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 52730C6FA82 for ; Thu, 22 Sep 2022 14:40:38 +0000 (UTC) Received: from picard.linux.it (localhost [IPv6:::1]) by picard.linux.it (Postfix) with ESMTP id 79AAE3CAD81 for ; Thu, 22 Sep 2022 16:40:35 +0200 (CEST) Received: from in-3.smtp.seeweb.it (in-3.smtp.seeweb.it [IPv6:2001:4b78:1:20::3]) (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 5A2E43C93EF for ; Thu, 22 Sep 2022 16:40:25 +0200 (CEST) Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) (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-3.smtp.seeweb.it (Postfix) with ESMTPS id D43EC1A014F4 for ; Thu, 22 Sep 2022 16:40:24 +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-out2.suse.de (Postfix) with ESMTPS id A2E811F907; Thu, 22 Sep 2022 14:40:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1663857623; h=from:from: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=xlAYEECtVf/xvRI+opLggU70qH7RXFXmH9SZDWT6wXI=; b=FSyGiMYA33MJe2ttkCX562UDDYeOFNtZ1eRBxnuX20cKC64C420O6yMSskKiyUdpAvIsEe oW/GRaEqJZs1i3imQoFkWG7QENUHMTIEmG2MTslQmhr/vhdEQSd8OaBAt3CeQ9nebUOATV l5D1mVpDc9CdFL7DER6ab2b+ST6CwJw= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1663857623; h=from:from: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=xlAYEECtVf/xvRI+opLggU70qH7RXFXmH9SZDWT6wXI=; b=jwYoAsNkPwifqaX1h04wqohL4YXtcGMuko9ys8fTvLRaYS71URMJ0NB3mq7fZYv1Md4QXN 9ctHqOidDm2hQTAA== 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 8F5F81346B; Thu, 22 Sep 2022 14:40:23 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id lR12ItdzLGOlGwAAMHmgww (envelope-from ); Thu, 22 Sep 2022 14:40:23 +0000 Date: Thu, 22 Sep 2022 16:42:21 +0200 From: Cyril Hrubis To: Petr Vorel 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-3.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: , 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 ... 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. The question is if we really need to be able to distinguish them or if we can keep calling them by a common name. -- Cyril Hrubis chrubis@suse.cz -- Mailing list info: https://lists.linux.it/listinfo/ltp