[Stable Update] 2021-06-14 - Kernels, Browsers, Mesa, Deepin, Systemd, Gnome Apps 40.2, Pipewire, Haskell

I install manjaro on external USB SSD, it working find. But last week I upgrade the system from 21.0.6 to 21.0.7, then reboot, system boot failed:

mount: /new_root: no filesystem type specified.
You are now being dropped into an emergency shell
sh: can't access tty; job control turned off
[rootfs ]#

In emergency shell, the USB SSD not found:

[rootfs ]# lsblk
NAME                                          MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINTS
sdb                                             8:16   1  28.6G  0 disk  
├─sdb1                                          8:17   1   2.9G  0 part  
└─sdb2                                          8:18   1     4M  0 part 

from bootable USB iso, the USB SSD found:

# lsblk
NAME                                          MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINTS
sda                                             8:0    0 931.5G  0 disk   
├─sda1                                          8:1    0   200M  0 part  /boot/efi
├─sda2                                          8:2    0 464.9G  0 part   
└─sda3                                          8:3    0 466.3G  0 part   
 └─luks-bufara                               254:0    0 466.3G  0 crypt /
sdb                                             8:16   1  28.6G  0 disk  
├─sdb1                                          8:17   1   2.9G  0 part  
└─sdb2                                          8:18   1     4M  0 part  

I tried many methods to resolve it, changing the parameters in /etc/default/grub, /etc/mkinitcpio.conf, using grub-install to reinstall grub, etc., but nothing worked.

I decided to downgrade the kernel back to 5.10.41-1 and rebooted the system, wow! It worked, the system booted successfully.

I compared the dmesg logs of 5.10.41-1 and 5.10.42-1, found that:
5.10.41-1 contain the log of detect the USB SSD, like below:

# dmesg
[    1.488559] usb 4-1: new SuperSpeedPlus Gen 2 USB device number 2 using xhci_hcd
[    1.516106] usb 4-1: New USB device strings: Mfr=2, Product=3, SerialNumber=1
[    1.516108] usb 4-1: Product: Portable SSD T5
[    1.516109] usb 4-1: Manufacturer: Samsung
[    1.521592] usbcore: registered new interface driver usb-storage
[    1.526816] scsi host1: uas
[    1.526848] usbcore: registered new interface driver uas
[    1.527449] scsi 1:0:0:0: Direct-Access     Samsung  Portable SSD T5  0    PQ: 0 ANSI: 6
[    1.529242] sd 1:0:0:0: [sda] 1953525168 512-byte logical blocks: (1.00 TB/932 GiB)
[    1.529316] sd 1:0:0:0: [sda] Write Protect is off
[    1.529317] sd 1:0:0:0: [sda] Mode Sense: 43 00 00 00
[    1.529480] sd 1:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[    1.529676] sd 1:0:0:0: [sda] Optimal transfer size 33553920 bytes
[    1.588304]  sda: sda1 sda2 sda3

but 5.10.42-1 have not.

So I think that is the reason cause the problem.

I don’t know if 5.12 and 5.4 have the same problem. To confirm this, I decided to test it. I will feedback the rest result.