Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754736AbbHGH6b (ORCPT ); Fri, 7 Aug 2015 03:58:31 -0400 Received: from mail-io0-f173.google.com ([209.85.223.173]:36096 "EHLO mail-io0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754488AbbHGH6a (ORCPT ); Fri, 7 Aug 2015 03:58:30 -0400 MIME-Version: 1.0 In-Reply-To: <20150807074839.GA17851@lst.de> References: <1437118027-94602-1-git-send-email-hare@suse.de> <20150807073330.GB17618@lst.de> <20150807074839.GA17851@lst.de> Date: Fri, 7 Aug 2015 03:58:29 -0400 Message-ID: Subject: Re: [PATCH 0/4] loop: enable different physical blocksizes From: Ming Lei To: Christoph Hellwig Cc: Hannes Reinecke , Jens Axboe , Alexander Graf , Linux Kernel Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1482 Lines: 38 On Fri, Aug 7, 2015 at 3:48 AM, Christoph Hellwig wrote: > On Fri, Aug 07, 2015 at 03:44:58AM -0400, Ming Lei wrote: >> There shouldn't be any problem about looping over DASP which has >> 4k sector size. Also for debugging purpose, we can easily emulate 4k >> sector size disk by QEMU/virtio-blk. >> >> We can support 4k sector size on loop for debugging purpose too, but >> the side effect is that some images can't be loop mounted any more >> after its secror size is become larger, then people might complain that. > > Have you read the patches? > > There isn't any change in default behavior, but it allows you to expose > a non-512 byte sector size _optionally_. So no images will stop being > loop mountable, quite to the contrary - you can now loop mount an image > copied off from the 4k disk which otherwise would have been unusable > because the file system geometry didn't match what's returned by > the block layer as the sector size. I mean the following case: #losetup -B 4096 /dev/loop0 test.img #mount /dev/loop0 /mnt $... #umount /mnt #losetup -d /dev/loop0 #losetup /dev/loop0 test1.img #mount /dev/loop0 /mnt Then the last mount may fail becase the logical block size is still 4096. Thanks, Ming Lei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/