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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5032BEE49A4 for ; Sun, 10 Sep 2023 20:44:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231929AbjIJUoc (ORCPT ); Sun, 10 Sep 2023 16:44:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56616 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229605AbjIJUob (ORCPT ); Sun, 10 Sep 2023 16:44:31 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A15CA188 for ; Sun, 10 Sep 2023 13:44:27 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 30CB2C433CA; Sun, 10 Sep 2023 20:44:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1694378667; bh=dDkdJWGGiy//RR7AWWVhpLf78066+abk18LBiZ3RRqk=; h=Date:To:From:Subject:From; b=YBNg0geiUrQ553YBXFVOfQ8ODAgKaShN4ztmgp8h0GX6cKKuqPMhu/MGlxicV7ai1 4fvxUst31h0RAe3GfDa2pZJYx1j10md4vkaSZG2Ej7LrfIYaYx1TwRrJ7j7Xo9HzLw Nv7q0kmj4dw4EZn34F8k5vsHc/UXC9ROAadRZYsA= Date: Sun, 10 Sep 2023 13:44:26 -0700 To: mm-commits@vger.kernel.org, wsa+renesas@sang-engineering.com, loic.poulain@linaro.org, justin.he@arm.com, brauner@kernel.org, axboe@kernel.dk, jianyong.wu@arm.com, akpm@linux-foundation.org From: Andrew Morton Subject: + init-mount-print-pretty-name-of-root-device-when-panics.patch added to mm-nonmm-unstable branch Message-Id: <20230910204427.30CB2C433CA@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: init/mount: print pretty name of root device when panicing has been added to the -mm mm-nonmm-unstable branch. Its filename is init-mount-print-pretty-name-of-root-device-when-panics.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/init-mount-print-pretty-name-of-root-device-when-panics.patch This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Jianyong Wu Subject: init/mount: print pretty name of root device when panicing Date: Thu, 7 Sep 2023 09:10:25 +0000 Given a wrong root device, current log may not give the pretty name which is useful to locate root cause. For example, there are 2 blk devs in a VM, /dev/vda which has 2 partitials /dev/vda1 and /dev/vda2 and /dev/vdb which is blank. /dev/vda2 is the right root dev. When set "root=/dev/vdb", we get error log: [ 0.635575] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(254,16) It's not straightforward to find out the root cause as there is lack of the root devive name therefore hard for people to get those info from the device number, in the example, (254,16). It is more comprehensive way to hint the root cause if pretty name is given here, like: [ 0.559887] Kernel panic - not syncing: VFS: Unable to mount root fs on "/dev/vdb" or unknown-block(254,16) Link: https://lkml.kernel.org/r/20230907091025.3436878-1-jianyong.wu@arm.com Signed-off-by: Jianyong Wu Cc: Christian Brauner Cc: Jens Axboe Cc: Justin He Cc: Loic Poulain Cc: Wolfram Sang Signed-off-by: Andrew Morton --- init/do_mounts.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/init/do_mounts.c~init-mount-print-pretty-name-of-root-device-when-panics +++ a/init/do_mounts.c @@ -244,7 +244,7 @@ retry: for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1) printk(" %s", p); printk("\n"); - panic("VFS: Unable to mount root fs on %s", b); + panic("VFS: Unable to mount root fs on \"%s\" or %s", pretty_name, b); out: put_page(page); } _ Patches currently in -mm which might be from jianyong.wu@arm.com are init-mount-print-pretty-name-of-root-device-when-panics.patch