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From:   Fabio Estevam <festevam@gmail.com>
Date:   Tue, 6 Jun 2023 14:09:39 -0300
Message-ID: <CAOMZO5A6MoDDLmQHoFCvewjpuPhC8_nbOVrKZR9d8Fn1d+3VgQ@mail.gmail.com>
Subject: rootwait regression in linux-next
To:     Christoph Hellwig <hch@lst.de>
Cc:     Jens Axboe <axboe@kernel.dk>,
        linux-kernel <linux-kernel@vger.kernel.org>
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Hi Christoph,

I observe the following boot regression in linux-next 20230606:

[    1.757719] ALSA device list:
[    1.760705]   No soundcards found.
[    1.774453] mmc1: SDHCI controller on 30b50000.mmc [30b50000.mmc] using ADMA
[    1.786190] Disabling rootwait; root= is invalid.
[    1.792548] /dev/root: Can't open blockdev
[    1.796689] VFS: Cannot open root device "/dev/mmcblk1p1" or
unknown-block(0,0): error -6
[    1.804886] Please append a correct "root=" boot option; here are
the available partitions:
[    1.813270] 1f00           32768 mtdblock0

Kernel command line: root=/dev/mmcblk1p1 rw rootwait

If I try an ugly hack like this:

--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -412,7 +412,7 @@ static dev_t __init parse_root_device(char
*root_device_name)
                return Root_RAM0;

        error = early_lookup_bdev(root_device_name, &dev);
-       if (error) {
+       if (0) {
                if (error == -EINVAL && root_wait) {
                        pr_err("Disabling rootwait; root= is invalid.\n");
                        root_wait = 0;

Then the board boots fine:

[    1.790845] Waiting for root device /dev/mmcblk1p1...
[    2.058169] mmc1: host does not support reading read-only switch,
assuming write-enable
[    2.097079] mmc1: new ultra high speed SDR104 SDHC card at address aaaa
[    2.104925] mmcblk1: mmc1:aaaa SP32G 29.7 GiB
[    2.113269]  mmcblk1: p1 p2 p3
[    2.154538] EXT4-fs (mmcblk1p1): recovery complete
[    2.160651] EXT4-fs (mmcblk1p1): mounted filesystem
3e7994a8-04cb-45d2-a6f5-64462aa0ea05 r/w with ordered data mode. Quota
mode: none.
[    2.172828] VFS: Mounted root (ext4 filesystem) on device 179:97.

What is the appropriate fix for this issue?

Thanks