From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753397AbdFMM76 (ORCPT ); Tue, 13 Jun 2017 08:59:58 -0400 Received: from mx2.suse.de ([195.135.220.15]:55408 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752456AbdFMM75 (ORCPT ); Tue, 13 Jun 2017 08:59:57 -0400 Date: Tue, 13 Jun 2017 14:59:55 +0200 From: Jan Kara To: Pali =?iso-8859-1?Q?Roh=E1r?= Cc: Fabian Frederick , Jan Kara , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: udf: allow implicit blocksize specification during mount Message-ID: <20170613125955.GA20258@quack2.suse.cz> References: <201706122240.14996@pali> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <201706122240.14996@pali> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Mon 12-06-17 22:40:14, Pali Rohár wrote: > Hi! I found that following UDF patch was included into linus tree: > https://patchwork.kernel.org/patch/9524557/ > > It is really a good improvement to recognize UDF file system which have > block size different from disk sector size and also different from 2048. > > But should not detection on 4K native disks (4096/4096) try to also use > block size of 512 bytes? Because current loop is from logical sector > size to 4096. By definition, bdev_logical_block_size() is the smallest block size a device can support. So if it is larger than 512, the device driver had explicitely declared that it cannot handle smaller blocks... Look at the comment before "blk_queue_logical_block_size": /** * blk_queue_logical_block_size - set logical block size for the queue * @q: the request queue for the device * @size: the logical block size, in bytes * * Description: * This should be set to the lowest possible block size that the * storage device can address. The default of 512 covers most * hardware. **/ > Anyway, macro UDF_DEFAULT_BLOCKSIZE is not used in udf source code > anymore, so it can be deleted. I think its name was incorrect as default > block size for UDF should be logical block size of disk, not hardcoded > value 2048 which is logical block size for optical media. Thanks. Removed. Honza -- Jan Kara SUSE Labs, CR