Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753872AbbHRVGv (ORCPT ); Tue, 18 Aug 2015 17:06:51 -0400 Received: from mail2-relais-roc.national.inria.fr ([192.134.164.83]:41146 "EHLO mail2-relais-roc.national.inria.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752666AbbHRVGu (ORCPT ); Tue, 18 Aug 2015 17:06:50 -0400 X-IronPort-AV: E=Sophos;i="5.15,704,1432591200"; d="scan'208";a="174003667" Message-ID: <55D39E67.3010009@gmail.com> Date: Tue, 18 Aug 2015 23:06:47 +0200 From: Brice Goglin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.7.0 MIME-Version: 1.0 To: "Theodore Ts'o" CC: LKML Subject: Re: Why is SECTOR_SIZE = 512 inside kernel ? References: <20150817135450.GB27202@thunk.org> In-Reply-To: <20150817135450.GB27202@thunk.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 833 Lines: 21 Le 17/08/2015 15:54, Theodore Ts'o a ?crit : > > It's cast in stone. There are too many places all over the kernel, > especially in a huge number of file systems, which assume that the > sector size is 512 bytes. So above the block layer, the sector size > is always going to be 512. Could this be a problem when using pmem/nvdimm devices with byte-granularity (no BTT layer)? (hw_sector_size reports 512 in this case while we could expect 1 instead). Or it just doesn't matter because BTT is the only way to use these devices for filesystems like other block devices? thanks Brice -- 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/