From mboxrd@z Thu Jan 1 00:00:00 1970 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.subspace.kernel.org (Postfix) with ESMTPS id 9FE30204C0A; Tue, 4 Mar 2025 13:52:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741096337; cv=none; b=biNP+lmtxBPNegF3KY9e9zZP7lruh9B7ZqvpPJop0PiKgj6ZNvJKz2e2Inc94J8rXbvebp4tDAHfiDL/RP2uI/Ozdsr8oPFVybfV9RtW/kfB0doJDLi58KOYDhNkifEm4cb8TZvMYY7oA6AWVBOZZeO0TB2KuTqDWJoFVaMEMpQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741096337; c=relaxed/simple; bh=ndqJ+0eHcqZRGXMltnB0aqNjR+haFA5ToHrWEK/Dk7M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=C5GKOx/jp72/hdmWfsM8qtZH2Nmm9aUThPfIbO0OhuFWEV3hObCj9hOeQ08Cj4ewMCERlUUJhxMPtt9m4Z2vmGSw2o69R18X3hMVdtIBe+MwCLanUzsu91GSoCsHxTVBZAMJW0CNlj0rUxkIrg2unuX2q1dDhb4udM5bJGVYrtY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=T32fOR6W; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="T32fOR6W" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=VOaHS+ulMCTO2F4RvqbeepsYx3EWL/VD/LTZiKe7Itw=; b=T32fOR6WO+5AZuJnMw25Itml6J YymmlB27fCfNh1J5K4mJlQSK5PXShBOHDHaamvAIVWe+wALbypH+CfXB+NqUIv7SxKfTWtvDfqsty KfVWgzrHTFDy/dEGOdPVcK/kg+X941vM0pe0k16Wk7Py0z1JYlSL6ZAGsqhaw21JJBqTXSY+m5iOM NaEVa556T0cAjLlUORTv6VVr+lVjOEimT6VwrjV/AsbbPZXkUZXsYmvFfvp9qRudKqcC9lurFtIp0 f6PfGFEIvXZmyag9ztmLD1TmVpRO8R2A/0Ao0xNhBfDrKSoqNdNcFD7r0PVo42CPD/wNxMMF88GWs FlVjmrpw==; Received: from hch by bombadil.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1tpSgw-00000004qn8-44F0; Tue, 04 Mar 2025 13:52:14 +0000 Date: Tue, 4 Mar 2025 05:52:14 -0800 From: Christoph Hellwig To: Heinz Mauelshagen Cc: Christoph Hellwig , Mikulas Patocka , Jooyung Han , Alasdair Kergon , Mike Snitzer , zkabelac@redhat.com, dm-devel@lists.linux.dev, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] the dm-loop target Message-ID: References: <7d6ae2c9-df8e-50d0-7ad6-b787cb3cfab4@redhat.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Mon, Mar 03, 2025 at 06:34:45PM +0100, Heinz Mauelshagen wrote: > It is, unless you ensure the pre-allocated and fully provisioned file to be > immutable. Which you can't. > > > The inode fiemap() operation would avoid issues relative to outdated > > bmap(). > > > > No, using that for I/O is even worse. > > > > Are you saying it imposes more overhead than the VFS APIs? No, but the reporting in fiemap is even less defined than the already overly lose bmap. fiemap for btrfs for example doesn't report actual block numbers.