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 2291586347; Mon, 3 Mar 2025 13:59:08 +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=1741010351; cv=none; b=evP3rrl3txelBZJPWYtynXHqlKPUfDFC3k1hSddNetnkFuuNgNLxK5tDB4AjnXe/xQn1B10CDJJTqB7riowzkTDKON0QzI/FTg/rDzc+B2g/lH84vjRJWZNwOJhj1QW6w8CZFf88OIdL2awDXXdI+6Fa+PbsrNzXFb4CTaj0IA8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741010351; c=relaxed/simple; bh=8iKfJkNQrU4crLkC75d2xewvQHA+lVj1LfcNV3Q+XIs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=eD+LhLpchrVhNGW8Qtd1OSMLLS9MvkeUfNobzoflqE+XguCKoU4+htew8Z2wZ8QRTe7UAVrhYBLnbPGmRH/5HvBybMDWgBrMlStZjsB2bV1d3/9zFncl/YDIbkUCNisZE+rJ3LRb2nSQ/ZgVHA810aSN+3pGzB1Acos2ayWRm6c= 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=fTqYSiNS; 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="fTqYSiNS" 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=5X+YN9HLo1PBpCJ901n+jjHLjaif9nWTt/biwkwt76U=; b=fTqYSiNSmMk2YG+r8O4GzNLhuB 9H9FWaSaNv1LsPRcu1LwFwsPDjwA5ehyrqudIITIMFkFFOUVCyVOD67s3ABL6bgTg3AT2TWlL0OGi wkNUrbTzWuB//MbnzFfLJSNmmN0C6kVnk8eYXLq+ZfMvZU61TwtFQnjtunqRNLe7v40HclhZ7GC7h aJLzkNqXTlwM0J+RfeHYeTXH13EKxnSVcjhDUm0FNCrcqZXmeGqzGLmG5L7R2QfWaYLPdIbD6QmXG BR/mSW6chXIkW83p86HvI8cJTkrYigTLjY74qX82nleGzgivl3q56fwwWUAZUCx7NYo7Hfl5hBCvy A/q8fS2Q==; Received: from hch by bombadil.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1tp6K3-000000010Ky-3ArC; Mon, 03 Mar 2025 13:59:07 +0000 Date: Mon, 3 Mar 2025 05:59:07 -0800 From: Christoph Hellwig To: Mikulas Patocka Cc: 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: <7d6ae2c9-df8e-50d0-7ad6-b787cb3cfab4@redhat.com> 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 11:24:27AM +0100, Mikulas Patocka wrote: > This is the dm-loop target - a replacement for the regular loop driver > with better performance. The dm-loop target builds a map of the file in > the constructor and it just remaps bios according to this map. Using ->bmap is broken and a no-go for new code. If you have any real performance issues with the loop driver document and report them so that they can be fixed instead of working around them by duplicating the code (and in this case making the new code completely broken).