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=-5.2 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 40281C433E0 for ; Wed, 23 Dec 2020 16:27:49 +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 7E1B6222BB for ; Wed, 23 Dec 2020 16:27:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7E1B6222BB 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=hOZ4ZfFtEBu63Hlecaam+urMArYfhsWcHAsWuIKQdGA=; b=RIeoZZW/z8fQyykDUF1OFJ5GN dt3Ow0J3cZhUL4grXNWZC8MpN7vEeEpJv22uPUHnM9jymxKAm4/Il67j/QtV1hqn/NRvEz+6llA/C AUCa6S40nQc+If0UaXOEvJcZtyAR+K3RBa6pdpQWCdAGxlMTTfdwLnrItEKPfkL+uJt8h8941Mf1u wMPnvGNW6+zwZHkm2tf1AJWPqD6WG0ScEsiidF5cYVfM+q1FNzlL/2ctOYXl99jTd5/MgycjIZUfa DO/g0AlpwwZn6pExamj6nb50YqKzwd1JMt6498cQbcfnEHA3VX0kk8H35PmwbabWPJA0TZJvPTp0Z 4fgbei12w==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ks6zH-0006jP-F9; Wed, 23 Dec 2020 16:27:43 +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 1ks6zF-0006j2-B9 for linux-nvme@lists.infradead.org; Wed, 23 Dec 2020 16:27:42 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 2FC4F67373; Wed, 23 Dec 2020 17:27:38 +0100 (CET) Date: Wed, 23 Dec 2020 17:27:37 +0100 From: Christoph Hellwig To: Minwoo Im Subject: Re: [RFC] nvme: set block size during namespace validation Message-ID: <20201223162737.GA8688@lst.de> References: <20201223150136.4221-1-minwoo.im.dev@gmail.com> <20201223154904.GA5967@lst.de> <20201223161650.GA13354@localhost.localdomain> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201223161650.GA13354@localhost.localdomain> 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-20201223_112741_989657_F93C7121 X-CRM114-Status: GOOD ( 18.99 ) 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: Jens Axboe , Sagi Grimberg , linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, Keith Busch , Christoph Hellwig Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Thu, Dec 24, 2020 at 01:16:50AM +0900, Minwoo Im wrote: > Hello, > > On 20-12-23 16:49:04, Christoph Hellwig wrote: > > set_blocksize just sets the block sise used for buffer heads and should > > not be called by the driver. blkdev_get updates the block size, so > > you must already have the fd re-reading the partition table open? > > I'm not entirely sure how we can work around this except by avoiding > > buffer head I/O in the partition reread code. Note that this affects > > all block drivers where the block size could change at runtime. > > Thank you Christoph for your comment on this. > > Agreed. BLKRRPART leads us to block_read_full_page which takes buffer > heads for I/O. > > Yes, __blkdev_get() sets i_blkbits of block device inode via > set_init_blocksize. And Yes again as nvme-cli already opened the block > device fd and requests the BLKRRPART with that fd. Also, __bdev_get() > only updates the i_blkbits(blocksize) in case bdev->bd_openers == 0 which > is the first time to open this block device. > > Then, how about having NVMe driver prevent underflow case for the > request->__data_len is smaller than the logical block size like: Not sure this helps. I think we need to fix this proper and in the block layer. The long term fix is to stop messing with i_blksize at all, but that is going to take very long. I think for now the only thing we can do is to set a flag in the gendisk when the block size changes and then reject all I/O until the next first open that sets the blocksize. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme