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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2AEC1EED601 for ; Thu, 12 Sep 2024 13:15:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=GH0x62wguGVfEaPQ4/mMjSek9VkAJmbOgepYDy0YKW8=; b=k/lTfK0s4s4eDkaHahRfHo9bMi t1PuwgiVLcGkW+FNlJZdOBpfjGzH/f1Bc9zdYRiJE3qv9aSYtEUq1j0YKYbNNKD3Tx0xYNqvrHdk1 eARLQZKesXANG/WK0B0wX/8+dcKUjf9iffpyUJA99vO6PLNWxXvzMtLzHyamj+3eXLgUPRswct72m x0ghGV7mVvUcZa6rJ4q3CeMhaijnbybS6cRkTlwZ97FGUJaNM7vMDL2Ymreo3jHY4f+Ms7+VcNOkw oXu1AonaVj8XSPs5h7fdrm/Bv6OqjxuukOON4607djzanRKTkDJtnfvZsqkmINtchf8Yl036lCOJs 8IyibXPg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sojfG-0000000DACZ-1DXu; Thu, 12 Sep 2024 13:15:14 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sojfD-0000000DAC6-31hi for linux-nvme@lists.infradead.org; Thu, 12 Sep 2024 13:15:13 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 276EA227AAF; Thu, 12 Sep 2024 15:15:07 +0200 (CEST) Date: Thu, 12 Sep 2024 15:15:06 +0200 From: Christoph Hellwig To: John Garry Cc: axboe@kernel.dk, song@kernel.org, yukuai3@huawei.com, kbusch@kernel.org, hch@lst.de, sagi@grimberg.me, James.Bottomley@HansenPartnership.com, martin.petersen@oracle.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org Subject: Re: [PATCH RFC 1/4] block: Make bdev_can_atomic_write() robust against mis-aligned bdev size Message-ID: <20240912131506.GA29641@lst.de> References: <20240903150748.2179966-1-john.g.garry@oracle.com> <20240903150748.2179966-2-john.g.garry@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240903150748.2179966-2-john.g.garry@oracle.com> 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-20240912_061511_930216_39A36AEA X-CRM114-Status: GOOD ( 14.57 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Tue, Sep 03, 2024 at 03:07:45PM +0000, John Garry wrote: > For bdev file operations, a write will be truncated when trying to write > past the end of the device. This could not be tolerated for an atomic > write. > > Ensure that the size of the bdev matches max atomic write unit so that this > truncation would never occur. But we'd still support atomic writes for all but the last sectors of the device? Isn't this really an application problem? If not supporting atomic writes at all for unaligned devices is the right thing to do, we'll need to clearly document this somewhere. Any maybe also add a pr_once to log a message?