minimum sequential zone write alignment value in the block layer. 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=-5.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 DF92AC433E6 for ; Mon, 18 Jan 2021 18:25:33 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8883022CA1 for ; Mon, 18 Jan 2021 18:25:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8883022CA1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=/f7sxun2WUzPXqkpzlDgoRVJlDSc/7AGk4hYdvULayk=; b=b1oeVDgcLtlUpfXAbhpSYSDV2 Fl0k0DvKfqCdWcZyaVU5JAY79Cdy00Ao4kPaPBzIJkIa7w9x4p6XczNBRrafZp0iShRTm8dcUZjus +AoBcRf30Vj24vaNIBUScZ8+/KWTdMlA6hn4Ea/JryGysGqLI1H6GYXddzZdAzq/jx/vJcSepi8z1 m7YGY/rwLKY0BCb5kVFh/RygQPcLtrQxuKTYZRK/LK/2Id5aCKdOhted9CEp9SlpXUlCzrUaGIfbc 69kgGA0w47gUceGLRm4slybN18K7i1EUFTsQTdTXj115y7jJrTnGsrY/pO2TaxkbHhpACWDiIwlu3 +71XqvL5Q==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l1ZDM-0008PQ-Ip; Mon, 18 Jan 2021 18:25:20 +0000 Received: from verein.lst.de ([213.95.11.211]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l1ZDJ-0008Oy-Pm for linux-nvme@lists.infradead.org; Mon, 18 Jan 2021 18:25:18 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id A2DE96736F; Mon, 18 Jan 2021 19:25:15 +0100 (CET) Date: Mon, 18 Jan 2021 19:25:15 +0100 From: Christoph Hellwig To: Damien Le Moal Subject: Re: [PATCH V9 4/9] nvmet: add ZBD over ZNS backend support Message-ID: <20210118182515.GC11082@lst.de> References: <20210112042623.6316-1-chaitanya.kulkarni@wdc.com> <20210112042623.6316-5-chaitanya.kulkarni@wdc.com> <20210112074805.GA24443@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210118_132517_958944_82E5BB9E X-CRM114-Status: GOOD ( 12.34 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "linux-block@vger.kernel.org" , "linux-nvme@lists.infradead.org" , Christoph Hellwig , Chaitanya Kulkarni , "sagi@grimberg.me" Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org T24gVHVlLCBKYW4gMTIsIDIwMjEgYXQgMDc6NTI6MjdBTSArMDAwMCwgRGFtaWVuIExlIE1vYWwg d3JvdGU6Cj4gPiAKPiA+IEkgZG8gbm90IHVuZGVyc3RhbmQgdGhlIGxvZ2ljIGhlcmUsIGdpdmVu IHRoYXQgTlZNZSBkb2VzIG5vdCBoYXZlCj4gPiBjb252ZW50aW9uYWwgem9uZXMuCj4gCj4gNTEy ZSBTQVMgJiBTQVRBIFNNUiBkcml2ZXMgKDUxMkIgbG9naWNhbCwgNEsgcGh5c2ljYWwpIGFyZSBh IGJpZyB0aGluZywgYW5kIGZvcgo+IHRoZXNlLCBhbGwgd3JpdGVzIGluIHNlcXVlbnRpYWwgem9u ZXMgbXVzdCBiZSA0SyBhbGlnbmVkLiBTbyBJIHN1Z2dlc3RlZCB0bwo+IENoYWl0YW55YSB0byBz aW1wbHkgdXNlIHRoZSBwaHlzaWNhbCBibG9jayBzaXplIGFzIHRoZSBMQkEgc2l6ZSBmb3IgdGhl IHRhcmdldAo+IHRvIGF2b2lkIHdlaXJkIElPIGVycm9ycyB0aGF0IHdvdWxkIG5vdCBtYWtlIHNl bnNlIGluIFpOUy9OVk1lIHdvcmxkIChlLmcuIDUxMkIKPiBhbGlnbmVkIHdyaXRlIHJlcXVlc3Rz IGZhaWxpbmcpLgoKQnV0IGluIE5WTWUgdGhlIHBoeXNpY2FsIGJsb2NrIHNpemUgZXhwb3NlcyB0 aGUgYXRvbWljIHdyaXRlIHVuaXQsIHdoaWNoCmNvdWxkIGJlIHdheSB0b28gbGFyZ2UuICDQhmYg d2Ugd2FudCB0byBkbyB0aGlzIGNsZWFubHkgd2UgbmVlZCB0byBleHBvc2UKYSBtaW5pbXVtIHNl cXVlbnRpYWwgem9uZSB3cml0ZSBhbGlnbm1lbnQgdmFsdWUgaW4gdGhlIGJsb2NrIGxheWVyLgoK X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KTGludXgtbnZt ZSBtYWlsaW5nIGxpc3QKTGludXgtbnZtZUBsaXN0cy5pbmZyYWRlYWQub3JnCmh0dHA6Ly9saXN0 cy5pbmZyYWRlYWQub3JnL21haWxtYW4vbGlzdGluZm8vbGludXgtbnZtZQo=