From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754345AbZC1SRD (ORCPT ); Sat, 28 Mar 2009 14:17:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753521AbZC1SQw (ORCPT ); Sat, 28 Mar 2009 14:16:52 -0400 Received: from mail-bw0-f169.google.com ([209.85.218.169]:44112 "EHLO mail-bw0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753486AbZC1SQv (ORCPT ); Sat, 28 Mar 2009 14:16:51 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:subject:date:user-agent:cc:mime-version:content-disposition :message-id:content-type:content-transfer-encoding; b=iWLuKVYuHHL4IrRoF/HhIhK6wLZfLLslMuVlNeWb4iKF9hHrQDtP1aLaZz6ZQeDaV0 ErmdV+EpPFYoh9ZCH6EMjqmkZPkI/bmFHHrypkWDxRg0BABxm6XHXil58Dgzr4+21tl7 Ry24MbboZPvecIXFOaV/oiVume3AJeGZ7skXg= From: Bartlomiej Zolnierkiewicz To: Jens Axboe Subject: [RFC][PATCH] block: enable by default support for large devices and files on 32-bit archs Date: Sat, 28 Mar 2009 19:16:06 +0100 User-Agent: KMail/1.11.1 (Linux/2.6.29-next-20090327-dirty; KDE/4.2.1; i686; ; ) Cc: "Theodore Ts'o" , linux-kernel@vger.kernel.org MIME-Version: 1.0 Content-Disposition: inline Message-Id: <200903281916.06905.bzolnier@gmail.com> Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Enable by default support for large devices and files (CONFIG_LBD): - With 1TB disks being a commodity hardware it is quite easy to hit 2TB limitation while building RAIDs etc. and many distros have been using CONFIG_LBD=y by default already (at least Fedora 10 and openSUSE 11.1). - This should also prevent a subtle ext4 filesystem compatibility issue: mke2fs.ext4 defaults to creating filesystems with huge_files feature enabled and such filesystems cannot be later mounted read-write on machines with CONFIG_LBD=n (it should be quite easy to hit this issue when trying to use filesystem created using distro kernel on system running the self-build kernel, think about USB disk enclosures & co.). While at it: - Clarify config option help text w.r.t. mounting ext4 filesystems (they can be mounted with CONFIG_LBD=n but in the read-only mode). Cc: "Theodore Ts'o" Signed-off-by: Bartlomiej Zolnierkiewicz --- Unfortunately to also update the existings [def]configs the config option rename would be needed. Actually, since the performance impact and kernel size increase seem to be minimal (at least on x86-32) maybe we should just go ahead and remove CONFIG_LBD (== always use 64-bit sector_t/blkcnt_t)? I can make needed changes once there is agreement on preferred approach... block/Kconfig | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) Index: b/block/Kconfig =================================================================== --- a/block/Kconfig +++ b/block/Kconfig @@ -26,6 +26,7 @@ if BLOCK config LBD bool "Support for large block devices and files" depends on !64BIT + default y help Enable block devices or files of size 2TB and larger. @@ -38,11 +39,13 @@ config LBD The ext4 filesystem requires that this feature be enabled in order to support filesystems that have the huge_file feature - enabled. Otherwise, it will refuse to mount any filesystems - that use the huge_file feature, which is enabled by default - by mke2fs.ext4. The GFS2 filesystem also requires this feature. + enabled. Otherwise, it will refuse to mount in the read-write + mode any filesystems that use the huge_file feature, which is + enabled by default by mke2fs.ext4. - If unsure, say N. + The GFS2 filesystem also requires this feature. + + If unsure, say Y. config BLK_DEV_IO_TRACE bool "Support for tracing block io actions"