From nobody Mon May 11 11:30:55 2026 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 B4B77C433F5 for ; Sat, 9 Apr 2022 03:40:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238700AbiDIDmG (ORCPT ); Fri, 8 Apr 2022 23:42:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49008 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238554AbiDIDlz (ORCPT ); Fri, 8 Apr 2022 23:41:55 -0400 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C7C18AC928; Fri, 8 Apr 2022 20:39:48 -0700 (PDT) Received: from linux.localdomain (unknown [113.200.148.30]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9Dx3xP9_1BiOesbAA--.5440S3; Sat, 09 Apr 2022 11:39:44 +0800 (CST) From: Tiezhu Yang To: Jens Axboe , Jonathan Corbet Cc: linux-block@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/3] init: print some info about UUID and LABEL in name_to_dev_t() Date: Sat, 9 Apr 2022 11:39:39 +0800 Message-Id: <1649475581-12139-2-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1649475581-12139-1-git-send-email-yangtiezhu@loongson.cn> References: <1649475581-12139-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf9Dx3xP9_1BiOesbAA--.5440S3 X-Coremail-Antispam: 1UD129KBjvJXoW7ZryxGF43uFy5Aw1kZw45GFg_yoW8uw4kpw 47K345Kr92qr4DA3WUAF1rXry5Ja1Y93WFqFWFvws7uwsIgF9rX3W0yF1jy34UJw1rA3W2 qa15Jr93CF4YyaDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBFb7Iv0xC_tr1lb4IE77IF4wAFF20E14v26r4j6ryUM7CY07I2 0VC2zVCF04k26cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI 8067AKxVWUGwA2048vs2IY020Ec7CjxVAFwI0_Jrv_JF4l8cAvFVAK0II2c7xJM28CjxkF 64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW8JVW5JwA2z4x0Y4vE2Ix0cI8IcV CY1x0267AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIE14v26r4UJVWxJr1l84ACjcxK6I8E87Iv 6xkF7I0E14v26r4UJVWxJr1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4 CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvj eVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwCY02Avz4vE14v_Gr4l42xK82IYc2 Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s02 6x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r126r1DMIIYrxkI7VAKI48JMIIF0x vE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r1j6r4UMIIF0xvE 42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6x kF7I0E14v26r1j6r4UYxBIdaVFxhVjvjDU0xZFpf9x07jw2-5UUUUU= X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" If there is no valid initrd, but root=3DUUID or root=3DLABEL is used in the command line, boot hangs like this: [ 5.739815] VFS: Cannot open root device "UUID=3D19957230-2e15-494c-8dfa= -84aab3591961" or unknown-block(0,0): error -6 [ 5.750280] Please append a correct "root=3D" boot option; here are the = available partitions: [ 5.856059] 0800 125034840 sda [ 5.856061] driver: sd [ 5.862124] 0801 307200 sda1 d5077411-3d87-4f85-b312-8cc309ef= 9073 [ 5.862128] [ 5.870603] 0802 1048576 sda2 aae0dd30-e5f5-44e1-994e-d47bf5ce= 2e52 [ 5.870606] [ 5.879080] 0803 52428800 sda3 759079ee-85fa-4636-9de7-1ac0643a= b87e [ 5.879083] [ 5.887558] 0804 8388608 sda4 439c4b0a-7b4f-4434-82f1-f9d380b5= 5fb9 [ 5.887560] [ 5.896035] 0805 62860288 sda5 ee52e951-1315-4fab-a3e5-45c6eeae= 6ce6 [ 5.910575] Kernel panic - not syncing: VFS: Unable to mount root fs on = unknown-block(0,0) [ 5.918796] ---[ end Kernel panic - not syncing: VFS: Unable to mount ro= ot fs on unknown-block(0,0) ]--- The above log is very useful, but some users still need time to analysis the cause [1, 2]. It is better to print some info to explicitly tell the users root=3DUUID or root=3DLABEL is not supported without initrd. [1] https://unix.stackexchange.com/questions/93767/why-cant-i-specify-my-ro= ot-fs-with-a-uuid [2] https://unix.stackexchange.com/questions/302795/how-to-identify-root-pa= rtition-via-uuid-without-initramfs-initrd Signed-off-by: Tiezhu Yang --- init/do_mounts.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/init/do_mounts.c b/init/do_mounts.c index 7058e14..2c1c492 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -290,6 +290,14 @@ dev_t name_to_dev_t(const char *name) if (strncmp(name, "/dev/", 5) =3D=3D 0) return devt_from_devname(name + 5); #endif + if (strncmp(name, "UUID=3D", 5) =3D=3D 0) { + pr_info("root=3DUUID is not supported without initrd\n"); + return 0; + } + if (strncmp(name, "LABEL=3D", 6) =3D=3D 0) { + pr_info("root=3DLABEL is not supported without initrd\n"); + return 0; + } return devt_from_devnum(name); } EXPORT_SYMBOL_GPL(name_to_dev_t); --=20 2.1.0 From nobody Mon May 11 11:30:55 2026 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 07CF8C433FE for ; Sat, 9 Apr 2022 03:39:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238795AbiDIDmA (ORCPT ); Fri, 8 Apr 2022 23:42:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48914 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238549AbiDIDly (ORCPT ); Fri, 8 Apr 2022 23:41:54 -0400 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id AEC81338B5; Fri, 8 Apr 2022 20:39:47 -0700 (PDT) Received: from linux.localdomain (unknown [113.200.148.30]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9Dx3xP9_1BiOesbAA--.5440S4; Sat, 09 Apr 2022 11:39:46 +0800 (CST) From: Tiezhu Yang To: Jens Axboe , Jonathan Corbet Cc: linux-block@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/3] docs: kernel-parameters: update description of root= Date: Sat, 9 Apr 2022 11:39:40 +0800 Message-Id: <1649475581-12139-3-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1649475581-12139-1-git-send-email-yangtiezhu@loongson.cn> References: <1649475581-12139-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf9Dx3xP9_1BiOesbAA--.5440S4 X-Coremail-Antispam: 1UD129KBjvdXoWrtFWfGry7tw1DKF17Aw47Jwb_yoWfGFcE9w 4rXF4vqayUA34Syr13Jan5XF1Y9r4SvFZ29w4DGrs8G3sYyws0yF95Jry8Aw4rWrZ7ur13 uasrAr97KFnrXjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbS8YjsxI4VW3JwAYFVCjjxCrM7AC8VAFwI0_Xr0_Wr1l1xkIjI8I 6I8E6xAIw20EY4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l82xGYIkIc2x26280x7 IE14v26r15M28IrcIa0xkI8VCY1x0267AKxVWUCVW8JwA2ocxC64kIII0Yj41l84x0c7CE w4AK67xGY2AK021l84ACjcxK6xIIjxv20xvE14v26ryj6F1UM28EF7xvwVC0I7IYx2IY6x kF7I0E14v26r4j6F4UM28EF7xvwVC2z280aVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE c7CjxVAFwI0_Gr1j6F4UJwAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzV Aqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S 6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JMxkIecxEwVAFwVW8GwCF04k20xvY0x 0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E 7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcV C0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF 04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7 CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07jI_M-UUUUU= X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" root=3DUUID or root=3DLABEL is not supported without initrd. It is better to update description of root=3D to explicitly tell the users. Signed-off-by: Tiezhu Yang --- Documentation/admin-guide/kernel-parameters.txt | 1 + 1 file changed, 1 insertion(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentatio= n/admin-guide/kernel-parameters.txt index 3f1cc5e..c3eb142 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -5120,6 +5120,7 @@ port and the regular usb controller gets disabled. =20 root=3D [KNL] Root filesystem + root=3DUUID or root=3DLABEL is not supported without initrd. See name_to_dev_t comment in init/do_mounts.c. =20 rootdelay=3D [KNL] Delay (in seconds) to pause before attempting to --=20 2.1.0 From nobody Mon May 11 11:30:55 2026 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 D0B7BC433EF for ; Sat, 9 Apr 2022 03:40:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238907AbiDIDmE (ORCPT ); Fri, 8 Apr 2022 23:42:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238553AbiDIDly (ORCPT ); Fri, 8 Apr 2022 23:41:54 -0400 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 2A6DB396B5; Fri, 8 Apr 2022 20:39:47 -0700 (PDT) Received: from linux.localdomain (unknown [113.200.148.30]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9Dx3xP9_1BiOesbAA--.5440S5; Sat, 09 Apr 2022 11:39:46 +0800 (CST) From: Tiezhu Yang To: Jens Axboe , Jonathan Corbet Cc: linux-block@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/3] block: print correct sectors in printk_all_partitions() Date: Sat, 9 Apr 2022 11:39:41 +0800 Message-Id: <1649475581-12139-4-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1649475581-12139-1-git-send-email-yangtiezhu@loongson.cn> References: <1649475581-12139-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf9Dx3xP9_1BiOesbAA--.5440S5 X-Coremail-Antispam: 1UD129KBjvJXoW7ZryxGF43uFy5Aw1kZw45GFg_yoW8KrW5pr 43KFn5GFW8Wr1DZ3WDCF1UXFWrCayrZa1rtFWI93sru3s8Wrnrta4akrWjyw12qF1fXay2 vw48Wr9IyFn8CaUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUB2b7Iv0xC_KF4lb4IE77IF4wAFF20E14v26ryj6rWUM7CY07I2 0VC2zVCF04k26cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI 8067AKxVWUWwA2048vs2IY020Ec7CjxVAFwI0_Gr0_Xr1l8cAvFVAK0II2c7xJM28CjxkF 64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcV CY1x0267AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIE14v26r4UJVWxJr1l84ACjcxK6I8E87Iv 6xkF7I0E14v26r4UJVWxJr1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4 CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvj eVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwCY02Avz4vE14v_Gr4l42xK82IYc2 Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s02 6x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r126r1DMIIYrxkI7VAKI48JMIIF0x vE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF0xvE 42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6x kF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjxUsNeoUUUUU X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" If there is no valid initrd, but root=3DUUID or root=3DLABEL is used in the command line, boot hangs like this: [ 5.739815] VFS: Cannot open root device "UUID=3D19957230-2e15-494c-8dfa= -84aab3591961" or unknown-block(0,0): error -6 [ 5.750280] Please append a correct "root=3D" boot option; here are the = available partitions: [ 5.856059] 0800 125034840 sda [ 5.856061] driver: sd [ 5.862124] 0801 307200 sda1 d5077411-3d87-4f85-b312-8cc309ef= 9073 [ 5.862128] [ 5.870603] 0802 1048576 sda2 aae0dd30-e5f5-44e1-994e-d47bf5ce= 2e52 [ 5.870606] [ 5.879080] 0803 52428800 sda3 759079ee-85fa-4636-9de7-1ac0643a= b87e [ 5.879083] [ 5.887558] 0804 8388608 sda4 439c4b0a-7b4f-4434-82f1-f9d380b5= 5fb9 [ 5.887560] [ 5.896035] 0805 62860288 sda5 ee52e951-1315-4fab-a3e5-45c6eeae= 6ce6 [ 5.910575] Kernel panic - not syncing: VFS: Unable to mount root fs on = unknown-block(0,0) [ 5.918796] ---[ end Kernel panic - not syncing: VFS: Unable to mount ro= ot fs on unknown-block(0,0) ]--- In the above log, the sectors are not consistent with the output of fdisk command, fix it. [root@linux loongson]# fdisk -l /dev/sda Disk /dev/sda: 119.2 GiB, 128035676160 bytes, 250069680 sectors Units: sectors of 1 * 512 =3D 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: gpt Disk identifier: 01D1BA1C-232F-45CA-AC12-0AF2A5D8CE0D Device Start End Sectors Size Type /dev/sda1 2048 616447 614400 300M EFI System /dev/sda2 616448 2713599 2097152 1G Linux filesystem /dev/sda3 2713600 107571199 104857600 50G Linux filesystem /dev/sda4 107571200 124348415 16777216 8G Linux swap /dev/sda5 124348416 250068991 125720576 60G Linux filesystem Signed-off-by: Tiezhu Yang --- block/genhd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/genhd.c b/block/genhd.c index b8b6759..453ce42 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -761,7 +761,7 @@ void __init printk_all_partitions(void) printk("%s%s %10llu %pg %s", bdev_is_partition(part) ? " " : "", bdevt_str(part->bd_dev, devt_buf), - bdev_nr_sectors(part) >> 1, part, + bdev_nr_sectors(part), part, part->bd_meta_info ? part->bd_meta_info->uuid : ""); if (bdev_is_partition(part)) --=20 2.1.0