From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from picard.linux.it (picard.linux.it [213.254.12.146]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E2DE4C54EE9 for ; Thu, 22 Sep 2022 20:23:09 +0000 (UTC) Received: from picard.linux.it (localhost [IPv6:::1]) by picard.linux.it (Postfix) with ESMTP id 172813CAD6A for ; Thu, 22 Sep 2022 22:23:06 +0200 (CEST) Received: from in-4.smtp.seeweb.it (in-4.smtp.seeweb.it [217.194.8.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384)) (No client certificate requested) by picard.linux.it (Postfix) with ESMTPS id 5F95D3CAD4A for ; Thu, 22 Sep 2022 22:22:54 +0200 (CEST) Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by in-4.smtp.seeweb.it (Postfix) with ESMTPS id 788C0100117E for ; Thu, 22 Sep 2022 22:22:54 +0200 (CEST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 8AA0A219E0; Thu, 22 Sep 2022 20:22:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1663878173; h=from:from:reply-to:reply-to:date:date:message-id:message-id:to:to: cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=nGUF566vzGAokPxDFkFWGqgPBOuXXakZgLZc1QFvzbc=; b=OHVx0O2uouSSRioDISSw7XvvtZ/yQBJOwUtDRCppf6AvPuNccCb0orLBowpclbJDxqQ9ke 8FofnP9ORZ5ws2ofqU8gaqDDu+LezT7dMpCpYlpHClDHd/usQgzj40yFbRJhLmbV1WNDCt PuO6OWfxTxGcmVaGIa2WlkvI8X/yHPI= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1663878173; h=from:from:reply-to:reply-to:date:date:message-id:message-id:to:to: cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=nGUF566vzGAokPxDFkFWGqgPBOuXXakZgLZc1QFvzbc=; b=helBuIDhUHgdOsqxfrcrZXCGurvvmlw1/QloX9CxAAF6WxVg7pxZBnxpgrs0WoQg/psDI+ NcPnmLqztO6xhzBg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id CB72713AA5; Thu, 22 Sep 2022 20:22:52 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id y+QYJhzELGP0GQAAMHmgww (envelope-from ); Thu, 22 Sep 2022 20:22:52 +0000 Date: Thu, 22 Sep 2022 22:22:50 +0200 From: Petr Vorel To: Cyril Hrubis Message-ID: References: <20220921155006.13360-1-mdoucha@suse.cz> <5541d648-f9ba-16c1-6767-4d8838863a25@suse.cz> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Virus-Scanned: clamav-milter 0.102.4 at in-4.smtp.seeweb.it X-Virus-Status: Clean Subject: Re: [LTP] [PATCH] tst_supported_fs: Implement checking paths against skiplist X-BeenThere: ltp@lists.linux.it X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux Test Project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Petr Vorel Cc: LTP List Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ltp-bounces+ltp=archiver.kernel.org@lists.linux.it Sender: "ltp" > Hi! > > Should I understand this that you don't trust /proc/self/mountinfo output? > > (show_mountinfo() in fs/proc_namespace.c in kernel git)? > Not much as I wouldn't trust it, it's just that the ext2/ext3/ext4 names > are just short names for a subset of additional functionality. > Consider this: > $ dd if=/dev/zero of=fsimage.img bs=1024 count=32768 > $ mkfs.ext3 fsimage.img > $ tune2fs -O ^has_journal fsimage.img > $ mount -o loop fsimage.img /mntpoint > $ cat /proc/self/mountinfo > 43 19 7:0 / /mntpoint rw,relatime - ext3 /dev/loop0 rw > Now we have mounted ext3 without journaling, is that really ext3? > $ umount /mntpoint > $ mount -t ext2 -o loop fsimage.img /mntpoint > $ cat /proc/self/mountinfo > 43 19 7:0 / /mntpoint rw,relatime - ext2 /dev/loop0 rw > Now we mounted the same filesystem as ext2. > And in both cases this is handled by the ext4 kernel driver anyways: > $ dmesg > ... > EXT4-fs (loop0): mounting ext3 file system using the ext4 subsystem > ... > EXT4-fs (loop0): mounting ext2 file system using the ext4 subsystem > ... Thanks a lot for a nice example to document the problem. > So I would argue that these are not three different filesystems, but > just one that can turn on and off various features. And if you look at > 'man ext4' you will see that the set of supported features for any extX > variant does change with kernel version. Makes sense. > The question is if we really need to be able to distinguish them or if > we can keep calling them by a common name. As I noted before, using Martin's patch require to use ext2/ext3/ext4 for .skip_filesystems and $TST_SKIP_FILESYSTEMS. I'm OK with it, although it's a bit misleading. Kind regards, Petr -- Mailing list info: https://lists.linux.it/listinfo/ltp